沉积物监测方法和质量基准研究现状及进展

介绍了中国、美国、加拿大及ISO等国家和组织的沉积物监测方法及质量基准研究现状和进展。我国目前关于地表水沉积物的监测方法尚未形成体系,淡水水体沉积物质量基准研究还处于萌芽阶段,尚无系统的研究,同时对沉积物质量基准评价依据不统一,不能客观反映水体沉积物的质量现状。对此,提出了开展地表水沉积物污染调查,建立符合我国国情的沉积物监测方法体系,尽快制定沉积物环境质量基准,实现对沉积物质量的目标管理等建议。     

渭河沉积物中重金属释放的动态实验研究

随河流沉积物中重金属释放过程的进行，ＰＨ值所所降低，而溶出碱显著增加，碱度溶出平衡与重金属释放平衡几乎同时完成；通过验发现水流紊动强度提高，溶出碱度与重金属释放强度同步增大，反映了释放过程中重金属碳酸盐结合态的变化规律，实验结果证明，将重金属翻译放过程中泥沙运动看作为平衡沙是合理的，但试验初期，悬沙颗粒组成存在一定程度的沿程细化，悬沙颗粒的沿程细化对重金属释放动力学过程的影响不明显，对颗粒态重金属     

温榆河沉积物中重金属污染评价

对温榆河沉积物中重金属污染状况进行调查,并采用地积累指数法和Hakanson潜在生态风险指数方法评估了7种重金属的环境风险,简要分析了其潜在来源。结果表明:潜在生态风险指数法比地积累指数法更适于全面评价重金属对水生态系统的综合影响;参与评价的7种重金属中除Cd有1个点呈现中等生态风险外,其余重金属在各点均呈现轻微生态风险;Zn的较高含量可能与温榆河流域工业废水排放有关。     

浈水水体的重金属迁移与吸附特性

本文着重研究浈水河水悬浮物对Ｐｂ，Ｚｎ，Ｃｄ吸附与迁移特性。指出重金属迁移与水土流失的关系，提出减少污染物扩散的重要措施是防止水土流失。     

阳宗海表层沉积物中的重金属生态风险评估

对从阳宗海湖底表层采集的25组沉积物样品中的10种重金属质量比进行分析,结果表明,Ti、Mn、Zn、V、Cr、Cu、Ni、Co、Pb和As的质量比平均值均超过了当地土壤背景值。而重金属系统聚类分析表明,Zn、Cr、Pb、As高度相关,其污染主要由于人类活动造成;Ti、Mn、V、Cu、Ni、Co的分布特征相似,其污染原因以岩石风化等自然因素为主。单因子富集系数评价表明,阳宗海10种重金属均达到了中度富集程度,其中As、Cu、Cr富集程度较为突出。用Hakanson潜在生态风险指数法评价阳宗海表层沉积物中重金属的生态风险,结果表明,阳宗海表层沉积物中重金属的生态风险总体属轻微程度,阳宗海南岸局部区域达到中等生态风险程度。几种重金属对阳宗海生态风险的贡献由大到小依次为As、Cu、Co、Ni、Pb、Cr、V、Zn、Mn、Ti,其中,As是阳宗海最突出的生态风险因子。     

潭江下游及黄茅海沉积物重金属污染调查

通过对潭江下游和黄茅海沉积物中重金属污染的调查研究，发现潭江下游沉积物中，重金属Ni，Cd，Cu，Hg含量超标，污染较严重；黄茅海沉积物中，重金属Ni，Hg含量超标，其余6种重金属均未超标。针对调查结果，分析说明重金属含量与沉积物理化性质以及重金属之间都存在着复杂关系。     

长江重庆城区段表层沉积物重金属污染特征分析

采用污染负荷指数法、美国国家海洋大气管理局(NOAA)水体泥沙质量标准及香港公务局疏浚污泥重金属污染程度分类法,对长江重庆城区段(包括嘉陵江段(A)、汇合前长江段(B)与汇合后长江段(C))表层(0~10 cm)沉积物重金属Pb、Zn、Cu污染程度进行评价。结果表明:①重庆城区段长江水体表层沉积物重金属质量比变异较大,最低值均低于全球背景值而最高值则均超过全球背景值;②Pb、Zn、Cu平均质量比顺序为A相似文献   

漳卫南运河沉积物重金属污染及其潜在生态风险评价

本文简要介绍了Hakanson潜在生态风险指数法，并以当地土壤最高背景值为参比值对漳卫南运河表层沉积物重金属进行了评价。结果表明，漳卫南运河多数河段表层沉积物都受到重金属的中强度污染，具有较高的潜在生态风险。污染最严重的河段是卫运河的塔湾。污染最严重的重金属元素是Cd、Hg，其次是As、Cu、Cr，Zn与Pb相对污染较轻。     

海河流域典型区域重金属沉积物生态风险研究

针对水库重金属污染及其生态效应问题,分析海河流域北部4座典型水库沉积物中6种重金属(As、Cr、Cu、Ni、Pb和Zn)的分布情况,并评价污染物类型的相关性。采用地累积指数法、潜在生态风险指数法和物种敏感性分布法分析4个水库沉积物中重金属的生态风险。结果表明：沙河水库、密云水库和于桥水库的重金属沉积物生态风险等级为优,官厅水库重金属沉积物生态风险等级为良。不同重金属对5%的底栖生物物种的危害质量分数(HC5)不同,由高到低依次为As(0.210 mg/kg)>Ni(0.071 mg/kg)>Cr(0.052 mg/kg)>Zn(0.050 mg/kg)>Cu(0.006 mg/kg)>Pb(0.005 mg/kg)。研究成果有助于了解水库沉积物中重金属的生态风险,为水库生态管理提供依据。     

骆马湖沉积物重金属及营养盐污染研究

利用137 Cs定年技术对骆马湖沉积物柱状样进行了定年,同时测定了沉积物中重金属和营养盐含量的垂直剖面与水平分布。结果显示:骆马湖沉积物的平均沉积速率为3.5mm/a;在垂向上,随着沉积物深度变浅,营养盐含量逐渐升高,而大部分金属元素含量保持稳定或减少,只有Cd和Pb含量明显升高;在平面上,大部分金属元素的含量峰值出现在湖心区域,而营养盐的含量峰值出现在西部和南部湖区。可见骆马湖受人为污染影响严重的主要是重金属中的Cd与Pb和营养盐,且湖心区域污染较重。     

Assessment of element distribution and heavy metal contamination in Chilika Lake sediments (India)

Chilika Lake is situated on the Indian east coast. It is one of the largest lagoons in the world, with a unique assemblage of marine, brackish water and freshwater species. Due to the opening of new connections to the sea in the years 2000 and 2008, an environmental change is expected in the lagoon. The study gives an assessment of sediment contamination by heavy metals on the verge of this change (sampling campaign in 2000). Sediment samples from two surface levels (0–5 and 30–35 cm), and from depth profiles, were analysed for mineralogical composition, main and trace element concentrations, and element bonding forms. Background concentrations from a depth profile were also examined. The profile spans a time of ≈13 500 years. Age determinations by radiocarbon dating and the ¹³⁷Cs- and ²¹⁰Pb-method were carried out. The composition of the surface sediments is generally uniform. The heavy metals exhibit slightly decreasing concentrations from NE to SW, thus indicating the supply of contaminants from the Mahanadi River. The anthropogenic portion of the heavy metal supply is mainly bound to Fe-oxide-hydroxides. Phosphorus is enriched in the sediments of the southern lake sector. Changes in element concentrations in the last 13 500 years have occurred mainly in two steps. The long-term variations exceed the anthropogenic changes caused by the Mahanadi River inputs. The very sensitive response of coastal area fabrics on climate changes also causes fast geogenic changes in element concentrations in sediments (similar grain sizes). This prevents the use of element concentrations from deep sediment horizons to define contaminations in those areas.     

Nutrient and heavy metal storage and mobility within sediments in Kouris Reservoir,Cyprus

The objective of this study was to evaluate the risks associated with nutrient and heavy metal pollution in the water and sediments of Kouris Reservoir in Cyprus, and to recommend applicable measures to alleviate them. The reservoir drainage area contains various historic abandoned copper mines existing in an ophiolite geological substrate. Kouris Reservoir water is classified as oligotrophic to mesotrophic, with phosphorus being the limiting factor for algae growth. The thermal stratification of the reservoir enhances anoxic conditions in the reservoir hypolimnion, initiating phosphorus release back into the water column from the lake bottom sediments. The increased phosphorus release, in combination with increased water temperatures during the summer months (i.e. reaching 27 °C in August), may be the key factors enhancing the growth of microbial communities and cyanobacteria blooms. The sediment of Kouris Reservoir is classified as ‘low risk’ on the basis of the Ecological Risk Index scheme, in contrast to the Geoaccumulation Index, which indicates a moderate degree of contamination for chromium (Cr), nickel (Ni) and copper (Cu), and a high degree for lead (Pb). Heavy metals are strongly bound to the sediment matrix at pH values between 7 and 9, but can be released back into the water column at potential acid pH values. In addition, the sediments exhibit a high copper and chromium absorption affinity under current water quality conditions in the reservoir, as shown by batch absorption experiments. The experimental results suggest dredging of the reservoir sediment, and its subsequent dumping of the sediments near influent streams, would have adverse effects on the environment in the event of acid rain or other environmental changes that might acidify the sediment.     

生物炭吸附重金属污染物的研究进展

生物炭作为新型吸附剂,其物理化学特性以及其对环境中的重金属污染物的吸附固定被广泛研究。本文主要对生物炭的表征、特性以及其对重金属污染物的吸附固定的机理研究进展进行综述,并扼要对生物炭的研究方向进行了展望,为未来生物炭的应用提供一定的思路。通过文献总结,我们发现重金属在生物炭上的吸附机理的研究仍然存在矛盾之处;生物炭本身重金属毒性的释放研究是未来生物炭还田应用的研究方向;利用化学手段对生物炭进行化学修饰,以提高其吸附的有效性和针对性是在节能环保的前提下,未来生物炭发展的新方向。     

南通市河流底泥重金属污染及潜在生态风险评价

通过对南通市区5条主要河道柱状底泥样品重金属元素质量比的实验分析,探讨河道重金属污染的分布特征,并进行潜在生态风险评价。结果表明:①各重金属元素质量比均超过土壤背景值,污染较重,其中Hg污染最为严重;②重金属污染在垂直分布上分为未受干扰、正常沉积的"表层高、底层低"和受清淤治理措施影响的非正常沉积的"表层低、底层高"两种分布格局,在水平分布上具有"城市中间河流高、外围河流低"和"中上游河段高、下游河段低"的分布特征;③从重金属污染的潜在生态风险看,濠河和法伦寺河潜在生态风险强,姚港河生态风险中等,任港河和南川河生态风险轻微。各重金属元素对生态风险的影响程度大小依次为:HgCuZnCrPb。     

潮汐作用对河网区重金属输移的影响

根据相关文献,推导了只考虑溶解态和悬浮态输移过程的一维河流重金属输移模型的表达式。根据2005年12月北江镉污染事故背景资料,对该模型的参数进行率定,以分析珠江流域西、北江河网区潮汐对重金属输移的影响。设定北江上游突发污染事故与下游大、中、小潮相遭遇的情景,将情景资料代入重金属输移模型进行模拟,根据模拟结果评价了事故对佛山市水厂供水带来的影响。分析结果发现,潮汐作用造成河流内水流往复震荡,对污染物的迁移过程影响较大;不同的潮汐作用导致西江、北江的水流补给形式发生变化,进而影响污染物的传播途径;污染事故与大潮相遭遇时,对供水造成的危害要远大于与中、小潮相遭遇时。     

广州车陂涌底泥重金属污染及生态风险评价

合理处置重金属污染超标的底泥,是河道清淤工程的重点。以车陂涌清淤工程为例,通过原位测试、化学检验等,掌握河道清淤段不同位置底泥的污染特征。采用潜在生态危害指数法进行底泥污染潜在生态风险评价,得出河涌底泥低风险占31.71%、中等风险占29.27%、较高风险占2.44%、极高风险占36.59%,说明大多底泥需要处理。采用内梅罗综合污染指数法来评价底泥作为农用地土壤的适宜性,73.2%样点属于清洁,尚清洁、轻微污染各占9.8%,中度及严重污染共占7.2%,说明大部分底泥可用于农田。最后提出了该清淤工程应注意的问题,为车陂涌水环境治理提供科学依据。     

浐灞河下游河段水质模拟研究

根据浐灞河下游河段水质系统的状况,从管理角度和水质模型的空间维数来考虑,选取河流一维稳态水质模型,依据大量的实测数据率定降解系数,设定现状调查排放源、许可固定排放源与规划排放源3种工况,模拟浐灞河下游河段沿程各断面水质影响变化。通过对比3种工况对水质影响关系,得出在现状调查排放源和许可固定排放源条件下,水质受到污染;在规划排放源条件下,呈现出较好的水质状况。研究结果为河道的水环境管理提供了依据。     

闸控感潮河段重金属迁移转化规律研究

以长江感潮江段的某入江河道为典型案例,根据闸控条件下的水文特征、污染物迁移转化特性分别建立了由入江河道及长江相关河段构成的动态二维水动力及重金属数学模型,模拟分析了闸门控制下入江河道的水流运动规律、点源连续排放的重金属浓度随时间变化及二维平面分布特征。模拟结果表明:在长江潮汐、水闸控制影响下,入江河道内重金属浓度在一定范围内呈现周期性波动的现象,重金属浓度整体呈增大趋势,随着污水排放时间的推移,河道内各断面处重金属浓度最大值和波动区间均趋于稳定;典型超周期内,河道内落潮流污染带长度大于涨潮流。重金属在潮汐河道内的变化是一个非常复杂的过程,对这一过程的模拟,可以为河道水质治理和污染防治提供技术依据。     

施工截流标准风险率及其区间估计

本文分析了截流施工过程中影响截流标准风险的各种不确定性因素，建立了基于龙口落差的截流标准风险率的数学模型，研究了基于龙口落差的截流标准风险率的点估计和区间估计，给出了风险率的点估计和区间估计的计算公式。实例计算说明本文给出的模型和计算公式是符合实际的。     

River, reservoir and lake sediment contamination by heavy metals downstream from urban areas of Switzerland

This paper quantifies sediment contamination by heavy metals in four reservoirs and one lake located downstream from major urban areas in Switzerland. The waterbodies include the Wettingen Reservoir (located on the Limmat River downstream from Zürich), the Klingnau Reservoir (on the lower Aare River), the Wohlen Reservoir (downstream from Berne), the Verbois Reservoir (downstream from Geneva) and Vidy Bay (Lake Geneva, city of Lausanne). For all sediment cores and contaminants, a trend is observed from high contaminant values in the lower part of the cores, decreasing to lower concentrations in the upper part of the cores. However, for each site and each element, specific features are recognized. Applying the criteria of the Swiss ordinance on soil protection, all sediment cores must be classified as contaminated by one or more contaminants and at variable levels. From these data, it is concluded that: reservoirs and lakes located downstream from major urban centres in Switzerland have accumulated significant volumes of contaminated sediments in the past, representing the largest, but not the most intensely, contaminated sites on a national scale; the main environmental risk is remobilization of the contaminants and their return to the food chain, particularly by infiltration into the groundwater; and although the processes of remobilization are identified, the conditions of occurrence and the amplitude of the processes are still poorly known. Different options of reservoir and lake sediment management also are discussed and further research topics defined.