2023 Vol. 13, No. 3

Display Method:
Technologies, standards, practices and philosophical thinking of "Near Zero Emission" of power station air pollutants
WANG Shumin, ZHANG Yi, ZHU Jiangtao, WANG Qiang, CHEN Yunfeng, YU Xuehai, GU Yongzheng, ZHANG Yongsheng, TANG Hong
2023, 13(3): 897-908. doi: 10.12153/j.issn.1674-991X.20230036
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The construction of ecological civilization is a revolution involving production methods, lifestyles, ways of thinking, and values. The background and the development of environmental policies and emission standards of "Near Zero Emission" (NZE) of clean coal combustion were summarized. The development status of pollutant emission control technologies regarding particulate matter, sulfur dioxide (SO2), nitrogen oxides (NOx) and heavy metals including mercury and the technical route of NZE of coal-fired units were discussed. Typical cases in different zones were analyzed in detail. The results indicated that the emission of particulate matter, SO2, NOx from typical units was lower than 5, 35, 50 mg/m3 for a long period, respectively. The emission level of pollutants in Jinjie Power Plant Phase Ⅲ, and Shouguang Power Plant was lower than 1, 10, 20 mg/m3, respectively. Moreover, Zhoushan Unit 4 and Sanhe Unit 4 had been in stable operation for more than seven years after achieving the NZE standard of clean coal combustion. The economy of the NZE was studied, the benefits of NZE of clean coal combustion in the views of economy, environment, and society were analyzed, the philosophical thinking on NZE technologies, standards, and practices were proposed, and the green development direction of clean electricity was projected. The NZE technologies and engineering practices promoted the development of environmental protection standards in China, while the standards promoted the advancement of related technologies. Based on China's national conditions, it was of great significance to continuously promote coal utilization in a clean and efficient way and continuously improve environmental protection standards, to guarantee energy security and sustainable development.

Characteristics and sources apportionment of size-segregated atmospheric particles in Ili Valley Urban Agglomeration in summer
DAI Ran, GU Chao, XU Tao, LI Xinqi, YIN Baohui, ZHAO Xueyan, ZHENG Zhensen, HAN Jinbao, YANG Wen
2023, 13(3): 909-920. doi: 10.12153/j.issn.1674-991X.20220598
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To analyze the composition characteristics and sources of atmospheric particulate matter with different particle sizes in Ili Valley Urban Agglomeration, PM2.5 and PM10 samples were collected at six sampling sites in four cities/counties, including Yining City, Yining County, Qapqal Xibe Autonomous County and Huocheng County from July 19 to 29, 2021. The chemical components, including elements, ions and carbon components, of these samples were analyzed, and the chemical mass balance model was used to analyze their sources. The results showed that the concentrations of PM2.5 and PM10 in the urban agglomeration in Ili Valley core area were at low levels during the sampling period, which were (22.81±2.79) and (58.81±6.95) μg/m3, respectively. Among the four cities/counties, the concentrations in Yining City and Yining County were higher than those in Huocheng County and Qapqal Xibe Autonomous County. The results of chemical mass closure analysis showed that mineral dust was the main component of PM2.5 and PM10 during the study, accounting for 39.8% and 54.1%, respectively. Organic matter was the next, accounting for 33.2% and 19.8%, respectively. Secondary inorganic ions also accounted for 20.2% and 10.7% of PM2.5 and PM10, respectively. The result of sources apportionment by chemical mass balance model showed that PM2.5 was mainly contributed by secondary particulate matter (29.1%), dust sources (28.3%), industrial sources (16.1%), motor vehicles (10.5%) and coal combustion sources (9.3%), and PM10 by dust sources (42.3%), secondary particulate matter (14.7%), industrial sources (14.1%), motor vehicles (8.4%) and coal combustion sources (7.3%).

Effect of urban spatial development on spatial and temporal variation of NO2 concentration in Wuchangshi Metropolitan Area
CAO Yang, LI Yanhong
2023, 13(3): 921-928. doi: 10.12153/j.issn.1674-991X.20220366
Abstract(225) HTML (121) PDF(2902KB)(22)

In order to explore the impact of urban spatial development on NO pollution in Wuchangshi Metropolitan Area, the center of gravity of the north slope of Tianshan Mountain Economic Belt, multi-source remote sensing data was used to study the temporal and spatial variation of NO emissions in Wuchangshi Metropolitan Area. The results show that: based on the OMI remote sensing data from 2006 to 2020, according to the average amount of NO2 emission in Xinjiang, it is found that the low emission zone of NO2 in Xinjiang is Hotan and other small cities; the low emission zone is Kashgar and Hami and other regions; the medium emission zone 1 is in the western part of Xinjiang; the second high emission zone appears in the middle of Bayingoleng Mongolian Autonomous Prefecture, a medium-sized city on the southern slope, and the high pollution emission zone In the Wuchangshi Metropolitan Area. In terms of spatial pattern, the urban land and construction land are growing with one city and five urban districts of Urumqi as the main center, and Changji City, Fukang City and Shihezi City as the sub-centers. The urbanization process of Wuchangshi Metropolitan Area is accelerated, and the closer it is to the urban area, the more N. The higher the concentration, the higher the degree of pollution to the surrounding environment. During the second management in Wuchangshi Metropolitan Area, the concentration of NO decreased the most. The potential source contribution factor (PSCF) and concentration weight locus (CWT) of Wuchangshi Metropolitan Area were analyzed before and after the critical period of novel coronavirus (2019-2021). The results showed that the main potential source areas were the local region of Urumqi and the neighboring cities in the southwest of Changji Hui Autonomous Prefecture.

Research on air pollution characteristics and influencing factors of typical urban road traffic densified monitoring stations
ZHANG Yonglin, WU Rui, YANG Xiaowen, YANG Daoyuan, LI Yue, WANG Renjie, XU Honglei
2023, 13(3): 929-939. doi: 10.12153/j.issn.1674-991X.20221266
Abstract(267) HTML (104) PDF(6099KB)(41)

Based on the requirements of the 14th Five-Year Plan (2021-2025) of ecological environment monitoring, aiming at the lack of study about air pollution characteristics and influencing factors of typical urban road traffic densified monitoring stations in China, the concentrations of six conventional air pollutants and meteorological parameters were monitored at different points and heights on both sides of typical roads in Lanzhou City, Gansu Province, where mobile sources were the main source of air pollution. Meanwhile, road traffic flow and vehicle type information were acquired to explore the characteristics and influencing factors of air pollution. The results showed that there existed differences in the concentrations of air pollutants on both sides of the road and at different locations on the same side of the road. The concentrations of PM2.5 and PM10 declined with the height of the monitoring sites increasing, peaking at 2-meter height, whereas SO2, NO2, CO, and O3 showed a trend of first increasing and then decreasing with height, reaching their highest concentrations at 4-meter height. Hourly concentrations of SO2, NO2, PM2.5, PM10 and CO peaked at 05:00 to 09:00 and troughed at 15:00 to 17:00; while O3 peaked and troughed at exactly the opposite time. The concentrations of NO2 and CO were greatly affected by the traffic flow. Furthermore, NO2 concentrations had a very strong correlation with the volume of heavy-duty trucks and CO concentrations had a strong correlation with the volume of light-duty passenger vehicles during the representative time period. During the monitoring period the daily average concentrations of the six pollutants were negatively correlated with relative humidity; the daily average concentrations of NO2, PM2.5, PM10 and CO were negatively correlated with wind speed, while O3 was positively correlated with wind speed.

Analysis of transmission spatio-temporal pattern of atmospheric heavy pollution events based on spatiotemporal data mining
TU Xingyue, SHAO Shegang, ZHANG Xiaotian, WANG Wei, SUN Caiping, WANG Biao, KANG Yulin
2023, 13(3): 940-948. doi: 10.12153/j.issn.1674-991X.20220696
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In order to explore the spatiotemporal pattern of regional air pollution transmission and diffusion and to support the regional joint prevention and emergency control of atmospheric environment pollution, a new spatiotemporal data mining approach was proposed based on air-quality ground observation data. The algorithms were built to identify the regional transmission paths and intensity of heavily polluted air masses. The case study on PM2.5 heavy pollution events in Beijing-Tianjin-Hebei region during January-March and October-December, 2021 was conducted to verify the algorithms. The results showed that there were 17 regional heavy pollution events during this period in Beijing-Tianjin-Hebei region. There were 3, 7, and 7 long (>48 h), medium-long (24-48 h), and short (<24 h) pollution events, respectively. All long pollution events occurred in spring. Their pollution intensity was the highest among the three event types, and the polluted area and pollution transmission area covered the entire study area. The medium-long and short pollution events occurred in spring and winter. Their pollution intensity was lower than that of long events. Medium-long events' polluted area coverage (>80%) was higher than that of short events (<63%). There were seasonal differences in the area covered by pollution transmission for medium-long pollution events. In terms of the transportation intensity coefficient of heavy pollution transmission in Beijing-Tianjin-Hebei region generally conformed to the law that local pollution intensity coefficient (0.32-1.00) was the highest, followed by intra-city pollution transmission (0.01-0.95), and inter-city pollution (0.00-0.28). Among them, the inter-city transmission intensity of Xingtai was greater than its intra-city transmission, and the impact of Hengshui on surrounding cities was lower than the average level.

A rapid detection method for gasoline detergency and the regulatory scheme
JIA Ming, ZHANG Rongshuo, PANG Yujie, LIU Jia, LIU Mingyu, WANG Bowen, WANG Mingyu, MA Yao, ZHU Rencheng, BAO Xiaofeng
2023, 13(3): 949-954. doi: 10.12153/j.issn.1674-991X.20220527
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The detergency of vehicle gasoline is closely related to vehicle exhaust emissions and fuel economy. In order to improve the detection efficiency of gasoline detergency and enhance the supervision ability of relevant functional departments, an on-board multi-channel rapid simulation detection (MCRSD) method of gasoline detergency was proposed. Compared with the rapid simulation detection (RSD) method of gasoline engine inlet valve deposits recommended by the regulations, the total test time for a single sample of the MCRSD method decreased by 77.8%, and the total test time for multiple samples of the method decreased by 94.4%, with 80% reduction in fuel consumption and 90% reduction in cost. The MCRSD method had a good correlation with the RSD method (Pearson correlation coefficient was 0.4-0.8), and could be used for the rapid detection of gasoline detergency. Finally, the on-site supervision and testing scheme of gasoline detergency was proposed.

Evaluation method of gasoline particulate filter regeneration interval mileage in a low-temperature environment
FU Yumin, QIAN Liyun, XU Chuang
2023, 13(3): 955-964. doi: 10.12153/j.issn.1674-991X.20220654
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The gasoline particulate filter (GPF) regeneration interval mileage in a low-temperature environment was studied based on a temperature correction method for GPF soot load estimation.The GPF soot regeneration action rate was measured by the engine dyno test, and the activation energy of the regeneration reaction was obtained by the logarithm method and the line fitting method. It was shown that the activation energy of oxygen and soot was 81.6-91.4 kJ/mol, and that of carbon dioxide and soot was 159.2-218.9 kJ/mol. The activation energy was then used to calculate the correction coefficients for the soot regeneration action rate in variant environment temperatures. The accumulated velocity of the soots in the cold start stage of the test vehicle was measured, and the correction coefficients for soot emission in a low-temperature environment were acquired. Based on the type I test of CHINA 6 for light-duty vehicle emission, GPF active regeneration interval mileage in a low-temperature environment was simulated by applying the temperature correction coefficient of soot emissions and regeneration rate. Compared with GPF soot accumulation data from test vehicles driving on road in cold region, the simulation result had enough precision to predict GPF soot load accumulation rate for vehicle usage under different working conditions in cold region. Both the simulation and test results indicated that GPF soot accumulation rate was easily affected by low temperature when the vehicle running at low speed.

Numerical simulation study on flow field optimization of electrostatic precipitator inlet flue duct in coal-fired units
MA Xiuyuan, SUN Zunqiang
2023, 13(3): 965-972. doi: 10.12153/j.issn.1674-991X.20220019
Abstract(297) HTML (185) PDF(3703KB)(23)

Resistance increase of connecting flue ducts between environmental protection facilities is one of the main factors influencing fan energy consumption increase in coal-fired units. Accordingly, it is an effective method of saving energy and reducing consumption to optimize the flow field of flue ducts and to reduce resistance and fan energy consumption in coal-fired power plants. CFD numerical simulation was applied to optimize the inlet flue duct of the electrostatic precipitator in a 660 MW coal-fired unit. The varying rules of flue duct resistance, fan energy consumption, ash mass flow distribution, ash concentration and guiding plates wearing rate were studied with a comparative analysis of five different schemes. The results showed that the flue duct resistance was reduced by 28.7% through setting reasonable structural form and quantity of guiding plates. A maximum fan energy consumption of 190 kW·h could be saved for a single unit, and the energy saving and consumption reduction were remarkable. The addition of guiding plates could regulate the distribution ratio of ash mass flow in the flue gas. After optimization, the deviation of ash mass flow distribution ratio reduced from 14.8% to 6.6% on sides A and B, which improved the comprehensive removal efficiency of dust particles by electrostatic precipitator. The optimization of the flue flow field not only improved the uniformity of ash concentration field distribution, but also reduced the wearing rate of guiding plates. After optimization, the average wearing rate of guiding plates decreased from 1.33×10−7 to 0.56×10−7 kg/(m2·s), with a decrease of 57.6%. The service life of guiding plates was 2.4 times that before optimization, and the safety and reliability of the unit operation improved.

Investigation on migrations and fates of arsenic, selenium and lead in ultra-low emission coal-fired power plants based on field measurement
CHEN Xiameng, WANG Huasheng, CAO Yuanming, DENG Shuang, ZHANG Chen, LONG Hongyan, GUO Fengyan
2023, 13(3): 973-981. doi: 10.12153/j.issn.1674-991X.20230076
Abstract(178) HTML (69) PDF(2500KB)(18)

Extensive field tests were performed in ultra-low emission coal-fired power plants (ULE CFPPs), respectively installed with pulverized coal (PC) and circulating fluidized bed (CFB) boilers to investigate the migrations and fates of heavy metals such as arsenic (As), selenium (Se), and lead (Pb). Flue gas was simultaneously sampled at the inlet and outlet of each air pollution control devices (APCDs) and subsequently analyzed. Meanwhile, the samples of feed coal, fly ash, bottom ash, low-temperature economizer (LTE) ash, wet flue gas desulfurization (WFGD) slurry, and wet electrostatic precipitator (WESP) wastewater were collected for analyses. The results showed that the total synergistic removal efficiencies for As, Se, and Pb by APCDs in the two selected ULE CFPPs were all higher than 96%. The concentrations of pollutants in the clean flue gas were low, with As, Se, and Pb being 0.13-0.49, 1.05-2.15 and 0.86-3.19 μg/m3, respectively. Significant discrepancies were found in APCDs performance for heavy metal removal. The removal efficiency of fabric filter (FF) for As, Se, and Pb was the highest (99.56%-99.74%), followed by electrostatic precipitator (ESP) (85.61%-98.44%), while WFGD had a large fluctuation in the removal efficiency. WESP efficiency varied in the range of 11.61%-55.08%. The majority of As, Se, and Pb (74.38%-95.24%) were found in fly ash for the tested power plants. 3.51%-24.08% of these heavy metals remained in the bottom ash for CFB boiler. For PC boiler, 5.85%-12.11% of the metals were in LTE ash. They were below 6% in WFGD slurry. Around 0.68% and 0.62% of the metals were found in WESP drainage and outlet flue gas. More As and Pb were enriched in the bottom ash for CFB boiler in comparison with PC boiler. In terms of Se, no obvious effect of combustion modes was observed since it had relatively higher volatility. Its proportion in the clean flue gas was much higher than As and Pb for the two tested power plants.

Characteristics of water quality change during the 13th Five-Year Plan period and trend prediction during the 14th Five-Year Plan period in three major basins of Hainan Island
FU Shiyu, WANG Lina, LÜ Fengchun, CHEN Biaojuan, XU Shiqin, GUO Xin
2023, 13(3): 982-991. doi: 10.12153/j.issn.1674-991X.20220618
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Based on the monitoring data of Hainan Province surface water environment quality network, the water quality, concentration of major pollutants, variation of composite pollution index in three major basins of Nandu River, Changhua River, Wanquan River in Hainan Island during the 13th Five-Year Plan period were analyzed, and Spearman rank correlation coefficient was used to research and judge the pollution changecharacteristic, and the mean GM(1,1) model (EGM) was used to predict the trend of water quality change during the 14th Five-Year Plan period for servicing the water ecological environment protection of Hainan Free Trade Port. The results showed that the water quality of three major basins in Hainan Island was getting better steadily during the 13th Five-Year Plan period. The proportion of Grade Ⅰ-Ⅲ water quality of Environmental Quality Standards for Surface Water (GB 3838-2002) in Nandu River basin and Wanquan River basin increased to 96.3% and 100%, respectively. The proportion of Grade Ⅰ-Ⅲ water quality in Changhua River basin remained at 100%. The average annual concentrations of permanganate index, chemical oxygen demand, ammonia nitrogen and total phosphorus were all at a low level, which were lower than the standard limits of Grade Ⅱ, and the average annual concentration of chemical oxygen demand was lower than the standard limits of Grade Ⅰ. The average annual concentration of ammonia nitrogen was decreased during the 13th Five-Year Plan period. The average annual concentrations of permanganate index, chemical oxygen demand and total phosphorus were increased or fluctuated during the 13th Five-Year Plan period, with an increase range of 6.7% to 23.8%. The composite pollution index of the mainstream declined with a range of 0.03 to 0.04. The composite pollution index of the main tributaries increased with fluctuations from upstream to downstream. EGM predicted that during 14th Five-year Plan period, the comprehensive pollution index of the mainstreams of three major basins and most of the tributaries showed an upward trend, with a maximum increase of 108.3%. The water environment of three major basins in Hainan Island would face high pressure, and especially the pollution load from the tributaries should not be neglected. According to the prediction results, in order to improve the water quality of the three major basins, it was necessary to implement measures such as “Governance of Six Waters” and “One River One Policy” in a systematic protection approach during the 14th Five-Year Plan.

Groundwater quality characteristics and pollution causes in typical hilly areas of North China: the case of Longan District, Anyang City, Henan Province
HAN Xuemeng, CAI Wenqian, WANG Junqiang, LI Huiying, XU Xiangqin, TIAN Shengyan
2023, 13(3): 992-1000. doi: 10.12153/j.issn.1674-991X.20220624
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In order to ascertain the groundwater quality in Longan District, Anyang City, a typical hilly area in North China, the data of 24 water quality indicators from 127 monitored well samples were obtained, and the groundwater quality characteristics and pollution causes were analyzed. On the basis of hydrochemical statistics and water quality evaluation, the inverse distance weighting (IDW) spatial interpolation method was used to analyze the spatial distribution of different pollutants, and the principal component analysis was used to identify pollution sources. The results showed that HCO3-Ca type was the typical chemical type of shallow groundwater in Longan District. The NO3 concentration at 93.0% of samples exceeded the class Ⅲ standard defined in Standard for Groundwater Quantity (GB/T 14848-2017), whose maximum exceeding multiples was 47.1. The single factor evaluation showed that the NO3 pollution index of groundwater monitoring well samples in Longan District reached a maximum value of 48.10, among which 27% were heavy pollution level, and 19% were serious to extremely heavy pollution levels. The concentration of SO4 2− reached moderate pollution level, while Cl, NH4 +, and F reached mild pollution level. Nemero comprehensive evaluation results showed that the comprehensive groundwater pollution index was between 0.01 and 34.69, and the groundwater quality was generally at good condition. Among them, 4% of the monitored well samples were at extremely poor pollution level, which were mainly distributed in the middle of Longan District. The highest concentrations of NO3 , NH4 +, SO4 2−, Cl were mainly located in the middle, presenting the spatial distribution characteristics of higher concentration in the middle than that in the east and west. The concentration of F was higher in the east and lower in the west, and the highest was mainly distributed in the groundwater retention area. Source analysis showed that the groundwater quality was mainly affected by regional geohydrologic conditions, groundwater geochemical characteristics, and agricultural non-point source pollution.

Hydrodynamic water quality characteristics and driving mechanism in Hengshui Lake
FAN Zhenyu, LIU Zhenjie, BAI Jing, XIE Pei, SUN Ning, QIAO Fei, ZHANG Bingye, HUANG Faming
2023, 13(3): 1001-1010. doi: 10.12153/j.issn.1674-991X.20221145
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In order to explore the characteristics of the hydrodynamic water quality of Hengshui Lake, a two-dimensional hydrodynamic water quality model of Hengshui Lake was built based on the Environmental Fluid Dynamics Code (EFDC) model on the basis of field investigation. The model was calibrated and validated using observation data such as water level, temperature, and water quality from 2018 and 2019, respectively, to better reflect the hydrodynamic and water quality conditions of Hengshui Lake. The characteristics of the hydrodynamic and water quality changes in space and time of Hengshui Lake were simulated, and the driving mechanism of the hydrodynamic water quality evolution of the lake was analyzed. The results showed that the hydrodynamic force of Hengshui Lake was weak, and water replenishment was an important way to improve the hydrodynamic force, which had a promoting effect on maintaining the ecological water level of the lake and improving the water exchange capacity. The large amount of nutrients brought in by water replenishment had a significant impact on the water quality of the lake area. The water quality indicators at various stations fluctuated greatly during the water replenishment period, with Wangkou Gate and Xiaohuxin stations being greatly affected. In the case of poor inflow water quality, water replenishment could easily aggravate lake water pollution, and control of inflow water quality could not be ignored.

Source analysis of heavy metal lead in Luoma Lake sediments based on Pb stable isotopes
ZHANG Jiagen, XIA Jiandong, CHEN Shuqin, WU Yusheng, PANG Yan, HUANG Tianyin
2023, 13(3): 1011-1020. doi: 10.12153/j.issn.1674-991X.20220454
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As an important storage lake and water source of the east route of South-to-North Water Transfer Project, Luoma Lake's water environment safety has a far-reaching impact on northern Jiangsu and even the east route of South-to-North Water Transfer Project. By analyzing the Pb content and Pb isotopic composition of the surface sediments of Luoma Lake and rivers into the lake, and the soil of potential pollution sources in the surrounding areas, the spatial distribution of lead was evaluated. The ecological risk assessment of heavy metal Pb was carried out by using the enrichment coefficient method, and the binary linear mixed model was applied to analyze the polluting sources and calculate the relative contribution rate of each source. The results showed that the content of Pb in surface sediments of Luoma Lake ranged from 8.09 to 27.97 mg/kg, with an average of 20.94 mg/kg, and Pb in surface sediments of Luoma Lake showed a clean-slight pollution level. Spatial analysis showed that Pb pollution of surface sediments in Luoma Lake was mainly concentrated in the eastern and northern lakes. The values of 206Pb/207Pb and 208Pb/(206Pb+207Pb) (the ratios of abundance) in the surface sediments of Luoma Lake were 1.170-1.249 and 1.125-1.131, respectively, and the Pb pollution mainly came from the Laoyi River and the direct discharge of agricultural pollution from fishery farming. The relative contribution rate of agricultural sources was 46.71%. In order to prevent and control the pollution risk of Pb in Luoma Lake water environment, it was necessary to strengthen the standardized management of fishery culture and the pollution control of rivers entering the lake.

Distribution characteristics, source analysis and risk assessment of heavy metals in sediments of Wanghu Lake of Hubei Province
ZHAO Xianlin, DUAN Lei, ZHOU Jianli, LIU Xiaowei, LU Wenzhou, QIU Jinrong, KE Hua, ZHENG Hesong
2023, 13(3): 1021-1030. doi: 10.12153/j.issn.1674-991X.20220729
Abstract(174) HTML (91) PDF(4984KB)(16)

To reveal the characteristics of heavy metal pollution in the sediments of Wanghu Lake in Hubei Province, the methods of spatial interpolation, principal component analysis, and geo-accumulation index were used to investigate the pollution features, source identification, and ecological risk status of heavy metal pollution. The results showed that the average concentration of five heavy metals decreased in the order of Zn>Cr>Cu>Pb>Cd, and all of them exceeded Hubei soil background values. Pearson correlation analysis revealed a positive correlation (P<0.05) between Zn and Cd, Zn and Pb, and a negative correlation (P<0.05) between Cu and Zn, Cu and Cr. Principal component analysis revealed that principal component 1 was consisted of Pb, Cd, and Zn, which were primarily influenced by river transportation and agricultural activities; principal component 2 was consisted of Cr and Cu, which were mainly affected by natural background such as mineral weathering and pollution from human activities such as industrial activities and aquaculture. The geo-accumulation index results suggested that heavy metals in Wanghu Lake were in a low risk condition, although Cd and Cu reached moderate pollution and were the major pollutants that should be monitored.

Speciation and pollution evaluation of arsenic in the surface sediment of Nansi Lake
LIU Haozhi, ZHANG Ju, JIA Runna, ZHANG Jiankang, WU Jinjia, DENG Huanguang
2023, 13(3): 1031-1038. doi: 10.12153/j.issn.1674-991X.20220501
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In order to study the occurrence and distribution characteristics of arsenic (As) and its pollution status in the surface sediments of Nansi Lake, the total content and speciation of As in 59 surface sediment samples were analyzed by aqua regia digestion-atomic fluorescence spectrometry and modified Tessier sequential extraction methods, respectively. Also, its pollution and ecological risk were evaluated by the methods of the ratio of secondary phase to primary phase (RSP) and risk assessment code (RAC). The results showed that the total arsenic (TAs) content in the surface sediments of Nansi Lake ranged from 8.81 to 25.14 mg/kg, with an average value of (18.06±5.26)mg/kg, which was higher than the soil background value of Shandong Province as well as the sediment background value of the mainstream of the Yellow River. The average content of As in each form was in the order of residual fraction (17.30 mg/kg) > humic acid - bound fraction (0.31 mg/kg) > Fe-Mn oxidation fraction (0.30 mg/kg) > ion exchange fraction (0.05 mg/kg) = water-soluble fraction (0.05 mg/kg) > carbonate-bound fraction (0.04 mg/kg) > strong organic-bound fraction (0.004 mg/kg). As in the sediments of Nansi Lake was mainly in residue fraction, and the extractable As only accounted for about 4.46% of the total As. The assessment results of RSP suggested that As in the surface sediments of Nansi Lake was all at a clean level, while the results of RAC showed that the sediments of Nansi Lake had no ecological risk in general, but sediments in about 28.8% of the sampling sites showed mild ecological risk.

Spatiotemporal distribution characteristics and ecological risk assessment of nitrogen, phosphorus and heavy metals in the surface sediments of Qianwu Reservoir
WANG Enrui, YANG Guang, CHANG Sheng, ZHANG Kunfeng, FAN Yueting, WANG Shanjun, FU Qing
2023, 13(3): 1039-1049. doi: 10.12153/j.issn.1674-991X.20220636
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To understand the environmental quality of the surface sediments of Qianwu Reservoir in wet and dry seasons (August and October) of 2019, nitrogen and phosphorus contents and 8 heavy metals were monitored at 6 sampling points in the reservoir area, and the ecological risk assessment and traceability analysis were carried out by using the comprehensive pollution index method, the geo cumulative index method and the potential ecological risk index method. The results showed that the average values of TN and TP contents in the surface sediments of Qianwu Reservoir in wet and dry seasons were 2 010 and 433, 1 873 and 308 mg/kg, respectively. It presented the temporal and spatial distribution characteristics of high in the middle and low in the north and south ends. The comprehensive pollution index evaluation results showed that the overall TN of Qianwu Reservoir was heavily polluted, and TP was mildly polluted. The average contents of Hg, As, Cr, Mn, Ni, Cu, Zn, and Pb in the surface sediments of Qianwu Reservoir were 0.22, 10.64, 30.97, 293.25, 17.51, 21.01, 102.65, and 55.32 mg/kg, respectively. In terms of temporal and spatial distribution, except for Mn and Zn, the pollution of other heavy metals was heavier in wet seasons than in dry seasons. Affected by the topography of the reservoir and seasonal water transfer, except for Mn and Pb, the concentration levels of other heavy metals showed that the area from the head to the middle of the reservoir (points Q3 and Q4) during the wet season, and the area from the middle to the tail of the reservoir (Q2 and Q3) was high during the dry season. The evaluation results of the geoaccumulation index method and the potential ecological risk index method both showed that Hg was the main ecological risk contributing factor, with a contribution rate of 75.8%. The overall potential ecological risk level of the reservoir area was medium risk.

Variation characteristics and source analysis of dissolved organic matter along the river into Baiyangdian Lake
YUE Longfei, LI Hongbo, LIANG Shuxuan, LI Ping, JIANG Tiantian, LIU Jing, ZHAO Jianguo
2023, 13(3): 1050-1060. doi: 10.12153/j.issn.1674-991X.20220425
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The spectral characteristics of chromophoric dissolved organic matter (CDOM) in three inflow rivers of Baiyangdian Lake (Fu River, Xiaoyi River and Baigouyin River) were analyzed by UV-vis absorption spectroscopy, three-dimensional fluorescence spectroscopy, parallel factor analysis and principal component analysis, and the composition, sources and the influence mechanism of CDOM on water quality were explained. The results showed that the order of CDOM average concentration was Fu River>Xiaoyi River>Baigouyin River. The aromaticity and molecular weight of CDOM in the Fu River were higher than those in other rivers, the degree of humification in the Baigouyin River was higher than those in other rivers, and the proportion of endogenous substances in CDOM in the Xiaoyi River was higher than those in other rivers. Humic-like components C1, C2, C3 and protein-like components C4 were detected in the three rivers, among which C1, C2 and C3 were similar in origin and different from C4. The variation of maximum fluorescence intensity and total fluorescence intensity of each component in the three rivers showed that CDOM of the Fu River was from point and non-point mixed sources, CDOM of the Xiaoyi River was mainly from point sources, and CDOM of the Baigouyin River diversion was contained by the water source itself.

Prediction of the impact of benzo(a)pyrene on shallow groundwater during natural infiltration of reclaimed water-receiving rivers
REN Jie, MA Weifang
2023, 13(3): 1061-1069. doi: 10.12153/j.issn.1674-991X.20220832
Abstract(213) HTML (135) PDF(4367KB)(11)

To predict the influence of reclaimed water-receiving rivers on groundwater quality, the spatiotemporal distribution and migration evolution prediction of benzo(a)pyrene [B(a)P] was conducted by investigating and monitoring its levels in the Liangshui River, which received reclaimed water, with Hydrus-1D coupled GMS model. The research results were as follows: The vertical infiltration rate of B(a)P in the vadose zone was 0.102 m−1, which was only 0.73% that of water migration. B(a)P penetrated the 16 m depth vadose zone for 63 years owing to the attenuation function of adsorption and biodegradation, with contribution ratios of 78.4% and 19.3%, respectively. When B(a)P intersected with groundwater, driven by groundwater flow, the migration of B(a)P was mainly in the direction of groundwater flow. The migration rate of B(a)P in groundwater along the direction of groundwater flow was 6.65 m/a, which was 2.42 times and 16.22 times of the diffusion rate in the vertical groundwater flow direction and vertical downward direction, respectively. The spatiotemporal distribution indicated that B(a)P concentration decreased with the crow-fly distance from the river with attenuation rate constants of 1.19×10−4, 3.05×10−4, and 3.67×10−3 m−1 in parallel groundwater flow direction, vertical groundwater flow direction and vertical downward direction, respectively, which were negatively correlated with migration rate. However, B(a)P content increased over the extension of infiltration time with an accumulation rate of 7.3×10−2 d−1. The migration and accumulation of B(a)P induced potential harm to coastal residents taking groundwater as drinking water, which would result in the groundwater safety utilization range decreasing from 438, 276, and 19.8 m to 568, 324, and 27.7 m far from the river in parallel groundwater flow direction, vertical groundwater flow direction and vertical downward direction, respectively, 20 years later.

Applicability of different water quality evaluation methods in river-connected lakes: a case study of Dongting Lake
YIN Xueyan, YAN Guanghan, WANG Xing, HUANG Daizhong, LI Liqiang
2023, 13(3): 1070-1078. doi: 10.12153/j.issn.1674-991X.20220397
Abstract(158) HTML (55) PDF(2071KB)(22)

The operation of the Three Gorges Project has significantly changed the relationship between the river-connected lakes and the Yangtze River, thus affecting the water environment of the river-connected lakes. It was particularly important to effectively evaluate the water quality of Dongting Lake, the largest river-connected Lake in the Yangtze River basin. In 2019, monthly monitoring data were collected at 15 sampling sites in Dongting Lake, including nine water quality factors. The single factor index method, principal components analysis (PCA) method, Nemero pollution index method and Shannon-Weaver biodiversity index method were used to evaluate the water quality of Dongting Lake. The single factor index method could quickly and accurately evaluate water quality categories, and the Nemerow pollution index method was simple to calculate and widely used in water quality evaluation. However, the two methods could not accurately give the difference of pollution degree between different sampling points, and the Shannon-Weaver diversity index evaluation results were not consistent with the actual situation of some sampling points. To comprehensively consider the applicability and accuracy of different evaluation methods, it was recommended to use the PCA method to carry out Dongting Lake water quality evaluation. PCA method could not only reflect the main pollution index and its contribution rate, but also rank the pollution degree of different regional water bodies, and the evaluation results were objective and practical, so it was more suitable for the water quality evaluation of Dongting Lake region. However, in the daily work of water quality evaluation management, it was suggested that the single factor index method should be combined to determine the water quality categories, so as to ensure the effectiveness of management.

Differential responses of five wetland plants and their root microbial communities under ofloxacin pollution stress
QIN Yuchun, ZOU Tao, ZHANG Xuan, WANG Yongqiang, GUO Xiaochun, LIU Xiaohui, LU Shaoyong
2023, 13(3): 1079-1087. doi: 10.12153/j.issn.1674-991X.20220380
Abstract(188) HTML (89) PDF(3490KB)(22)

The plants and their root microorganisms in the constructed wetland have a good removal effect on the antibiotics in the environment, but the understanding of the response characteristics of various plants and microorganisms under antibiotic stress is still insufficient and unclear, so it is necessary to clearly study the differential response characteristics of plants and microorganisms under different concentrations of antibiotic stress. The removal performance of ofloxacin (OFL) by five wetland plants (Gladiolus hybrids, Cyperus alternifolius, Scirpus validus Vahl, Oenanthe javanica, Juncus effusus L.) microbial systems under the stress of OFL, a typical polar antibiotic, was studied. Based on the removal efficiency of OFL by different plants, the root activity, active oxygen and antioxidant system of Gladiolus hybrids and Cyperus alternifolius were studied, and the response characteristics of their root microorganisms under OFL stress were analyzed. The results showed that the five wetland plants had significant differences in the removal of OFL, among which the Cyperus alternifolius had the best removal performance of OFL, followed by Gladiolus hybrids. The plant-microbial systems showed different sensitivities under OFL stress of different concentrations. Taking 10 mg/L as the turning point, when OFL concentration was below 10 mg/L, it could promote plant root growth, plant root activity and root antioxidant enzyme activity. When OFL concentration exceeded 10 mg/L, Gladiolus hybrids and Cyperus alternifolius roots were poisoned by OFL, and plant root activity and antioxidant enzyme activity were inhibited. The measurement results of root microbial community using high-throughput sequencing technology showed that low concentration OFL (1 mg/L) was positively correlated with plant root microbial community diversity and species richness, while high concentration OFL (50 mg/L) was negatively correlated. Using PICRUSt function software to predict the function of microbial community, it was found that high concentration OFL stress could accelerate the metabolic rate of plant root microorganisms.

Inhibition and removal characteristics of trichloroethylene on anaerobic hydrolysis acidifying bacteria
SONG Yupei, MA Yushi, ZHANG Chaozhi, SHEN Zhiqiang, ZHOU Yuexi
2023, 13(3): 1088-1096. doi: 10.12153/j.issn.1674-991X.20220650
Abstract(180) HTML (72) PDF(1964KB)(9)

Trichloroethylene (TCE) is a typical organic pollutant in petrochemical wastewater, which is highly toxic to microorganisms. Batch bioassays of volatile fatty acid were carried out to explore the inhibitory effect of TCE on acid production of anaerobic hydrolysis acidifying bacteria, the variation of extracellular polymeric substances (EPS) and mud zeta potential of hydrolysis acidifying bacteria under TCE shock, and the removal characteristics of TCE. The results showed that TCE at a concentration of 75 mg/L (semi-inhibitory concentration, EC50) had an inhibitory effect on the acid production of hydrolysis acidifying bacteria. With the increase of TCE concentration, the protein concentration in EPS of hydrolsis acidifying bacteria first increased and then decreased. The maximum value of protein concentration in EPS was (33.94±0.25)mg/L when TCE concentration was 50 mg/L. The results of zeta potential showed that the coagulation performance of sludge increased with the increase of TCE concentration (0-100 mg/L). The dechlorination ability of anaerobic hydrolysis acidifying bacteria to TCE decreased with the increase of TCE concentration, and the dechlorination rate of TCE converted by hydrolysis acidifying bacteria was 77.83% when the concentration of TCE was 10 mg/L. It decreased to 6.67% at 200 mg/L. TCE had a strong inhibitory effect on hydrolysis acidifying bacteria. TCE mainly inhibited microbial activity by inhibiting the protein synthesis of cells, thereby limiting the ability of hydrolysis acidifying bacteria to degrade TCE.

Water quality analysis and groundwater health risk assessment of acid mine inflow from abandoned coal mines around Guangyuan City
ZHU Mingtan, LI Bo, LIU Guo
2023, 13(3): 1097-1107. doi: 10.12153/j.issn.1674-991X.20220622
Abstract(240) HTML (98) PDF(5311KB)(38)

The abandoned coal mines around Guangyuan City were taken as the study area to reveal the impact of acid mine wastewater on the water quality composition of its surrounding groundwater and surface water, as well as the potential hazard of metal element in the groundwater to human health, The conventional index and metal elements in 23 groundwater samples and 39 surface water samples in the target region were determined and analyzed. The environmental quality of groundwater and surface water in the study area was analyzed on the basis of the Nemero comprehensive index method and the pollution index method, and the health risk assessment model was applied to evaluate the health risk of groundwater in the study area. The research showed that the groundwater within the study area contained a high level of total dissolved solids (TDS), SO4 2−, Ca2+ and Mg2+ with the highest average mass concentration of TDS and SO4 2−, which exceeded Class Ⅲ limits in Environmental Quality Standards for Surface Water (GB 3838-2002). In addition, high levels of TDS, SO4 2−, Ca2+ and Mg2+ caused poor groundwater quality. Among the above elements, SO4 2−and TDS had the highest average mass concentrations. The average concentrations of heavy metals in the studied groundwater were in the following order: TFe (sum of Fe2+and Fe3+) > Al3+>Pb2+>Zn2+>Mn2+>Cu2+>TCr (sum of Cr3+ and Cr6+)>Cd2+>As>Hg, with nine heavy metals exceeding Class Ⅲ limits in Standard for Groundwater Quality (GB/T 14848-2017). According to the results, the eastern region had more metal element in its groundwater than the west; and the groundwater quality in Wangcang County was the most seriously polluted by heavy metals. According to the Nemero index evaluation, most surface water evaluation results were good or excellent, and a few were poor or very poor. This was in good agreement with the pollution index evaluation results, which indicated that the pollution was mainly caused by the discharge of mine water inflow. According to the health risk evaluation results, the groundwater in the study area had a high health risk. The main carcinogenic elements were As, Cd and Cr. The carcinogenic risk of these three elements was all above the maximum risk limit of 10−4. Meanwhile, the total non-carcinogenic risk of the groundwater exceeded 1 (the acceptable health risk limit), indicating a serious risk of non-carcinogenic disease. The potential non-carcinogenic risk from oral exposure to groundwater in the survey area exceeded that of skin exposure, and the adults bore higher potential non-carcinogenic risk than minors. The results of this study indicated that the quality of groundwater within the study area posed a great threat to people’s health, and the groundwater in the study area was not suitable for drinking. As for the future use of the water bodies, more significance should be attached to the prevention and control of risk from the heavy metals Al, Pb, Zn and Fe.

Adsorption effect and mechanism of sulfamethoxazole and trimethoprim on corncob
ZHANG Yanjie, DONG Weiyang, WANG Huan, YAN Guokai, CHANG Yang, WANG Haiyan, LING Yu
2023, 13(3): 1108-1117. doi: 10.12153/j.issn.1674-991X.20220375
Abstract(199) HTML (69) PDF(2611KB)(17)

To explore whether agricultural wastes can adsorb antibiotics and whether there is an interaction between different antibiotics, the physicochemical characteristics analysis of corncob, Fourier Infrared Spectroscopy analysis, adsorption kinetics, and adsorption isotherms analysis were used to study the adsorption effect and mechanism of sulfamethoxazole (SMX) and trimethoprim (TMP) on corncob. The results showed that SMX and TMP adsorption capacities on corncob were 131.18 and 358.75 mg/kg in the system with single antibiotic (the initial concentration was 10 mg/L) at 25 ℃ and corncob concentration of 25 g/L , and they were 131.02 and 358.74 mg/kg in the coexistence system with both SMX and TMP(the initial concentration both were 10 mg/L), respectively. There was non-interactive adsorption between SMX and TMP in the coexistence system. The adsorption kinetics of SMX and TMP were better represented by the pseudo-second-order kinetic model in the two systems. Both Langmuir and Freundlich isotherms were well fitted with the SMX adsorption process, and the adsorption of TMP was described well by the Freundlich isotherm. SMX was mainly adsorbed by electrostatic interaction and π-π stacking mechanism, and the electrostatic interaction played the main role. The adsorption of TMP was mainly due to the hydrophobic distribution, π-π stacking, and hydrogen bonding.

Influence mechanism of amide-based amphoteric molecules on uranium adsorption capacity of WS2
ZHAO Jiayin, LIU Yuhui, WANG Ziming, TANG Meng, LU Yaning, ZHANG Shuang, WANG Yingcai, LIU Yunhai, DENG Sheng
2023, 13(3): 1118-1126. doi: 10.12153/j.issn.1674-991X.20220498
Abstract(242) HTML (101) PDF(3315KB)(10)

The recovery of uranium from uranium-containing wastewater is mainly based on the complexation between the material and UO2 2+ in [UO2(H2O)5]2+, but the electric dipole moment of H2O has a significant weakening effect on the complexation. The amide-based amphoteric molecule N,N-dimethyl-9-decenyl amide (NADA) was used for hydrogen bonding with [UO2(H2O)5]2+ to form UO2[(H2O)xC12H23NO]n * (x<5, UO2-Coordination Compound was named UO2-CC) ,Inert tungsten disulfide (WS2) was selected as the adsorption material, and the adsorption capacities of UO2 2+ and UO2-CC were studied by static adsorption experiments (different pH, contact time, concentration and temperature). The kinetic fitting results showed that the adsorption reaction was a chemisorption process. After NADA reconstruction, the adsorption time of UO2 2+ was shortened from 240 min to 180 min, and the quasi-second-order kinetic adsorption constant was increased by 1.35 times. The results of the isothermal adsorption study showed that the complexation process of WS2 and UO2-CC conformed to the Langmuir adsorption isothermal model, and the addition of NADA made the adsorption change from spontaneous endothermic process to spontaneous exothermic process, and the order degree of the adsorption reaction process increased. After in situ reconstruction of [UO2(H2O)5]2+ by NADA, the equilibrium adsorption capacity of UO2 2+ by WS2 increased from 45.03 mg/g (WS2/UO2 2+ system) to 122.14 mg/g (WS2/UO2-CC system). Spectroscopic analysis by X-ray photoelectron spectroscopy was used to deeply study the adsorption mechanism of NADA on WS2 after in situ reconstruction of [UO2(H2O)5]2+ at the molecular level, and to reveal the contribution of various forces (electrostatic, hydrogen bond and U-S covalent bond) to adsorption, especially the hydrogen bond of NADA.

Research progress in the application and degradation mechanism of perfluorooctanoic acid photocatalytic materials
WEI Jian, XU Xiaoyue, GUO Zhuang, DUAN Lijie, SONG Yonghui
2023, 13(3): 1127-1138. doi: 10.12153/j.issn.1674-991X.20220573
Abstract(485) HTML (132) PDF(1415KB)(78)

Perfluorooctanoic acid (PFOA) is a typical perfluorinated compound widely existing in the environment. It is highly toxic and difficult to degrade, which seriously threatens eco-environmental safety and human genetic, immune, neurological and reproductive health. Hence, considerable attention has been drawn to its environmental hazard and risk prevention and control. With mild conditions, high treatment efficiency, low application cost, free secondary pollution and other advantages, photocatalytic technology has a broad application prospect in the field of PFOA degradation. In order to develop new photocatalytic materials with strong activity, good visible light absorption performance, and high stability, and achieve efficient degradation of PFOA in water, research progress in the preparation of photocatalytic degradation materials of PFOA in the past twenty years was systematically reviewed. The degradation characteristics and existing problems of different photocatalytic degradation materials were comprehensively analyzed. The reaction mechanism and activity enhancement mechanism of photocatalytic degradation materials were summarized, combined with the existing materials of photocatalytic degradation of PFOA, and eventually the photocatalytic degradation pathway of PFOA was clarified.

Removal efficiency of 2,4-dichlorophenol by persulfate activated with ball-milling vanadium-titanium magnetite tailings
XIA Fu, XU Xiangjian, LU Hongli, GAO Puchuang, HAN Xu, XIAO Han, WANG Xingang, YANG Yu, JIANG Yonghai
2023, 13(3): 1139-1149. doi: 10.12153/j.issn.1674-991X.20220407
Abstract(164) HTML (102) PDF(5667KB)(29)

The removal feasibility of 2,4-dichlorophenol (2,4-DCP) in groundwater by persulfate (PS) activated with ball-milling vanadium-titanium magnetite tailings (B-VTMT) was investigated. The morphology and composition of B-VTMT were analyzed by scanning electron microscope, X-ray diffraction, and X-ray photoelectron spectroscopy. The effects of B-VTMT dosages, initial PS concentrations, initial pH, initial 2,4-DCP concentrations, and common anions in groundwater (Cl, NO3 , and SO4 2–) on 2,4-DCP removal efficiency were explored. The experiment results indicated that: The removal efficiency of 2,4-DCP was 45.4% within 39 h at room temperature under the conditions of B-VTMT dosage of 0.5 g/L, initial PS concentration of 5 mmol/L, initial 2,4-DCP concentration of 20 mg/L and initial pH 7.1. Radical quenching experiments and electron spin-resonance (ESR) spectroscopy confirmed that sulfate radical (SO4 ·) and hydroxyl radical (·OH) were the main free radicals of 2,4-DCP removal. Eight intermediates were identified by high performance liquid chromatography-mass spectrometry (HPLC-MS). The possible degradation pathways of 2,4-DCP were speculated. The presence of chloride ions promoted the 2,4-DCP removal efficiency, while nitrate ions and sulfate ions inhibited the 2,4-DCP removal efficiency. It was concluded that B-VTMT could effectively activate PS to remove 2,4-DCP in groundwater, which was a promising way of tailings resource utilization.

Technical research progress of controlling reverse solute flux and membrane fouling in osmotic microbial fuel cell
DUAN Liang, LI Shilong, XING Fei
2023, 13(3): 1150-1160. doi: 10.12153/j.issn.1674-991X.20220593
Abstract(197) HTML (89) PDF(1229KB)(23)

Forward osmosis microbial fuel cell (OsMFC) uses forward osmosis (FO) membrane to replace the proton exchange membrane in traditional microbial fuel cell (MFC), which can be used to treat the feed solution, i. e. anode sewage, and extract high quality water while recovering the bioelectricity. This technology attracts more and more attention. Compared with traditional MFC, OsMFC has been improved in electricity generation performance and effluent quality. However, the introduction of FO membrane makes the problems of reverse solute flux (RSF) and membrane fouling in OsMFC very prominent, which leads to the reduction of water flux of FO membrane, the degradation of OsMFC's electrical and water production performance, and limits the development and application of OsMFC. With the continuous development of materials and biology in recent years, the above problems can be solved by reasonable technical means. To optimize the performance of OsMFC, this paper focuses on the control of RSF and membrane fouling. It mainly included the inhibition of RSF through the selection of membrane materials, the selection of draw solutions and the electricity generation in OsMFC, as well as the control of membrane fouling by studying the formation mechanism of membrane fouling, the technical regulation of membrane fouling, membrane fouling cleaning, the membrane modification and the screening and cultivation of anode microorganisms. Finally, the technical developments for controlling RSF and membrane fouling in OsMFC in the future were prospected.

Research trend and hot spot analysis of antibiotic pollution in water environment in recent 20 years based on bibliometrics
YAN Yan, YOU Bensheng, LIU Weijing, ZHU Bingqing, CHEN Dongqiang, ZHANG Songhe
2023, 13(3): 1161-1167. doi: 10.12153/j.issn.1674-991X.20220343
Abstract(465) HTML (191) PDF(1223KB)(77)

To find out the present situation and development trend of antibiotic pollution characteristics in the water environment, based on the related literature information on the distribution characteristics of antibiotic pollution in the water environment published in Web of Science (WoS) database from 2000 to 2020, the annually published papers, citation frequency, authors, countries, institutions, journals, and keywords were analyzed by bibliometrics, the research progress in this field in the past 20 years was analyzed, and some suggestions for future development were put forward. The results showed that there were 3 312 papers published in the field of antibiotic pollution characteristics in the water environment from 2000 to 2020. The number of papers published annually showed an increasing trend. The literature covered 108 countries worldwide, and the number of published articles in China was 1 208, accounting for 36.46% of the total. Antibiotic resistanc, diversity and drinking water were keywords with high intermediary centrality and were also the core contents of antibiotic pollution research. Science of the Total Environment and Environmental Science and Pollution Research were the main periodical carriers of literature in this field. In recent years, the research on resistance genes' influence on aquatic ecosystem and their migration characteristics in the food chain were hot issues.

Bibliometric analysis of MOFs in the field of water treatment applications
QIN Weiwei, TANG Jia, DU Cong, DUAN Xiaohu, XIAO Shuhu, YAN Bingfei
2023, 13(3): 1168-1178. doi: 10.12153/j.issn.1674-991X.20220433
Abstract(219) HTML (144) PDF(2692KB)(23)

Metal-organic frameworks (MOFs) are widely used in water treatment due to their excellent properties such as large specific surface area, high porosity, and tunable structure and function. In order to deeply understand the research hotspots and growing trends of MOFs in the field of water treatment applications, the bibliometrics method was used, and the VOSviewer software was used to quantitatively analyze the related papers of MOFs in the field of water treatment applications in the Web of ScienceTM core collection database. The results show that: from 1995 to 2021, MOFs published a total of 1 281 papers in the field of water treatment applications, and the number of papers generally increased year by year; China was the country with the highest total number of papers and total citations in this field, with a total of 800, but with relatively low citations per paper; Jhung S H is the most productive author in the field, with 14 published papers and a total of 1 657 citations. The research hotspot is the modification and compound of MOFs materials (such as MOFs-derived carbon, MOFs membrane, etc.), and the use of adsorption removal, catalytic degradation and other methods to treat typical pollution such as dyes and heavy metal ions in water. In the future, attention should be paid to the exploration of inexpensive and efficient synthesis methods, the improvement of material stability and reproducibility, the structure-activity relationship between modification methods and the structural characteristics of pollutants, and the study of the mechanism of action of complexes or derivatives.

Transport fluxes of nitrogen, phosphorus, cadmium and arsenic at farmland plot scale in the typical areas of Pearl River Delta region
XUE Xue, MAO Yupeng, ZHANG Hong
2023, 13(3): 1179-1186. doi: 10.12153/j.issn.1674-991X.20220391
Abstract(199) HTML (112) PDF(2504KB)(21)

The transport of nitrogen, phosphorus, cadmium and arsenic is the main factor affecting agricultural production as well as a significant non-point source of pollution of farmland. Taking the experimental farmland of the Foshan Institute of Agricultural Science and Technology (FIAST) in the Pearl River Delta as a typical research area, and based on the soil apparent balance model, a soil apparent balance model of nitrogen, phosphorus, cadmium and arsenic was constructed at the farmland plot scale, to analyze the transport structure and balance of nitrogen, phosphorus, cadmium and arsenic in the soil. The results showed that fertilization was the main input of the four elements in the study area, but the main outputs were different. The main output of nitrogen and phosphorus was crop enrichment, accounting for 57.5% and 39.0%, respectively, whilst the main outputs of cadmium and arsenic were surface runoff and crop enrichment, accounting for 66.7% and 10.7%, respectively. The enrichment was observed for all four elements in the study area to different degrees. On the plot scale, the balance of nitrogen and phosphorus was in surplus, while cadmium and arsenic were in deficit, with their intensity being 37.40, 8.88, −1.35 and −20.50 kg/(hm2·a), respectively. Nitrogen and phosphorus were within the local soil environmental safety thresholds. The analysis of cadmium and arsenic enrichment in five types of vegetables showed that the enrichment coefficient of arsenic was greater than 70.0% in all the types of vegetables, while the enrichment of cadmium was only found in pepper leaves, with a coefficient of 57.5%. Therefore, more attention should be paid to the effective utilization of fertilizer input and the monitoring of heavy metals in irrigation water, crops and surface runoff to ensure regional food security and water quality.

Experimental study on the making of sintered brick using municipal sludge in Shenyang City
ZHANG Junyi, WEI Jianbing, HAN Dong, XU Bintao, LU Qingxuan, CHENG Quanguo
2023, 13(3): 1187-1193. doi: 10.12153/j.issn.1674-991X.20220469
Abstract(182) HTML (58) PDF(1236KB)(23)

Taking municipal sludge of Shenyang City as an example, the operation processes and product application feasibility of sintered brick made of sludge mixed with coal gangue and shale were explored. The optimal sintering system was determined by optimizing the proportion of mixed materials through raw material test and evaluation and orthogonal experiment. On this basis, the influence of sludge addition on the performance of brick and the environmental safety of brick samples were evaluated. The results showed: The optimum sintering system for brick making with three kinds of mixed materials was as follows: sludge addition was 5%, sintering temperature was 1 050 ℃ and sintering time was 9 h. The performance of sintered brick samples met or exceeded Fired Common Bricks ( GB 5101-2003). In the test of mixed materials, the compressive strength of sintered bricks with sludge addition of 0%-15% could meet the factory standard. The sintered bricks with 0%-20% sludge, 1 050 ℃ sintering temperature and 9 h sintering time were safe and harmless for the environment.

Spatial-temporal evolution and ecological sustainability analysis of ecological footprint in Heilongjiang Province
LI Yunfeng, CHEN Zhuo, LEI Hailiang, LIU Chang, LU Yurun
2023, 13(3): 1194-1203. doi: 10.12153/j.issn.1674-991X.20220797
Abstract(190) HTML (93) PDF(7646KB)(24)

To analyze the ecological sustainability status of Heilongjiang Province, the equivalence factor and yield factor were constructed based on net primary productivity (NPP), and the ecological footprint and ecological carrying capacity of Heilongjiang Province from 2000 to 2020 were calculated by the improved ecological footprint model. Also, the spatial pattern changes of ecological footprint were revealed, and the status of ecological sustainability was analyzed. The results showed: Firstly, the equivalence factor of different lands was in the order of forest land > grassland > cultivated land > water area, and the value of the yield factor was water area > grassland > forest land > cultivated land. Secondly, the growth rate of ecological footprint per capita was much greater than the ecological carrying capacity per capita over the past 21 years in Heilongjiang Province, resulting in an increasingly serious ecological deficit per capita. However, ecological footprint per capita first showed increased status and then stabilized when considering domestic trade. It was in the state of ecological deficit from 2005 to 2010, then in the state of ecological balance after 2010, and there was obvious spatial heterogeneity. Thirdly, Heilongjiang Province had always been in a state of light consumption of asset stock and the capital flow of arable land and grassland could not meet social needs. The ecological footprint of fossil fuels had grown rapidly in-depth and it was manifested by a high ecological deficit. Lastly, the overall regional development of Heilongjiang Province was in a state of slightly unsafe and weak sustainable development and the grassland had been in a state of strong unsustainability for a long time. The ecological environment status of Heilongjiang Province had been effectively improved in recent years; however, the problem of uneven utilization of land resources was prominent and should be paid attention to.

Trophic structure and evolution trend of Lake Shankou ecosystem, in northeast China
SHI Zhanyao, ZHANG Jingtian, HUANG Weihui, WENG Nanyan, ZHANG Hanxiao, HUO Shouliang
2023, 13(3): 1204-1213. doi: 10.12153/j.issn.1674-991X.20220533
Abstract(364) HTML (120) PDF(2650KB)(48)

In order to explore the food web structure of Lake Shankou, an alpine lake in northeast China, and then predict a more reasonable ecological management mode for this ecosystem, the effects of physicochemical factors on primary production (PP) of Lake Shankou were identified through multivariate stepwise regression analysis. Ecosystem data of Lake Shankou from 2014 were used for Ecopath modeling, and the Ecosim model was applied to predict the succession trend of plankton and major fish species in the next 20 years (since 2014) under different scenarios. The future management modes of Lake Shankou were also explored based on correlation analysis. The results showed that Lake Shankou was a phosphorus-limited lake, and the PP of this ecosystem was positively correlated with water temperature and total phosphorus. Complex predator-prey relationships were observed in Lake Shankou ecosystem. Most energy flows of this ecosystem were concentrated on trophic level II or above, and the keystone species was the "other fish" function group. The results of the Ecopath modeling were highly reliable according to the Pedigree index (0.537). The increase in production rate (Production/Biomass, PD/B) of phytoplankton significantly promoted the relative biomass increase of crucian carp (Carassius auratus), common carp (Cyprinus carpio), and silver carp (Hypophthalmichthys molitrix). However, this promotion effect was not significant when PD/B of phytoplankton decreased by more than 5% annually. The increasing search rate of Hypophthalmichthys molitrix would enhance its predatory efficiency to zooplankton (i.e. copepod, cladocera, and rotifer), and result in a slight increase in the relative biomass of phytoplankton via trophic cascade effects. Combined with scenario analysis and correlation analysis, the elevation of phytoplankton biomass would increase fishery production, and silver carp control for controlling algae was not effective in Lake Shankou. The controlling of exogenous nutrient input was more important in future ecosystem management.

Ecological restoration zoning in farming-grazing transitional zone based on the supply and demand of the ecosystem services: a case study of the upper reaches of the Sanggan River
GAO Yuan, YUAN Ye, ZHAO Yifang
2023, 13(3): 1214-1222. doi: 10.12153/j.issn.1674-991X.20220387
Abstract(281) HTML (242) PDF(2543KB)(49)

The research on ecological restoration zoning, based on the ecological background and socio-economic characteristics of the farming-grazing transitional zone, will contribute to its ecological security and sustainable socio-economic development. The upper reaches of the Sanggan River, located in the farming-grazing transitional zone, were selected as the research area to identify the ecosystem services, including carbon sequestration, food supply, water production and soil conservation. The multi-source data about land use, meteorological observation and statistical yearbooks, etc., were employed in InVEST model and ArcGIS spatial analysis module, to explore the spatial distribution of the supply and demand of the ecosystem services in the upper reaches of the Sanggan River in 2020. Moreover, Quadrant matching method and coupling and coordination model were adopted to conduct research of the zoning of ecological restoration. The results showed that: In 2020, the spatial distribution of the supply of the four ecosystem services in this area was almost consistent with its topography, forming a semi-closed loop of high value around the backbone artery of the Sanggan River. The high demand for ecosystem services was located where densely populated areas occurred. Matching types of the supply and demand of ecosystem services in the river basin were "high supply -high demand" and "high supply-low demand". The average value of coupling and coordination degree between the supply and demand was 0.23, which was in a state of mild imbalance and indicated a mismatch between the supply and demand of ecosystem services. Based on the matching types and coupling and coordination degree of the supply-demand of the ecosystem services as well as the socio-economic characteristics in the upper reaches of the Sanggan River, the tributary was divided into Shentou Springs ecological restoration area, the ecological barrier zone along the northern ancient Great Wall, the sand-fixation belt in Datong Basin, the water conservation and biodiversity protection area along the inner regions of the Great Wall, and the ecological restoration and biodiversity protection area of the Sanggan River. Coupled with the ecological restoration measures such as assisted regeneration, natural restoration, ecological reconstruction, and protection and conservation, the ecological functions of each zone, mainly focusing on carbon sequestration and conservation, cultivated land protection, water conservation, and water and soil conservation, would be greatly promoted.

Spatio-temporal characteristics and prediction of carbon storage in terrestrial ecosystems in Lijiang River basin
WEI Xi, SHAO Ya, CAI Xiangwen, LIN Zhenming, XIAO Liangang, LIU Zehao
2023, 13(3): 1223-1233. doi: 10.12153/j.issn.1674-991X.20220378
Abstract(286) HTML (211) PDF(12208KB)(41)

Evaluating ecosystem carbon storage is of great significance to regional ecological management. Using InVEST model and PLUS model, based on the interpreted land use data and future land use forecast data, the temporal and spatial characteristics of land use change and carbon storage in Lijiang River basin from 2000 to 2020 were studied, and the variation of carbon storage in different future scenarios was predicted. The results showed that land use change in Lijiang River basin from 2000 to 2020 was manifested in the reduction of cultivated land, forest land and grassland, and the increase in the area of ​​water, construction land and unused land. Under the influence of land use change, the carbon storage in Lijiang River basin decreased by 0.945×106 t from 2000 to 2020, among which the decrease was the largest from 2015 to 2020. The high carbon storage areas were mainly distributed in the high altitude area of the northwest, southwest and east of the basin, while the low carbon storage areas were mainly distributed in the central plain of the basin and obviously expanded from 2000 to 2020, and the carbon reserves of Lingui, Xing'an and Lingchuan counties in the basin decreased significantly. According to prediction, the carbon storage of Lijiang River basin would further decrease under the natural development scenario in 2030, the carbon storage under the cultivated land protection scenario would increase by 0.345 × 106 t compared with the natural development scenario, and the carbon storage under the ecological protection scenario would increase by 1.540 × 106 and 1.195×106 t compared with the natural development scenario and cultivated land protection scenario, respectively. The cultivated land protection scenario could protect the amount of cultivated land, but the expansion of construction land was limited to a great extent; the ecological protection scenario could enhance carbon sequestration capacity, but could not effectively control the reduction of cultivated land area. In the future national land spatial planning of Lijiang River basin, ecological protection and cultivated land protection measures needed to be comprehensively coordinated to enhance the regional carbon sequestration capacity and achieve green and sustainable development.

Research on hills ecological restoration planning under the background of territorial spatial planning: a case study of Nanning City
2023, 13(3): 1234-1241. doi: 10.12153/j.issn.1674-991X.20220973
Abstract(338) HTML (219) PDF(5385KB)(82)

To explore a new path of systematic and large-scale hills ecological restoration under the background of territorial spatial planning, taking Nanning City as an example, the evaluation index system of hills ecosystem services was constructed, and hills ecological function evaluation was carried out. Then ecological function zoning of hills was divided, and the scheme of hills ecological restoration and promotion was formulated. So, a method of regional hills ecological restoration planning was established, based on background evaluation, function zoning, restoration and promotion. The results showed that the main hills in the study area accounted for about 37.26%, all of which were spatially contiguous and concentrated. The hills area was of 85% highly and moderately important area, all of which were the core area of hills ecological protection and restoration. The study area was divided into 8 types of hills ecological function zones, including hills ecological conservation area, water source protection area, ecological recreation coordination area, etc., which implemented corresponding control measures separately. Considering the needs of hills ecological protection and restoration and urban development, the hills ecological restoration and promotion scheme was formulated, from the aspects of fast-growing eucalyptus planting adjustment, hills community structure optimization, hills ecological recreation belt planning, and ecological restoration guidelines of damaged hills. The regional hills ecological restoration planning should coordinate ecological protection and restoration with urban development, integrate the protection, restoration and utilization of hill resources, and formulate plans by zoning and classification.

Effect of external admixtures on the growth and shear strength of Festuca arundinacea roots in vegetated concrete
LI Shuangyang, CHEN Fangqing, XIONG Danwei
2023, 13(3): 1242-1248. doi: 10.12153/j.issn.1674-991X.20220657
Abstract(230) HTML (139) PDF(1441KB)(13)

In order to reveal the effects of external admixtures on the root growth and soil consolidation and slope protection of vegetation concrete, Festuca arundinacea was used as the research material, and different contents of coconut fiber and fly ash were added to construct vegetation concrete to measure the growth characteristics of Festuca arundinacea underground root system and the shear strength of root-soil complex. The results showed that the content of coconut fiber and fly ash had significant effects on the growth of Festuca arundinacea root system. The total root length, root surface area, root average diameter and underground biomass all increased first and then decreased with the increase of the content of coconut fiber and fly ash. When the content of coconut fiber was 0.3% and the content of fly ash was 2%, they reached the maximum value, which increased by 31.39%, 30.20%, 30.57% and 12.80%, respectively, compared with the treatment without coconut fiber. Compared with the treatment without fly ash, they increased by 42.17%, 22.85%, 16.48% and 29.22%, respectively. The coconut fiber content and fly ash content also had significant effects on the shear strength of the vegetated concrete substrate. The shear strength of the substrate increased first and then decreased with the increase of the addition content, and reached the maximum value when the content of coconut fiber and fly ash was 0.3% and 2%, respectively. The comprehensive evaluation showed that the improved vegetation concrete with Festuca arundinacea root system mixed with 0.3% of coconut fiber and 2% of fly ash had the best growth, and the shear strength of vegetation concrete was the highest.

Analysis of cost and potential of energy-conservation technologies in iron and steel industry: a case study of the Yangtze River Delta region
YANG Zhongya, SUN Qihong, SHEN Peng, SONG Xiaocong, WANG Jiadeng
2023, 13(3): 1249-1258. doi: 10.12153/j.issn.1674-991X.20221235
Abstract(233) HTML (90) PDF(3342KB)(38)

As a typical resource and energy intensive industry, energy saving and emission reduction is the effective green and low-carbon transformation and development path of the iron and steel industry. Energy-conservation technologies are vital to improve energy efficiency, reduce carbon emissions and decrease air pollution in the iron and steel industry. The Conservation Supply Curve method was used to evaluate the techonolies’ energy-conservation cost of the iron and steel industry in the Yangtze River Delta region. And the energy conservation potential realized by the technologies in the region in 2030 was evaluated. The results showed that 28 energy-conservation technologies in the iron and steel industry were expected to save 875.74 PJ of energy in 2030, which was about 34% of the total energy consumption of the iron and steel industry in the Yangtze River Delta in 2020. When different income items were considered, the energy-conservation cost of technologies was different; when no income was considered, the energy-conservation cost of technologies was the highest; when the co-benefit was taken into account, the energy-conservation cost was reduced to a lower level. The discount rate, the trading price of greenhouse gases or pollutants and other factors would have an impact on the energy-conservation cost of the technologies. The higher the discount rate, the higher the capital cost, and the higher the energy-conservation cost of the technologies. A rise in the price of greenhouse gases or pollutants would increase the benefit of energy conservation and thus reduce the cost of energy conservation of the technologies.

Compilation of natural resource assets sheet: a case study of Qilianshan Mountains in Qinghai Province
DU Leshan, LIU Haiou, MA Chao, ZHANG Ying, LI Junsheng
2023, 13(3): 1259-1268. doi: 10.12153/j.issn.1674-991X.20220511
Abstract(129) HTML (64) PDF(1111KB)(15)

Qilianshan Mountains is an important ecological function area in China; also, it is an important ecological safety barrier and water conservation area in northwest China. It is of great significance to carry out the balance sheet compilation of natural resources in this region to find out the natural resources background and guide the regional green development. Factors such as land resources, forest resources, water resources and mineral resources were comprehensively considered, and according to the compilation principle of "first physical quantity, then value quantity, first stock, then flow, first classification, then synthesis", the reporting system of General table -Classification table -Extended table -Basic table was built, to comprehensively assess the physical quantity and value quantity of natural resources in Qilianshan mountains and to form a natural resource balance sheet. The evaluation results showed that the natural resource assets of Qilianshan Mountains in Qinghai Province had been increasing steadily since 2011. The total assets in 2011, 2015 and 2017 were 9 167.231 billion yuan, 9 167.495 billion yuan and 9 169.819 billion yuan, respectively. Among them, land resource assets accounted for more than 99%, followed by mineral resources and water resources, and forest resources value was the least. The reporting system and accounting results provided important technical support for the wok of balance sheet compilation of natural resources in Qilianshan Mountains and even in Qinghai Province.

Study on the cost-effectiveness of paid use policy of pollutant emission allowance in China
LÜ Zhixian, SHI Guangming, WU Yufei, LI Caiyan, TAN Zhengzheng
2023, 13(3): 1269-1274. doi: 10.12153/j.issn.1674-991X.20220566
Abstract(178) HTML (99) PDF(607KB)(15)

In order to analyze the cost-effectiveness of the paid use policy of pollutant emission allowance and the environmental tax policy on the emission trading market in China, the principles of promoting enterprise pollutant emission reduction by three environmental management instruments (i.e. emission trading, paid use of pollutant allowance, and environmental tax) were analyzed, based on the principles of emission trading. After that, ten virtual enterprises were set up to simulate and analyze the cost-effectiveness of different policy scenarios. The results showed that the coexistence of three policy instruments had no effect on the emission trading of enterprises when the emission trading policy was dominant. Meanwhile, the role of the paid use policy of pollutant emission allowance and the environmental tax policy in the emission trading market was the same; both could reduce the transaction price of the emission allowance and increase pollutant abatement cost. If the paid use price of pollutant emission allowance or the environmental tax rate (or the sum of both) exceeded the marginal abatement cost of the enterprises when the original emission trading market was balanced, the emission trading market would appear "failure" phenomenon, which meant that the enterprises would no longer seek to carry out the emission trading, but pay the compensated fee for the use of pollutant emission right or the environmental tax (or both).