地下水硝酸盐原位修复技术研究进展

介绍了地下水硝酸盐原位修复技术,对目前使用较多的渗透反应墙与注射井引入工程实例加以说明。指出原位修复技术不同的适用条件,同时提出浅层地下水系统本身的自然净化机制对大范围的地下水硝酸盐的防治更具经济优势。     

潼关金矿区农田土壤铅污染生态风险研究

土壤铅污染的潜在生态风险程度是土壤污染防治的前提和基础,为揭示土壤铅的潜在生态风险程度,在前期土壤污染调查评价的基础上,采用Hakanson的潜在生态危害指数法,以华阴市孟塬乡无工矿影响区的农田土壤中铅含量均值作为参比值,对矿区土壤进行了铅污染评价及潜在生态环境危害评估。结果表明：铅污染程度严重,研究区内铅污染风险总体较轻,轻度风险占样品总数的82.71%,中等占11.28%,强的占2.26%,很强占1.50%,极强占2.26%。但由于土壤中铅含量的平均值远大于中值,表明局部污染非常严重,应对高风险区进行合理治理和修复。     

濮阳东北部金堤河两岸地下水污染状况分析

采集濮阳东北部金堤河两岸的浅层和深层地下水样进行水化学分析,指出HCO3 Na型是该研究区地下水的主要化学类型。选择水化学类型为HCO3 Na型且远离非HCO3 Na型水样点集中区域的监测点的水质数据,计算出浅层和深层地下水的水化学组分对照值,并在此基础上进行地下水污染评价,确定浅层和深层地下水的污染现状和主要污染因子。结果表明:35个浅层地下水监测点中,26个点均受到不同程度的污染,主要污染因子是COD、NO2- N和NH3 N;5个深层地下水监测点中,仅靠近金堤河的2个点的数据显示受到微污染,污染因子是溶解性总固体、SO24-和NO2- N。研究区浅层地下水受人类活动影响较强,主要污染源为含氮的农药、化肥和被污染的地表水等。     

Escherichia coli survival and transfer in estuarine bed sediments

Bed sediment resuspension is a potential source of faecal microorganisms in the water column of estuaries. As such, it is important to identify the survival of faecal microorganisms in these bed sediments and understand how bed sediment resuspension impacts the quality of estuarine waters. This study explores the effect of bed sediment resuspension on Escherichia coli concentrations in the water column and the persistence of E. coli in the water column and bed sediments of the Yarra River estuary in South‐Eastern Australia. Using sediment cores, we identified that the resuspension of both surficial sediments (e.g., by tidal movements) and deeper bed sediments (e.g., by large storm events) can increase E. coli concentrations in the water column by up to 20 times in estuaries in oceanic climates. Bed sediment resuspension can result in increased E. coli concentrations in the water column even up to 24 days after E. coli first enters the estuarine water. This study demonstrates that faecal microorganisms, such as E. coli, can persist for extended periods in estuarine bed sediments, which may then be re‐entrained into the water column via recreational activities, high flow events, or tidal fluctuations. If the survival and resuspension processes observed here hold true for pathogenic microorganisms, the resuspension of bed sediments may indeed represent an increased public health risk.     

Ecological change associated with historic industrial activity in the St. Lawrence River at Cornwall,ON: A paleo-ecotoxicological assessment using subfossil chironomid assemblages

Twentieth-century historic industrial activity in Cornwall, ON loaded high amounts of metals and metalloids to the St. Lawrence River. Despite industrial improvements and the eventual closure of point-source polluters, sedimentary contamination in the Cornwall waterfront remains above provincial guidelines, causing concern for ecosystem management. We analysed chironomid (Order: Diptera) subfossils from modern-day surface-sediment samples and a sediment core from the Cornwall waterfront in order to better understand historic pollution impacts and potential recovery. Modern-day chironomid assemblages were diverse (48 genera, >70 species) and overall assemblage structure was weakly related to sedimentary zinc concentrations, with Procladius, Paratanytarsus, and Ablabesmyia identified as zinc-tolerant and Rheotanytarsus, Polypedilum and Paratendipes identified as zinc-sensitive. The sediment core showed peak total mercury (THg) concentrations were an order of magnitude higher than in modern-day surface sediments. In sections of the core below 10 cm in depth, THg concentrations were high (~30–50 µg/g) and chironomids were nearly absent from the record. Above 10 cm (c. 1980) THg concentrations decreased and chironomid taxa returned in low abundances. Subsequent intervals displayed an increase in diversity, abundance, and the relative abundance of metal-sensitive taxa. This study provides evidence of ecological change which co-occurs with Cornwall’s historic industrial activity and indicates progress toward related ecological goals identified in the current management strategy.     

西丽水库泥沙问题及对策分析

西丽水库是深圳市最重要的供水水库之一，随着周边区域开发的加剧，泥沙淤积和底泥对水质的影响已不容忽视。阐述西丽水库目前的泥沙淤积情况及底泥污染状况，并分析探讨应采取的对策。     

我国城市水污染控制和水环境综合整治标准体系框架结构的研究

研究建立城市水污染控制和水环境综合整治标准体系已列入水体污染控制与治理科技重大专项研究实施方案。着重讨论了相关背景,标准体系建立的必要性、依据和基础;提出了城市水污染控制和水环境综合整治的过程控制,标准体系的框架结构以及与相关标准体系的关系等。     

PRB技术在地下水污染修复中的研究进展

综述可渗透反应墙(PRB)的技术关键、零价铁修复的原理和PRB的最新进展和实例应用,介绍PRB技术处理地下水的技术优势及存在问题。     

地下水环境修复工艺优化设计研究进展

介绍了3种应用相对广泛的地下水修复技术,即抽出处理法、可渗透反应墙和自然降解法,重点回顾和评述了地下水修复系统优化设计的方法,探讨了结合健康风险评价体系和不确定性研究的地下水修复系统优化设计,旨在为地下水资源的修复和管理提供理论依据。     

地下水补给对河流污染物浓度衰减过程的影响

在许多河流的上游或者在河流的枯水季节,地下水的补给作用对河流水质有着重要影响.用以忽略弥散的一维水质模型为基础的、考虑地下水补给影响的新的水质模型解析解,讨论其在地下水与河流之间无水量交换和河段起始段面上游没有来水两个特定条件下的数理意义和论证该解析解的正确性.通过对比新解析解和不考虑地下水补给的经典解,讨论点源与线源之间的内在联系和本质区别,论证新解析解不是经典解的简单迭加.利用新解析解,定量研究了地下水补给强度对河流污染物浓度沿河衰减过程的影响规律.以安徽省境内颍河为例,利用实测数据研究地下水补给对河流污染物浓度的影响程度;研究表明,在枯水季节,忽略地下水补给的作用,将导致水质模型计算误差的理论值达到9.3%.