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1.
钱塘江流域污染负荷及水环境容量研究   总被引:5,自引:1,他引:4  
采用排污系数法计算了钱塘江流域不同污染源COD和氨氮的污染负荷,研究了整个流域90%、75%和so%水文保证率下的水环境容量.以流域水质目标为出发点,考虑污染负荷和流域社会经济发展需求相协调的原则,确定了钱塘江流域水污染总量控制阶段性目标.  相似文献   

2.
基于SWAT模型,以武烈河流域为例,研究流域不同类型水环境治理项目在不同水期的环境效益净值,为流域优化管理提供技术支持。结果表明:水环境治理对考核断面水质的改善情况,在不同水期存在一定的差异性。丰水期的COD和氨氮是枯水期的2~16倍,是平水期的1~3倍;平水期的COD和氨氮是枯水期的1~8倍。在枯水期和平水期,城镇生活污染治理项目对雹神庙断面COD和氨氮的改善贡献程度最大;在丰水期,农村面源污染治理项目对雹神庙断面COD和氨氮的改善贡献程度最大。  相似文献   

3.
钱塘江水系富春江段水污染现状调查研究   总被引:2,自引:0,他引:2  
通过对钱塘江水系(富春江段)水质状况的监测调查及桐庐、富阳两县(市)主要污染源的排查,分析了富春江段水环境质量现状,以及主要污染来源,为钱塘江流域水污染防治及水资源的保护提供参考依据。  相似文献   

4.
定量评估"十一五"期间总量减排的水质改善效益,科学真实反映减排成效,是重点流域总量减排工作持续进行的关键。以松花江流域为例,核算不实施总量减排情景下松花江流域的COD排放量,基于流域一维水质模型、SPARROW模型、GBNP模型等建立松花江流域COD排放总量与水质的对应关系,模拟预测不减排情景下各断面的COD浓度。研究结果表明,流域一维水质模型的模拟结果相对合理,根据模型预测,若不实施减排,2010年松花江流域总体COD将增幅20.5%,其中干流COD浓度增幅4.2%,支流COD浓度增幅36.0%。  相似文献   

5.
传统水环境容量以90%保证率下的设计枯水流量作为计算条件,存在水文计算条件单一、计算结果固定等局限性,不能很好地表征水流方向不定、产汇流过程复杂、污染负荷分散的江南平原河网的水环境容量。以宜兴市官林镇水系为研究对象,基于MIKE11水质模型计算河网控制单元水环境容量,以探究江南平原河网水环境容量的动态特性。结果表明:MIKE11模型法下官林控制单元COD、氨氮和总磷月均水环境容量为-152.80、0.92和-1.69 t;桐梓控制单元COD、氨氮和总磷月均水环境容量为220.23、4.49和1.45 t;皇新控制单元COD、氨氮和总磷月均水环境容量为15.42、0.90和0.14 t,呈现出明显动态特征。代表河道水环境容量与流量流速等水文要素有密切关系,市镇级等水质达标河道水环境容量与流速呈正相关,村级等未达标河道水环境容量与流速呈负相关。本研究可为平原河网水环境保护与管理提供重要参考和新思路。  相似文献   

6.
为改善流域水环境质量,以乡镇单元为流域污染物总量控制单元,基于公平与效益原则构建了多目标水污染负荷分配模型,分别采用理想点法与基于淘汰算子的改进非支配排序遗传算法Ⅲ(NSGA-Ⅲ-EO)求解分配模型。以眉山市东坡区江东片区为研究区,对研究区COD入河总量进行分配,分析了两种求解算法的优化性能,并制定了兼顾公平与效益的污染物排放方案。研究结果表明:理想点法获得的优化分配方案具有较高的污染物削减率(16.65%);NSGA-Ⅲ-EO得到的综合最优分配方案的效益与公平性更佳,其中污染物削减率为12.70%,综合环境基尼系数为2.489 8,环境效益为37.84亿元,污染排放成本为89.89亿元。证实了流域污染总量控制中存在兼顾社会公平和效益的均衡策略,构建的优化模型可为流域污染防治提供多种可选的污染防控方案,为各利益主体提供策略参考。  相似文献   

7.
基于SWAT模型研究了滹沱河流域内氨氮污染负荷结构,为区域水污染控制和水质改善提供依据。分析表明,不同水期各子流域氨氮污染负荷结构具有一定的差异性。从全年整体来看,生活氨氮污染负荷最大,农业次之,工业最小,与平、枯水期一致;丰水期农业氨氮污染负荷最大,生活次之,工业最小。  相似文献   

8.
20 0 1年 7月 2 5日 ,由浙江省环境保护科学设计研究院承担的省科技厅重点项目《钱塘江流域水污染综合防治研究》通过省级鉴定。该项目根据水质调查结果并结合已有资料 ,对流域的水环境质量作出全面的科学评价 ,确定流域主要污染源和主要污染物 ,查清沿岸城市和地区社会经济发展对钱塘江水环境的影响 ,制定钱塘江流域水污染防治综合对策和今后五年的行动计划。该研究的基准年为 1 997年 ,1 998年启动 ,2 0 0 0年结束。主要创新点为建立一系列模型 ,完成了钱塘江流域水质—水量关系分析、中上游非感潮河段水质模拟、下游感潮河段水质模拟和闻…  相似文献   

9.
基于MIKE11模型构建了北运河干流(北京段)一维河流水动力、水质模型。以2010年为基准年,综合考虑"十二五"期间人口增长、经济发展及农业规模和布局情况,设置3套减排方案。选择北京市榆林庄断面为主控监测断面,以氨氮低于5mg/L、COD低于40mg/L为水质控制目标,开展不同减排措施效果评估。结果表明,污水处理厂提标改造是改善北运河流域(北京段)水质的最有效手段,能使榆林庄断面COD和氨氮相比2010年分别下降27.2%、60.6%,COD达到水质控制目标。氨氮减排难度较大,除了实施污水处理厂提标改造外,应同步提高综合排放标准,使氨氮排放相对2010年下降73.5%,达到水质控制目标。同时,还应加强对城市暴雨径流污染的控制,以有效降低前汛期水体污染物峰值浓度。  相似文献   

10.
重庆市重污染次级河流伏牛溪水污染控制与水质改善   总被引:1,自引:0,他引:1  
雷沛  王超  张洪  周健 《环境工程学报》2019,13(1):95-108
针对重庆市部分次级河流耗氧污染物负荷高、水动力学弱化、河流生态系统退化等问题,选取重庆市典型次级河流伏牛溪为研究对象,以水质目标管理为指导思想,开展重污染河流水污染控制与水质改善研究。以V类水为水质目标,通过划分治理单元,开展河流水环境容量核算,分别提出基于现状条件、规划用地及上游补水2种情景下的污染负荷削减计算;根据削减负荷分配的结果,提出各个治理单元的污染负荷削减目标与治理措施,并开展目标可达性分析。治理工程实施后,重庆市伏牛溪水体中主要污染物的平均浓度及年达标率满足考核要求,该方案为我国山地城市重污染河流的水环境治理提供很好的参考。  相似文献   

11.
We reported previously that trichodiene, a volatile trichothecene derivative, was produced by a Stachybotrys isolate, also known to produce highly cytotoxic, non-volatile, macrocyclic trichothecenes (satrotoxins). We investigated the relationship between the production of trichodiene and various non-volatile trichothecenes for several molds. Volatile metabolites were concentrated by adsorption on Tenax TA and analyzed by GC/MS, while non-volatile metabolites were separated by HPLC, derivatized and analyzed by GC/MS. Stachybotrys chartarum isolates producing macrocyclic trichothecenes secreted significantly larger amounts of trichodiene and other sesquiterpenes than isolates which only produced simple trichothecenes. The amounts of secreted trichodiene were relatively small in all cases. With the exception of Memnoniella, which excreted small amounts of sesquiterpenes, the other isolates produced varying amounts of sesquiterpenes, including trichodiene, as well as simple tricothecenes, no detectable trichodiene, but large amounts of griseofulvin derivatives. In Stachybotrys there is apparently a correlation between trichodiene and macrocyclic trichothecene production. In the remaining isolates, there was no simple relationship between trichodiene and non-volatile trichothecene synthesis. Trichodiene is produced in larger amounts by Stachybotrys isolates, which also produce satratoxins, but it will be difficult to utilize this metabolite to detect toxic isolates in buildings due to the relatively small amounts excreted.  相似文献   

12.
Abstract

The purpose of this study was to determine radionuclide and trace element concentrations in bottom‐feeding fish (catfish, carp, and suckers) collected from the confluences of some of the major canyons that cross Los Alamos National Laboratory (LANL) lands with the Rio Grande (RG) and the potential radiological doses from the ingestion of these fish. Samples of muscle and bone (and viscera in some cases) were analyzed for 3H, 90Sr, 137Cs, totU, 238Pu, 239,240Pu, and 241Am and Ag, As, Ba, Be, Cr, Cd, Cu, Hg, Ni, Pb, Sb, Se, and Tl. Most radionuclides, with the exception of 90Sr, in the muscle plus bone portions of fish collected from LANL canyons/RG were not significantly (p<0.05) higher from fish collected upstream (San Ildefonso/background) of LANL. Strontium‐90 in fish muscle plus bone tissue significantly (p<0.05) increases in concentration starting from Los Alamos Canyon, the most upstream confluence (fish contained 3.4E‐02 pCi g‐1 [126E‐02 Bq kg‐1]), to Frijoles Canyon, the most downstream confluence (fish contained 14E‐02 pCi g‐1 [518E‐02 Bq kg‐1]). The differences in 90Sr concentrations in fish collected downstream and upstream (background) of LANL, however, were very small. Based on the average concentrations (±2SD) of radionuclides in fish tissue from the four LANL confluences, the committed effective dose equivalent from the ingestion of 46 lb (21 kg) (maximum ingestion rate per person per year) of fish muscle plus bone, after the subtraction of background, was 0.1 ± 0.1 mrem y‐1 (1.0 ± 1.0 μSv y‐1), and was far below the International Commission on Radiological Protection (all pathway) permissible dose limit of 100 mrem y‐1 (1000 μSv y‐1). Of the trace elements that were found above the limits of detection (Ba, Cu, and Hg) in fish muscle collected from the confluences of canyons that cross LANL and the RG, none were in significantly higher (p<0.05) concentrations than in muscle of fish collected from background locations.  相似文献   

13.
14.
Approximately 25, 000-35, 000 dry cleaning facilities currently operate in the U.S. The release of perchloroethylene and other solvents from these establishments represents a major source of soil and groundwater contamination. The manner in which dry cleaning solvents escape from dry cleaning plants is, for all practical purposes, identical for chlorinated and petroleum hydrocarbon solvents and is related to one of the following events: the catastrophic failure of a component of the dry cleaning system, the improper installation, operation or maintenance of the dry cleaning equipment or a combination of all of these causes. Acceptable customs, codes and regulations can also dictate what is authorized for operation of a dry cleaning facility in a particular community, geographic area during a particular time frame. Environmental litigation dealing with the origin of a solvent release from dry cleaners tends to focus on the design and manufacture of dry cleaning industry machines such as washers, washer extractors, tumblers, solvent filters, water separators, stills and spotting boards. A thorough analysis of the daily operations of dry cleaners often reveals that poor maintenance, failure to follow the manufacturer's instructions and the actions of the operator are the most likely causes of soil and groundwater pollution. In order to forensically evaluate the most probable origins of a solvent release and to examine issues regarding liability, a thorough understanding of the history of dry cleaning and a detailed analysis of the operation and maintenance of the dry cleaning equipment are necessary. The discovery of solvent plumes in the vicinity of dry cleaning plants may suggest that the solvent source is the dry cleaning plant; however, the presence of these plumes does not necessarily indicate that the dry cleaning equipment was defectively designed or manufactured. A thorough review of the type of equipment used over the life of the dry cleaning plant and verifiable solvent mileage records frequently indicates that operators of the plant have disposed of solvent and contaminated solids into the municipal sewer or on ground surfaces.  相似文献   

15.
Abstract

This paper summarizes radionuclide concentrations (3H, 90Sr, 137Cs, 238Pu, 239,240Pu, 241Am, and totU) in muscle and bone tissue of mule deer (Odocoileus hemionus) and Rocky Mountain elk (Cervus elaphus) collected from Los Alamos National Laboratory (LANL), Los Alamos, New Mexico, lands from 1991 through 1998. Also, the committed effective dose equivalent (CEDE) and the risk of excess cancer fatalities (RECF) to people who ingest muscle and bone from deer and elk collected from LANL lands were estimated. Most radionuclide concentrations in muscle and bone from individual deer (n = 11) and elk (n = 22) collected from LANL lands were either at less than detectable quantities (where the analytical result was smaller than two counting uncertainties) and/or within upper (95%) level background (BG) concentrations. As a group, most radionuclides in muscle and bone of deer and elk from LANL lands were not significantly higher (p<0.10) than in similar tissues from deer (n = 3) and elk (n = 7) collected from BG locations. Also, elk that had been radio collared and tracked for two years and spent an average time of 50% on LANL lands were not significantly different in most radionuclides from road kill elk that have been collected as part of the environmental surveillance program. Overall, the upper (95%) level net CEDEs (the CEDE plus two sigma for each radioisotope minus background) at the most conservative ingestion rate (50 lbs of muscle and 13 lbs of bone) were as follows: deer muscle = 0.22 mrem y‐1 (2.2 μSv y‐1), deer bone = 3.8 mrem y‐1 (38 μSv y‐1), elk muscle = 0.12 mrem y‐1 (1.2 μSv y‐1), and elk bone = 1.7 mrem y‐1 (17 μSv y‐1). All CEDEs were far below the International Commission on Radiological Protection guideline of 100 mrem y‐1 (1000 μSv y‐1), and the highest muscle plus bone net CEDE corresponded to a RECF of 2E‐06, which is far below the Environmental Protection Agency upper level guideline of 1E‐04.  相似文献   

16.
This study aimed to evaluate the leaching of pesticides and the applicability of the Attenuation Factor (AF) Model to predict their leaching. The leaching of carbofuran, carbendazim, diuron, metolachlor, α and β endosulfan and chlorpyrifos was studied in an Oxisol using a field experiment lysimeter located in Dom Aquino – Mato Grosso. The samples of percolated water were collected by rain event and analyzed. Chemical and physical soil attributes were determined before pesticide application to the plots. The results showed that carbofuran was the pesticide that presented a higher leaching rate in the studied soil, so was the one representing the highest contamination potential. From the total carbofuran applied in the soil surface, around 6 % leached below 50 cm. The other pesticides showed lower mobility in the studied soil. The calculated values to AF were 7.06E-12 (carbendazim), 5.08E-03 (carbofuran), 3.12E-17 (diuron), 6.66E-345 (α-endosulfan), 1.47E-162 (β-endosulfan), 1.50E-06 (metolachlor), 3.51E-155 (chlorpyrifos). AF Model was useful to classify the pesticides' potential for contamination; however, that model underestimated pesticide leaching.  相似文献   

17.
Endosulfan in China 2—emissions and residues   总被引:4,自引:0,他引:4  
Background, aim, and scope  Endosulfan is one of the organochlorine pesticides (OCPs) and also a candidate to be included in a group of new persistent organic pollutants (UNEP 2007). The first national endosulfan usage inventories in China with 1/4° longitude by 1/6° latitude resolution has been reported in an accompanying paper. In the second part of the paper, we compiled the gridded historical emissions and soil residues of endosulfan in China from the usage inventories. Based on the residue/emission data, gridded concentrations of endosulfan in Chinese soil and air have been calculated. These inventories will provide valuable data for the further study of endosulfan. Methods  Emission and residue of endosulfan were calculated from endosulfan usage by using a simplified gridded pesticide emission and residue model—SGPERM, which is an integrated modeling system combining mathematical model, database management system, and geographic information system. By using the emission and residue inventories, annual air and soil concentrations of endosulfan in each cell were determined. Results and discussion  Historical gridded emission and residue inventories of α- and β-endosulfan in agricultural soil in China with 1/4° longitude by 1/6° latitude resolution have been created. Total emissions were around 10,800 t, with α-endosulfan at 7,400 t and β-endosulfan at 3,400 t from 1994 to 2004. The highest residues were 140 t for α-endosulfan and 390 t for β-endosulfan, and the lowest residues were 0.7 t for α-endosulfan and 170 t for β-endosulfan in 2004 in Chinese agricultural soil where endosulfan was applied. Based on the emission and residue inventories, concentrations of α- and β-endosulfan in Chinese air and agricultural surface soil were also calculated for each grid cell. We have estimated annual averaged air concentrations and the annual minimum and maximum soil concentrations across China. The real concentrations will be different from season to season. Although our model does not consider the transport of the insecticide in the atmosphere, which could be very important in some areas during some special time, the estimated concentrations of endosulfan in Chinese air and soil derived from the endosulfan emission and residue inventories are in general consistent with the published monitoring data. Conclusions  To our knowledge, this work is the first inventory of this kind for endosulfan published on a national scale. Concentrations of the chemical in Chinese air and agricultural surface soil were calculated for each grid cell. Results show that the estimated concentrations of endosulfan in Chinese air and soil agree reasonably well with the monitoring data in general. Recommendations and perspectives  The gridded endosulfan emission/residue inventories and also the air and soil concentration inventories created in this study will be updated upon availability of new information, including usage and monitoring data. The establishment of these inventories for the OCP is important for both scientific communities and policy makers.  相似文献   

18.
This study is aimed at investigating the impact of water quality on the uptake and distribution of three non-essential and toxic elements, namely, As, Cd and Pb in the watercress plant to assess for metal toxicity. The plant was hydroponically cultivated under greenhouse conditions, with the growth medium being spiked with varying concentrations of As, Cd and Pb. Plants that were harvested weekly for elemental analysis showed physiological and morphological symptoms of toxicity on exposure to high concentrations of Cd and Pb. Plants exposed to high concentrations of As did not survive and the threshold for As uptake in watercress was established at 5 ppm. Translocation factors were low in all cases as the toxic elements accumulated more in the roots of the plant than the edible leaves. The impact of Zn on the uptake of toxic elements was also evaluated and Zn was found to have an antagonistic effect on uptake of both Cd and Pb with no notable effect on uptake of As. The findings indicate that phytotoxicity or death of the watercress plant would prevent it from being a route of human exposure to high concentrations of As, Cd and Pb in the environment.  相似文献   

19.
Concentrations of mono- (MBT), di- (DBT), and tri-(TBT) butyltin compounds were measured in eggs, liver, and muscle of nine species of fish from four regions of the Baltic Sea - the Firth of Vistula, the Gulf of Gdańsk, Puck Bay, and the mouth of the Vistula River. The overall concentration ranges among all the fish sampled from the four sites were: < 7 to 79 ng/g for MBT, 6 to 1100 ng/g for DBT, 7 to 3600 ng/g for TBT, and 16 to 4800 ng/g for total BTs, on a wet wt basis. The highest concentration of total BTs was found in herring liver from the Firth of Vistula (4800 ng/g, wet wt) and in roach muscle from Puck Bay (3300 ng/g, wet wt), while the least concentration was found in burbot eggs and liver from the Vistula River (39 and 32 ng/g, wet wt, respectively). TBT was the major form of BTs present in most samples analyzed. Sediment samples collected from shipyards in the Gulf of Gdańsk contained butyltin concentrations ranging from 1.2 to 46 μg/g (dry wt) for MBT, 2.0 to 42 μg/g for DBT, and 2.6 to 40 μg/g for TBT. As with the fish, the majority of the BTs in sediment were present as TBT, which suggested recent exposure of the aquatic environment of the region to TBT.  相似文献   

20.
The effect of malathion [diethyl(dimethoxythiophosphorylthio)succinate] at sublethal concentration (0.006 ppm) on intestinal parameters of cricket frog (Fejervarya limnocharis) was studied for 24 hrs to 240 hrs of exposure and remarkable histopathological alterations were observed. The study on intestinal parameters revealed acute pathological conditions in the intestinal wall. The toxic effect became evident as the cytoplasm of the cells disintegrated and the cells became empty and vacuolated. The cell membranes were also ruptured. Degenerative changes of the absorptive surface (villi) of the intestine in the different periods of exposure were pronounced. Severe atrophic nature (necrotic mucosa) of the intestine began from 48 hrs onwards to 96 hrs of exposure.  相似文献   

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