2023 Vol. 13, No. 2

Display Method:
Spatio-temporal evolution characteristics of carbon emissions in Beijing-Tianjin-Hebei urban agglomeration derived from integrated data of DMSP-OLS and NPP-VIIRS
LI Yunyan, SHENG Qing, DAI Jian
2023, 13(2): 447-454. doi: 10.12153/j.issn.1674-991X.20220089
Abstract(463) HTML (133) PDF(1315KB)(80)

Beijing-Tianjin-Hebei urban agglomeration(BTHUA) was taken as the study area to explore the spatio-temporal evolution characteristics of carbon emissions at the city level and above. By fitting the optimal model, NPP-VIIRS data was transformed into DMSP-OLS scale nighttime light data, and the long-time series nightlight image set of BTHUA from 2005 to 2019 was obtained. Combined with the provincial energy consumption statistical and carbon emission data, a municipal scale carbon emission estimation model at the city level and above in BTHUA was constructed. The spatial distribution of carbon emissions in BTHUA was simulated, and the temporal and spatial evolution characteristics of carbon emissions were explored in combination with the tendency value method. The results showed that: From 2005 to 2019, the correlation between nighttime light data and carbon emissions of energy consumption in BTHUA was high, and the significance test of 1% was passed. From 2005 to 2019, the carbon emissions of 13 cities in BTHUA were basically increasing gradually. Overall, the growth rate of carbon emissions in BTHUA was relatively slow from 2005 to 2019. Among them, Beijing-Tianjin-Tangshan area had a rapid growth rate. In 2019, many of the 13 cities in BTHUA reduced their carbon emissions per unit of GDP by more than 40% compared with that in 2005. The research showed that the nighttime light data could be used to estimate the carbon emissions of BTHUA, and the carbon emissions in Beijing-Tianjin-Tangshan area were high and the growth rate was fast, so it should be regarded as a key carbon emission reduction area.

Analysis of the present situation of greenhouse gases and air pollutants co-control in Guangdong-Hong Kong-Macao Greater Bay Area
LIU Haiyan, YU Huibin, WANG Zhigang
2023, 13(2): 455-463. doi: 10.12153/j.issn.1674-991X.20220321
Abstract(307) HTML (194) PDF(2525KB)(64)

Regional joint prevention and control can realize the coordinated emission reduction of greenhouse gases and air pollutants. Guangdong-Hong Kong-Macao Greater Bay Area (GBA) has carried out a number of environmental cooperation projects, which has a good foundation for the co-control of climate change and air pollution. It is of great significance to study the current situation of the co-control of greenhouse gases and air pollutants at the regional level. Based on the historical data of 11 cities/regions in GBA from 2005 to 2020, a co-control evaluation index system of greenhouse gases and air pollutants was constructed by selecting 4 first-level indicators and 20 second-level indicators based on the global entropy method, and the coupling coordination degree model was used to measure the coupling degree of each indicator. The results showed that the comprehensive evaluation score of the co-control of greenhouse gases and air pollutants in GBA showed an upward trend, and the score of the eco-environmental level index lagged behind, which affected the improvement of the co-control level. The scores of co-control level of 11 cities/regions all had varying degrees of increase, but the score difference between the first-level indicators was larger. The coupling between the four subsystems was high coupling, and the coupling coordination degree was low coordination level. The subsystems were in the stage of coordinated development, and the interaction force between them was still small, so there was a large space for improvement. The different environmental management systems and environmental governance demands of the three areas were the main reasons that restricted the co-control development of greenhouse gases and air pollutants in GBA.

Analysis of research progress in carbon neutrality based on bibliometrics
ZHANG Nan, LÜ Lianhong, WANG Siyi, ZHAO Mingxuan, BAI Zihan, LUO Hong
2023, 13(2): 464-472. doi: 10.12153/j.issn.1674-991X.20220275
Abstract(483) HTML (172) PDF(2318KB)(101)

Carbon neutrality is an important initiative to address global climate change, and it has extremely important theoretical and practical significance for global climate governance and the building of a community of human destiny. The research on carbon neutrality has been continuously conducted by scholars internationally. Based on the search of SCI-E and SSCI databases in the Web of Science core collection, the carbon neutral literature from 1991 to 2021 was analyzed and mined by using bibliometric methods. The study showed that the number of carbon neutral publications was on the rise, and the research areas were mainly concentrated in the natural sciences, with the top 3 journals in terms of the number of publications being Sustainability, Journal of Cleaner Production and Applied Energy. National Natural Science Foundation of China funded 459 studies in this field, much higher than the relevant institutions in other countries; the backbone of the research was concentrated in the United States and the United Kingdom, whose average citations per article were 51.24 and 43.21, respectively, much higher than those of China (16.91). The current carbon neutral research could be summarized in two major aspects, namely carbon neutral technology and carbon neutral policy, while biomass, hydrogen energy, carbon capture and storage, etc. were the key technologies and research directions for achieving carbon neutrality in the future.

Pollution characteristics of volatile organic compounds above subtropical forest canopy in Lingnan and the influence of regional anthropogenic emissions
JIA Tianjiao, GE Yanli, LIU Ben, SUN Jiayin, WU Wenlu, YE Jianhuai, WU Cheng, LI Yongjie, FU Tzungmay, CHEN Qi
2023, 13(2): 473-482. doi: 10.12153/j.issn.1674-991X.20220298
Abstract(341) HTML (148) PDF(6888KB)(59)

Volatile organic compounds (VOC) in the atmosphere have significant impacts on air quality, climate change, and human health. Atmospheric VOC concentrations in subtropical forests of southern China are affected by regional anthropogenic source emissions. To quantitatively explore the impacts of regional anthropogenic source emissions on forest atmosphere, VOC and ozone concentrations at different vertical levels above the canopy were collected by drone-based samplers in the afternoon and evening in Dinghushan (DHS) and Chebaling (CBL) Nature Reserves in August and September 2019 and were analyzed offline. Moreover, WRF-GC model simulations and scenario analysis were conducted to quantitatively evaluate the impact of regional anthropogenic source emissions on the atmosphere in forest areas. The results showed that the biogenic VOC (BVOC) concentrations were low and anthropogenic VOC (AVOC) concentrations were relatively high at both sites. Compared with DHS, the AVOC concentrations in CBL were lower and the BVOC concentrations were higher, which could be attributed to less anthropogenic influence by regional transport. The ratios of (MVK+MACR)/isoprene at both sites were high, indicating a rapid atmospheric conversion. No significant difference in AVOC concentrations at different sampling heights were found at both sites. BVOC concentrations in CBL were also similar for both of the sampling heights. In DHS, the concentrations of isoprene and α-pinene were significantly different for 25 and 100 m sampling heights, which may be explained by vertical eddy diffusion. Moreover, the surface concentrations of air pollutants in DHS were well simulated by WRF-GC model. Under the scenario of no anthropogenic emissions, the simulated daily average concentrations of isoprene increased by 4 times and that of ozone decreased by 3 times in DHS compared with the default setting. This result suggested that because of the influence of anthropogenic emissions in southern China, the conversion of BVOC to its oxidation products was accelerated to promote the formation of biogenic secondary organic aerosol (SOA). Meanwhile, the ozone concentrations were greater than the plant tolerance threshold, for which long-term exposure would cause vegetation damage in the forested area.

Characteristics of the air pollution and the causes of heavy air pollution in winter in the northern slope of Tianshan Mountains: case study of Shihezi City
YANG Xin, HE Youjiang, LIAN Hanyang, ZHAO Yuxi, CHEN Yizhen, YANG Xiaoyang, LI Fuqiang, PENG Yujie, LI Weijun
2023, 13(2): 483-490. doi: 10.12153/j.issn.1674-991X.20220166
Abstract(476) HTML (162) PDF(4559KB)(82)

Taking Shihezi City, a typical city on the northern slope of Tianshan Mountains, as the case, based on the ground conventional pollutant monitoring, meteorological observation, the LiDAR observation, and the mesoscale Weather Research and Forecast (WRF) model simulation results, the impact of meteorological parameters and boundary layer structure changes on the air quality in Shihezi City were comprehensively analyzed. The results showed that the seasonal differences of air quality in Shihezi City were quite significant, with the highest difference of 11.4 times of PM2.5 concentrations between winter and summer, and the occurrence rate of air pollution episodes in December to February in winter is as high as 81.2%, with 59.1% of heavy and above polluted days. In the winter of 2020-2021, four heavy pollution processes occurred, and each heavy pollution process lasted for 7-27 d, with the interval period of only 1-3 d. Each process was dominated by fine particle pollution. In total, the period of December-February could be considered as a continuous "pollution season", with the peak value of 373-425 μg/m3 of PM2.5, and the average value of 0.82 for PM2.5/PM10. After entering autumn and winter, the continuous low temperature and high humidity meteorological conditions on the ground had a significant negative effect on PM2.5 concentration, and the main influence conditions were T<−3 ℃ and 65%<RH<92%. Under these conditions, the significant declining of boundary layer height and the change of near-ground diffusion caused by continuous strong inversion were the fundamental reasons for the formation of winter "pollution season". In the heavy pollution process on January 16-22, 2021, the continuous low temperature, high humidity and breezy/still wind conditions were the dominant ground meteorological conditions, and the generation and dissipation of heavy pollution only changed with the boundary layer and inversion conditions. The boundary layer height in the pollution accumulation period decreased by nearly 5 times compared with that in the clean days, and the intensity of the inversion temperature exceeded 1.5 ℃/(100 m). Immediately after the heavy pollution episode, 3 clean days appeared following with the receding of inversion temperature and the rising of boundary layer height.

Pollution characteristics and refined source apportionment for VOCs in Tianjin Industrial Area in spring and summer
LI Congshu, LIU Yongquan, LIU Huan, LIU Jinyu, CHENG Shaoling, JIANG Shengping
2023, 13(2): 491-500. doi: 10.12153/j.issn.1674-991X.20220214
Abstract(226) HTML (117) PDF(3777KB)(44)

109 volatile organic compounds (VOCs) in the ambient air of Tianjin Industrial Area were monitored offline from March 2021 to August 2021 by thermal desorption gas chromatography-mass spectrometry method. The composition characteristics, ozone formation potential (OFP) and sources of VOCs were studied, and refined analysis of industrial emission sources was carried out. The results showed that VOCs concentrations fluctuated between (46.6±19.7) and (136.8±55.7) µg/m3 during the observation period, with alkanes, halogenated hydrocarbons and oxygenated volatile organic compounds (OVOCs)contributing more to VOCs concentrations, and alkanes and aromatic hydrocarbons showed a daily trend of low at noon and high in the morning and evening, while OVOCs did the opposite. Alkanes, aromatic hydrocarbons, olefin and OVOCs accounted for a large proportion of OFP contribution, the contribution proportions of alkanes to OFP were mainly influenced by their percentage of concentration, the contribution proportions of aromatic hydrocarbons and olefins to OFP was significantly higher in summer, and their emission control should be strengthened in order to control ozone (O3). Source apportionment showed that the main emission sources in spring and summer were industrial sources, solvent use sources, diesel vehicle exhaust emissions sources, oil vapour volatilisation sources and natural sources. The refined analysis of industrial sources showed a positive correlation between the concentration of aromatic hydrocarbons and the production of coke and soda ash, a positive correlation between the concentration of OVOCs and the production of natural gas, ethylene and agricultural nitrogen, phosphorus and potassium fertilizers, a positive correlation between the concentration of halogenated hydrocarbons and the production of natural gas, automobiles, agricultural nitrogen, phosphorus and potassium fertilizers, and soda ash, and a positive correlation between the concentration of olefins and the production of power generation equipment. It was preliminarily determined that the aromatic hydrocarbons, OVOCs, halogenated hydrocarbons and olefins in the ambient air of the region were likely to come from these significantly correlated sub-segments of industrial enterprises.

Characteristics and sources apportionment of air pollution during heating period in Xuzhou
FENG Chunli, RAO Yongcai, MENG Qingjiang, LI Hui, DENG Guoqing, SUN Rui
2023, 13(2): 501-509. doi: 10.12153/j.issn.1674-991X.20220300
Abstract(254) HTML (105) PDF(7731KB)(38)

The concentrations of air pollutants in Xuzhou have decreased significantly in recent years. However, the problem of air pollution during the heating periods is still serious. Studying the characteristics and sources of air pollution during the heating periods plays an important role in the early warning and prevention and control of air pollution. A set of approaches, such as ground monitoring, remote sensing satellite monitoring, PM2.5 composition analysis, potential source contribution factor method (PSCF) and concentration-weighted trajectory analysis (CWT), were comprehensively adopted. The air pollution characteristics of Xuzhou in five heating periods from 2016 to 2020 were analyzed, and the sources of PM2.5 in the heating periods were analyzed. The results showed that the air quality in Xuzhou had significantly improved in recent years, but the concentrations of most air pollutants during the heating periods were significantly higher than that in the non-heating periods. The heating had a great impact on the concentration of PM2.5, and during the heating periods, the concentration of PM2.5 increased by 40%-71% compared with those before and after the heating periods. The concentrations of Cl, NO3 , SO4 2−, and NH4 + in the heating periods were significantly higher than those before and after the heating periods, indicating that the concentration of NH4 + had a strong correlation with NO3 , SO4 2− and Cl during the heating periods. The contribution of coal combustion and industrial emission to PM2.5 during the heating periods was 9.9% and 13.9%, respectively, higher than that after the heating periods, the SOR and NOR during the heating periods were significantly higher than those in non-heating periods, and the secondary conversion efficiency of SO2 and NOx increased significantly. The trajectory analysis indicated that the potential source areas contributed to Xuzhou during the heating periods were mainly distributed in Hebei Province and the areas neighboring Xuzhou, and the main contributing areas with PM2.5 concentration higher than 75 µg/m3 were from Shandong, Henan, northern Anhui, and southern Hebei.

Research progress of air pollution prevention and control based on enterprise electricity consumption data
CHEN Jianhua, LI Zheng, LIU Hanqing, GAO Jian, YANG Yan, ZHU Shuang
2023, 13(2): 510-516. doi: 10.12153/j.issn.1674-991X.20220272
Abstract(338) HTML (182) PDF(557KB)(71)

At present, China is in the critical development period of the 14th Five-Year Plan, and new requirements for "Precise Pollution Control, Scientific Pollution Control and Lawful Pollution Control" is required for pollution prevention and control. Electric power is a strategic resource and core production factor of an enterprise. The electricity consumption data of an enterprise can reflect the economic operation and industrial operation of the enterprise, which has great data mining value and broad application prospects in the field of air pollution prevention and control. The current domestic and foreign research was reviewed on the construction of enterprise pollution emission models based on enterprise electricity consumption data, the identification and supervision of "small unlicensed and polluting" enterprises and "stealthy and leakage emission" enterprises, the supervision and evaluation of pollutant emissions during special control periods, and the construction of fine air pollution source emission inventory. The analysis showed that the use of enterprise electricity consumption data could realize the precise supervision of pollutant discharge of enterprises (especially small and micro enterprises), which could make up for the deficiencies of environmental protection supervision to a certain extent and greatly improve work efficiency. Several issues that needed to be paid attention to in the application of power consumption big data were summarized, and suggestions for the further application of power data in the field of air pollution prevention and control were put forward.

Uncertainty analysis of air pollution under accidents of flue-gas treatment facilities for waste lead paste smelting regeneration
QIU Panpan, XU Ya, NAI Changxin, LIU Yuqiang, DONG Lu, LIN Ting, ZHANG Luyu
2023, 13(2): 517-526. doi: 10.12153/j.issn.1674-991X.20220253
Abstract(286) HTML (118) PDF(2522KB)(15)

Smelting regenerating is one of the most widely used ways to recycle heavy metal hazardous waste. Under the failure of the flue-gas treatment units of smelting facilities, the exhaust gas emission has the characteristics of significant source intensity, strong randomness of short-term emission diffusion parameters, and strong randomness of the environmental consequences, which poses a great challenge to the accurate monitoring and scientific decision-making in the emergency response. In this regard, a risk assessment method based on Gaussian Plume Model-Stochastic Response Surface Method (GAUSS-SRSM) coupling was proposed to quantitatively evaluate the random distribution and probability characteristics of pollutants under complex source intensities, diffusion parameters and their uncertainties. An enterprise in North China was selected to carry out a case study. The results showed that under the typical climatic conditions of the region, the concentrations of SO2 and Pb at 0.8-2.2 km and 0.75-1.5 km downwind might exceed the standard. The probability of exceeding the maximum ground concentration limit was 44% and 28%, respectively. The exposure concentrations characterized at 95% confidence level were 0.68 and 0.005 2 mg/m3, which exceeded Ambient Air Quality Standards (GB 3095-2012) by 1.36 times and 1.16 times, respectively. Seasonal differences in wind speed and temperature, etc. led to large differences in pollution and its probability characteristics in different seasons at the same facility. In the case of Pb, for example, the maximum range of potential exceedances in winter differed by 0.6 km from that in summer, with 24% difference in exceedance probability and 0.003 9 mg/m3 difference in exposure concentration. The uncertainty of climate and source intensity made the air pollution consequences have obvious uncertainty, with the maximum uncertainty of 3.85 at 0.5 km downwind. As the distance increased, the uncertainty decreased, with only 1.74 at 3.0 km. As the large degree and high possibility of pollution occurred at 0.8-2.2 km downwind, it was necessary to avoid the deployment of pollution-sensitive equipment or devices in this area, and it should be used as a key area for emergency monitoring after the accident; while the uncertainty of 0.5-1.2 km was large, it was also necessary to overcome the random error by strengthening the monitoring frequency.

Catalytic combustion performance of copper manganese catalyst for low concentration ethanol
YANG Xinu, LUO Lanni, ZHOU Jingyi, LIU Jianying, HE Junliang, ZHUO Lei, LI Yun, YU Haichen
2023, 13(2): 527-533. doi: 10.12153/j.issn.1674-991X.20220193
Abstract(193) HTML (129) PDF(3073KB)(25)

In addition to the three conventional pollutants (CO, NOx and HCs) of traditional gasoline vehicles, gasohol vehicle exhausts also contained alcohols and aldehydes which led to photochemical smog and ozone pollution. CuOx, MnOx and CuMnOx catalysts were prepared by the co-precipitation method for catalytic combustion of low-concentration ethanol emitted from gasohol vehicles in cold start. Moreover, the catalysts were characterized by BET nitrogen adsorption-desorption, X-ray diffraction (XRD), hydrogen temperature programmed reduction (H2-TPR), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The results showed that CuMnOx catalyst had a better low-temperature catalytic activity for low-concentration ethanol. When the reaction temperature was 185 °C, the yield of CO2 was as high as 86%, better than that of single CuOx catalyst (about 20%). Meanwhile, CuMnOx had a higher CO2 selectivity than MnOx. The interactions between Cu and Mn altered the texture, structure and oxidation performance of the catalyst, resulting in the changes in the crystal morphology and electronic environment of the catalyst. There were a large number of oxygen defect sites on the surface of CuMnOx, which was in favour of the adsorption of oxygen molecules, then turning into surface active oxygen species.

Sequencing optimization and benefit analysis based on quality evaluation of SCR denitration catalyst
HUANG Kui, HE Shanshan, LIU Haiqiu
2023, 13(2): 534-540. doi: 10.12153/j.issn.1674-991X.20220270
Abstract(217) HTML (93) PDF(11031KB)(19)

Taking the three-layer catalyst M2-N1-N2 of a coal-fired power plant as an example, the indexes of main chemical composition, specific surface area, trace elements and denitration efficiency were tested, the quality of the existing three-layer catalyst was analyzed and evaluated, and the sequencing of the three-layer catalyst was optimized, to ensure NOx to meet the emission standard. The results showed that, compared with SCR catalyst N1/N2, SCR catalyst M2 had less chemical composition of CaO and Al2O3, which reacted with SO3 gas in the flue gas to generate less amount of CaSO4 and Al2(SO4)3, and it was not easy to deposit in the channel. At the same time, trace elements, such as Na, Mg, Fe and K, in the flue gas and fly ash accumulated less on the surface of catalyst M2 and occupied less effective acid sites. The overall denitration efficiency was tested, and the denitration efficiency of the single-layer SCR catalyst was also explored. The original sequencing three-layer catalyst was optimized to ensure the overall denitration efficiency to meet NOx emission requirements under the new sequencing. The benefit analysis was carried out from the multi-dimensions of environment, economy and resources. The economic cost accounting under different replacement methods showed that SCR catalyst under the new sequencing could save 4.719 million yuan or 3.3 million yuan for the plant. Moreover, it could save the manufacturing resources of the fresh SCR catalyst, and avoid the links of environmental pollution caused by the manufacture and handling of the SCR catalyst. SCR catalyst recycled would also prolong the life span of the catalyst.

Succession and driving factors of Lake Dianchi aquatic ecosystem in the past 60 years
JIANG Jianjian, HU Wen, YE Chun, SONG Di, WANG Zhiyun, LI Chunhua, LI Jie, TANG Cheng
2023, 13(2): 541-551. doi: 10.12153/j.issn.1674-991X.20220121
Abstract(724) HTML (564) PDF(2005KB)(156)

As an essential part of the ecological security barrier in the upper reaches of the Yangtze River and southwest China, Lake Dianchi plays a critical role in safeguarding national and regional environmental security. The succession process and driving factors of phytoplankton, zooplankton, macrophytes, zoobenthos, fish and other essential compositions in Lake Dianchi aquatic ecosystem were systematically analyzed using literature research and classification, combined with the water quality change and eutrophication evolution process of Lake Dianchi in 1950-2020. The results showed that before the 1960s, Lake Dianchi maintained its natural form and belonged to the stage of the macrophyte type lake. Between the 1970s and 1990s, the situation of eutrophication, the physical and chemical properties of the water changed rapidly, and nutrient-tolerant species increased. It indicated that the lake regime shifted from a macrophyte type lake to a macrophyte-algal type lake. From 2000 to 2015, the water environment of Lake Dianchi seriously deteriorated. The water quality was between “Inferior” and “Class V” of Environmental Quality Standards for Surface Water (GB 3838-2002), and the water use function was basically lost, indicating that it belonged to the stage of an algal lake. Since 2016, although the water quality of Lake Dianchi had gradually improved, the eutrophication had remained at a high level. The driving factors of the aquatic ecosystem succession of Lake Dianchi were natural factors, pollutant discharge exceeding Lake Dianchi's environmental capacity, and ecosystem habitat fragmentation. The results could provide important reference values and theoretical support for decision-makers and stakeholders in managing similar shallow lake-water ecosystems.

Coastal construction setback line in China: research progress, problems and recommendations
HOU Liping, HE Ping, PENG Bo, WANG Dewang, XU Jie, LI Daikui, LEI Kun
2023, 13(2): 552-558. doi: 10.12153/j.issn.1674-991X.20220146
Abstract(366) HTML (201) PDF(784KB)(64)

As an effective management and control means of coastal zone development and construction activities, coastal construction setback line has been widely used in the world. Some coastal provinces and cities in China have also carried out different methods of setback line delimitation and regulations exploration. The outline of China’s 14th Five-year Plan clearly puts forward to "explore the regulations of coastal construction setback line". The implementation progress, determination methods and initial baseline of coastal construction setback line in foreign countries, and the research and practice basis of China's coastal construction setback line were summarized. The main problems faced by the delimitation of coastal construction setback line in China were non-uniform delimitation standards, poor operability of control measures, lack of upper legal support for the delimitation of coastal construction setback line, and the inconsistency between scientific accuracy and management simplicity. The recommendations, such as standardizing the delimitation methods of coastal construction setback line, enforcing legislation and management regulations first, comprehensively determining alternative schemes, and carrying out pilot research, were put forward in order to provide technical support for coastal provinces and cities to comprehensively carry out the delimitation and management of coastal construction setback line.

Water ecological health assessment based on the biological integrity of macroinvertebrate: a case from Liaohe River Basin
LIU Sisi, SHANG Guangxia, GAO Xin, KONG Weijing, XIA Huijuan, DING Sen
2023, 13(2): 559-566. doi: 10.12153/j.issn.1674-991X.20210326
Abstract(407) HTML (145) PDF(1910KB)(74)

The benthic index of biological integrity (B-IBI) is widely used for river ecological health assessment all over the world. However, this index should be constructed separately according to the ecological environmental characteristics of each river basin. In this study, the Liaohe River Basin was taken as an example, the data of macroinvertebrates of 99 sites in Liaohe River Basin was used to calculate to B-IBI. Water quality and habitat quality were comprehensively used as the selection criteria for reference sites and impacted sites. The distribution range test, discriminant ability test and redundancy test were used to screen the core metrics of B-IBI. The ratio method was used to standardize the core metrics and add up to calculate B-IBI. The results showed that a total of 74 taxa of macroinvertebrates were found, and the dominant taxon was Insecta (accounting for 81.1% of the total taxa). The most dominant species was Hydropsyche kozhantschikovi. Five reference sites and six impacted sites were obtained after screening. Six core metrics including the number of total taxa, the taxa number of Trichoptera, the taxa number of Amphipoda and Mollusca, the relative abundance of direct collectors, the number of adherent taxa, and the Pielou evenness index, were selected from 28 candidate metrics. The evaluation results of B-IBI showed that 4 sites were in health grade, 15 sites in sub-health grade, 25 sites in normal grade, 41 sites in poor grade, 14 sites in bad grade, and the whole health level of Liaohe River Basin was poor in the survey period. The macroinvertebrate community was impacted in more than half of the sampling sites. B-IBI showed a good indicating ability for the change of water quality in Liaohe River Basin, and effectively distinguish damaged sections of the river. It was suggested that B-IBI could be used as a bioassessment tool for the river basin management in future.

Research on the application of EwE model in aquatic ecosystems and a case study of Changtan Reservoir
SHI Zhanyao, ZHANG Jingtian, HUO Shouliang
2023, 13(2): 567-577. doi: 10.12153/j.issn.1674-991X.20220131
Abstract(468) HTML (257) PDF(2108KB)(82)

Ecopath with Ecosim (EwE) model is commonly used to quantitatively study the food web structure and energy flow characteristics in the aquatic ecosystem. The principles and progress of Ecopath, Ecosim, Ecospace, and Ecotracer modules of EwE model and its application in different types of aquatic ecosystems were summarized. The results indicated that Ecopath could be used to estimate the maturity of the ocean and freshwater ecosystems, to determine key species and ecological capacity, and to clarify the important contribution of phytoplankton production (P) to total system throughput (TST) in the aquatic ecosystem. Ecosim was used to reveal the impact mechanisms of human activities (e.g. keystone species catching, port construction) on ecosystem structure and function on a time scale. Ecospace was used to clarify spatial variability of fishing activity and ecosystem structure under external factor effects (e.g. offshore platform construction, power plant operation, and volcanic eruption). Ecotracer was used to trace the immigration progress of isotopes, heavy metal, new pollutant, and other matters in the food web. Combined with Ecopath, the nutrient structure and energy flow of Changtan Reservoir were analyzed. The results showed that the trophic level was in the range of 1.000-3.093, indicating a simple food web structure. The total primary production/total respiration (TPP/TR) value was 2.445, indicating Changtan Reservoir was a relatively mature ecosystem, and it had a low energy transfer efficiency. In the future, studies on the impacts of climate change and human activities on the structural succession of aquatic ecosystems, and the enrichment characteristics of new pollutants in the food web should be strengthened to provide a scientific basis for the assessment of aquatic ecosystem health and the adjustment of fishery economic development policies.

Analysis of the coordination status and evolution law of development intensity and habitat quality in the Integrated Region of the Yangtze River Delta
2023, 13(2): 578-584. doi: 10.12153/j.issn.1674-991X.20220305
Abstract(205) HTML (104) PDF(2071KB)(22)

Exploring the coordination status and evolution law of development intensity and habitat quality in the integrated region of the Yangtze River Delta has important enlightenment significance for formulating or revising the regulation strategy of ecological green integration and high-quality development. Based on Landsat satellite remote sensing land use, the data were interpreted and counted. By using In VEST model and principal component analysis comprehensive evaluation method, the habitat quality and development intensity in the integrated region of the Yangtze River Delta from 2005 to 2020 were calculated. The coupling coordination model was used to investigate the coordination between them. The evolution law between them was explored by curve regression analysis. The results showed as follows: The development intensity index of the integrated region of the Yangtze River Delta increased from 0.383 3 in 2005 to 0.783 3 in 2020, and the habitat quality index decreased from 0.504 9 in 2005 to 0.493 7. The coordination degree between the two increased from 0.663 3 in 2005 to 0.788 6 in 2020, and the multi-year average was 0.734 7, which was in a moderate coordination state. The relationship between them was a quadratic parabola with the opening upward. During the 14th Five-year Plan period, its trajectory was still in the left half of the parabola. The contradiction between development intensity and habitat quality would be further intensified. Therefore, ecological green integration and high-quality development would face great challenges.

Occurrence of PPCPs in surface water and sediment in China and influencing factors of interactive migration
TIAN Yongjing, WU Yusheng, HUANG Tianyin, CHEN Shuqin, ZHANG Jiagen, PANG Yan
2023, 13(2): 585-596. doi: 10.12153/j.issn.1674-991X.20220418
Abstract(404) HTML (173) PDF(1610KB)(62)

Pharmaceuticals and personal care products (PPCPs), as a class of typical new pollutants, are often detected in the water environment due to their widespread use and pseudo-persistence, which has aroused worldwide attention. Sediments are important environmental repositories of PPCPs, and polluted sediments can be regarded as long-term pollution sources to cause the pollution of the overlying water. The research results at home and abroad in recent years were reviewed, the occurrence of PPCPs in typical surface water and sediment in seven regions of China were analyzed, and the effects of PPCPs characteristics, sediment components and environmental factors on the interaction migration of PPCPs in water-sediment system were summarized. The results showed as follows:1) The concentration of PPCPs detected in surface water in China ranged from undetected (ND) to 9 785 ng/L. There were 20 kinds of PPCPs with high detection rates and concentrations. The highest concentration was with caffeine (CAF), a non-antibiotic drug, followed by erythromycin (ETM) and sulfamethoxazole (SMX). PPCPs with the highest pollution concentration in the surface water of seven regions of China were non-antibiotic stimulants, which were highly polluted in North China, South China, and Southwest and Northwest, followed by macrolides and sulfonamides in antibiotics which were highly polluted in Northeast, East China and Central China. The highest level of PPCPs pollution in surface water was found in North China, followed by East China. 2) The concentration of PPCPs detected in sediments in China was ND-3 440 ng/g. There were 18 kinds of PPCPs with high detection rates and concentrations, among which triclocarban (TCC) had the highest concentration, followed by oxytetracycline (OTC) and norfloxacin (NOR). PPCPs with the highest pollution concentration in the sediments of seven regions of China were personal care antibacterial agents, with the highest pollution degree in South China, followed by tetracycline and quinolones. Tetracycline pollution degree was higher in East China, Central China and Northeast, and quinolones pollution degree was higher in north China, Northwest and Southwest. The pollution degree of PPCPs in sediments in South China was the highest, followed by East China. 3) PPCPs concentrations in surface water and sediments in China were at a higher level worldwide. The interaction migration of water-sediment system was mainly affected by the nature of PPCPs and sediment components, and the interaction migration mechanism of PPCPs under the coupling effect of sediment components and water environment conditions needed to be further clarified.

Fluorescence characteristics and sources of dissolved organic matter in Hulun Lake
BAI Kai, JUN Shan, ZHENG Shuofang, ZHANG Bo
2023, 13(2): 597-606. doi: 10.12153/j.issn.1674-991X.20220327
Abstract(253) HTML (160) PDF(3449KB)(41)

Hulun Lake is an important component part of the northern ecological security barrier in China. To study the components and sources of organic matter in Hulun Lake, the three-dimensional excitation-emission matrix spectra (EEMs) and parallel factor (PARAFAC) analysis techniques were used to analyze the fluorescence characteristics of dissolved organic matter (DOM) and its sources. The results showed that three fluorescent components were obtained in DOM using EEM-PARAFAC, namely tryptophan-like substances (C1), humic-like substances (C2) and fulvic-like substances (C3). The total proportion of C2 and C3 fluorescence intensity accounted for about 70%, showing that the humic-like substances were the main part of DOM in the water of Hulun Lake during the normal, wet and dry seasons. The fluorescence intensity of C2 and C3 in the inlet of the ecological supplement channel was higher than that in other regions in different seasons. The average value of the fluorescence index, the biological source index and the humification index of DOM in Hulun Lake were 1.50-1.54, 0.85-1.00 and 4.12-4.68, respectively, during the normal, wet and dry seasons, indicating that DOM of Hulun Lake came from land sources and autogenous sources with autogenous source characteristics. According to the monitoring data, the water quality of Hulun Lake exceeded Class Ⅴ of Environmental Quality Standards of Surface Water (GB 3838-2002) during the normal, wet and dry seasons in 2021. The average concentration of BOD5 in the normal and wet seasons was higher than that in the dry season in 2021. At the same time, the average concentration of the total organic matter in the normal season was higher than that in the wet and dry seasons. The results of the redundancy analysis showed that C2 was significantly and positively correlated with C3, indicating that the production and source of C2 were consistent with C3 in DOM.

Distribution and risk assessment of semi-volatile organic compounds in water and sediment of Ulansuhai Nur
HUANG Ziyan, ZHANG Yahui, CAO Jiale, DU Shilin, ZHANG Jin, HE Liansheng
2023, 13(2): 607-616. doi: 10.12153/j.issn.1674-991X.20220376
Abstract(255) HTML (130) PDF(3960KB)(31)

In order to study the pollution characteristics and risk level of semi-volatile organic compounds (SVOCs) in water and surface sediments of Ulansuhai Nur, water and sediment samples from 7 sites were detected and analyzed. The total concentration of SVOCs in water and sedimentary species ranged from 449.7 to 691.0 ng/L and 144.4 to 587.5 µg/kg, respectively. Polycyclic aromatic hydrocarbons (PAHs) and phthalate esters (PAEs) were the main contaminant compounds found in all samples. Other SVOCs were not detected or only trace. PAHs pollution in water and sediment mainly came from petroleum source and mixed source of coal and biomass fuel combustion. PAEs pollution mainly came from plastics and chemical industry and domestic wastes. The ecological risk of the main contaminants in water and sediment of Ulansuhai Nur was at a low level in general, and the health risk also presented a low level in terms of drinking water and exposure.

Impact of Three Gorges Reservoir water supply regulation on habitat suitability of typical submerged plants in East Dongting Lake
WU Qian, DAI Lingquan, REN Yufeng, TANG Zhengyang, DAI Huichao, LIU Xinbo, LIU Fen, ZHANG Qingsen
2023, 13(2): 617-624. doi: 10.12153/j.issn.1674-991X.20220047
Abstract(178) HTML (99) PDF(3355KB)(18)

Submerged plants are important species for ecological restoration of water in East Dongting Lake, and water depth is one of the key hydrodynamic factors affecting the growth of submerged plants. In order to quantitatively describe the impact of different water supply modes of the Three Gorges Reservoir (TGR) on typical submerged plants growth habitat in East Dongting Lake, taking Vallisneria spinulosa as the target species, the relationship between different outflow from TGR and the weighted usable area (WUA) of Vallisneria spinulosa growth habitat in East Dongting Lake during TGR water supply operation was established by using physical habitat simulation model (PHABSIM). The results showed that the suitable water depth range for the growth habitat of Vallisneria spinulosa was 0.2~1.8 m, the optimal water depth range was 0.5~1.0 m. After TGR implementing the water supply operation, WUA of Vallisneria spinulosa growth habitat in East Dongting Lake showed a uniform upward trend totally. During the period of TGR water supply, the outflow was 5 500~10 500 m3/s. With the increase of the outflow of TGR, WUA corresponding to the optimal water depth range for Vallisneria spinulosa growth habitat firstly increased and then decreased. When the outflow range was 9 500 m3/s, the maximum WUA was 74.46 km2. It could be considered that the optimal outflow range of Vallisneria spinulosa was 8 500~10 500 m3/s. The results were expected to provide reference for restoring and protecting the water ecological environment in East Dongting Lake through TGR ecological scheduling.

Study on the seasonal succession of phytoplankton functional groups in Eryuan West Lake of Dali City, Yunnan Province
YANG Yalan, GUO Longgen, YIN Chengjie, GONG Li, LUO Zefeng, XU Shulan
2023, 13(2): 625-631. doi: 10.12153/j.issn.1674-991X.20220097
Abstract(244) HTML (148) PDF(1640KB)(34)

To investigate the characteristics of the phytoplankton functional group and its relationship with environmental factors in the West Lake of Eryuan County, Dali City, Yunnan Province, phytoplankton samples and water environment factors were collected monthly from September 2019 to August 2020. The modified Carlson trophic state index and the phytoplankton functional group (FG) classification were used to evaluate the degree of eutrophication in the water column of the lake and to explore the seasonal succession characteristics of phytoplankton. The preliminary results showed that: 1) Eryuan West Lake was eutrophic water with low transparency and turbidity. 2) Seven phyla and 72 genera of phytoplankton were identified by microscopic examination during the study, which were divided into 23 phytoplankton functional groups. MP (Oscillatoria sp.), S1 (Anabaenopsis sp.), H1 (Dolichospermum sp.) and SN (Cylindrospermopsis sp.) were the four dominant functional groups, all of which were filamentous algae of cyanobacterial phylum. Phytoplankton in autumn was mainly dominated by Oscillatoria sp. and Cylindrospermopsis sp., while it was mainly composed of Anabaenopsis sp. and Oscillatoria sp. in winter and spring, and mainly Oscillatoria sp. and Dolichospermum sp. in summer. 3) The results of Redundancy analysis showed that the key environmental factors for phytoplankton functional group succession in Eryuan West Lake were water temperature, pH, PO4 3−-P and TDP, especially the change of soluble phosphorus concentration contributed to the seasonal succession of the dominant functional group. Therefore, filamentous cyanobacteria were dominant in the eutrophication state of Eryuan West Lake, with a homogeneous algal structure.

Effect of weathering behavior of polyethylene microplastics in water on coagulation process
XU Mingyao, PENG Shaoyin, QI Fei, LI Chen, WANG Zhenbei, GUO Mingyu
2023, 13(2): 632-638. doi: 10.12153/j.issn.1674-991X.20220032
Abstract(234) HTML (103) PDF(3459KB)(25)

Polyethylene (PE) microplastics with high abundance in surface water were used as the research object to conduct adsorption and coagulation experiments. Based on the study regarding the organic matter adsorption capacity of PE microplastics, the effect of weathering behavior of PE microplastics on the coagulation process was further explored by using photoaged PE microplastics with xenon lamp to simulate weathering behavior of microplastics under natural conditions. The results showed that PE microplastics with particle size 50-200 mesh could adsorb 310-350 mg/g (calculated by carbon) organic matter, indicating that the microplastic size would not significantly influence the adsorption performance of PE microplastics. In coagulation, compared with no PE microplastics conditions, the addition of unweathered PE microplastics was prone to decrease the organic matter removal rate, while the addition of weathered PE microplastics was able to obviously increase the removal efficiency of organic matter. Furthermore, the removal rate of weathered PE microplastics was remarkably higher than that of unweathered PE microplastics in coagulation, which suggested that the weathering behavior was beneficial to PE microplastics removal during the coagulation process. According to the floc properties in coagulation, it was notable that both unweathered and weathered PE microplastics would not influence floc average size in coagulation, but significantly increased the growth rate of flocs in this process.

Study on treatment of high-salt printing and dyeing wastewater by electroflocculation-micro-nano-bubble ozone oxidation process
ZHANG Liang, ZHOU Shucen, LI Pan, CHEN Wensong
2023, 13(2): 639-647. doi: 10.12153/j.issn.1674-991X.20220043
Abstract(508) HTML (218) PDF(13980KB)(91)

High-salt printing and dyeing wastewater has the characteristics of high chromaticity, poor biodegradability and unstable water quality, which makes it difficult to be treated efficiently by traditional biochemical methods. Micro-nano-bubble ozone (O3) advanced oxidation process and electric flocculation (EC) process were combined to treat high-salt printing and dyeing wastewater, the coupling effect of the two processes was explored, and the influence of current density, salt concentration, pH and other factors on the treatment effect of the combined process was studied. The experimental results showed that EC alone could decolorize dyeing wastewater and remove organic matter to a certain extent, but the efficiency was low. Under the same conditions, the treatment efficiency of printing and dyeing wastewater by EC+O3 process was higher than that by EC→O3 process (EC treatment for 30 min→O3 treatment for 120 min), and the ozone consumed by removing 1 mg COD was 0.46-1.39 mg. With the increase of current density and pH, the decolorization rate, UV254, COD and TOC removal rate increased. With the increase of salt concentration, the decolorization rate, UV254, COD and TOC removal rate increased slightly. The effects of ozone micro-nano-bubble process, H2O2/O3 of advanced oxidation process and EC+O3 processes on the treatment of actual printing and dyeing wastewater in Xinjiang and Zhejiang were compared, and the economic analysis was carried out. The electrical energy per order (EE/O) value of each stage of the three micro-nano-bubble treatment processes was EC+O3 < H2O2/O3 < O3 from low to high.

Effect of TY-BM1 multi-media membrane integrated equipment on rural domestic sewage treatment
YANG Ming, CHEN Jian, PAN Chengrong, ZHANG Lei, MA Jiechen, WANG Lin, GONG Mingjie, WANG Jun
2023, 13(2): 648-653. doi: 10.12153/j.issn.1674-991X.20220077
Abstract(195) HTML (81) PDF(1860KB)(16)

With the in-depth advancement of the rural revitalization strategy and the increasingly stringent sewage discharge standards, higher requirements have been placed on rural domestic sewage treatment technology. The mobile biofilm technology was optimized and improved when an upward-shunting multi-media biofilm operation system was developed. The treatment effect of the technology for actual rural domestic sewage was investigated, and its promotion and application value was discussed. The results indicated that the carbon source in the sewage system was utilized efficiently for denitrification. With the experimental conditions of hydraulic retention time longer than 0.15 d, the gas-to-water ratio greater than 3:1 and 1.50 times of nitrification liquid reflux ratio simultaneously, the removal rate of SS, TN, NH4 +-N, CODCr and TP in sewage reached 96.23%, 47.33%, 78.89%, 79.38% and 80.77%, respectively, without sludge return. Besides, the effluent quality was better than Level 1 A standard of Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant (GB 18918-2002).

Comprehensive evaluation research of livestock and poultry waste treatment technologies in the ecological fragile areas of Northwest China
WANG Ying, WANG Yue, WU Changyong, FAN Shuai, WANG Hao
2023, 13(2): 654-662. doi: 10.12153/j.issn.1674-991X.20220080
Abstract(185) HTML (143) PDF(1982KB)(37)

The applicability of livestock and poultry waste treatment technology is quite different in different regions. In order to comprehensively, objectively and scientifically screen out suitable livestock and poultry waste treatment technologies in Northwest China, the life cycle assessment, cost benefit analysis (CBA) and analytic hierarchy process (AHP) methods were coupled to establish a screening system for livestock and poultry waste treatment technologies in Northwest China. The system included five factors of technology, economy, climate, direct and indirect environmental impacts, with a total of 18 indicators. Taking the livestock and poultry waste treatment technologies in Lanzhou as an example, the applicability of the technologies of aerobic composting, anaerobic fermentation, and litter utilization were analyzed. The results showed that the comprehensive ranking of the applicability of livestock and poultry waste treatment technologies in Lanzhou City was litter utilization technology (72.21 points)>aerobic composting technology (71.55 points) > anaerobic fermentation technology (68.79 points). It was more suitable to use litter utilization technology in Northwest China. The environmental friendliness of litter utilization technology is obviously better than that of anaerobic fermentation and aerobic composting technologies. The use of aerobic composting and anaerobic fermentation technologies could generate additional profits for the breeding farm. This research could provide guidance for the construction and optimization of livestock and poultry waste treatment technology models in Northwest China.

Experimental study on the removal of Cr(Ⅵ) from water by biochar-based sulfide modification loaded with nano-zero valent iron
PAN Hong, WANG Xingrun, WANG Lei, ZHANG Yujia, YAN Xianghua
2023, 13(2): 663-668. doi: 10.12153/j.issn.1674-991X.20220250
Abstract(311) HTML (105) PDF(1266KB)(59)

In order to treat Cr(Ⅵ) pollution in groundwater, biochar-supported nano-zero valent iron (BC-nZVI) was prepared by the carbothermal method, and the modified material (M-BC-nZVI) was prepared by vulcanization modification of BC-nZVI. The chromium removal capacity, Cr to Fe ratio (Cr/Fe) and the reactivity of M-BC-nZVI were used to analyze the superiority of M-BC-nZVI for chromium removal. A failure rate model was established through the simulated column test to calculate the chromium removal capacity of M-BC-nZVI that completely failed. Finally, the application feasibility of M-BC-nZVI in removing Cr(Ⅵ) was analyzed by comparing it with the relevant studies. The results showed that the removal capacity, Cr/Fe and pseudo-first-order reaction rate constant (kobs) of M-BC-nZVI were 1.86, 1.95 and 3.00 times higher than those of BC-nZVI, respectively. Therefore, compared with BC-nZVI, M-BC-nZVI had certain advantages in various aspects. Each simulated column had no obvious blockage during operation, and the failure rate constant of M-BC-nZVI increased with the increase of influent concentration. The highest chromium removal capacity (12.70 mg/g) reached when the failure chromium removal rate was 1.0% of the initial chromium removal rate and the influent Cr(Ⅵ) concentration was 5 mg/L. By comparing Cr/Fe of M-BC-nZVI with iron-based materials and iron-based modified materials reported in other studies, Cr/Fe of M-BC-nZVI was 1.06 to 42.06 times that of other studies. Therefore, based on the chromic removal performance of the material, it was feasible to apply M-BC-nZVI to permeable reactive barrier to treat Cr(Ⅵ) pollution in groundwater.

Performance of a pilot-scale sequential batch reactor (SBR) on nitrogen and carbon removals and its characteristics of microbial community succession from biogas slurry from duck farm
WEN Hongping, YANG Xiaoming, CHENG Yunan, LIU Mengxue, LUO Zifeng, LI Qiang, LI Yongtao, ZHANG Zhen
2023, 13(2): 669-678. doi: 10.12153/j.issn.1674-991X.20220057
Abstract(222) HTML (92) PDF(5146KB)(18)

A pilot-scale sequential batch reactor (SBR) was built in the duck farm, the duck farm biogas slurry was diluted as the influent, and the influent COD was regulated with sucrose, to evaluate the efficiency of nitrogen and carbon removal and the microbial community succession in the process of SBR treating the biogas slurry of the duck farm. The results showed that Stage Ⅰ (1-20 d) was the sludge inoculation and water quality adaptation stage, in which the influent C/N was controlled to be less than 2, and the concentrations of COD and NH4 +-N were around 200 mg/L. It was found that the removal efficiencies of COD and NH4 +-N rapidly increased to 80% and 90%, respectively, within the first 8th day. Stage Ⅱ (21-55 d) was the stabilization stage, in which C/N of the influent was also less than 2, and the concentrations of COD and NH4 +-N were 200-500 and 200-400 mg/L, respectively. In this stage, the removal efficiencies of COD were fluctuated around 60%, while the removal efficiencies of NH4 +-N were more than 80%. Stage Ⅲ (56-95 d) was the simulation stage for organic concentration change, in which C/N of the influent was in the range of 1.2 to 5.5, while the influent COD and NH4 +-N concentrations were 300-1 400 and 150-400 mg/L, respectively, and the removal rate of COD and NH4 +-N was greater than 80% in this stage. Meanwhile, low temperature was one of the main limiting factors for SBR nitrogen and carbon removal. Full-length sequencing of 16S rRNA from microorganisms revealed that Proteobacteria and Gammaproteobacteria were the dominant microbial flora at the phylum and class levels in the system, respectively. A significant shift of microbial community in terms of genus level was detected. The dominant microbial community species with nitrogen and carbon removal functions were formed after the operation stabilization. In general, SBR could achieve efficient nitrogen and carbon removal and had promising application potential in the real practice of treating biogas slurry from duck farm with a characteristics of high COD concentration and low C/N.

Performance and carbon emission of applying CAST embedded with MBBR to retrofit a wastewater treatment plant
ZHANG Lingli, GU Dungang, LU Jiaqi, ZHANG Nan, LI Guanghui, HU Lijiang, JIA Hongbai, WANG Yinyi
2023, 13(2): 679-686. doi: 10.12153/j.issn.1674-991X.20220267
Abstract(231) HTML (176) PDF(7531KB)(44)

The effects of applying the cyclic activated sludge technology (CAST) process embedded with moving bed biofilm reactor (MBBR) on pollutant removal, electricity consumption, chemical consumption, and carbon emission were investigated by comparing and analyzing the operational data of a wastewater treatment plant (WWTP) in Zhejiang Province before and after upgrading and retrofit. The results showed that MBBR could strengthen the biological removal of nitrogen and phosphorus and improve the anti-shock loading capacity of the system. After retrofitting, the water quality of the effluent could meet the Zhejiang Provincial Standard for Discharge of Major Water Pollutants for Municipal Wastewater Treatment Plant (DB 33/2169-2018) stably, with the annual average values of COD, NH3-N, TN and TP being 13.7, 0.2, 4.3 and 0.05 mg/L, respectively. There was no significant change as to the distribution of electricity consumption within the WWTP after retrofitting. The electricity consumption per ton water increased by 19%, while the annual consumption of external carbon source, coagulants and disinfectants decreased by varying degrees, and the total chemical consumption per ton water decreased by 44%. The carbon emission of the WWTP decreased from 1.04 kg/m3 to 0.79 kg/m3 after retrofitting, and the direct methane emission and material consumption in the treatment process contributed greatly to the overall carbon emission of the WWTP.

Research on high-pressure water jet technology for sediment dredging of sewage pipeline in old urban area
CHEN Guorong, ZHAO Qingxia, LUO Guijun, TONG Shehua, LIU Jian, LI Wei, XU Chao, GONG Weiyou, LIU Zhifeng
2023, 13(2): 687-693. doi: 10.12153/j.issn.1674-991X.20220055
Abstract(235) HTML (91) PDF(1580KB)(23)

Taking the actual sewage pipeline in the urban area of a county in southern China as the research object, the sedimentation status and sediment properties of sewage pipelines in the residential quarter and vegetable market in the urban area were determined. By comparing various dredging methods, the high-pressure water jet method was selected for silting removal. The new inflatable sewage pipe plugging device, washing-suction integrated vehicle and KEG Emperor spray head were used. The orthogonal test of nozzle outlet pressure and nozzle moving speed was carried out to compare the silting effect, oil consumption, water consumption, silting time and total cost, and the best silting parameters with high efficiency and low cost were selected. The results showed that the degree of sewage pipeline silting in the residential quarter was about 50%, and that in the vegetable market was about 40%-50%. The fluidity of sludge in pipelines of the residential quarter was better than that of the vegetable market. Lower pressure at the nozzle outlet could satisfy sludge cleaning. The optimum dredging parameters for sewage pipes in the residential quarter were spray head outlet pressure 9 MPa and spray head movement speed 0.3 m/s, and the optimum dredging parameters for sewage pipes in the vegetable market were spray head outlet pressure 12 MPa and spray head movement speed 0.3 m/s.

Ecosystem service value change analysis of Chishui River Basin based on land use change
YANG Yingzeng, ZHOU Laifeng, XIA Wei, WANG Minzi
2023, 13(2): 694-703. doi: 10.12153/j.issn.1674-991X.20220158
Abstract(306) HTML (233) PDF(7337KB)(24)

Based on the remote sensing interpreted land use data of Chishui River basin in 1990, 1999, 2010 and 2018, the localization-corrected equivalent factor method and GIS spatial analysis techniques were used to analyze the land use change characteristics, the ecosystem services value (ESV) change characteristics and the effects of land use change on the change of ESV. The results showed that the area of cultivated land, grassland and unused land decreased, and the area of construction land, forest land and water increased from 1990 to 2018. The land use transfer was mainly reflected in the mutual flow between cultivated land-forest-grassland and the encroachment of construction land on cultivated land and grassland. From 1990 to 2018, ESV increased from 41.190 billion yuan to 41.354 billion yuan in Chishui River basin, forest land was the main contributing part of ESV, and the increase of water area was the main influencing factor of the increase of ESV. The spatial distribution of ESV showed the characteristics of "high in the middle reaches, low in the upper and lower reaches", and the distribution of high value areas overlapped highly with that of forest land. The continuous expansion of urban construction land caused a decrease in ESV, and forest land and watershed, and cropland and grassland contributed positively and negatively to ESV due to area changes, respectively. The implementation of policies such as the change of population structure between rural and urban areas, the return of farmland to forest and watershed ecological management had promoted an increase to ESV.

Spatial and temporal variation and impact factors analysis of ecosystem service value in low-mountain counties: taking Dexing City in Jiangxi Province as an example
ZHAO Qichen, YU Dun, WANG Jianping, LU Yiqian, ZHENG Yaping, LUO Tianxin
2023, 13(2): 704-714. doi: 10.12153/j.issn.1674-991X.20220247
Abstract(231) HTML (325) PDF(3195KB)(26)

Scientific assessment of ecosystem service value (ESV) and analysis of its temporal and spatial variation characteristics and impact factors are of great significance to ensure regional ecological security. Taking Dexing City, a typical low mountainous landscape, as an example, based on the remote sensing images in 2000, 2007, 2013 and 2018, the land use structure and dynamic changes were analyzed, the ESV was evaluated according to the equivalent factor coefficient correction method, the temporal and spatial variation characteristics of ESV were described by using spatial auto-correlation and hot-spot analysis method, and the impact factors of ESV spatial variation were explored by using GeoDetector. The results showed that: From 2000 to 2018, forest land was the main land use type in Dexing City, accounting for more than 75% of the total area. The construction land area increased the most (2 230.38 hm2), forest land area decreased the most (2 763.54 hm2), and the unused land area changed the most drastically. The ESV of Dexing City decreased by 110 million yuan, and the total change was relatively stable. The ESV showed a spatial distribution pattern of low in the northwest and high in the southeast, and there was a significant spatial agglomeration effect. During the study period, the area with significant changes in ESV accounted for about 20% of the total area, and the ESV changes in local areas were relatively drastic. The spatial distribution of ESV was affected by both natural conditions and human activities, the interaction between two factors was higher than that of a single factor, and there were spatial differences in the strength of the impact factors. In the future development, Dexing City should pay attention to the protection of ecological land such as forest land and water area, revitalize the stock of construction land, improve the utilization efficiency of national land resources, optimize the layout of urban and rural construction land, and at the same time, adopt differentiated and precise ecological control measures for different regional characteristics.

Spatial-temporal changes of land use and ecosystem service value in dry valleys: a case study of Panxi area, Sichuan Province
ZHOU Jianwei, YANG Haiqing, DENG Qingchun, LIU Hui, WANG Lei, LUO Jun
2023, 13(2): 715-724. doi: 10.12153/j.issn.1674-991X.20220336
Abstract(304) HTML (154) PDF(16021KB)(29)

Studying spatial-temporal evolution of land use and ecosystem services value (ESV) is of great significance to the optimization of land use structure and sustainable development of ecological environment in dry valleys. Based on high-precision land use remote sensing interpretation data, spatial statistical analysis and Geodetector were used to study the spatial-temporal evolution and differentiation characteristics of land use and ESV of Panxi area (typical dry valleys) and its inner regions from 2000 to 2020. The results showed that forest land was dominant in Panxi area and its internal divisions, and water area and construction land increased rapidly from 2000 to 2020. Except for the southern canyon industrial and mining area, ESV of Panxi area and its internal divisions showed an increasing trend. Contribution rate of forest land to ESV of Panxi area was the largest, but obstructive effect of construction land on ESV growth was gradually increasing. ESV generally showed high in the northwest and central and low in the northeast and south. The loss area was concentrated in the urban construction and forest degradation area, while the increasing area was concentrated in the construction of reservoirs, hydropower stations and farmland conversation area. The high-value area gradually expanded while the low-value area gradually decreased. During the study period, Moran's I of ESV and its changes were more than 0, and showed a significant spatial autocorrelation (P < 0.001), but the spatial aggregation of ESV decreased slowly. Human activities had a significant impact on the spatial differentiation of ESV in Panxi area and its internal divisions, and Human Active Index was over 48.45%.

Evaluation of ecological carrying capacity in Yangtze River Delta: a case study of Suzhou City
YUE Hui, JIN Wenlong, CHEN Kangli
2023, 13(2): 725-732. doi: 10.12153/j.issn.1674-991X.20210654
Abstract(314) HTML (204) PDF(1357KB)(47)

Based on three aspects of ecological elasticity, supporting capacity of carrying media and pressure of carrying objects, ten influencing factors were selected, including climate conditions, hydrological conditions, ground cover, resource supply, environmental governance, social development, resource consumption, environmental pollution, population pressure and economic growth, to construct an index system of ecological carrying capacity in the Yangtze River Delta. The index system included 35 indexes. The subjective and objective weights of the evaluation factors were determined by the analytic hierarchy process (AHP) and principal component analysis (PCA). Taking Suzhou City as an example, ecological carrying capacity evaluation and obstacle factor analysis were carried out. The results showed that the overall trend of the ecological carrying capacity index of Suzhou from 2011 to 2018 was stable, and the carrying capacity level was in a medium carrying state. The subsystem of ecological elasticity had experienced the evolution process of weak stability, high stability and medium stability; the supporting capacity subsystem of carrying media had the evolution process of low support, medium support, strong support and medium support; the pressure subsystem of the bearing object showed the evolution process of lower pressure, medium pressure and higher pressure. Combined with the analysis of the obstacle factor of the ecological carrying capacity of Suzhou, it was found that the supporting capacity of bearing media was the main influencing layer of the ecological carrying capacity of Suzhou. The main obstacle factors in the factor layer included hydrological conditions, environmental treatment and environmental pollution, while the main obstacle factors in the index layer included industrial smoke and dust emission, urban regional environmental noise value and industrial wastewater emission and per capita water resources. The research results objectively reflected the status of ecological carrying capacity of Suzhou. Finally, reasonable countermeasures and suggestions were put forward for the sustainable development of Suzhou, which could provide some reference for the study of ecological carrying capacity in the Yangtze River Delta.

Evaluation of habitat restoration effect based on fish spawning requirements
LU Yun, WU Zihan, LIU Qingyuan, CHENG Bixin, QING Jie, YAN Xin, ZHANG Zeyu, LI Yong
2023, 13(2): 733-741. doi: 10.12153/j.issn.1674-991X.20220532
Abstract(328) HTML (118) PDF(5422KB)(53)

It is vital to evaluate the restoration effect according to the spawning needs of fish to master the habitat status and guide the project design. Taking the Heishui River as an example and starting from the habitat requirements of fish spawning, in order to obtain the real restoration effect of the restoration project on fish spawning habitat, the reference status of spawning habitat was quantified through on-site monitoring of real spawning sites and numerical simulation. An index system was constructed to evaluate the quality of fish spawning habitat. The results showed that the comprehensive evaluation scores of fish habitat in the spawning period of the Heishui River from 2019 to 2021 were 63.04, 83.52 and 83.52, respectively, indicating that the fish spawning habitat had been improved year by year. The evaluation results showed that the ecological restoration project had an obvious effect on the restoration of the spawning habitat. Moreover, the spatial distribution of fish spawning habitat quality in different reaches of the Heishui River showed that the downstream reach (R4-R6) before restoration was better than the upstream reach (R1-R3). After restoration, the scores of different reaches increased in varying degrees, with an increase of 21.33%-59.15%. Through tracing the source of sensitive factors, it could be seen that the habitat quality of fish spawning in the Heishui River before restoration was mainly limited by river connectivity and hydraulic conditions, and the connectivity had been greatly improved after restoration. However, there was still a certain gap between the water flow velocity and Froude number and the preference for protecting fish spawning. In the later restoration work, local shaping and improvement of water flow pattern should be carried out according to the preference of fish spawning.

Research progress of wetland carbon cycle in China based on bibliometrics
QIAN Xiyi, MAO Sichen, JIANG Yujie, YE Chenghui, LU Binfu, SHAN Nan, YAN Yan
2023, 13(2): 742-752. doi: 10.12153/j.issn.1674-991X.20220029
Abstract(424) HTML (179) PDF(4052KB)(66)

In order to explore the research status and development trend of the carbon cycle of wetlands in China, based on the relevant published literature in Web of Science (WoS) and CNKI databases from 2000 to 2020, the annual number of publications, citation frequency, authors, countries, institutions, journals, and keywords, etc. were analyzed in the past 20 years at home and abroad, using the bibliometrics method. Some suggestions for the future development were also put forward. The results showed that a total of 2 998 pieces of literature related to the carbon cycle of wetlands in China were published from 2000 to 2020, with the number of literature published in WoS and CNKI databases being 1 120 and 1 878, respectively. The annual number of literature published showed a trend of fluctuation and increase. The literature in WoS database covered 51 countries around the world, of which 1 075 were published in China, accounting for 95.98% of the total. Wetland, soil organic carbon and methane release were the key words with high mediating centrality, which were the core content of wetland carbon cycle research. Ecological Engineering and Acta Ecologica Sinica were the main journal carriers of foreign and Chinese literature in this field, respectively. The mechanism and flux of greenhouse gas exchange, the effect of microorganisms on carbon cycle, the ecological stoichiometry of carbon in wetland soil, and the carbon cycle and global change of wetland carbon cycle had been the hot topics in wetland carbon cycle research in China in the recent five years. The results of econometric analysis were helpful in comprehensively understanding the research status and development progress of wetland carbon cycle research in China, and providing references for wetland carbon research at home and abroad.

Study on conservation effectiveness of reed sand barrier with different types
TIAN Meirong, TIAN Yuxin, YANG Weichao, FENG Chaoyang, GAO Jixi, WANG Shixi
2023, 13(2): 753-759. doi: 10.12153/j.issn.1674-991X.20220522
Abstract(202) HTML (143) PDF(1616KB)(28)

Sand barrier is one of the important measures to mitigate the surface wind erosion and protect the surface vegetation. In order to select the suitable mode of reed sand barrier for controlling wind and sand in Hulun Lake Basin, six types of reed sand barriers were set up including three belt sand barriers with the banded row spacing of 1 m, 1.5 m, 2 m and the square sand barriers of 1 m × 1 m, 1.5 m × 1.5 m, 2 m × 2 m. Four indexes including wind prevention efficiency, soil moisture content, surface evaporation, and the growth of ecological restoration species in sand barriers were selected to evaluate the ecological protection achievement of six types of reed sand barriers. The results showed that the ecological protection achievement of square reed sand barriers were higher than that of belt reed sand barriers. The average windbreak efficiency, soil surface moisture content and surface evaporation of square reed sand barriers from high to low were: 1 m × 1 m > 1.5 m × 1.5 m > 2 m × 2 m. The analysis of the ability vegetation growth of Agropyron cristatum (L.) Gaertn., Elymus dahuricus Turcz. ex Griseb. in Ledeb., and Caragana microphylla Lam. in the six types of reed sand barrier showed that Agropyron cristatum grew well in the 1 m×1 m square reed sand barrier. The preferred measure of sandy land control in Hulun Lake basin was the 1.0 m×1.0 m reed sand barrier planting Agropyron cristatum, which could inhibit wind speed and reduce soil moisture loss, and provide theoretical basis and practical reference for the restoration of sandy grassland in this area.

Ecological and health risk assessment of soil heavy metals in a mining park: a case study of M Mine in Hunan Province
DENG Hongrui, LI Jipu, LUO Lin, YANG Lu, GUO Pengfei, XIE Hongbin, LIU Jianxing
2023, 13(2): 760-768. doi: 10.12153/j.issn.1674-991X.20220246
Abstract(250) HTML (170) PDF(883KB)(33)

The construction of mining parks is an important way to restore and manage the ecological environment of mines, and the assessment of the soil remediation effect of mine parks is of great significance to the construction and operation of mining parks and the safety of tourists. 66 soil samples were collected from 0-30 cm of dry soil on unhardened ground in the mining park, and the contents of heavy metals Mn, Cr, Zn, Pb, As, Cu, Ni and Hg were measured. The comprehensive pollution index, potential ecological risk index and health risk assessment model were used to evaluate pollution status, potential ecological risk and human health risk of the remediated soil. The results showed that the average values of each metal element in M Mining Park were Mn > Cr > Zn > Pb > As > Cu > Ni > Hg, where the average values of Cr, Mn, Cu, As and Pb were 1.23, 1.80, 1.12, 2.05 and 1.34 times of the background values of Hunan soil, respectively. The Nemerow comprehensive pollution index was 0.51, which was at a safe level. The single factor potential risk index for each heavy metal element was at the low ecological risk level, and the average potential ecological risk index was 81.64, which was at the low ecological risk level, showing there was no potential ecological risk. The total non-carcinogenic risk value for children and adults was respectively 2.46×10−1 and 7.43×10−2, which did not cause non-carcinogenic risk, and the total carcinogenic risk index was 1.38×10−7, which did not have carcinogenic risk. Overall, after ecological restoration, the mine park would have no ecological risk and health risk of heavy metals in soil, suitable for tourism and recreation for various populations.

Heavy metal pollution characteristics and health risk assessment of soil from an abandoned site for lead smelting of waste lead batteries
ZHANG Hao, WANG Yang, WANG Hui, JU Wenjun, HUANG Rui, LIU Ran, DU Ming
2023, 13(2): 769-777. doi: 10.12153/j.issn.1674-991X.20220313
Abstract(216) HTML (124) PDF(808KB)(29)

The contaminated plot left by a typical illegal lead refining site for waste lead batteries was taken as the research object. The pollution characteristics of lead and arsenic and health risk in the site soil were analyzed and evaluated by using the comprehensive pollution index method, the potential ecological index method, and the human health risk assessment model, and the children's blood lead levels were evaluated combined with the integrated exposure uptake biokinetic (IEUBK) model at the same time. The results indicated that the mean values of lead and arsenic in the soil at all sites in the study area were 4.67×104 and 2.64×102 mg/kg, respectively, which were significantly higher than the soil background values in Henan Province and exceeded the risk screening values of Soil Environmental Quality - Risk Control Standard for Soil Contamination of Development Land (Trial) (GB 36600-2018) for Class Ⅱ land by 58.37 times and 4.41 times, respectively. The comprehensive pollution index and potential ecological index in various points of the research area followed the order of waste lead battery dismantling area>storage area>lead block molding area. Except for the lead block molding area where the soil arsenic was lightly polluted, the lead and arsenic in the soil of other research areas were heavily polluted, and there was an extremely strong potential ecological risk. Meanwhile, the carcinogenic and non-carcinogenic risks of heavy metals in three exposure pathways followed the order of ingestion of soil>dermal absorption of soil>inhalation of soil. The total cancer risk index of arsenic at each point was found to follow the order of lead smelting furnace area>waste lead battery dismantling area>storage area>lead block molding area>10−6. Lead and arsenic levels had a significant effect on the maximum total non-carcinogenic risk indices, counting 25.00, 160.69, 1.73, and 11.71 for adults and children, respectively, with the non-carcinogenic risk of lead to children being more obvious. Both were higher than the US EPA's maximum acceptable level, and there was an extremely strong potential health risk to nearby residents. In addition, the probability of children's blood lead concentration exceeding 100 μg/L was as high as 99.99%, calculated by the IEUBK model, which was much higher than the safety probability limit of 5%.

Status and development trend of soil pollutant health risk assessment technology
WANG Hongmei, WU Jianfang, TIAN Ziqiang, LI Yuting, GONG Bin
2023, 13(2): 778-784. doi: 10.12153/j.issn.1674-991X.20220027
Abstract(391) HTML (138) PDF(802KB)(84)

The overall situation of soil pollution in China is still severe. Human health risk assessment (HRA) on soil pollutants has become one of the core technologies which supports land classification management, industry access management and soil pollution risk control. The development status of soil pollutant HRA at home and abroad was summarized, and a conclusion was drawn that the trend of soil pollutant HRA technology followed the framework of traditional "four-step" procedure, and further integrated with the technologies of the spatialization of evaluation, refinement of bioavailability and quantification of exposure characteristics. Taking the target value of soil remediation and the environmental demand for rational planning of land safe use as examples, the shortcomings of soil HRA technology in management practice were analyzed, and it was put forward that soil pollutant HRA technology was still the weak link in carrying capacity evaluation and emission source management. In order to effectively control the soil risks, it was suggested that the focus of HRA technology in the future was to take the "pollution source-route-sensitive protection" as the breakthrough point and achieve the goal of guiding industrial adjustment by setting binding indicators of HRA risk for the control units.

Current utilization, disposal and environmental management of drilling cuttings from oil and gas field exploitation
ZHOU Qi, YAO Guangyuan, BAO Weilei, SUN Yingjie, HUANG Qifei
2023, 13(2): 785-792. doi: 10.12153/j.issn.1674-991X.20220169
Abstract(648) HTML (196) PDF(1098KB)(90)

Large quantities of water-based drilling cuttings and small quantities of oil-based drilling cuttings are produced in the process of oil and gas exploitation. Currently, drilling cuttings are preliminarily collected and processed by non-landing treatment in most oil and gas fields. The drilling cuttings have the characteristics of high pH, high salt ion concentrations, high COD, and high oil content for oil-based drilling cuttings, and therefore, the rational treatment and disposal of drilling cuttings is a difficulty for the green development of oil and gas fields. The current environmental management of drilling cuttings in China and other countries was compared and analyzed, and the corresponding problems of environmental management in China were identified. Based on the pollution characteristics of drilling cuttings, the research and application status of the follow-up resource and harmless technologies were summarized, and the treatment effect, the advantages and disadvantages of each technology were analyzed. Finally, some suggestions were put forward for the utilization and disposal of drilling cuttings in China, including establishing a water-based classification management system, improving the environmental management system for their utilization and disposal process, and strengthening the source reduction and end uses.

Effect of biotreatment of kitchen waste and excess activated sludge by black soldier fly
MAO Yuankun, ZHANG Zichen, LIU Shiqi, ZHANG Liqiu, FENG Li
2023, 13(2): 793-799. doi: 10.12153/j.issn.1674-991X.20220284
Abstract(437) HTML (166) PDF(1663KB)(59)

Kitchen waste or excess activated sludge could be disposed by the biotransformation technology of black soldier fly larvae (BSFL) to solve the problem of its disposal and resource utilization. The disposal and conversion of kitchen waste and excess activated sludge as culture substrate and the situations of BSFL growth and heavy metal enrichment under different feeding conditions (respectively with 0%, 25%, 50%, 75% and 100% excess activated sludge) were investigated. The results showed that after 15 d treatment process, the average reduction rate was 22.66%-56.16%, and the average biological conversion rate was 15.18%-27.84% in different groups. Furthermore, the treated food waste and excess activated sludge exhibited better characteristics and had no foul odor, indicating that preferable treatment efficiency of these solid wastes could be acquired in the synchronous disposition system by BSFL. Especially, when the mass ratio of excess activated sludge in the fodder reached less than 75%, BSFL could survive. The contents of crude protein (21.22% and 20.5%) and crude fat (18.91% and 18.5%) of BSFL in the 25% and 50% excess activated sludge groups were lower than that in the groups without excess sludge (40.75% and 37.56%), while a higher content of trace elements of the above two groups (14.24% and 14.59%) was observed in BSFL comparing to that of the groups without excess sludge (10.02%). The enrichment coefficients of heavy metals in 0% and 25% excess activated sludge groups were under the threshold value (<1). Based on these results, the BSFL fed with food waste could be served for the feed of aquatic organisms, and the BSFL fed with excess activated sludge could beserved as the feed of aquatic organisms, and the BSFL fed with excess activated sludge could be used as a feed additive for some poultry and livestock, thus enabling the resource utilization of BSFL cultivated with solid wastes.

Research on fluoride whole-process prevention and control in the electrolytic aluminum enterprise based on material flow analysis
LIN Yuchen, LIU Yuan, YIN Guang, DANG Chunge, XIONG Renyan
2023, 13(2): 800-807. doi: 10.12153/j.issn.1674-991X.20220351
Abstract(309) HTML (150) PDF(1796KB)(21)

Taking a large domestic electrolytic aluminum enterprise as an example, the key links of fluoride production were analyzed and tested, the fluorine balance of the enterprise was constructed by material flow analysis method, and the distribution features of the characteristic pollutant fluoride in the electrolytic aluminum production process was studied. The results showed that apart from the overhaul slag of electrolytic cell, unorganized flue gas and carbon slag were the key points of fluoride emission in electrolytic aluminum production. The fluoride content of unorganized flue gas was 0.374 kg/t per unit product, which was about 3.7 times of that of organized emissions. The fluoride content in carbon slag was 6.347 kg/t, which was about 2.7 times of that in overhaul slag. In order to strengthen the fluoride risk prevention and control in the electrolytic aluminum industry, some suggestions were put forward starting from the whole production process, including effectively controlling the unorganized emissions by improving the gas collecting efficiency of electrolytic cells and controlling the smoke emissions scientifically, optimizing the smoke exhaust pipes of the electrolytic cells to improve the efficiency of organized flue gas treatment, controlling the water content of raw materials to reduce fluoride production at source, and strengthening the control of fluorine-containing solid wastes. Through these methods, the fluorine pollution caused by electrolytic aluminum enterprises to the surrounding environment could be reduced.

Spatial pattern and influencing factors of coupling coordination degree between ecological vulnerability and comprehensive economic level in Gansu Province
WANG Yi, WU Jiangmin, MIAO Hanxiao, GAO Yan
2023, 13(2): 808-816. doi: 10.12153/j.issn.1674-991X.20220543
Abstract(296) HTML (191) PDF(1467KB)(25)

To explore the relationship between ecological fragility and comprehensive economic level in northwest China, the evaluation system of ecological vulnerability indicators in Gansu Province was constructed through Driving-Pressure-State-Impact-Response (DPSIR) model, and the evaluation system of comprehensive economic level indicators in Gansu Province was constructed from the social and economic aspects. The spatial distribution of different types of coupling coordination degree between ecological vulnerability and comprehensive economic level in Gansu Province was studied, and its influencing factors were explored. The results showed that: 1) The area of counties and districts with moderate or higher ecological vulnerability in Gansu Province accounted for 78.8%, and the ecosystem as a whole was relatively fragile; the area of counties and districts with medium or lower comprehensive economic level in Gansu Province accounted for 41.1%, and the overall comprehensive economic level was low. 2) The ecological environment and economy in Gansu Province were poorly coordinated. Only 9.2% of the counties and districts had coordinated economic and ecological development, accounting for 4.4% of the total area. The proportion of counties and districts with unbalanced economic and ecological development was 48.3%, accounting for 73.9% of the total area. The spatial distribution characteristics of each type were significantly different, among which the concentration of the imbalanced environment-lag type was the strongest, concentrated in the north of Gansu Province, where the climate was dry and the water and soil loss was serious. 3) The pressure of population growth, the restriction of natural environment and the backward living standard of residents were major obstacles to the coordinated development of ecology and economy in Gansu Province. Based on this, Gansu Province should adhere to the concept of sustainable and coordinated development, strengthen the protection and governance of ecological environment, and develop green economy according to local conditions, so as to realize the coordinated and high-quality development of regional ecological environment and economy as soon as possible.

Analysis of natural capital sustainability of the Yangtze River Delta urban agglomeration based on two-dimensional and three-dimensional ecological footprint models
SHENG Ruoyu, JI Rongting, CHEN Sujuan, CAI Jinbang, CHEN Mei, ZHAO Zhiqiang, LIU Chenwei, SU Lianghu, ZENG Yuan
2023, 13(2): 817-826. doi: 10.12153/j.issn.1674-991X.20220178
Abstract(289) HTML (91) PDF(2574KB)(25)

The continuous advancement of urbanization and industrialization has greatly threatened the natural capital and its sustainable utilization in urban agglomeration. In order to clarify the characteristics of natural capital sustainability changes during the construction process of urban agglomerations, taking the Yangtze River Delta urban agglomerations as an example, two-dimensional and three-dimensional ecological footprint models were applied to analyze the change of ecological footprint, ecological pressure index (EPI) and ecological economic coordination index (EECI), the natural capital stock consumption and natural capital flow occupancy, as well as the influencing factors and its related mechanisms, by adding the water resources account to the adapted ecological footprint model to reflect the water resource potential and demand in this area. The results showed that during the study period, the per capita ecological footprint and ecological carrying capacity of the Yangtze River Delta urban agglomeration were 4.46 hm2/person and 1.59 hm2/person, respectively; and the average per capita ecological deficit was 2.87 hm2/person; however, the ecological footprint per unit GDP continued to decline, indicating that the utilization rate of resources continued to rise. From 2005 to 2019, the EPI value of the Yangtze River Delta urban agglomeration increased from 2.48 to 3.25, and the EECI value fell from 1.30 to 1.25. Based on the revised three-dimensional ecological footprint model, it was found that the use of natural capital stock in the Yangtze River Delta urban agglomeration was increasing, and it had a significant inhibitory effect on the renewal of natural capital flows, and the consumption of natural capital stock was 2.26 times of capital flow in 2019, with the resource consumption occupied. The impact factors analysis showed that the industrial output value, total energy consumption, construction land area and urbanization rate played positive roles in promoting the ecological footprint and exerted greater pressure on the sustainability of natural capital. The relationships among the ecological pressure level, ecological environmental and economic development of the Yangtze River Delta urban agglomeration were quantitatively analyzed to provide a scientific basis and decision support for improving the ecological security and sustainable development of urban agglomerations.

Research and application of screening technology of industrial priority control pollutants list based on multi-method optimization
CAO Ting, LIU Zheng, WANG Xiaohui, WANG Fan, FANG Gang, DANG Chunge, FU Zhiyou
2023, 13(2): 827-838. doi: 10.12153/j.issn.1674-991X.20220213
Abstract(305) HTML (106) PDF(2517KB)(34)

In order to solve the problems of the lacking of industry-level research and imperfect screening technology for priority control pollutants, the comprehensive evaluation method, Hasse diagram method and analytic hierarchy process were integrated to form a comprehensive screening technology combining vector analysis and scalar analysis, according to the concepts of cleaner production and whole-process control, and based on the previous researches on the screening technology of the industrial priority control pollutants list. Then, the screening technology was applied in the printed circuit board (PCB) industry in Changzhou City. The results showed that after the whole process investigation and analysis of water samples by gas chromatography-mass spectrometry with 90% matching degree, the list of characteristic pollutants in PCB industry contained 172 substances. There were 30 kinds of substances in the list of priority control pollutants in PCB industry, including 3 kinds of halogenated hydrocarbons, 9 kinds of benzene series, 3 kinds of esters, 1 kind of aldehydes, 5 kinds of alcohols, 2 kinds of ketones, 5 kinds of metal ions, 1 kinds of salts and 1 kind of others. The proposed comprehensive screening technology could be used for the industry so as to obtain the list of pollutants under priority control in PCB industry in the city more scientifically and effectively.

Research progress of water environment regulation and its key issues from the perspective of sustainable development
AN Min, WANG Bei, HE Weijun, HUANG Jin, XIE Ping
2023, 13(2): 839-848. doi: 10.12153/j.issn.1674-991X.20220109
Abstract(239) HTML (117) PDF(3898KB)(27)

The world is facing serious water resource crisis, and effective water environment management is the key to regional sustainable development. As an important means of governance, environmental regulation has been studied by more and more scholars. Many achievements have been made in this field. A systematic review of the existing literature in this field can provide a scientific basis for subsequent research. Based on CiteSpace, visual knowledge map analysis was performed on water environment regulation literature extracted from Web of Science (WoS) database and CNKI database from 2002 to 2021. The results showed that: 1) The research in WoS database literature started early and developed rapidly, while that in CNKI database literature lagged behind. On the whole, there was little cooperation between domestic and foreign authors in this field, and a close cooperation network existed only among core authors. 2) The current research focused on the command-based water environment regulation dominated by government regulation, while the market incentive and implicit environmental regulation dominated by the market and the public were less involved. The research focused mainly on the regulation of water resources quality and quantity, the influence of external environmental uncertainty on water environment regulation and the improvement of water resources management methods. 3) From the perspective of research trends, the improvement of water pollution and water security was a continuous concern in this field. In addition, in the future, water resource regeneration and utilization would be the focus of water environment regulation research at home and abroad.

Study on decoupling relationship between industrial growth and carbon dioxide emission in the urban agglomeration in the Yellow River Basin
LIU Wei, MAO Xianqiang, LI Wei, CHENG Runhe
2023, 13(2): 849-856. doi: 10.12153/j.issn.1674-991X.20220461
Abstract(288) HTML (142) PDF(2168KB)(44)

The research on the coupling relationship between industrial growth, energy consumption and carbon emission in the Yellow River basin on the scale of urban agglomeration is of great significance for exploring the low-carbon transformation and high-quality coordinated development of urban agglomeration and industry. Hohhot-Baotou-Ordos-Yulin (HBOY), Guanzhong Plain (GZP) and Central Plains (CP) urban agglomerations were selected as the study areas. The Tapio decoupling model and LMDI factor decomposition method were used to study the decoupling relationship between industrial growth and carbon emission as well as the influencing factors. The results showed that: 1) The industrial economy and carbon emission of HBOY increased almost synchronously by 23 times, while GZP and CP showed obvious non-synchronization. 2) The HBOY moved from the "expansion connection" to the "expansive negative decoupling" since 2014, the GZP moved from the "expansion connection" to the "weak decoupling" since 2007,and the CP had been in a state of weak decoupling. 3) Industrial scale had always been the main restraining factor of carbon decoupling in the three urban agglomerations. Energy intensity had always played a role in promoting carbon decoupling in GZP and CP, but the impact in HBOY had changed from a promoting role to a restraining role since 2014. It was suggested that combined with the national action plan for peak carbon emissions by 2030, differentiated industrial green transformation and carbon emission reduction policies of urban agglomerations should be formulated, to further reduce the scale of high emission and high energy consumption industries in HBOY, to upgrade the industrial structure and energy saving transformation, and to improve the industrial energy efficiency and carbon reduction capacity of GZP and CP.

Study on the embodied carbon's flow process in China's industrial system based on social networks
ZHONG Shiyu, ZHANG Xiaomin, HUANG Zhe, WU Jia, WU Na, FENG Qiang, FU Zeqiang
2023, 13(2): 857-866. doi: 10.12153/j.issn.1674-991X.20220513
Abstract(177) HTML (292) PDF(3267KB)(35)

Embodied carbon is the sum of direct and indirect carbon emissions in the entire life cycle of products and services. Research on the flow characteristics of embodied carbon in the industrial system and the study on the position and role of different industrial sectors in the carbon emission relationship network is of great significance to the decomposition of carbon emission reduction responsibility, the formulation of carbon emission accounting standards, the establishment of carbon traceability mechanism and the formulation of carbon emission reduction plans. Based on the input-output tables in 2018, the embodied carbon flow of industrial sectors was calculated, a flow network related to embodied carbon in the industrial system was built by applying the theory and method of social network analysis, and the characteristics of the implicit carbon flow relationship between industrial sectors, the core sectors and clustering features were analyzed. The main conclusions were as follows: 1) The embodied carbon flow in the production process accounted for about 85.12% of the total direct carbon emissions, and electrical machinery and equipment manufacturing industry, metal mining and processing industry, and textile industry took the lead in the proportion of embodied carbon inflow, outflow and retention, respectively. 2) An embodied carbon flow network had been formed among industrial sectors, and the inter-departments were closely linked. The changes in carbon emissions in one industrial sector would drive changes in the entire industrial system. 3) Chemical product manufacturing industry, electricity, heat, gas and water production and supply industry, and transportation, warehousing and postal services industry were the core sectors in the network, with strong control and influence over other sectors. The embodied carbon transmission paths of metal mining, non-metal mining and other mining and processing industries to other sectors were shorter, and had higher embodied carbon flow efficiency. 4) There were obvious clustering characteristics among industrial sectors. The regulators centered on the chemical product manufacturing industry, and the direct carbon emission providers centered on the petroleum coking products and nuclear fuel processing industries played a role in balancing the embodied carbon flow of the entire industrial system. The industrial sectors centered on the construction industry and other service industries were the receivers of embodied carbon, while the industrial sectors centered on the production and supply of electricity, heat, gas, and water were the suppliers of embodied carbon.

Formulation ideas and implementation suggestions on technical specification for emission remote supervision system of heavy-duty vehicles
LI Gang, YIN Hang, JI Zhe, HE Kexun, XU Sha, GUAN Min, WANG Hongli, ZHANG Minghui
2023, 13(2): 867-872. doi: 10.12153/j.issn.1674-991X.20220333
Abstract(220) HTML (115) PDF(1114KB)(24)

In order to realize the intelligent and automatic supervision of pollutant emissions from heavy-duty diesel vehicles, The CPC Central Committee and the State Council Guidance on Comprehensively Strengthening Ecological and Environmental Protection and Resolutely Fighting the Battle of Pollution Prevention and Control (Zhongfa [2018] No. 17) and other policy documents put forward the construction requirements of "remote online monitoring system for heavy-duty vehicle emissions". In 2021, the Ministry of Ecology and Environment issued a series of standards of Technical Specifications of Remote Emission Supervision System for Heavy-duty Vehicles (HJ 1239-2021), which standardized the construction of the remote monitoring system. The necessity and significance of standard formulation, as well as the standard structure, positioning and main technical content formulation ideas and basis were fully interpreted. Combined with the current progress of heavy-duty vehicle emission remote monitoring, it was found that there were common problems such as low data quality and slow progress of data application models. Some suggestions such as building the data mining analysis and application models were put forward for standard implementation. It provided the reference for heavy-duty vehicle production enterprises to carry out heavy-duty vehicle networking and for competent departments to implement standards.

Construction and optimization of cadmium-responsive bacterial biosensor based on CadR
CAI Yeshen, ZHANG Tianyi, BAO Lingzhi, MA Jie, CHEN Shaopeng
2023, 13(2): 873-880. doi: 10.12153/j.issn.1674-991X.20220230
Abstract(342) HTML (181) PDF(1791KB)(29)

Using cadmium responsive protein (CadR) as detection element and green fluorescent protein as report element, a cadmium-responsive bacterial biosensor was constructed to detect heavy metal cadmium in water samples. Single factor experiment and orthogonal test for detection condition optimization were applied to improve the relative fluorescence intensity of the biosensor. Finally, the spiked Yangtze River water samples was detected with the constructed cadmium-responsive bacterial biosensor based on the given optimal combination. The results showed that the fluorescence response of the biosensor to cadmium in the concentration range of 0-200 μg/L conformed to the dose-dependent effect. The single-factor test showed that temperature, pH, induction time and cations had significant effects on the sensitivity of cadmium-responsive biosensor, while different anion ligands had no significant effect on the detection results. The orthogonal test showed that the optimal detection conditions for cadmium-responsive bacteria biosensor were as follows: temperature 37 ℃, pH 7, induction time 120 min, and adding Mg2+ with final concentration of 50 μg/L. The verifying experiment indicated that under the optimal combination condition, the fluorescence response of the biosensor to the same concentration of cadmium increased by 1.6 times. The detection results of the spiked Yangtze River water samples by the sensors showed their high performance in detecting cadmium in 0-500 μg/L environmental water samples, and the maximum fluorescence output reached 20 times of the background.

Research on key building parameters affecting the vapor intrusion of VOCs in contaminated sites
WU Linlin, WU Rongshan, GUO Yuting, LÜ Jiapei, GUO Changsheng, XU Jian
2023, 13(2): 881-888. doi: 10.12153/j.issn.1674-991X.20220081
Abstract(203) HTML (111) PDF(491KB)(33)

Inhalation exposure caused by vapor intrusion (VI) with the migration of volatile organic compounds (VOCs) from soil and groundwater into the indoor environment is essential to the human health risk assessment of VOCs in contaminated sites. Building parameters are important factors that affect the VOCs migration from the contaminated soil to indoor air and change the indoor concentration for population exposure. The technical documents of building parameters for exposure risk assessment in developed countries such as the UK and the US were elaborated systematically, and the determination methods of three key parameters affecting VI, namely, air exchange rate, building volume and foundation crack, were summarized. Furthermore, the research development of building parameters in China’s exposure risk assessment was illustrated, and the idea of improving building parameters and their technical methods were put forward, from the aspects of collecting cross-sectoral basic data and constructing regional localization parameters, to provide technical support for the refined exposure risks assessment in VOCs contaminated sites in China.

Study on the adaptability of farmers in Karst rocky desertification control area
JI Tianni, ZHOU Zhongfa, ZHU Changli, NIU Zihao, ZHANG Jiashuo
2023, 13(2): 889-896. doi: 10.12153/j.issn.1674-991X.20220123
Abstract(174) HTML (90) PDF(793KB)(13)

The adaptability of the farmers in Karst rocky desertification control area was explored, so as to promote farmers to adapt to environmental changes brought by rocky desertification control, and realize the sustainable and coordinated development of regional farmers and ecological environment. With Huajiang Demonstration Zone in Anshun City, Guizhou Province as an example, the evaluation index system of farmers' adaptability was constructed by introducing farmers' adaptation perception and sustainable livelihood framework. Besides, the adaptability of 509 farmers was quantitatively evaluated and compared through principal component analysis. The influencing factors were analyzed and the corresponding improvement strategies were given. The results showed that the perception ability of the surveyed farmers to the change of rocky desertification control was in the order of pure farmers > part-time farmers > non-farmers > multiple occupations farmers. As a whole, the surveyed farmers' adaptability to environmental changes brought by rocky desertification control was low. The multiple occupations farmers and part-time farmers had stronger adaptability than pure farmers and non-farmers. The main influencing factors affecting the adaptability of farmers in Huajiang included material and economic ability, human and natural ability, perception ability of rocky desertification control and diversification degree of livelihood. The adaptability of farmers in Karst rocky desertification control area could be improved by enhancing their livelihood capital, material economic ability and educational level.