萃取/薄层色谱分离/闪烁记数法分析丁基锡化合物

为了应用同位素示踪技术研究了三丁基锡化合物在环境中的迁移转化规律,建立了萃取／薄层色谱分离／闪烁记数法分析＾１４Ｃ标记丁基锡的方法,研究了薄层色谱分离条件以及影响因素,首次测定了＾１４Ｃ标记三丁基锡在水、底泥、生物等环境样品中的回收率。     

酸化模型及其发展趋势评述

本文将酸化模型分为指标评价模型、经验酸化模型和以湖泊－流域为基础的机理模型三大类。概述了几个典型的酸化模型的结构、对参数和过程的处理方法、存在的问题和应用范围并介绍了它们的一些具体应用。还以ＭＡＧＩＣ模型为例说明了酸化模型的发展及其趋势。作为模型的一个有机组成部分,本文还阐述了酸化模型的不确定性分析。     

长江南京段沉积物中铜、镉形态对水生生物富集的影响

为了全面定量地考察沉积物中各种金属结合形态对不同水生生物富集的影响,运用重金属逐级提取法及采用人工半合成方法,对长江南京段沉积物中铜、镉形态分布不同的情况下鲤鱼和螺蛳对这两种重金属的富集进行了研究。结果表明,沉积物通过对溶解态的贡献间接影响鲤鱼对铜、镉的富集,对螺蛳富集铜、镉同时有直接和间接影响,大小顺序为：阳离子可交换态≥碳酸盐结合态＞有机物和硫化物结合态＞铁锰氧化物结合态＞残渣态。并得出了溶解态和沉积物各态对螺蛳富集铜、镉影响的贡献方程式,指出离子可交换态对富集的贡献比残渣态大10⁵倍。据此可以认为,为了减少受重金属污染河流中水生生物体内的富集量,对生活在水上、中层的鱼类来说,主要应控制水中的重金属浓度;对底栖生物来说,水和沉积物中重金属浓度都应受到控制。     

Macrobenthic Monitoring in the Lower St. Johns River, Florida

The macrobenthos in the oligohaline 132 km reach of the Lower St. Johns River, Florida, is an unusual blend of freshwater and marine organisms within the annelid, mollusk, aquatic insect, and crustacean groups. During 1993–1994, the community composition was freshwater-oriented in the 47 km (seg I) and estuarine-dominated in the lower 85 km (seg II). Of the total 146 taxa collected, 89% were euryecious 'eutrophic' and 'pollution-tolerant' organisms. Densities ranged between 5000 and 20 000 individuals/m² ann av and maximum densities (85 000 individuals/m²) occurred in the muck substrate at the confluence of major tributaries and embayments. Throughout the lake-like seg II, benthic hypoxia existed during much of summer through fall. Biotic index values for grab, artificial substrate, and sled trawl samples reflected greatest stresses to the macrobenthos then. Both low taxonomic diversity and densities of organisms at the most downriver stations nearest the port of Jacksonville indicated that toxic substances also adversely affected the macrobenthos. Maintenance of the narrow band of littoral submerged aquatic vegetation (SAV) and adjacent shoreline riparian vegetation is important to sustain macrobenthic communities and other kinds of aquatic life in the river.     

Euro Chlor Risk Assessment for the Marine Environment Osparcom Region: North Sea - Principles and Purposes -

A voluntary programme on risk assessment for chlorinated chemicals was initiated by Euro Chlor (the European Chlorine Producers Federation). The study was targeted on the marine environment, starting with the North Sea, and the methodology used was based on the European Union risk assessment principles. Details of the method used are described in this paper. A first set of five compounds is published in this special issue: chloroform, 1,2-dichloroethane, 1,1,2-trichloroethane, trichloroethylene, tetrachloroethylene.     

Temporal and Spatial Trends in Chlorinated Hydrocarbon Concentrations of Mink in Canadian Lakes Erie and St. Clair

Mink (Mustela vison) carcasses were collected from local commercial trappers from fall 1998 to spring 2003 from tributaries and marshes within 4.8km from the shores of Lakes Erie and St. Clair, including the Wheatley Harbour and St. Clair River Areas of Concern (AOCs), as well as from inland sites (8 to 40km from shore). Liver concentrations, on a lipid weight basis, of chlorinated hydrocarbons were measured and compared among sites and to tissue concentrations of mink from two previous collections from similar sites over the past 25 years. Mink from the western Lake Erie sites, which included the Wheatley Harbour AOC, had significantly higher concentrations of sum PCBs and PCB Aroclors than those from the St. Clair corridor or inland sites, with concentrations from the rest of Lake Erie being intermediate. Dieldrin concentrations were also significantly higher in western Lake Erie than many other sites, and those of oxychlordane and mirex also tended to be higher (0.05 < p < 0.1). There were no differences in contaminant concentrations between the St. Clair River AOC and the downstream non-AOC Lake St. Clair site, with the exception of slightly higher levels of octachlorostyrene (OCS). Concentrations of PCBs and other chlorinated hydrocarbons in mink showed a general decrease over the past two decades. In contrast, PCBs and some organochlorine pesticides tended to increase, significantly so with oxychlordane, in western Lake Erie mink over the same time period. DDE declined at all sites. Currently, mink liver PCB concentrations are within the range associated with reproductive impairment, as determined from captive mink studies, in 11.7% of all animals collected from the Lakes Erie and St. Clair basin overall, but in almost 40% of individuals from western Lake Erie.     

Ecosystem Consequences of Contrasting Flow Regimes in an Urban Effects Stream Mesocosm Study1

Abstract: A stream mesocosm experiment was conducted to study the ecosystem‐wide effects of two replicated flow hydrograph treatments programmed in an attempt to compare a simulated predevelopment condition to the theoretical changes that new development brings, while accounting for engineering design criteria for urban stormwater management. Accordingly, the treatments (three replicates each) differed in base flow between events and in the rise to, fall from, and duration of peak flow during simulated storm hydrographs, which were triggered by real rain events occurring outside over a 96‐day period from summer to fall, 2005. Incident irradiance, initial substrate quality, and water quality were similar between treatments. Sampling was designed to study the interactions among the treatment flow dynamics, sediment transport processes, streambed nutrients, and biotic structure and function. What appeared most important to the overall structure and function of the mesocosm ecosystems beyond those changes resulting from natural seasonality were (1) the initial mass of fines that infiltrated into the gravel bed, which had a persistent effect on nitrogen biogeochemistry and (2) the subsequent fine sediment accumulation rate, which was unexpectedly similar between treatments, and affected the structure of the macroinvertebrate community equally as the experiment progressed. Invertebrate taxa preferring soft beds dominated when the gravel was comprised of 5‐10% fines. The dominant invertebrate algal grazer had vacated the channels when fines exceeded 15%, but this effect could not be separated from what appeared to be a seasonal decline in insect densities over the course of the study. Neither hydrograph treatment allowed for scour or other potential for flushing of fines. This demonstrated the potential importance of interactions between hydrology and fine sediment loading dynamics on stream ecosystems in the absence of flows that would act to mobilize gravel beds.     

漂浮植物塘协同处理农村分散生活污水研究

通过实验考察了漂浮植物塘对经模拟化粪池简易处理的农村分散生活污水的深度净化效果,结果表明：水葫芦、大薸、聚草塘对上述污水均具有良好的净化效果,水葫芦塘对TP的去除效果最好,大薸塘对TN和NH⁺₄-N的去除效果最好。当水力停留时间为20 d时,3种漂浮植物塘的出水污染物含量可低于GB/T 18921-2002观赏性景观环境用水河道类标准。在南方农村宅沟园河内种植漂浮植物是构建农村实用生活污水收集处理系统、控制农村生活污水对河道污染的一种有效措施。     

长湖水环境质量与水生生物状况

对长湖水环境质量和水生生物状况进行了评价。结果表明：长湖水质污染属有机污染型，总体评价属V类或劣V类水质，长湖属极富营养型湖泊。藻类群落结构随季节变化，其中，夏季长湖蓝藻为优势类群；磷是长湖藻类生长的限制因子；夏秋季浮游动物数量明显高于冬春季；菹草（Potamogeton crispus）、微齿眼子菜（Potamogeton maackianus）为沉水植物主要群落类型，水生维管束植物分布占全湖面积的80％～90％，春季生物量较高；藻类与沉水植物的生长处于相对平衡的状态。     

人工湿地中植物的修复作用原理与应用实例

植物修复在水污染防治中具有重要作用,有着广泛的应用前景。本文阐述了水生植物在湿地污水净化过程中的物理、化学、生物等方面的作用及原理,例举了植物修复在不同水质条件下的应用实例,提出应针对植物复氧能力、植物种类选择和收割植物后续处理等方面进行深入研究。