Seasonal Impact of Agricultural Non-point Source Pollution on Water Environment of Dianshan Lake Basin in Shanghai City

Taken the Dalian lake region as the study area,which represents the typical agriculture production mode and agricultural non-point source pollution （ANSP） in Dianshan lake area in Shanghai City,basis on the characteristics of regional ANSP and combing with the seasonal water quality monitoring of Dalian Lake and reaches of its main influents,the laws of seasonal impact on the water environment were investigated.The results showed that,the seasonal change of TN and COD concentration of regional water had no significant correlation with the local ANSP emissions,while the seasonal changes of TP was consistent with seasonal emissions of regional TP pollution,and it had a significant correlation with Chl.a in four seasons,indicating that regional TP pollutant was the constriction factor influenced the eutrophication degree of Dalian lake.Because more than 80% of TP emissions came from the drainage of intensive pounds in winter,summer and fall,TP pollutant control should be adopted as the control target of regional ANSP control.

Ordered mesoporous materials for water pollution treatment:Adsorption and catalysis

To meet the growing emission of water contaminants,the development of new materials that enhance the efficiency of the water treatment system is urgent.Ordered mesoporous materials provide opportunities in environmental processing applications due to their exceptionally high surface areas,large pore sizes,and enough pore volumes.These properties might enhance the performance of materials concerning adsorption/catalysis capability,durability,and stability.In this review,we enumerate the ordered mesoporous materials as adsorbents/catalysts and their modifications in water pollution treatment from the past decade,including heavy metals(Hg^(2+),Pb^(2+),Cd^(2+),Cr^(6+),etc.),toxic anions(nitrate,phosphate,fluoride,etc.),and organic contaminants(organic dyes,antibiotics,etc.).These contributions demonstrate a deep understanding of the synergistic effect between the incorporated framework and homogeneous active centers.Besides,the challenges and perspectives of the future developments of ordered mesoporous materials in wastewater treatment are proposed.This work provides a theoretical basis and complete summary for the application of ordered mesoporous materials in the removal of contaminants from aqueous solutions.

Ecological Remediation Measures for Non-point Source Pollution Based on Source-Sink Landscape Theory: A Case Study of Huanghou Basin

The growth of society and population has led to a range of water pollution issues.Among these,non-point source pollution assessment and treatment pose a particular challenge due to its formation mechanism.This has become a focal point and challenge in water pollution treatment research.The study area for this research was the Huanghou basin in Guizhou Province,southwest China.The land use type of the basin was analyzed using remote sensing technology,and water quality data was collected by distributing points throughout the basin,based on source-sink landscape theory.The distribution map of the basin’s source-sink landscape and the results of water quality data accurately and efficiently identified the areas with high risk of non-point source pollution in the western and southwestern residential and agricultural areas of the upper basin.Hence,a strategy of“increasing sinks and decreasing sources”was proposed.The strategy was implemented at both macro and micro levels to address non-point source pollution in the basin using ecological remediation techniques.The work to control karst rocky desertification should continue at a macro level.The rocky desertification area in the basin should gradually transform into grassland and forested land,while increasing the overall area of the sink landscape.Ecological restoration techniques,such as slope planting,riparian zone vegetation restoration,increasing plant abundance,and restoring aquatic plants,can effectively control non-point source pollution at the micro level.Compared to traditional control methods,this remediation strategy focuses on source and process control.It is more effective and does not require large-scale water pollution control projects,which can save a lot of environmental control funds and management costs.Therefore,it has greater research significance and application value.

Health risk assessment of heavy metal pollution in groundwater of a karst basin,SW China

To investigate the presence of metal elements and assess their health risk for the populace in the Nandong Underground River Basin(NURB),we conducted an analysis of eleven common heavy metals in the water body.A Health risk assessment(HRA)model was employed to analyze 84 water samples from the NURB.The detection results revealed the following order of heavy metals concentrations:Fe>Al>Mn>Zn>As>Cd>Pb>Cr>Ni>Cu>Hg.Correlation analysis indicated a certain similarity in material source and migration transformation among these eleven metal elements.Our study identified that the health risks for local residents exposed to metal elements in the water of NURB primarily stem from carcinogenic risk(10^(−6)–10^(−4)a^(−1))through the drinking water pathway.Moreover,the health risk of heavy metal exposure for children through drinking water was notably higher than for adults.The maximum health risks of Cr in both underground and surface water exceeded the recommendation standard(5.0×10^(−5)a^(−1))from ICRP,surpassing the values recommended by the Swedish Environmental Protection Agency,the Dutch Ministry of Construction and Environment and the British Royal Society(5.0×10^(−6)a^(−1)).The results of the health risk assessment indicate that Cr in the water of NURB is the primary source of carcinogenic risk for local residents,followed by Cd and As.Consequently,it is imperative to control these three carcinogenic metals when the water was used as drinking water resource.

Quantitative Evaluation of Heavy Metal Pollution and Its Influencing Factors in Water Bodies of Karst Areas

At present, there is relatively little research on the synergistic effects of heavy metals in soil, sediment, and bedrock on heavy metal pollution in water bodies. In this paper, heavy metals in soil, sediment, bedrock, and water of a typical karst watershed in southwest China were investigated. The results indicated that the average values of heavy metals in soil and sediment were relatively higher than those in bedrock except for Ni and As. During the research period, As and Cd were the main heavy metal elements polluting the soil and sediment in the study area, while water bodies were mainly polluted by Ni, As, and Cd. The pollution assessment indicated that there were instances of poor or very poor water quality in the study area during the study period;the soil as a whole was slightly polluted by Cd and As;sediment was subject to moderate Cd pollution and mild As pollution. Analysis of geochemical form for heavy metals showed that heavy metals in soil and sediment were mainly in residual form, and the proportions of exchangeable As and Cd were relatively high. Multiple statistical analysis showed that heavy metals in sediment, soil, and bedrock explained 23.8%, 16.8%, and 16.2% of the changes in heavy metals of water, respectively. The research results can provide scientific basis for the prevention and control of heavy metal pollution in water bodies.

Validation of an agricultural non-point source(AGNPS)pollution model for a catchment in the Jiulong River watershed,China

This study tested and evaluated the agricultural non-point source （AGNPS） model for the Wuchuan catchment, a typical agricultural area in the Jiulong River watershed, Fujian Province, China. The AGNPS model was calibrated and validated for the study area with observed data on ten storms. The data on eight storms in 2002 were used for calibration while data on two storms were used for validation of the model. Considering the lack of water quality data over a long-term series, a novel method, comparing an internal nested catchment with its surrounding catchment, was used to supplement the less long-term series data. Dual calibration and validation of the AGNPS model was obtained by this comparison. The results indicate that the correlation coefficients were 0.99 and 0.98 for runoff, 0.94 and 0.95 for the peak runoff rate of the large catchment and the small catchment, respectively, and 0.76 for the sediment of the small catchment only. Each pair of correlation coefficients is homogeneous for the same event for the two catchments. With the exception of the sediment yield and particulate phosphorus, the peak runoff rate and other nutrients were well predicted. Sensitivity analysis showed that the Soil Conservation Service curve number and rainfall quantity were the most sensitive parameters, which resulted in high output variations. Erosivity and other parameters had little influence on the hydrological and quality outputs.

Reductions in non-point source pollution through different management practices for an agricultural watershed in the Three Gorges Reservoir Area

Non-point source water pollution generated by agricultural production is considered a major environmental issue in the Three Gorges Reservoir Area （TGRA） of China. The Annualised Agricultural Non-Point Source Pollution （AnnAGNPS） model was selected to assess the impact of the application of various management treats, including seven crops, five fertilizer levels and three-group management practice scenarios, on water quality from Heigou River Watershed in TGRA. The scenario subsets include conservation tillage practice （CTP）, conservation reserve program （CRP） and conversion of cropland into forestland program （CCFP）. Results indicated that tea can not be replaced by other crops because comparatively tea resulted in a higher sediment yield. CTP with no-tillage was more effective to reduce sediment yield, but could increased nutrient loss. CRP reduced sediment yield significantly, but slightly benefited on nutrient loss. CCFP reduced not only sediment yield but also the nutrient loss significantly. The conversion of cropland with a slope greater than 10° into forestland was found to be the best scenario as the sediment yield export is less than 5 tons/ha and nutrient loss is within the permissible limit.

Combining CLUE-S and SWAT Models to Forecast Land Use Change and Non-point Source Pollution Impact at a Watershed Scale in Liaoning Province, China

Non-point source(NPS) pollution has become a major source of water pollution. A combination of models would provide the necessary direction and approaches designed to control NPS pollution through land use planning. In this study, NPS pollution load was simulated in urban planning, historic trends and ecological protection land use scenarios based on the Conversion of Land Use and its Effect at Small regional extent(CLUE-S) and Soil and Water Assessment Tool(SWAT) models applied to Hunhe-Taizi River Watershed, Liaoning Province, China. Total nitrogen(TN) and total phosphorus(TP) were chosen as NPS pollution indices. The results of models validation showed that CLUE-S and SWAT models were suitable in the study area. NPS pollution mainly came from dry farmland, paddy, rural and urban areas. The spatial distribution of TN and TP exhibited the same trend in 57 sub-catchments. The TN and TP had the highest NPS pollution load in the western and central plains, which concentrated the urban area and farm land. The NPS pollution load would increase in the urban planning and historic trends scenarios, and would be even higher in the urban planning scenario. However, the NPS pollution load decreased in the ecological protection scenario. The differences observed in the three scenarios indicated that land use had a degree of impact on NPS pollution, which showed that scientific and ecologically sound construction could effectively reduce the NPS pollution load in a watershed. This study provides a scientific method for conducting NPS pollution research at the watershed scale, a scientific basis for non-point source pollution control, and a reference for related policy making.

Integrated Control of Agricultural Non-point Source Pollution to Provide Safe and Healthy Drinking Water for Rural Areas

Agricultural non-point source pollution has become the main part of water pollution prevention and control in China. This paper made a brief introduction to the causes and hazards of agricultural non-point source pollution and the current situation of agricultural non-point source pollution prevention and control in China. In view of the serious agricultural non-point source pollution in water environment of Guangxi and the difference in quality of drinking water between urban and rural areas,it came up with recommendations for strengthening agricultural non-point source pollution prevention and control from scientific distribution,linked operation and maintenance,popular science education,and legal system construction,to guarantee safe and healthy drinking water in rural areas.

The river chief system and agricultural non-point source water pollution control in China

As part of their efforts to control water pollution,local governments in China introduced the river chief system,whereby a named individual undertakes responsibility for protecting a specified waterway.As one of the most prominent sources of water pollution,agricultural non-point-source(NPS)pollution is becoming increasingly serious.Determining whether the river chief system,an institutional reform in China's decentralized environmental regulation regime,is effective in alleviating NPS pollution is important for the realization of green development.The effect of the river chief system on reducing agricultural NPS pollution is explored in this study using panel data from 308 Chinese counties during the period from 2004 to 2015.The results reveal that the negative impact of manure output from animal breeding operations on surface water quality is reduced with the implementation of the river chief system.However,the river chief system is ineffective in dealing with the water pollution caused by fertilizer use.Furthermore,in the current system,cooperation among river chiefs only occurs within a province.Local governments should increase their efforts in reducing fertilizer source loads and preventing fertilizer loads from entering surface waters.In addition,the central government should improve cooperation among the river chiefs in upstream and downstream provinces.

Quantification of Effects of Natural Geographical Factors and Land-scape Patterns on Non-point Source Pollution in Watershed Based on Geodetector:Burhatong River Basin,Northeast China as An Example

Changes in natural geographic features and landscape patterns directly influence the hydrology and non-point source pollution processes in the watershed;however,to slow down non-point source pollution,it is necessary to distinguish their effects.But the non-point source pollution process is interactional as a result of multiple factors,and the collinearity between multiple independent variables limits our ability of reason diagnosis.Thus,taking the Burhatong River Basin,Northeast China as an example,the methods of hydrological simulation,geographic detectors,and redundancy analysis have been combined to determine the impact of natural geographic features and landscape patterns on non-point source pollution in the watershed.The Soil&Water Assessment Tool(SWAT)has been adopted to simulate the spatial and temporal distribution characteristics of total nitrogen and total phosphorus in the watershed.The results show that the proportions of agricultural land and forest area and the location-weighted landscape contrast index(LWLI)are the main indicators influencing the rivers total nitrogen and total phosphorus.The interaction of these indicators with natural geographic features and landscape configuration indicators also significantly influences the changes in total nitrogen(TN)and total phosphorus(TP).Natural geographical features and landscape patterns have different comprehensive effects on non-point source pollution in the dry and wet seasons.TN and TP loads are affected mainly by the change in landscape pattern,especially in the wet season.Although the ecological restoration program has improved forest coverage,the purification effect of increased forest coverage on the water quality in the watershed may be offset by the negative impact of increased forest fragmentation.The high concentration and complexity of farmland patches increase the risk of non-point source pollution spread to a certain extent.

SPATIAL ANALYSIS OF SOIL EROSION AND NON-POINT SOURCE POLLUTION BASED ON GIS IN ERLONG LAKE WATERSHED, JILIN PROVINCE

Data collection, factor composition, nappe analysis and integrative simulation of natural geographical factors in Erlong Lake watershed have been carried out based on GIS. The risk areas where non-point source pollution may occur were compartmentalized and assessed, and the total soil erosion and the runoffs of N and P with rainfall in this valley were worked out by experiment and GIS mapping. The study indicated that the main type of soil erosion was moderate (erosion modulus is 1000-2500t/(km(2).a)) at present, and the intense erosion areas are located in dry land with variable slope east of the lake and the middle-south parts of steep slope mountainous region (erosion modulus is more than 5000t/(km(2).a)). Though the area is small, it should be paid attention to. The trend of non-point source pollution (NSP) of nitrogen and phosphorus loss was corresponded with the soil erosion. Spatial distribution and the reasons of the distribution difference have been presented and it was emphasized that the human activities among the influence factors was the most important. It surely offers a scientific basis to control and prevent non-point source pollution in the watershed.

Agricultural Non-point Source Pollution in Drinking Water Conservation Area of the Hongfeng Lake in Guiyang City

On the basis of investigating rural population, land types, livestock and poultry breeding scale in drinking water conservation area of the Hongfeng Lake in Guiyang City, as well as the urban domestic pol utant discharge coefficient, livestock and poultry excretion coefficient, nitrogen fertilizer and phosphate fertilizer loss rate in the first national pollution source survey, this paper tried to explore current situation of agricultural non-point source pollution, and provide scientific support for the pollution control. The results showed that in the drinking water conservation area of the Hongfeng lake in 2013, contribution rate of pollution sources to the water pollution in the Hongfeng Lake followed the sequence "livestock and poultry breeding > rural life > farmland fertilizer". Among all agricultural non-point source pollutants, livestock and poultry breeding pollutants were major pollution sources, with a contribution rate to CODCr, TP and NH3-N in water above 50%; rural domestic pollutants were also important pollution sources, its contribution rate to CODCr and NH3-N was 43.49% and 46.69%, respectively; contribution rate of farmland fertilizer pollutants to TN and TP was 33.76% and 27.71%, respectively, higher than that of rural domestic pollutants(25.87% and 6.75%). Therefore, the control of non-point source pollution within the drinking water conservation area should be enhanced, so as to control the pollution from the source.

Landscape Ecology Researches on the Regulation of Non-point Source Pollution in Agroforestry Watershed

Non-point source(NPS) water pollution generated by agricultural production has become a major environmental issue in agroforestry watersheds such as the Three Gorges. Landscape ecology emphasizes the regulation and effect of landscape pattern on material flow, energy flow in the ecological processes. This paper reviewed landscape ecological approaches of controlling non-point source pollution in agroforestry watershed of the Three Gorges from the patch level and landscape level. Stage I: landscape ecological investigation. The investigation is to fi gure out landscape pattern characteristics of the watershed, major causes and key sections of the non-point source pollution, "source" patches and ecological process of non-point source pollution, and the feedback relationship between landscape pattern and non-point source pollution. Stage II: landscape ecological planning. In the patch level, the best management procedures(BMPs) are selected to judge the application effect. In the landscape level, new landscape elements are introduced, "source" and "sink" landscape patch types adjusted, landscape level regulation effect assessed. Stage III: landscape ecological management. Small-watershed landscape ecological construction is carried out from patch level and landscape level, BMPs implemented gradually, landscape ecological planning and management integrated, landscape heterogeneity enhanced, intensity of non-point source pollution controlled effectively to achieve sustainable development of small watersheds.

Spatial and Temporal Distribution Characteristics of Agricultural Non-point Source Pollution in Xixi Watershed of Jinjiang Basin

The SWAT model was applied to analyze the temporal-spatial distribution patterns of non-point source pollution loads and the difference of pollution loads of different land use types in Xixi Watershed of Jinjiang Basin. The results showed that both yearly nitrogen and phosphorus pollution loads were evenly distributed during 1973 to 1979,the annual TN pollution from non-point source was 1530 t,or 6. 3 kg / ha,and the annual TP pollution from non-point source was 270 t,or 1. 1 kg / ha during 1973 to 1979 in the watershed. Considerable differences were identified on both monthly nitrogen and phosphorus pollution loads. The TN and TP pollution loads during the flood season( from April to September) accounted for 76. 2% and 75. 8% of the annual load respectively. There were great differences in both TN and TP pollution loads of different land use types in the study area,and the pollution load of both farmland and orchard was higher than that of the other land use types. TN and TP pollution loads of farmland accounted for 66% and 83% of total watershed. There was a great spatial difference in the nonpoint source pollution load of the study area. The critical source areas of non-point source pollution are mainly located at Guanqiao Town,Longmen Town,Changkeng Town,Shangqing Town and Dapu Town,where the efforts of controlling pollution should be made.

Simulation on the Time Progress of the Non-Point Source Pollution Load in Initial Stage Runoff for Small Watershed

Taking a reservoir in South China as an example, we use rainfall-runoff unit hydrograph method to analyze the time changing process of surface runoff inflow, which generated by typical design rainfall. On the basis of time series data of flow and water quality in control section of the main rivers in Xili Reservoir, we establish mathematical response relation between non-point source pollutants flux, such as flux of COD, flux of NH3-H, in catchment area of control section and runoff. Then we simulate the time dynamic change progress of non-point source pollution load which generate with the initial stage runoff that generated by design rainfall and flow into reservoir. It can provide technical parameters for the design of non-point source which generate from early runoff treatment project.

Water Pollution Situation and Impacts in Rural China

With the development of national economics, water pollution is becoming a critical problem in rural China. This research presented a brief view of water pollution situation in rural areas of China in terms of water shortage, water-pollutant sources, eutrophication of water bodies and pollution development in temporal scale. Analysis was conducted on the negative effects of water pollution on human health, agricultural plantation and animal husbandry. Subsequently, some suggestions were proposed for wastewater treatment in rural areas.

Analysis on the Pollution Load of Non-point Source Pollution and Surface Runoff of A Typical Village in Baiyangdian Lake Basin

[Objective] The characteristic of non-point source pollution of a typical village in Baiyangdian Lake basin was studied.[Method] The discharge of domestic sewage and solid wastes of the typical village was investigated,and both pollutant and nutrient element content were monitored,as well as the water quality and quantity of rainfall runoff.[Result] The non-point source pollution of livestock manure was far more serious than the sum of domestic sewage and domestic waste in this village,and the annual emission of total organic carbon(TOC),total nitrogen(TN) and total phosphorus(TP) was 37 794.0,4 102.9 and 1 923.7 kg,respectively.The event mean concentration(EMC)of chemical oxygen demand COD,TN and TP in rainfall runoff was 44.5,78.8,1.3 mg/L,respectively,and annual pollution load was 7.6,13.4 and 0.2 kg/hm2,respectively,while the annual pollution load of COD accounted for 5.1% of standard farmland,and that of TN and TP occupied 4.5% and 0.49% of slope farmland.[Conclusion] Livestock manure was the main source of non-point source pollution in the village and the annual pollution load of non-point source pollution was obtained.

Analysis on the Status of Agricultural Non-point Source Pollution in Xinan River Basin

Taking Xinan River basin as research object,the status of agricultural non-point source pollution was analyzed based on field survey,as well as the effect of fertilizer and pesticide leaching and runoff,livestock and poultry breeding and rural domestic pollution on non-point source TN and TP.At last,some technical countermeasures of controlling non-point source pollution were put forward according to the characteristics of agricultural non-point source pollution in Xinan River basin.

Pollution of Environmental Endocrine Disrupting Chemicals(EDCs) in Water and Its Adverse Reproductive Effect on Fish

Environmental endocrine disrupting chemicals （EDCs）, commonly found in the environment, come from industry and agriculture, including pesticides, fungicides, insecticides, herbicides, and other chemicals. Nowadays, more and more EDCs were released into the environment. EDCs go into water body via atmosphere sedi-mentation, surface runoff, soil eluviation, etc., so water body becomes the main place for existing. In order to attract scientific and public attention worldwide and to prevent EDCs pol ution, in this study we reviewed the classification of EDCs and their concentrations in natural water bodies, drinking water sources and water plants, and the reproductive toxicity of EDCs to fish were reviewed. EDCs could disturb the endocrine system and make reproductive organs and reproduction abnor-mal, resulting in fertility descending, reproduction function damage, community quan-tity decrease and even species extinction. In addition, EDCs could disrupt the homeostasis maintained by hormones, which would result in defects of neural de-velopment and abnormalities of the endocrine and reproductive systems. The exact molecular mechanisms have not been completely reported, but researches have suggested that multiple mechanisms were involved in the action of EDCs. Although there have been researches on the biohazard of EDCs, there stil exist problems of weakness in fundamental researches, difficulties in recognizing and identifying EDCs and high cost, which restraint the knowledge on them.