钱塘江流域污染负荷及水环境容量研究

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.     

基于SWAT模型对武烈河流域不同水期的水环境治理项目效益分析研究

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。     

钱塘江水系富春江段水污染现状调查研究

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。     

基于模型法的松花江流域“十一五”总量减排水质改善效益分析研究

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%。     

基于MIKE11的江南平原河网动态水环境容量分析

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。     

基于公平与效益原则的流域水污染负荷分配研究

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。     

基于SWAT模型的滹沱河流域氨氮污染负荷结构

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。     

《钱塘江流域水污染综合防治研究》通过鉴定

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…     

北运河流域(北京段)主要污染物减排措施效果评估

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。     

重庆市重污染次级河流伏牛溪水污染控制与水质改善

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。     

Evaluation of trichloroethene recovery processes in heterogeneous aquifer cells flushed with biodegradable surfactants

The ability of two biodegradable surfactants, polyoxyethylene (20) sorbitan monooleate (Tween 80) and sodium dihexyl sulfosuccinate (Aerosol MA), to recover a representative dense non-aqueous-phase liquid (DNAPL), trichloroethene (TCE), from heterogeneous porous media was evaluated through a combination of batch and aquifer cell experiments. An aqueous solution containing 3.3% Aerosol MA, 8% 2-propanol and 6 g/l CaCl(2) yielded a weight solubilization ratio (WSR) of 1.21 g TCE/g surfactant, with a corresponding liquid-liquid interfacial tension (IFT) of 0.19 dyn/cm. Flushing of aquifer cells containing a TCE-DNAPL source zone with approximately two pore volumes of the AMA formulation resulted in substantial (>30%) mobilization of TCE-DNAPL. However, a TCE mass recovery of 81% was achieved when the aqueous-phase flow rate was sufficient to displace the mobile TCE-DNAPL toward the effluent well. Aqueous solutions of Tween 80 exhibited a greater capacity to solubilize TCE (WSR=1.74 g TCE/g surfactant) and exerted markedly less reduction in IFT (10.4 dyn/cm). These data contradict an accepted empirical correlation used to estimate IFT values from solubilization capacity, and indicate a unique capacity of T80 to form concentrated TCE emulsions. Flushing of aquifer cells with less than 2.5 pore volumes of a 4% T80 solution achieved TCE mass recoveries ranging from 66 to 85%, with only slight TCE-DNAPL mobilization (<5%) occurring when the total trapping number exceeded 2 x 10(-5). These findings demonstrate the ability of Tween 80 and Aerosol MA solutions to efficiently recover TCE from a heterogeneous DNAPL source zone, and the utility of the total trapping number as a design parameter for a priori prediction of DNAPL mobilization and bank angle formation when flushing with low-IFT solutions. Given their potential to stimulate microbial reductive dechlorination at low concentrations, these surfactants are well-suited for remedial action plans that couple aggressive mass removal followed by enhanced bioremediation to treat chlorinated solvent source zones.     

Chloroaromatic pollutants in mussels incubated in two finnish watercourses polluted by industry

Concentrations of different chlorinated compounds were measured in mussels incubated in two polluted watercourses, a river (the River Kymijoki) and a lake (Lake Vanaja) for four weeks in summer 1995. The sum concentrations of polychlorinated phenols (PCP) and biphenyls (PCB) were both about 1 μg/g lipid weight (lw) in Lake Vanaja mussels, while in the River Kymijoki mussels PCPs were non-detectable and PCBs were measured 120 ng/g lIw. The concentrations of toxic polychlorinated dibenzo-p-dioxin (PCDD) and dibenzofuran (PCDF) congeners ranged between <17 and 370 pg/g Iw in Lake Vanaja mussels and between <38 and 11,000 pg/g lw in the River Kymijoki mussels. Polychlorinated diphenyl ethers (PCDE) were detected in the mussels incubated in the River Kymijoki (0.4–1.1 ng/g Iw), but not in those incubated in Lake Vanaja. Polychlorinated phenoxyanisoles (PCPA) were measured 33 ng/g lw and polychlorinated phenoxyphenols (PCPP) 300 ng/g lw in the mussels incubated in the River Kymijoki. PCPAs were also detected in reference samples, which were sediment and pike from the River Kymijoki and Baltic salmon, seal and white-tailed sea eagle.     

The variation of street air levels of PAH and other mutagenic PAC in relation to regulations of traffic emissions and the impact of atmospheric processes

The occurrence of particle associated PAH and other mutagenic PAC was determined in 1996 in the street air of Copenhagen. In addition, particle extracts were tested for mutagenicity. The measurements were compared with previous measurements in 1992/1993. The levels had decreased in this period. The decrease was caused by an implementation of light diesel fuels for buses and the exchange of older petrol-driven passenger cars with catalystequipped new ones. About 65% of the reduction was caused by the application of the light diesel fuels. Under special conditions, chemical processes in the atmosphere produced many more mutagens than the direct emissions. The concentrations of S-PAC and N-PAC were 10 times lower than those of PAH, while the levels of oxy-PAH were in the same order of magnitude as those of PAH. Benzanthrone, an oxy-PAH, is proposed to be formed in the atmosphere in addition to direct emissions. Benzo(a)pyrene, often applied as an air quality criteria indicator, was photochemically degraded in the atmosphere. A strong increase in the mutagenic activities was observed to coincide with a depletion of benzo(a)pyrene.     

Teratological effects of pesticides in vertebrates: a review

Abstract

In the last decades, the use and misuse of pesticides in the agriculture have increased, having a severe impact on ecosystems and their fauna. Although the various effects of pesticides on biodiversity have been already documented in several studies, to our knowledge no consistent overview of the impact of pesticides in vertebrates, both terrestrial and aquatic, is available. In this review, we try to present a concise compilation of the teratogenic effects of pesticides on the different classes of vertebrates – mammals, birds, reptiles, amphibians and fish.     

Book review

The Pesticide Manual ‐ A World Compendium, 8th Edition, C.R. Worthing, Editor and S.B. Walker, Assistant Editor, British Crop Protection Council, BCPC Publications Sales, Bear Farm, Binfield, Bracknell, Berkshire RG12 5QE, England. 1987, 1100 pp., UK £50; Overseas £56. ISBN 0–948404–01–9.     

Patterns of volatile metabolites and nonvolatile trichothecenes produced by isolates of <Emphasis Type="Italic">Stachybotrys,Fusarium, Trichoderma,Trichothecium</Emphasis> and <Emphasis Type="Italic">Memnoniella</Emphasis>

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.     

Observations on the influence of water and soil pH on the persistence of insecticides

Abstract

The pH‐disappearance rate profiles were determined at ca. 25°C for 24 insecticides at 4 or 5 pH values over the range 4.5 to 8.0 in sterile phosphate buffers prepared in water‐ethanol (99: 1 v/v). Half‐lives measured at pH 8 were generally smaller than at lower pH values. Changes in half lives between pH 8.0 and 4.5 were largest (>1000x) for the aryl carbamates, carbofuran and carbaryl, the oxime carbamate, oxamyl, and the organophosphorus insecticide, trichlorfon. In contrast, half lives of phorate, terbufos, heptachlor, fensulfothion and aldicarb were affected only slightly by pH changes. Under the experimental conditions described half lives at pH8 varied from 1–2 days for trichlorfon and oxamyl to >1 year for fensulfothion and cyper‐methrin. Insecticide persistence on alumina (acid, neutral and basic), mineral soils amended with aluminum sulfate or calcium hydroxide to different pH values and four natural soils of different pH was examined. No correlation was observed between the measured pH of these solids and the rate of disappearance of selected insecticides applied to them. These observations demonstrate the difficulty of extrapolating the pH dependent disappearance behaviour observed in homogeneous solution to partially solid heterogeneous systems such as soil.     

The chemical stability of formulations of some hydrolyzable insecticides in aqueous mixtures with hydrolysis catalysts

Abstract

The active ingredients in commercial formulations of malathion, oxamyl, carbaryl, diazinon, and chlorpyrifos diluted to “spray tank”; concentrations with buffered distilled or natural water of pH 4–9 were stable for at least 24 hr. Formulations of trichlorfon were not stable at pH 7 or above but disappearance rates were slower than for the pure chemical in homogeneous solution. Cupric ion was observed to be an effective catalyst for the hydrolysis of a variety of pure organophosphorus insecticides but did not catalyze hydrolysis of the active ingredients of the formulations examined. Increasing the dilution of the formulation increased the susceptibility of malathion, oxamyl, and carbaryl to hydrolysis.     

Organochlorine compounds in a three-step terrestrial food chain

The concentrations of 15 organochlorine chemicals (PCBs and pesticides) were studied in a Central European oak wood food chain system: Great tit (Parus major), caterpillars (Tortrix viridana, Operophtera brumata, Erannis defoliaria), and oak-leaves (Quercus robur). Juvenile tits receive organochlorines from the mother via egg transfer and, eventually to a greater extent, from the caterpillar food source during nestling period. The concentrations of PCB 153 (2,2′,4,4′,5,5′-hexachlorobiphenyl, the most abundant in this study) was found in leaf material at ca. 1 ng/g, in caterpillars 10 ng/g, and in bird eggs 170 ng/g on an average and on a dry mass basis.     

Knowledge transfer initiative between molecular biologists and environmental researchers and regulators

A Natural Environment Research Council (NERC) funded Knowledge Transfer (KT) workshop was held in the United Kingdom (UK) to identify the needs and opportunities in the application of molecular biology and ‘omics’ techniques to environmental monitoring and risk assessment. Attendees highlighted a lack of effective communication between end-users and researchers as well as difficulties with data interpretation as reasons behind the slow uptake of molecular biology and omics techniques. A number of promising areas in which new techniques could be implemented at a practical level in the very near future were identified, thereby raising the profile of these recent technologies and providing vital proof of concept work. Molecular taxonomy, bacterial source tracking and pre-screening of chemicals for potential toxicities were all viewed as areas in which omics and molecular techniques could have immediate value, with the aim of reducing cost, increasing efficiency and providing more comprehensive data of improved quality.