给水处理中有机锡化合物的污染

运用SPME-GC-MS检测方法,对重庆市A、B两净水厂净水过程中丁基锡和苯基锡的污染状况进行了研究,并对有机锡污染来源和不同城市净水过程中有机锡污染状况进行了探讨。结果表明:A、B两水厂净水过程中MBT检出率最高(最高浓度为120.8ngSn/L),其次是DBT、MPT和DPT,偶尔检测到TPT(2.8ngSn/L),没有检测到TBT;A、B两水厂的有机锡均来自受污染水源,A水厂取水口上游仅0.1km处检测到较高浓度的TBT(161.8ngSn/L),对A水厂饮用水安全造成威胁;重庆A、B两水厂有机锡污染明显轻于同期天津某水厂有机锡污染;国内净水厂有机锡污染主要来自受有机锡污染的水源,而加拿大给水中有机锡污染主要来自用作给水输配水管道的PVC管材的析出。     

Concentration and distribution patterns of naturally occurring radionuclides in sediments and flood plain soils of the catchment area of the river Elbe

The impact of uranium mining and milling as well as that of traditional mining activities on river sediments and flood plain soils in the catchment area of the river Elbe was investigated over the years 1994 to 1995. Contamination resulting from mining activities has been identified by comparing the median values for the measured radionuclides, and by establishing the ratio between Ra-226 and Ra-228. The transport and deposition of contaminated materials as a result of high water events, and river discharge of waste water from mining and milling facilities, can be considered to be the main paths of sediment and soil contamination. Sediments and flood plain soils located in the vicinity of former uranium mining and milling sites are primarily influenced by discharges of waste water. Long distance transport and deposition at dams, barrages and on flood plains has mainly been caused by high water events. In many cases the radionuclide concentrations were higher in the subsurface layer than in the top layer of flood plain soil. Due to termination of uranium mining and milling activities, no significant contamination of newer or fresh sediments was found. Radiation exposure arising in relation to angling or walking on flood plains is low.     

Identification of gas supersaturation sources in the Upper Colorado River,USA

Atmospheric gas saturation levels were monitored throughout a 40‐km reach of the upper Colorado River during the summer and fall of 1995 to identify possible sources of gas supersaturation in the river. Gas saturation data from seven fixed sampling points and 40 random sampling points were analyzed using analysis of variance (ANOVA) and multiple regression methods. The lowest total gas saturations (ΔP=−27) were found at the bottom release of Williams Fork Reservoir. The highest total gas saturations (ΔP=77) were found at the spillway release of Windy Gap Reservoir and the confluence of Willow Creek and the Colorado River. Spacial and temporal effects were determined to be significant contributors to gas saturation levels. Gas supersaturation in the study area originated from both man‐made and natural sources. Water discharged from the spillway of Windy Gap Reservoir was found to be the main source of man‐made supersaturation, while photosynthetic activity of aquatic plants was determined to be the natural source of supersaturation in the study area. Copyright © 1999 John Wiley & Sons, Ltd.     

青海省副秘书长毛占彪：实施生态立省 切实加强三江源生态环境保护与建设

为认真贯彻党的十七大精神,深入贯彻落实科学发展观,2007年,青海省委、省政府审时度势,不断深化对省情的认识,立足青海生态的脆弱性、独特性和重要性,着眼于建设生态文明,做出了生态立省的战略决策。三江源区在全省五大生态功能区中区域面积最大,人口最多,生态地位最为突出,是生态保护和建设的重点地区。今后,我们将坚持生态立省,采取生物、工程、经济、法律等综合手段,构筑好高原生态屏障,为促进长江中下游地区科学发展做出不懈努力。     

Distribution, sources and ecological risks of polycyclic aromatic hydrocarbons in an urban landscape river

The contents of 16 priority water-borne polycyclic aromatic hydrocarbons (PAHs) in water, potential external pollution sources and sediment from the famous landscape of the Qinghuai River were measured by gas chromatography-mass spectrometry (GC-MS). The distribution, composition, source and ecological risk of PAHs were analyzed. The following results were obtained: (1) Benzo[a]pyrene and benzo[ghi] perylene were not detected in all samples. The total contents of 16 priority PAHs (PAH16) varied from 52.5 to 745.3 ng l(-1) with the average of 174.0 ng l(-1) in water, from 96.0 to 1,064.6 ng l(-1) with the average of 329.2 ng l(-1) in potential sources, from 931.7 to 15,295.5 ng g(-1) with the average of 7,133.6 ng g(-1) in sediments. (2) The concentration of PAH16 in water is lower than in sediment and higher rings are more easily detected in sediment. The percentage of higher ring (four- to six-rings) PAHs accounted for more than 55.6% of PAHs in sediment. (3) The value of FLA/(FLA+Pyr) was higher than 0.5 at most sampling points which illustrated the source was related with petrogenic such as liquid fossil fuel combustion. (4) The potential ecosystem risk of low ring PAH for upstream conflux of external Qinhuai River was less than 10%, while it was 10-50% for other sampling points; The four rings PAH shows lower potential ecosystem risk than other ring PAH in this study area; Dibenzo [ah] anthracene (DahA) shows high potential ecosystem risk at all sampling points.     

The Elbe flood in August 2002--occurrence of polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans (PCDD/F) and dioxin-like PCB in suspended particulate matter (SPM), sediment and fish.

As a result of extreme precipitation in August 2002 major flooding occurred in the catchment area of the rivers Elbe, Vltava (Moldau) and Mulde. Pollutants from industrial sites and from municipal sewage treatment works (STW) entered the Elbe and led to a serious pollution problem in the river. PCDD/F concentrations (in pg WHO-TEQ/g dw) in SPM ranged from 7-150, in sediments from 3-140; the "safe sediment value" of 20 was exceeded in 46% of the samples. 24 eels showed a wide concentration variation for these contaminants. The WHO-PCDD/F+PCB-TEQ values lay in the range from 11-56 pg/g ww, whereby the WHO-PCB-TEQ values were several times higher than the WHO-PCDD/F-TEQ values. The maximum permitted value of 4 pg WHO-PCDD/F/g ww (EU Directive No. 2375/2001) was reached or exceeded in 54% of the individuals. A statistical analysis using data from SPM and sediment samples showed that in the Czech river section the flooding activated a contamination source in the vicinity of the Spolana works. The influence of the tributary Mulde could be clearly demonstrated. Only a major clean-up of the contaminated sites in Bitterfeld can lead to a mid to long term improvement in respect of PCDD/F and dioxin-like PCB input into the Elbe.     

重庆河段卵石来源来量及特征研究

随着三峡工程蓄水发电,作为三峡水库库尾的泥沙(包括卵石)状况备受关注.在重庆河段卵石没有经过大规模挖掘,河段卵石还基本处于天然状况的情况下,长江水利委员会荆江局于1991年经过大规模的坑探、水下取样和调查,获得了大量卵石实测资料.通过分析和较为系统的研究,基本阐述了重庆河段原型卵石特征、物质来源并估算了卵石来量.按寸滩多年实测推移质平均值28万t/a计算,嘉陵江年汇入总量为5.85万t,长江相对汇入总量为22.15万t,长江上段和嘉陵江卵石年汇入总量比值约为4∶1.     

城市水源地突发污染事故风险源项辨识与分析

我国许多城市正处于高速的城市化进程之中,水源保护和城市发展之间的矛盾逐渐显现,突发性水源污染已成为一个日益突出的问题。对城市水源地突发水污染事故风险源进行了辨识及分类,提出了水源地突发水污染事故风险源项的分析方法,以及城市水源地突发性水污染事故应急管理措施等。以黄浦江水源地突发性水污染事件为案例进行了风险识别,表明准水源保护区内的工业污染源以及流域内的船舶航运污染源是目前威胁黄浦江水源地取水口安全的最主要的风险源。     

"三江源"地区生态修复与环境保护初探

青海省"三江源"地区是我国重要的高原湿地和水源涵养地,也是生态非常脆弱、生态问题突出的地区之一.保护好"三江源"地区的生态与环境不仅对民族地区的经济发展和社会稳定有利,而且对支持长江、黄河、澜沧江中下游地区的可持续发展意义重大.对保护好"三江源"地区的生态与环境,提出了对策和建议.     

三江源区生态与环境保护的监督管理对策

三江源区是我国生态与环境保护的关键地区，其生态与环境的变化直接关系到我国的生态安全。要建立三江源区生态与环境保护的长效机制,应确立有利于三江源生态与环境保护的发展模式，制定并实施切实有效的政策和法律，健全完善监督机制,提高三江源区生态与环境保护的科技支撑能力，加强公众对生态与环境保护的广泛参与。     

非点源污染河流水质的人工神经网络模拟

本文应用非点源污染河流水质的BP人工神经网络模型,模拟长乐江水体的总氮、总磷和溶解氧浓度的变化。通过模拟的水质参数相关性分析,协同非点源污染河流的机理性水质模型分析,确定适当的BP网络模型结构。采用实测的水质、水文逐月数据资料,对不同结构的BP网络模型进行了训练与验证。结果表明,相关性与机理性模型协同分析的方法,能较好地解决BP网络输入层参数的选择问题,所选择的参数较全面地表达了流域非点源污染发生的主要驱动因素和河流中污染物自净过程的主要影响因素。BP网络模型可以较精确地模拟非点源污染河流的水质变异,各水质参数模拟结果的平均相对误差在±10%以内。单隐含层结构的BP网络模型模拟结果比多隐含层结构模型结果更准确;单参数输出结构的网络模型模拟结果,优于多参数输出结构模型的模拟结果。     

长江饮用水源地水质监测保障系统研究

研制并实施了长江张家港市饮用水源地监测保障系统,将水源地水质自动遥测预警系统、移动应急监测系统、实验室固定监测系统和突发事件应急对策预案4个子系统有机结合,解决了国内水质监测工作中的数据准确性、连续性和实时性不能兼顾的难题.该系统大大减少野外水质遥测站的单站建设投资及年运行和维护费用;在发生污染事故时,可以提前部署各项应急工作,有效地减少了饮用水源污染的危害.     

P-pollution in a heavily urbanized river basin from point and diffuse sources: the River Ruhr case study (Germany).

An area-differentiated model approach (MEPhos) for the quantification of mean annual P-inputs from point and diffuse sources is presented. The following pathways are considered: artificial drainage, wash-off, groundwater outflow, soil erosion, rainwater sewers, combined sewer overflows, municipal waste water treatment plants and industrial effluents. Based on the modelling results "hot spots" for high P-loads can be localized and management option for the input reduction to surface waters proposed. The model is applied to the River Ruhr basin (4,485 km2) in Germany with contrasting natural conditions, land use patterns as well as population and industry densities.     

Methods to quantify and identify the sources of uncertainty for river basin water quality models.

Worldwide, the application of river basin water quality models is increasing, often imposed by law. It is, thus, important to know the degree of uncertainty associated with these models and their application to a specific watershed. These uncertainties lead to errors that are revealed when model outputs are compared to observations. Such uncertainty is typically described by calculating the residuals. However, residuals should not be seen as an estimate of total uncertainty, since through the calibration process, the residuals may be reduced by over-adjustment to the data, which is typically the case for over-parameterised models. Over-adjustment during a calibration period can also lead to highly biased results when the model is applied to other periods or environmental conditions. The total model uncertainties are, therefore, assessed by four components: the sum of the squares of the residuals (SSQ), parameter uncertainties (that can be ignored when their error is much smaller than SSQ), input data uncertainties, and an additional predictive uncertainty that is expressed when the model appears to be biased when it is applied for data other than the data used for calibration. The sources are ranked according to a quantification criterion (magnitude) as well as an identification criterion that depends on the number of observations that are covered by the confidence region. This approach is illustrated with SWAT2003 simulations for flow and sediment of Honey Creek, a tributary of the Sandusky River basin (Ohio). The results show the dominance of the model uncertainty. The input data uncertainty is less important.     

岷江源头植被景观与土壤侵蚀强度相关性研究

土壤侵蚀生态过程复杂,常常受空间景观异质性影响.深入研究土壤侵蚀与景观的相关性对旨在减少水土流失的流域生态恢复工作来说十分重要.利用遥感和GIS技术对岷江源头区(约11 100 km2的集水盆地)的植被景观和土壤侵蚀强度的变化(1974、1994年2002年)进行了分析,并从景观水平上分析了该区域土壤侵蚀强度与植被景观变化的相关性.研究结果表明,植被景观的香农多样性指数、景观破碎度指数、景观形状指数和景观聚集度指数均与土壤侵蚀强度有明显的相关性.在侵蚀强度较低的区域,植被景观的多样性更为丰富,其组分和结构更加复杂,破碎程度更低,斑块形状更为复杂,且空间异质性也更强.     

德惠市浅层地下水污染源识别及空间分布

为实现德惠市浅层地下水的污染源识别及其空间分布特征研究,收集德惠市2014年43组水质资料,进行水化学特征统计分析,在此基础上采用因子分析法进行多元统计分析,提取5个公因子(F1—F5)分别为矿化度、有机物和硝酸盐氮、氨氮、铁锰、氯化物作为浅层地下水水质的主控因子,进一步分析其污染物来源,并根据因子得分利用ArcGIS差值工具绘图分析各污染源的污染程度及空间分布特征。结果表明:5个公因子(F1—F5)的方差贡献率分别为19. 947%、14. 082%、13. 661%、12. 630%和12. 144%。其中,有机物和硝酸盐氮、氨氮(F2、F3)是研究区内的主要污染物,受控于人为作用;矿化度污染则受控于迁移-富集作用;铁锰、氯化物污染分别受控于自然作用和地表水地下水交互作用。研究区范围内,城区、郭家镇、菜园子镇、大房身镇、五台乡污染较严重,其他乡镇水质状况良好;依据综合得分可以将浅层地下水划分为3个区域:禁止开采区、农业用水区和生活饮用水区,评价结果可以为政府决策提供参考。     

Historical changes of a large river in an urban area: The Garonne river,Toulouse, France

Man-made structures have greatly modified the flow pattern of the Garonne River at Toulouse (France) since at least the 12th century. The first of many small dams was constructed in 1182. Destructive floods regularly destroyed the dams, flooded protions of the city, changed the river course, and destroyed the wooden bridges, the first of which was probably built during the first half of the 13th century. The first stone bridge was completed in 1660, after a 100 year period of constuction. After 1680 attempts to control the river led to a variety of river responses: increased sedimentation in some locations and erosion in others, a reduction in the number of islands from seventeen to four, and a 63 per cent reduction in the length of shoreline in the urban area of Toulouse.