2021 Vol. 11, No. 4

Display Method:
Cover + Contents
2021, 11(4): .
Pollution characteristics and source analysis of water-soluble ions in PM2.5 during autumn in Liaocheng City
ZHANG Jingqiao, LUO Datong, WANG Shaobo, WANG Han, HU Wenzheng, LI Hui, LIU Ruize, WANG Shulan
2021, 11(4): 617-623. doi: 10.12153/j.issn.1674-991X.20200228
PM2.5 samples were collected during autumn in Liaocheng City from October 15th to November 14th, 2017, and the water-soluble ions (Na+, NH 4 + , K+, Mg2+, Ca2+, F-, Cl-, NO 3 - and SO 4 2 - ) were analyzed to study the pollution characteristics of PM2.5 in autumn in Liaocheng City. The results showed that PM2.5 mean concentration was (104.9±50.5) μg/m3 during the observation period, 0.40 times higher than the daily average concentration limit of Grade Ⅱ standard of Ambient Air Quality Standards (GB 3095-2012). The average concentration of water-soluble ions was (52.2±35.1) μg/m3, which accounted for 45.7%±11.3% of PM2.5. SO 4 2 - , NO 3 - and NH 4 + were the main ions, accounting for 85.2% of the water-soluble ions and 45.0% of PM2.5. As the air pollution got serious, the concentrations of water-soluble ions increased. In addition, the proportion of NH 4 + increased gradually, that of SO 4 2 - , No 3 - increased first but then decreased, while that of other ions especially Ca2+decreased, which indicated that the increase of PM2.5 concentration was mainly affected by the secondary inorganic transformation. The average sulfur oxidation rate (SOR) and nitrogen oxidation rate (NOR) during the observation period were 0.28 and 0.27, respectively, which showed that the secondary transformation of SO2 and NO2 was higher in autumn and the secondary pollution was much serious. In addition, SOR and NOR were positively correlated with temperature and relative humidity, and SOR was more sensitive to relative humidity, but NOR to temperature. PM2.5 in Liaocheng City presented weak alkaline in autumn, and NH 4 + were primarily in NH4NO3 and (NH4)2SO4 forms. The results of the principal component analysis revealed that secondary inorganic transformation, dust sources and industry emissions were the main sources of water-soluble ions of PM2.5 during autumn in Liaocheng City.
Pollution characterization and source analysis of water-soluble ions in PM2.5 of Yinchuan City
LI Hui, WANG Shulan, ZHANG Jingqiao, WANG Han, ZHANG Yulong, JIN Yan, WANG Ping
2021, 11(4): 624-630. doi: 10.12153/j.issn.1674-991X.20200247
PM2.5 samples were collected in Yinchuan City in autumn and winter of 2016 and spring and summer of 2017, and nine kinds of water-soluble ions (Na+, NH 4 + , K+, Mg2+, Ca2+, F-, Cl-, NO 3 - , SO 4 2 - ) in PM2.5 were analyzed to study the seasonal variation characteristics of water-soluble ions in PM2.5. The results showed that the sum of the average concentration of nine water-soluble ions in PM2.5 was (23.5±16.8) μg/m3, accounting for 24.1% of PM2.5. The concentration of water-soluble ions showed the characteristics of high values in autumn and winter, and low values in spring and summer. The concentration order from high to low was SO 4 2 - > NO 3 - > NH 4 + > Cl-> Ca2+> K+> Na+> Mg2+> F-. The proportion of SNA ( SO 4 2 - , NO NO 3 - an dNH 4 + ) to the total ion concentration was 80.3%, and that to PM2.5 was 20.2%. The contribution of SNA to PM2.5 on heavy pollution days was 1.7 percentage points higher than that on non-heavy pollution days, which indicated that the higher the PM2.5 concentration, the more serious the secondary pollution in the city. During the observation period, the average CE/AE of Yinchuan City was 1.4±0.8, and the average CE/AE of spring, summer, autumn and winter was 2.8±1.1, 2.0±0.4, 1.0±0.2 and 1.1±0.2, respectively, indicating that in spring and summer the contribution of basic inorganic cations to PM2.5 was greater, and the cation and anion in autumn and winter were basically balanced. The results of the principal component analysis showed that the secondary inorganic sources, industrial sources and dust sources were the main sources of water-soluble ions in PM2.5 of the city. The backward trajectory cluster analysis showed that the polluted air mass mainly came from the south during the observation period, and the particle concentration was higher. The air mass from the south was greatly influenced by the secondary pollution sources.
Chemical pollution characteristics of PM10and PM2.5 during heavy air pollution in spring and winter in four functional areas of Beijing and their associated influencing factors
LIU Yanju, YANG Zheng, LIU Qingyang, QI Xuekui, ZHANG Tingting, WANG Xinxin, ZHU Minghao
2021, 11(4): 631-646. doi: 10.12153/j.issn.1674-991X.20200214
PM10 and PM2.5 samples were sampled at four sites located in four functional regions of Beijing, including West 3-Ring Road (traffic site), Huayuan North Road (commercial area), Changping countryside (rural area), and Milu Park (suburban area), during four heavy pollution processes in spring and winter, 2015. Principal components analysis (PCA) was used to analyze the sources of PM10and PM2.5 obtained from the four sampling sites. The pollution characteristic of chemical components, including ten water-soluble ions, organic carbon/element carbon, 16 polycyclic aromatic hydrocarbons (PAHs) and seven heavy metal elements (Zn, Mn, Pb, Ni, Cu, Cr and As), were analyzed. Combined with meteorological conditions and back trajectory, the meteorological influencing factors and the differences of particulate matter chemical compositions of several typical pollution events were discussed. The results showed that the daily-average PM10 and PM2.5concentrations of West 3-Ring Road on April 9 and 15, Huayuan North Road on March 16-17, Changping rural area on November 12-16, and Milu Park on March 28-29 were greater than 200 and 100 μg/m 3, respectively, which exceeded the Class Ⅱ concentration limits in Ambient Air Quality Standards (GB 3095-2012), and belonged to heavy pollution weathers. The major chemical components in the particulate matter at the four sampling sites were secondary water-soluble ions NO 3 - , SO 4 2 - , NH 4 + and secondary organic carbon (SOC). PAHs in the particles were mainly 4-6 rings, and the heavy metals were mainly Zn and Mn.About 50%-95% of water-soluble ions, 43%-93% of PAHs and 44%-97% of seven heavy metals in the four functional areas were concentrated in PM2.5. The chemical components of particulate matter in different functional areas featured in their own chemical characteristics. Higher fractions of water-soluble ions were observed for NO 3 - at West 3-Ring Road, Cl- and NH 4 + at Huayuan North Road, NH 4 + at Changping countryside and Ca2+ at Milu Park. In addition, greater fractions of particulate matters were found for PAHs in Huayuan North Road, and Ni and PAHs in Changping rural site. During the sampling period, the major sources contributing to PM10and PM2.5 were coal combustion, mobile and secondary sources, as well as biomass sources.
The variation law of air pollutant concentrations and their correlations with other factors in Huairou District, Beijing City
SHAN Ruijuan, WU Lin, YANG Ning
2021, 11(4): 647-656. doi: 10.12153/j.issn.1674-991X.20200205
On the basis of 5-minute data of air pollutants SO2, NOx, CO and O3and the monitoring results of PM10 and PM2.5 in Huairou District in 2019, the on hour data, daily data, daily data of each month, hourly data, daily maximum 8-hour average O3 data, monthly data, seasonal hourly data and daily data of each season were collected. Furthermore, the influences of various factors including PM 2.5, meteorological conditions and precipitation on the concentration of air pollutants were analyzed, so as to provide data and theoretical support for relevant departments in Huairou District to formulate measures of reducing pollutant emissions, controlling urban air particulate matters and improving urban ambient air quality. The results were as follows: among the air pollutants, O3had the maximum over-standad days, followed by PM2.5, PM10. The daily and seasonal variation characteristics of air pollutants were obvious. The characteristics of SO2, and NOx were similar, with the maximum concentration appearing in winter, the second in spring and autumn, and the minimum in summer. The pollution in January was the most serious. O3had the opposite seasonal variation characteristics, with the highest value appeared in summer and the lowest value appeared in winter. The highest concentrations of PM10 and PM2.5 appeared in March (spring), followed by winter and autumn, and the lowest concentrations appeared in summer. The effect of precipitation on the removal of SO2 and NOx was not obvious, and it was easy to increase the concentration of air pollutants on light rainy days. On the whole, the precipitation was more efficient for the removal of NO x than SO2, and the removal amount of large-size particles was more than that of small-size particles.
Research on atmospheric environmental carrying capacity based on adjustment of pollution sources layout
CHAI Yingying, MENG Xiaojie, SHEN Lu, XUE Mingming, LIAO Fengjuan
2021, 11(4): 657-662. doi: 10.12153/j.issn.1674-991X.20200200
For the areas with better environmental quality background values, the atmospheric environmental carrying capacity calculated based on the national environmental quality standard was relatively large, and the allowable emission of planned pollution was excessively high. In order to solve the above problems, a linear programming model for atmospheric environmental carrying capacity was proposed. Regional atmospheric environmental carrying capacity was estimated with the predicted concentrations of planned pollution sources as the control targets, combined with pollution sources layout optimization. Then, an industrial park in Pingdingshan City was taken as an example for verification. The results showed that, under the control target of national secondary standards, primary standards and 50% of the primary standards, the atmospheric environmental carrying capacity of SO2 was about 7 to 275 times emissions of the planned pollution sources, while that of NO2 was about 38 to 129 times. Taking the predicted values of the planned pollution sources as the environmental quality control targets, through the optimization of pollution sources layout, the allowable emissions of SO2 and NO2 were 1.23 and 1.42 times, respectively, of the planned sources emissions, which was closer to the actual planning requirements.
NH3 distribution and uniformity adjustment of ammonia spray in SCR area
TAO Li, XIAO Yujun
2021, 11(4): 663-669. doi: 10.12153/j.issn.1674-991X.20200196
Aiming at the specific implementation of the principle of the ammonia injection optimization and adjustment for Selective Catalytic Reduction (SCR) system, a numerical model of a typical SCR system was established by the simulation method to study the regional distribution of NH3 on the export monitoring section and the pathlines of NH3 in the device, which was injected by the ammonia sprayed branch pipe. The flue gas velocity and NH3 concentration at the ammonia sprayed grid area were analyzed under different flue gas volumes. Furthermore, the distributions of NH3 concentration on the export monitoring section before and after adjustment was compared and analyzed. The results showed that there occurred irregular changes for the positive correspondence between the outlet sections which was evenly divided and the ammonia injection branch pipes, due to the influence of the position of the branch pipe and the structure of the flue. The irregular correspondence increased the complexity of adjusting the amount of ammonia injection of the corresponding branch pipe according to NOx concentration in a separate area on the outlet section. The pathlines of ammonia sprayed by the lateral partitioned branch pipes were limited in the corresponding region by the deflector structures, while the pathlines of ammonia sprayed by the vertical partitioned branch pipes had a tendency to shift to the one side with the flue gas. Under the condition of the uniform ammonia injection, the relative standard deviations of NH3 concentration on the section S-2 under the 50%, 75%, and 100% flue gas treatment volume was 19.79%, 19.23%, and 17.17%, respectively, which did not changed significantly due to the changes of the flue gas treatment volume. After optimization adjustment, the relative standard deviations of NH3 concentration on the section S-2 was 3.8%.
Diagnosis and countermeasures of eco-environmental problems in Changtan Reservoir
XIAO Zhe, LI Wenpan, ZHANG Jingtian, HE Zhuoshi, MA Chunzi, XI Beidou, HUO Shouliang
2021, 11(4): 670-677. doi: 10.12153/j.issn.1674-991X.20200168
Taking Changtan Reservoir as the research object, the characteristics of water environmental factors and phytoplankton community were analyzed, and the spatial-temporal distribution characteristics of nitrogen and phosphorus nutrients in water body were discussed. The effects of land use type variation on water quality and the main environmental factors driving the seasonal change of phytoplankton community were clarified. The corresponding suggestions were put forward aiming at the main environmental problems. The results indicated that the non-point source pollution of cultivated land and forest land was the main source of total phosphorus. The retention rates of TN and TP were 41.71% and 51.17%, respectively, in the reservoir impoundment area, resulting in the formation of N/P ratio of 34.5 in this reservoir. The phosphorus-restricted water body led to the advantage of cyanobacteria growth. The seasonal abundance of cyanobacteria ranged from 33.72% to 82.47%, and the dominant phytoplankton species were cyanobacteria. The toxigenicCylindrospermopsis raciborskii had the greatest dominance (Y=0.078). The redundancy analysis (RDA) results indicated that the environmental factors explained 61.1% of the succession of community structure. The water temperature, nitrogen and phosphorus nutrients concentrations were the main driving factors for community succession. The concentration of ammonia nitrogen ( NH 4 + -N) was significantly correlated with the abundance of Cylindrospermopsis raciborskii (correlation coefficient 0.999, P<0.02). The abundance ofCylindrospermopsis raciborskii could be reduced by 51% when the domestic sewage treatment rate was increased to 95% and the NH 4 + -N in effluent was lower than 1.5 mg/L. The main measures and countermeasures were put forward, including constructing non-point source pollution isolation zone, regulating and shortening hydraulic residence time in the reservoir area to reduce the growth advantage of cyanobacteria and improve the water ecological condition of Changtan Reservoir.
Distribution and source analysis of nutrients in sediments of Huangda Lake
MA Jinyu, WANG Wencai, LUO Qianli, LI Weijie, LUO Yan, FAN Zhongya
2021, 11(4): 678-685. doi: 10.12153/j.issn.1674-991X.20200257
In order to study the source of nutrients in the sediments of Huangda Lake, the surface sediments and columnar sediments were collected from 13 points in Huangda Lake. Total nitrogen (TN), total phosphorus (TP) and organic matter (OM) contents were measured, the spatial and vertical distribution of nutrients in the sediments of Huangda Lake analyzed, and the sediment pollution degree assessed. The results showed that TN concentration of the surface sediments in Huangda Lake varied from 1 112 to 3 277 mg/kg with an average value of 2 016 mg/kg, TP concentration varied from 547.19 to 784.43 mg/kg with an average value of 651.84 mg/kg, and OM concentration varied from 5.21% to 11.21% with an average value of 8.6%. The spatial distribution of TN, TP and OM showed consistency, mainly in the northwest> southeast> middle of the lake center, and the vertical concentration of TN, TP and OM generally showed a decline with depth. The pollution caused by TN and OM was more serious than that of TP, and the spatial distribution of pollution degree was consistent with the spatial distribution of TN, TP and OM. Pearson correlation analysis showed that TN and OM were significantly positively correlated, indicating that they were homologous; TP and OM were not significantly correlated, suggesting that they were poorly homologous. The average C/N ratio of the sediment was 25.43, indicating that OM in the sediment mainly came from exogenous particulate organic matter. The increase of C/P ratio and N/P ratio in the upper 20 cm of the columnar sediments indicated that nutrients in the sediment were greatly affected by human activities surrounding Huangda Lake in recent years.
Spatial and temporal variation of soil conservation function and its in fluencing factors in Liaohe Conservation Area
JIA Zhenyu, WANG Shixi, LIU Xue, SUN Qianying, YANG Chunyan, FENG Chaoyang
2021, 11(4): 686-692. doi: 10.12153/j.issn.1674-991X.20200231
Soil conservation is one of the regulation services provided by ecosystems, which plays an important role in maintaining ecological security. Taking Liaohe Conservation Area as the research object, based on China Soil Loss Equation (CSLE) model and Geodetector analysis, the temporal and spatial variation of soil conservation function and its influencing factors were analyzed. The results showed as follows: from 2010 to 2018, the soil erosion in Liaohe Conservation Area was mainly slight and mild erosion, the amount of soil erosion showed a decreasing trend, and the areas with serious soil erosion were mainly located on both sides and lower sections of the river. The function of soil conservation was increasing, and the areas with higher soil conservation were concentrated in the upper and middle sections of the river. The soil conservation function decreased at first then increased with the increase of rainfall and elevation, increased with the increase of slope and vegetation coverage, and decreased in the gradient of forest land, cultivated land, grassland and shrubwood. Landuse type was the dominant factor in the soil conservation pattern in Liaohe Conservation Area. The amount of soil conservation per unit area was the lowest, when the land use type was cultivated land, the rainfall was 657-735 mm, the slope was 35°-68°, the elevation was-73--26 m, and the vegetation coverage was 0-0.3. In this case, Besides, the combination of landuse type with slope has the strongest explanation for the soil conservation ability.
Water quality evaluation of the mainstream of Liaohe River based on fuzzy membership model
LIANG Guanglin, JIA Zhenyu, GAO Yanni, SUN Qianying, DAI Xia, HOU Chunfei
2021, 11(4): 693-700. doi: 10.12153/j.issn.1674-991X.20200235
Scientific assessment of the river water quality spatiotemporal variation is of great significance for river water pollution prevention. In order to comprehensively measure the spatiotemporal changes of water quality in Tieling, Shenyang and Panjin sections of Liaohe River mainstream, an water quality integrated assessment indicator system was constructed. The thresholds and grading standards for each specific indicator and their integrated indexes were set based on the water quality monitoring data of three main national control sections in Liaohe River mainstream from 2012 to 2018. A fuzzy membership model was used to construct the comprehensive evaluation method of water quality. The results showed that the water quality of each monitoring section fluctuated at moderate and good levels according to the integrated assessment index, which varied between 0.5-0.7. In general, the downstream water quality was worse than the upstream water quality, and the water quality showed obvious regular changes with the seasonal changes. Some suggestions were put forward to realize the joint regulation and fine management of water resources and water environment in Liaohe River Basin. These included establishing a dynamic water use regulation mechanism based on water environment capacity in Liaohe River Basin as soon as possible, formulating a scheme of real-time relation between sewage discharge control and water quality monitoring, increasing the investment for water pollution control, and continuously improving the working mechanism of joint prevention and control of water pollution in the river basin.
Practice of ecological protection and restoration of mountain-river-forest-farmland-lake-grassland based on connotation of ecosystem service theory: taking the pilot project of South-Taihang Area in Henan Province as an example
CHEN Yang, WANG Xiping, ZHEN Na, ZHANG Gang, GUO Yujuan, I Zhe, REN Hongtao
2021, 11(4): 701-710. doi: 10.12153/j.issn.1674-991X.20200190
The scientific implementation of ecological protection and restoration of mountain-river-forest-farmland-lake-grassland (MRFFLG) is an important part of the construction of ecological civilization. It combines the improvement of ecosystem service functions with the ecological protection and restoration project of MRFFLG. The pilot project of South-Taihang Area in Henan Province, a third-batch national pilot project for ecological protection and restoration of MRFFLG, was taking as an example, and the practice of ecological protection and restoration projects in MRFFLG in South-Taihang Area to improve the supply capacity of ecological products and to maintain the ecological safety was initially explored. A comprehensive analysis of the location characteristics and eco-environmental problems of South-Taihang Area showed that the value of ecosystem services in South-Taihang Area had been declining in recent years and the eco-environment had been severely damaged. Many problems of ecological damage and environmental pollution left over by history from mines needed to be resolved urgently. The current status of biodiversity conservation was worrying. Based on the regional outstanding eco-environmental problems and the main ecological function orientation, and in accordance with the goal of “pattern optimization, system stabilization and function enhancement”, the overall layout and performance goals of ecological protection and restoration of “one mountain, one canal, and two watersheds” in South-Taihang Area were identified, which was divided into 5 ecological function areas and 7 engineering treatment areas. According to different functional areas and governance areas, the remediation plans and engineering treatment measures were proposed respectively. The project pilot program had been implemented for more than one year, and the progress to various performance targets had been relatively good, having achieved a good combination of ecological, economic and social benefits.
Spatial distribution characteristics of soil salinity in the middle and eastern plain of Tianjin
JIA Jiao, HE Ping, XU Jie, REN Ying, HOU Liping
2021, 11(4): 711-719. doi: 10.12153/j.issn.1674-991X.20200221
Soil salinization is an important influence factor in the ecological protection and restoration of coastal areas. In order to understand soil salinization degree in Tianjin plain, soil samples outside the embankment were collected and investigated along three rivers from sea to land, including the Yongding New River, the Haihe River and the Duliujian River. The spatial gradient and variability of soil salinity in the sea-land direction were analyzed, by combining geostatistics with geographic information system (GIS) technology. The study potentially provided scientific basis for ecological protection and restoration, and land and sea coordination in Tianjin. The results showed that soil water-soluble salt content and soil alkalization appeared to be decreased gradually from the southeast to the northwest. Severe and above salinized soil was mainly distributed in Binhai New Area with 15 km from the coastline to the land. Solonchak and severe alkaline soil were primarily distributed in Dagang within 10 km to the sea, Tanggu and Hangu within 5 km from the coastline. Moderate saline soil was mainly distributed along the Duliujian River within 15-60 km from the coastline. Slight saline soil was mainly distributed along the mainstream of the Haihe River within 10-60 km from the coastline. The predominant cation in soil was mostly Na+, while the predominant anions transferred from Cl- and SO 4 2 - to SO 4 2 - and CO 3 2 - + HCO 3 - in the landward direction. Sulfate-chloride and chloride-sulfate soils were the primary saline soil types along the Duliujian River, sulfate-soda soil was the primary saline soil type along the central plain of the Haihe River, and sulfate-chloride and soda-sulfate soils were the primary saline soil types along the Yongding New River.
Characteristics of microbial community diversity in PAHs contaminated soil of a coking plant
WANG Li, ZHANG Tengfei, YANG Sucai, LIU Zhihao, GOU Yaling, ZHAO Qianyun, SUN Zhongping, QIAO Pengwei
2021, 11(4): 720-726. doi: 10.12153/j.issn.1674-991X.20200251
Soil microorganism plays an important role in the degradation of polycyclic aromatic hydrocarbons (PAHs). Taking the soil of a coking plant in North China as the research object, 30 soil samples were collected at 5 sampling sites (each site was divided into 6 layers). Soil environmental factors (physical and chemical properties and PAHs concentration), microbial abundance and community structure were analyzed, and the relationship between soil microbial composition and soil environmental factors was discussed. The results showed that the abundance of bacteria in soil ranged from 5.33 to 8.89, which was significantly negatively correlated with soil depth (P<0.01), and positively correlated with soil PAHs, organic carbon and total nitrogen concentrations (P<0.05). The dominant bacteria group (phyla) in the soil was Proteobacteria, whose relative abundance accounted for up to 90%, followed by Chloroflexi, Actinobacteria, Firmicutes and Acidobacteria, which accounted for 64%-97% of the bacteria in the level classification of phyla. Redundancy analysis of bacteria groups and environmental factors showed that the soil bacterial community structure in the coking plant was the result of the combination of PAHs pollution and environmental factors. Soil pH, available potassium, PAHs and total nitrogen content had the most obvious effects on soil bacterial community composition. Abundance of Proteobacteria (a potential PAHs degrading bacterium) was positively correlated with PAHs, total nitrogen, available phosphorus, available potassium and organic carbon content.
Fluorine pollution characteristics and risk assessment of electrolytic aluminum plant site in high fluoride area
HAN Wei, YE Yuan, LI Yanxi, TIAN Yu, LI Yafeng
2021, 11(4): 727-733. doi: 10.12153/j.issn.1674-991X.20200243
Based on the environmental investigation of the fluorine-contaminated site located at a typical fluorine rich region in China, the distribution characteristics of fluoride pollution level were analyzed, the underground migration characteristics of fluoride in different depth soil layers in the heavily polluted areas investigated, and the environmental risk effect of fluoride of the sites evaluated based on different landuse functions. The results showed that the concentrations of fluoride in surface soil ranged from 3 340 to 38 400 mg/kg, while the water-soluble fluoride content ranged from 0.06 to 25.40 mg/L. The over-standard rate was as high as 96% compared with the local soil fluoride background value. The occurrence forms of fluoride in soil were mainly residual state with percentage of 93.88% and the water-soluble percentage was 0.85%. The underground migration behaviours of fluoride were affected by soil types of the contaminated site, where the fluorine was strongly adsorbed and detained by the clay layer. The healthy risk was over the acceptable level when the contaminated site was used as the Classification Ⅰ lands, represented by residential land. If it was used as Classification Ⅱ lands, represented by industrial land, its hazard did not exceed the acceptable risk level.
Research on engineering application of stabilization technology for arsenic contaminated site soil
GU Qian, ZHANG Zhuo, ZHANG Li, YANG Wenxiao, LI Huanru, YU Yang, LIU Xiaoyu, BI Xue
2021, 11(4): 734-739. doi: 10.12153/j.issn.1674-991X.20200203
Based on the batch stabilization experiments upon arsenic (As) contaminated soil samples with three concentration levels (WSL, WSX, and FZ), As stabilization performance of Fe/Mg compound-typed (F2M), Ca/Fe compound-typed (CF), and MetaPro©-ani(As) typed (MPA) stabilizers were tested, and the effect of stabilizer dosage on stabilization performance were further analyzed. The materials with better stabilization effects were selected for engineering construction verification (based on FZS soil sample). The As leaching concentrations of WSL, WSX, FZ, and FZS soil samples turned to be: FZ > FZS > WSX > WSL. The results showed that: for WSL and WSX soil samples with low/medium concentration, F2M and CF typed stabilizers presented good remediation performance with low dosages; for FZ soil samples with high concentration, MPA series stabilizers showed much better stabilization performance than the former two composite ones; for the actual construction samples of FZS soil samples with high concentration, MPA series stabilizers achieved ideal stabilization effect under the open condition, with the best performance of MPA-Ⅰ typed stabilizer.
Research progress of biochar’s application in environmental remediation based on bibliometrics
PANG Xinyu, LIU Wenshi, LI Meng, GONG Tiancheng, ZHAO Ying, SUN Mengyang, HUANG Gang, JIAO Yuxin, YANG Tianxue
2021, 11(4): 740-749. doi: 10.12153/j.issn.1674-991X.20200261
Based on bibliometrics, a quantitative and qualitative analysis of the achievements of biochar applications in environmental remediation both at home and abroad, which had been widely concerned in recent years were conducted, and the overall situation of the research and the future key and hot research directions sorted out. The results showed that a total of 1 272 related Science Citation Index Expanded (SCI-E) source papers were published from January 1, 2009 to September 1, 2019. The number of relevant articles increased year by year, with an average annual growth rate of about 273.67%. China’s total number of publications and independent publications ranked the first, with a total of 617 articles (48.51%). 40% of the top 15 authors were from China. However, there were fewer high-cited articles. The analysis direction showed that soil remediation, adsorption and heavy metals, etc. were the research hotspots in this field. The cluster analysis showed that nano-zero-valent iron, surface complexation, and fixed heavy metals were the three main research directions in the field of biochar enhanced remediation. It was suggested that biochar remediation of emerging pollutants in the environment, soil improvement and synthetic biochar-based nanocomposites might become the potential research hotspots in the future. And reducing costs to realize the transformation of production and process integration, performing systematic and comprehensive researches on the mechanism of biochar and pollutants, realizing the recycling and reuse of biochar, and formulating standardized application guidelines for biochar, etc. could be the focuses of further research.
fertilizer preparation from food waste with different microbial agents
LIU Xiaopei, LI Mingxiao, DAI Xin, LI Xueqi, DOU Runqi, WANG Yong, JIA Xuan, FENG Zuoshan, AN Lichao
2021, 11(4): 750-755. doi: 10.12153/j.issn.1674-991X.20200229
The commercialized food waste degradation agent and self-selected anti-acidification microbial consortium were adopted to produce liquid organic fertilizer from food waste. The impacts of different microbial agents on the solid-liquid transformation of substances in the process of preparing liquid organic fertilizer from food waste were compared and analyzed. The transformation law of organic matter, sugars, crude protein and other substances was expounded. The results indicated that both microbial agents could lower the content of organic matter and crude protein, and increase the content of liquid free amino acids in food waste. The best effect was inoculated with anti-acidification microbial consortium, and its solid organic matter and crude protein decreased 1.17% and 15.41%, respectively, which were 3.66 times and 1.66 times higher than those from food waste degradation agent group; when reacting for 96 h, the content of liquid free amino acids increased to 770.6 mg/L, which were 1.24 times higher than that from food waste degradation agent group. In the first 48 hours, the utilization rates of total sugar and reducing sugar both reached more than 91% in the liquid anti-acidification microbial consortium, but the both rates are only 28.52% for the kitchen waste biodegradable bacteria group. Therefore, anti-acidification microbial consortium could effectively promote the conversion of macromolecular organic matter into soluble micromolecular organic matter and free amino acids, which was expected to provide technical support for the preparation of high-value liquid organic fertilizer from food waste.
Effect of aluminum sludge filler improved bioretention tank on runoff pollutant reduction
ZHANG Ruibin, PAN Zhuoxi, XI Daoguo, ZHOU Nai, ZU Baiyu
2021, 11(4): 756-762. doi: 10.12153/j.issn.1674-991X.20200183
In view of the poor effect of traditional filler bioretention tank on the reduction of nitrogen, phosphorus and other pollutants, the study on improving the bioretention tank with different proportions of aluminum sludge filler was carried out. The bioretention tanks with aluminum sludge and zeolite ratio of 3:2 (low ratio) and 4:1 (high ratio) were set up to study the permeability and removal effect of simulated rainwater with high, medium and low concentrations. The results showed that compared with the low proportion aluminum sludge filler bioretention tank, the high proportion aluminum sludge filler bioretention tank had stronger permeability, and with the growth of the operation cycle, its permeability decreased slowly. The high proportion aluminum sludge filler could improve the service life of the bioretention tank; by increasing the aluminum sludge filler ratio, it could significantly improve the removal efficiency of pollutants of high concentration rainwater. Especially, the removal rates of TP, COD, TN and NH3-N could reach 89.0%, 62.4%, 66.4% and 68.0%, respectively. There was no significant difference in the removal efficiency of low concentration rainwater pollutants by high or low aluminum sludge ratio.
Thallium pollution status and treatment technology of wastewater from lead-zinc smelting industry in China
LU Ran, WANG Xiahui, WU Siyang, LIN Xingjie, WANG Ning, JIA Zhibing
2021, 11(4): 763-768. doi: 10.12153/j.issn.1674-991X.20200220
Thallium and its compounds are highly toxic. The discharge of thallium containing wastewater into the water environment can easily cause abnormal surface water quality. The sources, main characteristics and pollution status of thallium-containing wastewater from some lead-zinc smelting enterprises were summarized and analyzed. Various treatment technologies for thallium-containing wastewater were discussed, and thallium removal processes adopted by lead-zinc smelting enterprises were summarized. The results showed that thallium and its compounds volatilized into the flue gas in the high-temperature smelting process of the lead-zinc smelter, and entered the wastewater in the process of acid pickling of flue gas. The total thallium concentration in the wastewater from flue gas purification was relatively high, and the average value of total thallium in the wastewater of investigation enterprises was 0.76 mg/L. The treatment technologies of thallium-containing wastewater included oxidation method, precipitation method and adsorption method, etc. At present, the lead-zinc smelting enterprises mainly carried out modifications based on the original wastewater treatment process, and mostly adopted sedimentation methods such as sulfide precipitation, biological agent precipitation and electric flocculation to remove thallium. Prevention and control countermeasures for thallium containing wastewater in the lead-zinc smelting industry were proposed, such as strengthening source pollution prevention, strengthening management of thallium-containing wastewater discharge and promoting the research and development of thallium-containing wastewater treatment technologies.
Research progress of subsurface flow constructed wetland filler and its pollutant removal mechanism
WANG Mingming, WEI Jun, HUANG Rongmin, KONG Lingwei, LI Zhongjian, YANG Bin
2021, 11(4): 769-776. doi: 10.12153/j.issn.1674-991X.20200199
The filler is the main medium of constructed wetland, especially the bed of subsurface flow constructed wetland. It is the main carrier of wetland physical, chemical and biological reaction, and has a decisive influence on the removal of contaminants. The literature on the sources, physical properties and chemical composition of common substrate media and practical applications were reviewed, including natural product fillers, industrial/agriculture by-product fillers and synthesis fillers. The mechanisms of substrate media for contaminants removal in water were summarized, including adsorption-sedimentation, ion exchange, slow-release carbon source- electron donor, oxidation-reduction. The removal ability of nitrogen, phosphorus and heavy metal pollutants in subsurface flow wetland was discussed, and the removal effect of different fillers was compared. Finally, the selection of subsurface constructed wetland fillers and prospects for strategy research in the future were prospected, in order to provide scientific guidance and theoretical basis for the further development of constructed wetland and wastewater treatment technology.
Effects assessment of water environment treatment projects based on SWMM-EFDC coupling simulation in Xinfeng River Basin
CHEN Yan, XIA Rui, WANG Lu, SUN Mingdong, ZHANG Lujun, MA Shuqin, JIA Ruining, ZHANG Xiaojiao, YANG Zhongwen
2021, 11(4): 777-788. doi: 10.12153/j.issn.1674-991X.20200283
Scientific evaluation of the environmental effects of water environmental control projects is of great significance for the formulation and optimization of river and lake control schemes and the promotion of scientific pollution control. Xinfeng River Basin is an important water security area in the sub-center of Beijing, and the water pollution problem (black and smelly) was prominent. In order to scientifically evaluate the effects of water environment comprehensive control projects in the Xinfeng River, a technical method of engineering environmental effects assessment were established by coupling model of water-land integration based on SWMM and EFDC. The quantitative simulation evaluation of the environmental effects was carried out for the projects of watershed pollution interception and treatment, wetland construction, water diversion and replenishment, and initial rain regulation and storage. The results showed that the main factor affecting the effect of projects included pollution interception rate, wetland treatment standard, water quality and storage capacity of primary rain. Comprehensive projects and individual projects had made positive contributions to the improvement of water quality. In terms of average reduction rate of water quality concentration, the the project contribution was in the sequence of comprehensive projects (69.8%) > sewage interception (63.1%) > water diversion (51.7%) > wetland construction (50.5%) > initial rain storage (3.8%). In terms of average compliance rate, the sequence was comprehensive projects (96.7%) > sewage interception (85.2%) > wetland construction (32.6%) > water diversion (32.5%) > initial rain storage (0.9%). In terms of load reduction, the sequence was sewage interception (512.4 t/a) > comprehensive projects (319.3 t/a) > wetland construction (89.9 t/a) > initial rain storage (21.9 t/a)> water diversion (-62.6 t/a). The water-land integrated coupling model based on SWMM and EFDC had good applicability in the evaluation of water environment treatment engineering effect, and had certain guiding significance for water pollution control of urban rivers.
Screening and identification of priority control chemicals based on the comprehensive evaluation of hazards: taking a city in the south as an example
YU Boping, HAN Qi, YI Xiuling, CHEN Hongfang, JIN Xingliang, DAI Zhiguang, YUAN Zhongzhao, LI Chaolin
2021, 11(4): 789-796. doi: 10.12153/j.issn.1674-991X.20210015
A comprehensive evaluation system of chemical hazard including 2 hazardous influencing factors, i.e. toxic effects and environmental effects, and 8 indicators was constructed based on the analytic hierarchy process. This evaluation system was applied to the priority control chemicals of a city in southern China. The relevant laws and regulations of the city, US toxic substance database and pollution source survey data were sorted out. The raw and auxiliary materials of chemicals and their actual use were analyzed. And the primary list of priority control chemicals was determined. The calculation of the hazards of chemicals was carried out, and the environmental priority control risk values were finally determined, so as to screen and identify the city’s priority control chemical list. The results showed that there were 23 chemicals in the primary list of chemicals in the city, and the chemicals with higher risk values for environmental priority control were decabromodiphenyl ether, hexabromocyclododecane, nonylphenol, and short-chain chlorinated paraffins, which were mainly involved in rubber, plastics, fiber, electronic products, metal processing and other industries or fields. It was recommended to conduct an in-depth full life cycle environmental impact assessment for the city’s priority chemicals, and combine source reduction, process control and end treatment to reduce the environmental risks of priority chemicals.
Evaluation on VOCs terminal emission reduction technologies in rubber products industry in China
TIAN Yu, FANG Gang, ZHOU Changbo, ZHANG Yixin
2021, 11(4): 797-806. doi: 10.12153/j.issn.1674-991X.20200227
Rubber refining, calendaring, vulcanization and other processes in the production process of rubber products industry can produce waste gases containing volatile organic compounds (VOCs), with large emissions and high non-methane hydrocarbon contents, which can cause serious pollution to the surrounding environment. Therefore, it is urgent to effectively control VOCs emissions in rubber products industry. However, at present, the assessment of VOCs emission reduction technologies in rubber products industry is not perfect, and the benefits of VOCs terminal emission reduction technologies cannot be fully understood. By analyzing VOCs generation and emission characteristics of rubber products industry, and investigating the application status of different terminal emission reduction technologies, the evaluation index system with technical performance, economic benefits, resources and energy, environmental pollution as the primary indexes was established, and the fuzzy comprehensive evaluation method used to evaluate VOCs terminal emission reduction technologies. The aim was to screen out the best feasible VOCs terminal emission reduction technologies and provide evaluation basis and technical support for VOCs emission reduction in rubber products industry. The results showed that the carbon fibre adsorption-desorption method had good comprehensive emission reduction performance and was the optimal terminal control technology for VOCs emission reduction in rubber products industry.
Life cycle assessment of photovoltaic module considering disposal stage
ZHAO Ruonan, DONG Li, QIAO Qi, LIU Jingyang, BAI Lu, ZHANG Yue, XIE Minghui
2021, 11(4): 807-813. doi: 10.12153/j.issn.1674-991X.20200258
To analyze the environmental impacts of whole life cycle of photovoltaic module, Life Cycle Assessment (LCA) was conducted to analyze the environmental impacts of photovoltaic module whose life-cycle stages included manufacture, mounting and disposal. The energy, mass inputs and the environment emissions data of manufacture and mounting stages were obtained through field and questionnaire survey, while the data of energy, material input, output and pollutant emission in the disposal stage were obtained by development and application of specific recovery technology. To calculate the environmental impact potentials of manufacture, mounting and disposal stage, the landfill, disassembly and pyrolysis scenario were set up according to different disposal technologies. The results were compared and analyzed. It showed that: 1) The environmental impact potential of manufacture and mounting stages was 13.98 and 1.50 Pt, respectively, for 1 m2 photovoltaic module, that of disposal stage under three scenarios was 0.04, -0.62, -3.59 Pt, respectively, and thus that of the whole life cycle was 15.52, 14.86, 11.89 Pt, respectively for the three scenarios. 2) From the viewpoint of environmental impact categories, the whole life cycle environmental impacts focused on respiratory system damage, carcinogenic and climate change. From the viewpoint of factors, power consumption was the main factor, accounting for 64.81%, 67.70% and 84.61%, respectively, under the three scenarios. 3) The environmental impact potential of 1 kW·h of electricity generation from photovoltaic module under the three scenarios was 3.34×10-3, 3.20×10-3, 2.56×10-3 Pt/(kW·h), respectively, which was equivalent to 4.8%, 4.6%, 3.7%, respectively, of that from the current electrical power system (70.1×10-3 Pt/(kW·h)). 4) From the perspective of carbon emission level, the carbon emission of 1 kW·h of electricity generation from photovoltaic module was 35.68, 33.53, 23.70 g CO2-eqv/(kW·h), respectively, which was lower than the level of similar studies and China’s electrical power industry. 5) The photovoltaic modules of China installed in the early years were nearing the disposal stage. The vigorous development of the recovery technology could not only achieve resources recovery, but also reduce the environmental impact and carbon emissions of the whole life cycle of photovoltaic modules, thus achieving a win-win situation between environment and energy.
Research on air and surface water quality evaluation method incorporated with the coefficient of variation
FENG Ran, ZHAI Dechao, YUAN Yongsheng
2021, 11(4): 814-822. doi: 10.12153/j.issn.1674-991X.20200262
Air Quality Index and Composite Pollution Index, as the most commonly used environmental quality assessment methods in China in recent years, took the maximum and average values, respectively of the sub-quality indexes for all the monitoring items. However, the former focused only on the primary pollutant, while the latter ignored the importance differences between pollutants. In order to solve these problems, the coefficient of variation was incorporated to adjust the weight distribution among pollutant items dynamically, and the total quality index was the weighted average of each sub-index. By setting the number of days or months of moving extraction, the sensitivity of the evaluation index to long-term/short-term pollutants was regulated according to the local conditions, which improved the rationality and practicability of these two evaluation methods. The environmental monitoring data of Miyun and Ximaoshan in Beijing from 2015 to 2019 were taken as an instance to verify the effectiveness of these two methods. The spatiotemporal distribution variation of the air quality in Beijing in the past five years was analyzed by the improved method. The results showed that the coefficient of variation of PM2.5 and PM10 (air quality) together with dissolved oxygen, total phosphorus and total nitrogen (surface water) were larger, and the air quality had been getting better and presented a gradient distribution from north to south.
Environmental risk assessment method of coal mine rust water to drinking water sources and case study
LI Yun, TAN Wei, LI Jiao, LI Junchao, JIANG Jinyuan
2021, 11(4): 823-828. doi: 10.12153/j.issn.1674-991X.20200238
To evaluate the environmental risk of coal mine water to drinking water sources, the analytic hierarchy process was used to construct an evaluation index system composed of four aspects and 12 indexes. The four aspects included risk source, risk receptor, migration channels and emergency management. An environmental risk assessment method was established so as to evaluate qualitatively and quantitatively the environmental risks of three coal mines to the drinking water sources in a county area of Sichuan Province. The qualitative analysis results showed that the three coal mines were identified as risk sources, the water quality indexes of Fe, Zn, Mn exceeded the standard by a high multiple, which may cause environmental risks. In recent years, the water quality up-to-standard rate of the drinking water sources as risk recipients was 100%, and the environmental capacity was large. The migration channels from the risk sources to the risk receptors had a long distance, and the stream, soil and vegetation along the way had certain dilution, degradation and absorption capacity. The quantitative evaluation results showed that the environmental risk index of the three coal mines was 0.504 2, 0.494 4 and 0.288 9, respectively, and the corresponding environmental risk classification was average, average and low, respectively.