2021 Vol. 11, No. 2

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2021, 11(2): .
Abstract:
PM2.5 source apportionment over Jinan Metropolitan Area
LI Mingzhu, XU Jun, LIU Houfeng, GONG Anbao, DU Xiaohui
2021, 11(2): 209-216. doi: 10.12153/j.issn.1674-991X.20200145
Abstract:
Based on the PSAT particulate source tracing technology of camx model, the quantitative analysis of PM2.5 pollution, regional transport law and sector contribution for cities over Jinan Metropolitan Area were performed for year 2016. The results showed that in terms of the annual mean source apportionment of PM2.5, for the local area of Jinan City, the emission accounted for about 50%, while the whole Jinan Metropolitan Area contributed 75%. The mutual contributions among Jinan Metropolitan Area cities were obvious, up to 13%. In summer, the local contribution was the largest and the regional transport in the eastern Shandong region had the highest impact on the study area by 24%. While in winter, affected by the winter monsoon, the regional transport from Beijing-Tianjin-Hebei Region increased, up to 24%. At present, as far as Jinan Metropolitan Area was concerned, the major sectors contributed to PM2.5 included industrial boilers, steel industry, fugitive dust, chemical industry, metallurgical industry, building material industry, and automobile source. The targeted counter-measure for the above sectors may be a fast and effective approach to reduce PM2.5 pollution.
Characteristics of ozone pollution and its relationship with meteorological factors in Langfang City
LI Na, ZHOU Tao, LIU Xiaoxue, XU Min, LI Hongxing
2021, 11(2): 217-225. doi: 10.12153/j.issn.1674-991X.20200147
Abstract:
The over-standard characteristics of the surface O3 in Langfang City and its relationship with meteorological factors were discussed by using the hourly data of 4 environmental monitoring stations and the continuous observation data of the national meteorological station in Langfang City from 2014 to 2019 with statistical methods. The results showed that the phenomenon of O3 exceeding the standard mainly appeared from May to September and had obvious seasonal characteristics. The diurnal distribution of the over-standard rate of O3 presented a clear unimodal pattern with its peak appearing around 16:00 for O3 1 h concentration and 19:00 for O3 8 h concentration. The O3 8 h concentration was positively correlated with daily average temperature, and was negative correlated with daily mean sea level pressure, and was nonlinear correlated with daily average relative humidity and wind speed. The concentration of ozone was easy to exceed the standard in Langfang City with the daily mean temperature higher than 25 ℃, daily mean relative humidity was 40%-80%, wind direction were south and east, daily mean wind speed was 0.5-2.5 m/s and daily mean sea level pressure less than 1 010 hPa. The prediction equation of O3 8 h concentration from May to September was established by multiple linear regression method, and the results showed that the prediction model had good fitting degree and accurate predictability.
Emission inventory of motor vehicle based on traffic flow for Yangquan City in 2017
XIE Shuxia, HUANG Zhihui, WANG Xin, TANG Yisu, HE Weinan, JI Liang, WANG Yanjun, NI Hong
2021, 11(2): 226-233. doi: 10.12153/j.issn.1674-991X.20200169
Abstract:
The basic data of traffic flow, vehicle type and vehicle speed of road network in Yangquan City were obtained through the simulation by van Aerde speed-traffic flow model and the traffic flow survey. Based on the actual road traffic flow data, vehicle emission factors and road sections, the emission inventory of motor vehicle of Yangquan City was constructed by using the bottom-up method, and the emission characteristics of vehicle exhaust were analyzed. The results showed that the emissions of CO, HC, NOx and PM from the road vehicles in the city in 2017 was 4.56×104, 0.96×104, 1.76×104 and 0.024×104 t, respectively. According to road category, the highway (including urban expressway) was the main contributor of CO, HC, NOx and PM, accounting for 48.4%, 48.9%, 40.0% and 34.3% of total emissions respectively. In terms of vehicle type, car was the main contributor of CO and HC emission and heavy truck was the main contributor of NOx and PM emission. Based on emission stages, vehicles of national stage 4 emitted the main proportion of CO and HC, vehicles of national stage 3 emitted the highest proportion of NOx and PM. In the view of geographical distribution, Yu County was the largest pollutants emission area, followed by Pingding County and suburbs. The research showed that the actual emissions of motor vehicles on the road were closely related to the road category, the administrative region of the road and the vehicle type.
Practice of mountain-river-forest-farmland-lake-grassland ecological conservation and restoration of the source area of alpine inland rivers:a case study in intersection area of Shule River and Hala Lake in Qilian Mountains of Qinghai Province
SHANG Honglei, HAN Yongwei, CAI Xuan, LÜ Fengchun, WANG Shixi, MENG Xiaojie, JI Wei
2021, 11(2): 234-240. doi: 10.12153/j.issn.1674-991X.20200052
Abstract:
The internal relations of mountains, rivers, forests, farmlands (natural grasslands), lakes and grasslands, as well as the major eco-environmental problems in the catchment area of Shule River and Hala Lake in Qilian Mountains of Qinghai Province were analyzed. Focusing on the key areas such as the source area of Buha River, Shule River, Datong River, the source exit section of Shule River and the east bank of Hala Lake, a series of priority projects were put forward, such as ecological restoration of historical legacy abandoned mines, wetland conservation, integrated management of black soil beach degraded grassland, harnessing of desertification land, improvement of degraded grassland, grassland ecosystem fragmentation governance, prairie rodent pests prevention, comprehensive environmental harness of population aggregation areas and ecological restoration and treatment for rivers. Three key tasks were proposed, including construction of ecological security pattern, improvement of water conservation function, and restoration of broken habitat, and the ecological conservation and restoration of the mountain-river-forest-farmland-lake-grassland (MRFFLG) system in the source area of alpine inland was explored, which could fulfill the purpose of transformation of the MRFFLG life community, promotion of regional ecosystem services and ecological barriers function to effectively guarantee the ecological security of the northwest inland areas and the country.
Analysis of water scarcity characteristics in data-deficient watersheds based on hydrological model: taking Minjiang Tributary Mangxi River Basin as an example
LING Bing, LIU Xiaobo, HUANG Wei, CHEN Xuekai
2021, 11(2): 241-248. doi: 10.12153/j.issn.1674-991X.20200245
Abstract:
Aiming at the problems of large spatial and temporal scale and low precision in current analysis of basin water scarcity, a method suitable for the study of water scarcity in data-deficient watersheds was established, using the SWAT model to calculate the total amount of water resources of the watershed. Based on the statistical data, the water demand of the watershed was calculated, and the monthly change characteristics of water scarcity in the watershed studied. The method was applied to Mangxi River Basin, with the characteristics of water shortage being analyzed from perspectives of different time, different space and different industries. The results showed that the annual average total water resource in Mangxi River Basin was 564.6 million m3, the available water was 105.99 million m3, the total water demand was 126.5 million m3, and the water scarcity was 31.34 million m3. Affected by rainfall and agricultural irrigation, the water scarcity in Mangxi River Basin was mainly in the dry season, especially in April and May when the agricultural irrigation needs were the greatest.
Fluorescence spectra and multivariate statistical model characterization of DOM composition structure of Baitapu River sediment
LIU Dongping, GAO Hongjie, CUI Bing, YU Huibin, YANG Fang
2021, 11(2): 249-257. doi: 10.12153/j.issn.1674-991X.20200204
Abstract:
Three-dimensional excitation-emission matrix spectroscopy (EEMs), parallel factor (PARAFAC) analysis, and hierarchical clustering analysis (HCA) with classification and regression tree (CART) were applied for spectroscopic data to characterize fluorescent components of dissolved organic matter (DOM) in the surface sediment samples, which were collected in rural, urban and city sections of the Baitapu River, a typical urbanization river in Northeast China. The spatial characteristics of fluorescence components were analyzed, the key factors of DOM characteristics identified, and the pollution sources distinguished. The results showed that six DOM fluorescent components were extracted from DOM of Baitapu River sediment, which contained fulvic acid (C1), microbial metabolites (C2), humic acid (C3), tryptophan-like (C4), tyrosine-like (C5) and phenolic (C6) materials. The fluorescence concentration of DOM was the highest in the town section of the Baitapu River, followed by the city section and the lowest in the rural section. The DOM fractions in the rural section was dominated by autochthonous origins, while the DOM fractions in the town and urban sections by terrigenous and autochthonous substances. The pollution degree of bottom sediment of the Baitabu River was ordered as town section>urban section> rural section, and the bottom sediment DOM showed the differentiation characteristics of rural section, town section and urban section. C1 and C5 were two key factors to recognize the DOM characteristics of sediment.
Estimation and sources apportionment of non-point source nitrogen and phosphorus loads in Beishahe sub-catchment of Beijing
XI Haojun, LIU Beibei, HUANG Yajuan, MA Xueqing, DENG Yajing, LIU Fuyu, ZHU Hongtao, SUN Dezhi
2021, 11(2): 258-266. doi: 10.12153/j.issn.1674-991X.20200076
Abstract:
Beishahe sub-catchment of Beijing was studied for the source apportionment of non-point source (NPS) pollution. The NPS pollutants in this area were generalized into two types: the dissolved and the adsorbed. The dissolved and adsorbed nitrogen and phosphorus NPS pollution loads were estimated based on the precipitation runoff model (soil conservation service curve number, SCS-CN), soil erosion model (revised universal soil loss equation, RUSLE), and the pollutant output load model empirical equation. The spatial distribution characteristics of nitrogen and phosphorus loads produced by different land use types were also analyzed. The simulation results showed that the average annual load of total nitrogen (TN) in Beishahe sub-catchment was 0.625 t/(km2 ·a), of which the dissolved nitrogen was 0.190 t/(km2 ·a) and the adsorbed nitrogen was 0.435 t/(km2 ·a); the average pollution load of total phosphorus (TP) in Beishahe sub-catchment was 0.118 t/(km2 ·a), of which the dissolved phosphorus was 0.011 t/(km2 ·a) and the adsorbed phosphorus was 0.107 t/(km2 ·a). The rural area produced the most TN of 0.855 t/(km2 ·a) among all different land use types, followed by the forest land (0.713 t/(km2 ·a)) and the unused land (0.619 t/(km2 ·a)). For TP, the land use types with highest annual pollution load was the grassland (0.238 t/(km2 ·a)), the forest land (0.126 t/(km2 ·a)) and the unused land (0.115 t/(km2 ·a)). Generally speaking, the losses of nitrogen and phosphorus were mainly in the form of adsorbed in the Beishahe sub-catchment. Therefore, controlling of the soil erosion, water and soil loss should be highlighted for the reduction of the loads of adsorbed nitrogen and phosphorus in Beishahe sub-catchment.
Dynamic differences of microcystins and their relationship with environmental factors in spring in Lake Chaohu and Lake Taihu
YUAN Qiang, YU Li, LI Weihua, YANG Houyun, WANG Rong, XU Dumin
2021, 11(2): 267-277. doi: 10.12153/j.issn.1674-991X.20200225
Abstract:
In order to explore the dynamic differences of intracellular microcystins (IMCs) and key influencing factors in spring for Lake Chaohu and Lake Taihu, samples were analyzed from different lake areas of this two lakes in March, April and May of 2019. The results indicated that IMCs showed obvious temporal and spatial distribution characteristics in Lake Chaohu and Lake Taihu during the sampling period, the concentration of IMCs increased month by month, and IMCs in the high eutrophication lake area was significantly higher than that in the low eutrophication lake area. IMC-LR was the main isomer of IMCs in the two lakes, accounting for 65.10% and 58.10%, respectively. IMCs concentration between the two lakes were significantly different, the average concentration of IMCs in Lake Chaohu (0.077, 0.238, 0.632 μg/L) was obviously higher than that in Lake Taihu (0.021, 0.031, 0.166 μg/L), and the toxicity of IMCs per unit biomass (IMCs/Chla and IMC-LR/Chla) was also significantly higher than that in Lake Taihu. The correlation analysis showed that TN, TP and TN/TP were the key environmental factors affecting the concentration of IMCs and the toxicity of IMCs per unit biomass, and the abundance and capacity of toxin-producing algae may be the important reasons for the difference.
Estimation of fish productivity in Tangxun Lake under ecological fishery culture model and its impact on endogenous pollution
DU Mingpu, WANG Hongli, LIU Kangfu, YUAN Saibo, ZHANG Jing, LI Zhenyu, RUAN Rui
2021, 11(2): 278-282. doi: 10.12153/j.issn.1674-991X.20200092
Abstract:
The biomass of natural bait in Tangxun Lake was investigated to evaluate the fish productivity of Tangxun Lake under the condition of neither fertilizer nor bait. The pollution load generated by excretion and defecation and the amount of nutrients stored in fish body by growth gain in ecological fishery culture were evaluated according to the main fish productivity growth metabolic parameters. The results showed that, in Tangxun Lake, the natural fish productivity was around 2 975.49 t/a, and the ecological fishery stocking density could be controlled around 29 g/m3; nitrogen and phosphorus from the sources of excretion and defecation was 309.28 and 13.06 t/a, respectively; in which nitrogen was higher than the weight gained from the nutrition metabolism in fish bodies (73.10 t/a); and phosphorus was lower than the weight gained from the nutrition metabolism in fish bodies (15.90 t/a). Ecological fishery culture produced a certain amount of endogenous pollutant nitrogen, but it could reduce the endogenous pollutant phosphorus in water, which could be used as one of the measures to control lake eutrophication.
Comprehensive benefit evaluation of planting models for the prevention and control of celery non-point source pollution
YE Jiahui, HU Mengtian, HAN Yongwei, GAO Xinting, LIU Hui
2021, 11(2): 283-290. doi: 10.12153/j.issn.1674-991X.20200114
Abstract:
The questionnaire survey, analytic hierarchy process, expert consultation methods were adopted to construct a comprehensive benefit evaluation index system with 12 indexes, for the evaluation of planting models for the prevention and control of celery non-point source pollution, considering economic benefit, product quality and environmental benefit. Based on the index system, an empirical study was carried out to evaluate benefits of different planting models for non-point source pollution control, combining different fertilization methods, application of soil loosening and rooting agent and bio-based film in Chaohu Lake Basin. The results showed that: the best model of economic benefit was the combination of reduced fertilization with soil loosening and rooting agent, the optimal model of product quality benefit was the reduced fertilization model, the best environmental benefit model was organic-inorganic mixture fertilization plus soil loosening and rooting agent plus bio-based film model, and the optimal comprehensive benefit mode was the combination of organic-inorganic mixture fertilization, rooting agent and bio-based film model. Combined with the experimental results, the reduced fertilization and organic-inorganic mixed fertilization should be preferred, and the technical combination of soil loosing and rooting agent and bio-based film can effectively improve the comprehensive benefits.
Comparison of two methods in groundwater quality assessment in typical karst areas: taking Disu underground river as an example
QIAO Xiaocui, LI Xue, LIU Yan
2021, 11(2): 291-297. doi: 10.12153/j.issn.1674-991X.20200120
Abstract:
The appropriate evaluation method of groundwater is the key to ensure the scientific and reasonable evaluation results. Taking Disu underground river system basin area in typical southwest karst area as an example, the fuzzy comprehensive index method and the water quality index method were applied to evaluate the groundwater quality of the representative sampling points of the underground river system. The results showed that the groundwater quality in the whole basin was relatively good and the percent of water points whose quality was worse than Class Ⅲ of Standard for Groundwater Quality (GB/T 14848-2017) was 21.43% and 32.14%, respectively, according to the two assessment methods. The main indicator exceeding the standard was NO 3 - , whose maximum detection concentration was 2.3 times of the Class Ⅲ water quality limit, and the over-standard points mainly concentrated in Disu village where the activities of human beings were intense. Among the 28 points, 15 points got the same evaluation results by the two methods and the other points were only one water quality grade different. The water quality index method could meet the requirements of water quality classification and quantitative evaluation, but for the water samples with different over-standard indexes, the comparability was poor. The fuzzy comprehensive index method could precisely reflect the approaching degree of the actual concentration and water quality classification limit of the indexes, quantify the impact weight of all groundwater quality evaluation indexes and make the result more accurate. On the other hand, the calculation for this method was complex, with bad maneuverability, unable to identify the main over-standard indexes, and the impact of the indexes that posed a greater threat to human health and ecological environment may be covered up when quantifying all the evaluation indexes. Therefore, in practical applications, the appropriate evaluation method should be selected according to the monitoring data and evaluation purpose, so that the evaluation results could not only reflect the actual situation of water body, but also meet the needs of management.
Microcosm experimental study on microbial degradation of trichloroethylene in contaminated groundwater
SUN Zhongping, WU Naijin, YANG Sucai, WEI Wenxia, SONG Yun
2021, 11(2): 298-306. doi: 10.12153/j.issn.1674-991X.20200150
Abstract:
Volatile chlorinated hydrocarbons such as trichloroethylene have become one of the most highly detected organic pollutants in groundwater of China. In order to enrich the theoretical support of bioremediation of groundwater polluted by chlorinated hydrocarbons in China, the aquifer sediments and groundwater samples were collected from a chlorinated hydrocarbons contaminated site in Beijing. The effects of different concentrations of sodium acetate, sodium lactate and lactic acid on the removal of trichloroethylene under anaerobic conditions were preliminarily investigated by the microcosm experiments. Combined with the analysis of the intermediate products and the change of microbial diversity in each anaerobic system, the reaction mechanism was elaborated. The results showed that under the anaerobic condition, the removal rate of trichloroethylene in the system of 1.0 g/L sodium acetate was the highest, and the degradation rate was 94.5%. The test system with sodium acetate could maintain neutral pH and low redox potential for a long time, and at the same time, it could achieve the highest TOC degradation rate. Only cis-1,2-dichloroethylene was detected in the intermediates of anaerobic degradation on the 30th day of the reaction. It was inferred that the main mechanism of biodegradation of trichloroethylene under the anaerobic condition was hydrogenolysis. In the microcosm system, the dominant microbes at the phylum level contained Proteobacteriae and Firmicutes, which were potential high-efficiency biodegradable bacteria for chlorinated hydrocarbons. The qPCR results showed that the total amount of bacteria increased greatly in each reaction system, and a high level of tceA was detected in each sample (about 106-107copies/L), suggesting that the hydrogenolysis of TCE might be carried out under the function of tceA.
Research progress o fthe effects of extracellular polymeric substances (EPS) on wastewater treatment system
TAN Yu, FU Liya, ZHOU Jian, LI Min, WU Changyong
2021, 11(2): 307-313. doi: 10.12153/j.issn.1674-991X.20200178
Abstract(1036) PDF(1122KB)(130)
Abstract:
Extracellular polymeric substances (EPS) is a common microbial by-product of biological treatment process in wastewater treatment plants. Its occurrence has different effects on various processes of wastewater treatment system. Firstly, on the basis of previous studies, the definition of EPS was summarized, and the structure, compositions and functions of it was described in detail. Secondly, the effects of EPS on the growth of microorganisms, the formation of granular sludge, the flocculation and sedimentation performance of microbial aggregates in the biological treatment process, the permeability of the membrane and the mass transfer of the catalyst in the advanced treatment process, the impact of sludge digestion and dehydration performance in the sludge treatment process were reviewed. The behavior mechanisms of EPS in different wastewater treatment process were summarized and explored. Finally, the future research directions and contents of EPS in wastewater treatment were proposed.
Research progress on environmental behaviors and ecotoxicity of tetracycline antibiotics
AO Mengmeng, WEI Jian, CHEN Zhonglin, LIU Li, SONG Yonghui
2021, 11(2): 314-324. doi: 10.12153/j.issn.1674-991X.20200096
Abstract(1961) PDF(1134KB)(343)
Abstract:
Tetracycline antibiotics (TCs) are among the most widely used antibiotics in the world. They are hardly absorbable by organisms, and resistant to biodegradation in the environment, thus being difficult to remove in conventional wastewater treatment systems, and posing serious threats to ecosystems and human health. The sources and pollution occurrence of TCs in the environment were reviewed, their transfer, transformation and degradation were described, and their ecological and bio-toxic effects were summarized. Finally, the ecological risks of these pollutants and the prospects of future research were proposed. It was suggested that the environmental behaviors of TCs should be assessed at the multi-media environmental levels. More studies should be conducted on their ecotoxic mechanisms and their joint toxic effects with other environmental pollutants.
Application andprospect of polymer/clay nanocomposites in sewage treatment
WU Linlin, CHEN Xiaofeng, XU Qiujin, DU Peng
2021, 11(2): 325-331. doi: 10.12153/j.issn.1674-991X.20200140
Abstract:
The adsorption method is a simple, economical, efficient and sustainable method for the treatment of pollutants in water, with wide applications. It is urgent to develop and prepare new efficient, green and environmentally friendly adsorption materials. The new functional polymer/clay nanocomposites (PCNs) prepared by composite polymers and clay minerals are characterized by large specific surface area, high adsorption efficiency and stable chemical properties, which reveals prominent advantages and great development potential in sewage treatment. The research progress of PCNs in the wastewater treatment was summarized from the aspects of adsorbent characteristics, main categories, pollutant removal types and application in wastewater treatment technology. The influencing factors of pollutant removal efficiency of PCNs were analyzed, and the research prospect of PCNs in water treatment was prospected.
Research progress on joint toxic effects and mechanisms of the mixture of TCDD and mercury, cadmium, lead, arsenic
ZHANG Yuanyuan, GUO Shaojuan, WANG Feifei, YANG Lixin
2021, 11(2): 332-342. doi: 10.12153/j.issn.1674-991X.20200217
Abstract:
Chemicals usually exist in the environment in the form of mixtures. Heavy metals and organic chemicals are two kinds of common pollutants in the environment, and their toxic effects have been concerned for a long time. Considering the complexity of toxic effects of chemicals mixtures and the limitation of risk assessment methods, most of the existing studies focus mainly on the toxic effects of single chemicals or a group of chemicals, but few on the joint toxic effects of different types of chemical pollutants. A number of studies related to environmental sources, concentrations, single and joint toxic effects and molecular mechanisms of 2,3,7,8-tetrachlorodibenzo-dioxins (TCDD), mercury, cadmium, lead and arsenic were analyzed and summarized systematically. Combined with a transcriptome analysis of single and mixed induced expression genes, a quantitative study of gene expression level, and the application prospect of metabolomics and exposure omics and other technologies in the study of joint toxic effects and mechanisms, a method based on specific gene expression level was proposed to study and assess the joint toxic effects.
Technical research progress of reducing activation internal resistance and ohmic internal resistance in microbial fuel cells
ZHAO Yang, SONG Yonghui, DUAN Liang
2021, 11(2): 343-353. doi: 10.12153/j.issn.1674-991X.20200167
Abstract:
Microbial fuel cells (MFCs) technology is a new type of wastewater treatment and energy recovery technology combining wastewater treatment with energy recovery. However, due to the limitations of the irreversible reaction processes on the cathode and anode, the losses of electricity caused by the activation loss and ohmic loss make it difficult to obtain a high and stable energy output, which restricts the further development of MFCs. With the technological progress in materials and biology in recent years, the above losses can be reduced by reasonable design. Aiming at the two main components of reducing internal resistance, i.e. activation internal resistance and ohmic internal resistance, the recent technological advances in the improvement of electricity generation performance of MFCs were systematically summarized, including the screening of electricity-producing bacteria, the explanation of electron transfer mechanism, the innovation of electrode materials and functional modification methods, the advancement of partition materials and the optimization of reactor configuration. Finally, the technical development for reducing internal resistance of MFCs in the future was prospected.
Operation effect and microbial community changes of A/O denitrification reactor enhanced by microbial agents
JIN Weidong, JIAO Julong, LI Jianping, YANG Suwen, YAN Yuhong, ZHANG Yue
2021, 11(2): 354-364. doi: 10.12153/j.issn.1674-991X.20200083
Abstract:
A reactor which combined traditional anoxic aerobic process with biofilm was applied to treat simulated domestic sewage, of which the optimum operating condition was determined by adjusting the hydraulic residence time (HRT), carbon/nitrogen ratio (C/N) and reflux ratio of nitrating liquid. Besides, the operation efficiency of the reactor was investigated by adding ammonia nitrogen removal agent and denitrifying agent. The results showed that the reactor tended to be stabilized in 30 days after startup. When the HRT was 24 h, C/N was 4, and reflux ratio was 200%, the reactor operating effect was the best. The average removal rates of chemical oxygen demand (COD), ammonia nitrogen ( NH 4 + -N) and total nitrogen (TN) was 80.3%, 79.9% and 47.8%, respectively. The capacity of the reactor to remove ammonia nitrogen was strengthened after adding microbial agent. Accordingly, the average removal rates of the three pollutants turned into 79.5%, 90.2% and 56.6%, respectively, among which the maximum removal rate of TN could be increased to 70.0%. Besides, the tolerance of reactor to influent load was improved to a certain extent. Furthermore, the high throughput sequencing (HTS) analysis showed that Proteobacteria and Bacteroidetes were the main functional microorganisms in the original sludge, of which the total relative abundance ratios were 77.8%. During the operation of the reactor system, the relative abundance of the two phyla showed a tendency of decreasing first, then increased and tended to be stable. After the addition of microbial agent, the species number and diversity of microorganisms in the anoxic pool increased significantly, and the relative abundance of the two phyla in the aerobic pool reached 92.3%.
Technology approach and development mode on distributed treatment of organic contaminants in rural towns and villages
LI Yaozhong, XI Beidou, ZHANG Bo, LIU Yonghong
2021, 11(2): 365-370. doi: 10.12153/j.issn.1674-991X.20200133
Abstract:
The characteristics and treatment performance of rural domestic sewage and solid organic contaminants in China were analyzed, and relevant government policies and advanced foreign experiences were also discussed. The technology approach and development mode of the distributed treatment based on the combination of flexible suspended carrier moving bed biofilm reactor (SC-MBBR) system and aerobic digestion for the degradation of organic contaminants in rural towns and villages was proposed, which could achieve synergistic treatment and reclamation of domestic sewage, excess sludge, straw, kitchen waste and livestock manure. With regard to the construction, operation and maintenance of organic contaminants disposal projects in rural towns and villages, a three-level joint governance mode consisting of projects packaging, decentralized and centralized treatment, and optimized management of county projects was proposed from aspects of overall planning, integrated construction and unified management, combined with the government policies, modern financial innovation modes, networking and intelligent application.
Effects of thermal treatment on properties and ecological functions of contaminated soil
YE Yuan, XU Xuehui, LI Yanxi, HAN Wei
2021, 11(2): 371-377. doi: 10.12153/j.issn.1674-991X.20200134
Abstract:
Thermal treatment is one of the hot technologies in the field of contaminated site remediation due to the advantages of good treatment efficiency and short construction period, therefore, it is of great significance to clarify the comprehensive impacts of thermal treatment on the soil properties and ecological functions for the assessment the soil values after treatment. Based on the analysis of a large number of relevant research and application cases, the impacts of thermal treatment remediation technology on the physical and chemical properties like soil organic matter, pH, nutrient components, together with the ecological effects on soil microorganisms, soil animals and plants exposed to the treated soil were summarized. The effects of thermal treatment process on the soil contaminant derivatives and the remediation efficiency for combined pollution were analyzed. Finally, the comprehensive effect of thermal treatment on soil and its guiding significance for practical remediation engineering were discussed. The key research focuses and directions of thermal treatment in the field application in the future were analyzed.
Problems in the implementation of China Cleaner Production Promotion Law and the improvement approaches
YANG Yi, ZHI Jing, LI Yanping, ZHANG Xin, ZHAO Yazhou, ZHANG Qingling
2021, 11(2): 378-384. doi: 10.12153/j.issn.1674-991X.20200118
Abstract:
China Cleaner Production Promotion Law is the world?s first special law for cleaner production, which has played an important role in guiding and regulating cleaner production in China for 17 years of implementation. In current stage, the green development and environmental management in China put forward many more requests to cleaner production. However, the defects of the law become increasingly obvious, such as the definition of cleaner production, cleaner production audit system and the incentive measures. In view of the whole-process control, the adverse effect on promoting the idea of cleaner production and the technology development that brought by the narrow definition was analyzed. Aiming at the problems that the mandatory cleaner production audit system did not meet the current environmental management objectives and the incentive measures could not effectively play a guiding role, suggestions on improvement approaches were put forward, including strengthening the whole-process control idea, cancelling the scope of mandatory cleaner production audit and targeting cleaner production audit at emissions reduction, clarifying the normalization of the acceptance procedures, strengthening the business guidance for cleaner production audit institutions, and establishing coordinated propulsion mechanism of regional cleaner production. Some cleaner production incentive measures were also suggested, including the implementation of tax preferences and financial credit support for enterprises that achieved significant resources, environment and economic benefits through cleaner production, and the simplification of the procedures of environmental impact assessment, and the setting-up of model enterprises.
Development of environmental management lexicon based on new word discovery and its empirical application
WANG Zhijun, CHANG Miao, ZHOU Li, GUO Peikun, GU Meifeng
2021, 11(2): 385-392. doi: 10.12153/j.issn.1674-991X.20200127
Abstract:
With the rapid development of environmental policies in China, collating, inducing, analyzing and interpreting a large number of policies and regulations in a purely manual way has become more and more difficult. Therefore, it is of great significance to use computer technologies, such as text mining, to support intelligent environmental policy management and environmental policy analysis, including information extraction and text analysis. Accurate word segmentation, or tokenization, is the basis of all text mining functions. In order to improve the effect of policy text segmentation, the environmental policies published on official websites of China?s ecological and environmental departments of all levels were collected and taken as corpus. New word discovery algorithms and manual supplement and modification were adopted to develop the environmental management professional lexicon. The empirical results showed that with addition of the environmental lexicon, the accuracy of environmental policy segmentation could improve from 72.6% to 94.1%, and the misjudgment rate of policy automatic classification based on support vector machine could reduce by 22.7%. Besides, the results of word frequency statistics and keyword extraction after adding lexicon could also provide more comprehensive and more timely statistical information for environmental policy analysis.
Analysis of the impact of R&D investment on the performance of listed environmental protection companies in China
CHEN Jingyi, ZHANG Baoliu, LUO Hong, LÜ Lianhong
2021, 11(2): 393-400. doi: 10.12153/j.issn.1674-991X.20200224
Abstract:
R&D investment is the foundation of technological innovation, and innovation is the core competitiveness of an enterprise, which directly affects the benefit and development of an enterprise. Select the panel data of 61 listed companies in the environmental protection industry in Shanghai and Shenzhen Stock Exchange from 2016 to 2019 as the research object, this paper use the method of multiple regression analysis to empirically analyze the impact of R&D investment on corporate performance of environmental protection listed companies, and analyze the lag effect of R&D investment. The results show that the intensity of R&D investment has a negative effect on the company?s performance in the current period. It is positively correlated with the return on assets when one period is lagging, and has a positive correlation with the profit rate of the main business when the lag is two periods; while the investment intensity of R&D personnel has a positive effect on the corporate performance in the current period. To promote the high-quality development, enterprises should increase the long-term investment in R&D funds, enhance the innovation capabilities of R&D personnel, and strengthen the transformation of R&D achievements.
Analysis of the characteristics of environmental emergencies in China
LI Xu, LÜ Jiapei, PEI Yingying, GUO Changsheng, XU Jian
2021, 11(2): 401-408. doi: 10.12153/j.issn.1674-991X.20200119
Abstract:
The statistics and analysis were made on 3 203 environmental emergencies and their environmental pollution emergencies in China from 2011 to 2017 from six aspects, including the development trend, spatial distribution, receptor types, pollution factors, pollution causes and industrial characteristics. The results showed that from 2011 to 2017, the number of environmental emergencies was on the whole decreasing, and the general environmental events were the main events, accounting for 95.50%. East China was the main site of environmental emergencies, accounting for 46.99%. Shanghai had the largest cumulative number of environmental emergencies (761), followed by Shaanxi Province (360) and Jiangsu Province (347). The water was the main pollution acceptor of environmental pollution emergency events, accounting for 85.59%. The wastewater from industrial enterprises was the main pollution factor causing environmental pollution emergency events, accounting for 26.73%. Human factors were the main factors causing environmental pollution emergency events, among which the contribution rate of illegal pollutant discharge by enterprises reached 36.56%. The production and supply of water power and the manufacturing of chemical raw materials and chemicals were the industries with frequent environmental pollution emergency events. The research showed that it was necessary to improve the risk management system of environmental emergencies, strengthen the diversified supervision of industrial wastewater discharge, and reinforce the management of industries with high accident rate to effectively prevent and control environment pollution emergency events.