铅锌冶炼厂周边重金属的空间分布及生态风险评价

以关中西部某铅锌厂周边农田为对象,研究了厂区周边土壤中7种重金属含量的水平及垂直分布特征,用Lars Hakanson潜在生态危害指数对重金属的危害程度进行了评价.研究表明,厂区周围土壤中重金属在水平分布上具有局部高度富集的特征.以厂区为中心,重金属水平分布主要在西北-东南方向上,地势低的土壤中重金属含量明显较高;重金属在垂直分布上主要富集在0～ 25 cm的表层土壤中,且随着深度的进一步增加,土壤中重金属浓度变化幅度减弱,基本趋于稳定.厂区周边Cd和Hg污染水平为重度污染,Pb污染水平为中度污染,潜在生态危害程度为重度.     

关中清灌区农田生态系统污染现状研究

对陕西关中地区清灌区土壤、粮食、地下水及农田退水中的重金属、含氮化合物等污染物进行了分析研究,结果表明：灌区土壤重金属含量在陕西土壤背景值范围内,主要粮食作物尚未受到污染（除F外）,但地下水已受到重金属、含氮化合物的污染。同时,灌区农田退水中三氮含量较高,直接排放渭河水体后,影响了渭河水质。另外还发现灌溉能减低土壤F污染。     

江苏省某镇土壤重金属污染评价

为了解江苏省某镇表层土壤重金属污染特征,采集并测定了190个土壤样品的As、Cd、Hg和Pb 4种重金属含量,分析土壤重金属的分布特征,综合运用内梅罗综合污染指数法和污染负荷指数法两种评价方法对土壤重金属污染状况进行评价。结果表明:该镇表层土壤中As、Cd和Pb含量平均值高于土壤背景值,Hg与之相反。4种重金属都是主要受到点源污染的影响,其中As的高含量区主要分布在镇的正西边,Cd和Pb的高含量区主要分布在镇的中心区域,Hg的高含量区主要分布在东部以及东北区域。经内梅罗综合污染指数法评价,安全、警戒线、轻污染、中污染和重污染样点的比例分别为5.79%、32.11%、52.11%、4.74%和5.26%。经污染负荷指数法评价,无污染、轻度污染、中度污染和重度污染样点的比例分别为73.69%、25.26%、1.05%和0%。在内梅罗综合污染指数法和污染负荷指数法评价的结果中,有55.26%的样点评价结果相同,而44.74%的样点不同,但都显示出污染程度从镇中心向四周逐渐降低的变化态势。     

资源枯竭区不同地貌类型土壤重金属污染特征及风险评价

为探究资源枯竭区不同地貌土壤重金属污染的特征及风险，以河北峰峰矿区为研究对象，分析了213个土壤表层(0～20 cm)样品中Cd、Pb、Cu、Zn含量。结果表明，研究区土壤中4种重金属均高于河北省土壤元素背景值，4种地貌类型中土壤Cd、Pb均值分别为0.39、98.23 mg/kg,分别为背景值的4.15、4.57倍；Cd、Cu形成了局部污染；研究区的内梅罗综合污染指数和综合潜在生态风险指数分别为8.95和153.71,为重污染和中等生态风险；东部倾斜平原区中南部的Cd、北部的Pb为本区域土壤重金属形成污染的重要影响因素。     

污泥耐受性草本植物的筛选及其对重金属Cu、Zn的富集

为探索植物修复污泥中重金属污染的可行性,配制不同污泥含量的介质土开展盆栽实验,对从河南、云南和上海等地收集的抗逆性强的19种草本植物进行污泥适应性筛选；研究了植物对污泥的生理响应及其对重金属Cu、Zn的吸收和分布.结果表明,上海市浦东新区白龙港污水处理厂污泥农用是可行的,农用时污泥比例应控制在60％以下；筛选出三叶鬼针草、稗子、荆芥和金叶马兰4种污泥耐受性植物；三叶鬼针草具有修复重金属Cu、Zn污染土壤的潜力；稗子具有修复重金属Zn污染土壤的能力；金叶马兰具有修复重金属Cu、Zn污染土壤的能力.     

苏北灌溉总渠灌区土壤砷污染及调查研究

在对苏北灌溉总渠沿线灌区土壤采样分析的基础上,评价该灌区砷的污染状况,探讨了土壤中As的含量、分布、成因及其与人类活动的关系。结果表明,长期利用污水灌溉,导致砷在灌区耕层产生累积,土壤受到一定程度的污染,应当引起关注。     

桉树人工林地土壤养分和重金属现状分析与评价

为了评价大面积人工种植桉树对当地土壤养分变化和重金属富集效应的影响，本研究以普洱市3.75万hm²桉树人工林为研究对象，通过定位观测并将其与当地次生林、撂荒地进行比较，分析土壤养分变化情况、重金属污染等级以及两者之间的相关性。结果表明，桉树林表层土壤养分的含量均高于背景值，其中有效磷、水解性氮、全磷、全钾、有机质和速效钾极显著高于撂荒地（P<0.01），全氮略高但差异不显著；与次生林相比，桉树林土壤养分全氮和水解性氮显著低（P<0.05），全钾和全磷的含量显著高（P<0.05），有效磷的含量极显著高（P<0.01），有机质和速效钾略高但差异不显著。桉树林表层土壤样品重金属综合污染指数为1.08，低于撂荒地的1.14而高于次生林的0.67，说明桉树林土壤已处于轻微度污染等级，有可能会引起农作物污染，其中铅、锌、铜、镍、砷和铬等6种重金属含量处于安全水平，而镉的单因子污染指数值介于1~2之间，表明桉树林土壤属于轻度镉污染，但相关性分析结果表明，桉树林表层土壤养分的含量与重金属的含量无显著相关。     

煤矿复垦区土壤重金属分布特征与质量评价

为保证煤矿复垦区种植农作物的充填复垦土壤的生态安全,以淮南矿区煤矸石充填复垦地为研究对象,通过对研究区内Cd、Cr、Ni、Pb、Cu、Zn和Hg 7种重金属不同深度含量分析,总结其纵向分布特征,并将研究区土壤重金属含量与淮南市土壤背景值、《土壤环境质量标准》(GB 15618-1995)作比较,分析这7种重金属的污染程度.结果表明,这7种重金属都有不同程度的污染,其中土壤受Cd污染最严重,土壤中重金属垂直方向上无确定分布规律.总体而言,土壤重金属潜在生态风险属于强生态危害.从垂直方向来看,重金属潜在生态风险指数(RD随着深度的增加出现先下降后升高的趋势,其中40～60 cm深度的RI最大.重金属生态危害程度依次为Cd＞ Hg＞ Ni＞ Cu＞ Cr＞ Pb＞ Zn,其中Cd为矿区土壤中最主要的重金属污染生态风险因子.     

铜污染土壤电动修复研究

应用实验方法研究了土壤重金属污染的电动力学修复方法，分析了土壤重金属污染物的迁移和变化特征。实验结果表明，在电场作用下土壤中重金属的浓度分布发生明显变化，使得大部分重金属能在电极附近富集而被去除。当实验的电场强度为0.5 V/cm时，在阳极附近土壤中铜的去除效率达到71.1%。阳极附近的pH值由开始时的6.8逐渐变小到4.4，而阴极附近则相反，由开始时的6.6逐渐增大到9.1，此外电动修复过程中电极附近的温度会发生相应的变化。     

EDTA对土壤中Pb的赋存形态分布的影响及其环境意义

研究了 EDTA淋洗重金属污染土壤前后 Pb的赋存形态的分布变化。结果表明 ,EDTA淋洗后的土壤中 Pb主要以残渣态和酸可提取态存在。酸可提取态 Pb含量的增加对于运用植物提取技术修复 Pb污染的土壤是有利的     

不同土壤重金属复合污染的有效态离子冲量表征

选择红壤、黄棕壤和潮土为对象，依据中国土壤环境质量二级和三级标准确定土壤重金属铜、锌、镉的污染浓度，通过生物盆裁试验研究在重金属Cu、Zn、Cd复合污染条件下牧草（黑麦草、紫花苜蓿）体内重金属含量和土壤中重金属有效态含量的相关性，结果表明，在3种不同性质的污染土壤上，牧草体内重金属的离子冲量与其对应土壤中重金属有效态的离子冲量之间均存在明显的相关性。校正土壤pH、牧草品种等因素后，土壤有效态离子冲量可以有效表征不同土壤-牧草系统的重金属复合污染。     

某矿区土壤和地下水重金属污染调查与评价

为了解湘南某矿区土壤和地下水重金属污染状况，对该矿区东河流域附近重金属污染源进行了调查，同时，对地下水和土壤样品进行了采样分析，结果表明：（1）该矿区东河流域附近的主要污染源有18个，其中有色金属选厂、尾矿库、采矿场和冶炼厂是排放重金属较多的污染源；（2）20个采样点中土壤重金属Pb、Cd、Zn、As和Hg大部分超过国家土壤环境质量标准（GB15618-1995），综合污染指数P综〉1，该矿区主要的重金属污染元素为Cd、As和Hg，且土壤中Cd、Zn和As的含量两两之间存在着极显著的正线性相关关系；（3）重金属元素在土壤中的纵向迁移不明显，该矿区附近20个采样点的地下水并未受到污染，综合污染指数P综〈1。20个采样点地下水Pb、Cd、Zn、As、Hg浓度均能达到地下水质量标准（GB／T14848．9）中的Ⅲ类标准。     

SBR法处理麻生物脱胶废水

利用 SBR工艺处理麻生物脱胶废水 ,对 CODcr、NH3-N的降解、SBR厌氧段和处理后水是否可回用进行了研究。实验结果证明 ,当进水 CODcr 15 0 0 mg/ L左右 ,MLSS的 CODcr负荷≤ 0 .74kg/ kg· d时 ,废水各项指标均可以达到 GB8978-1996苎麻脱胶废水综合排放二级标准 ,且可回用脱胶     

雷州半岛土壤重金属分布特征及其污染评价

在雷州半岛采集了106个土壤表层样品,分析了其中8种重金属元素(Cu、Pb、Zn、Cr、Ni、Cd、Hg和As)的全量.结果表明,雷州半岛土壤重金属污染由高到低排序为Ni＞Cr＞Hg＞Cu＞Zn＞Cd＞As＞Pb,Zn、Cd、As和Pb质量浓度均没有超标,Hg和Cu质量浓度超标率亦不高,但Ni和Cr平均质量浓度达49.81、87.13 mg/kg,高于国内外其他对照区域,超标率分别为25.47%和24.53%;重金属元素在雷州半岛各土壤利用类型中分布规律不明显,按4种主要土壤利用类型受重金属污染程度大小排序为甘蔗地＞果园土＞水田＞菜地;雷州半岛土壤综合污染指数总平均为0.970,土壤总体上尚清洁,重金属污染处于警戒水平;雷州半岛各区域中,徐闻、雷州两地土壤重金属质量浓度明显高于其他地区,其主要原因是徐闻、雷州两地成土母质主要为玄武岩,造成土壤Cr、Ni及其他重金属背景值较高.     

Assessing heavy metal pollution in the surface soils of a region that had undergone three decades of intense industrialization and urbanization

Heavy metals in the surface soils from lands of six different use types in one of the world’s most densely populated regions, which is also a major global manufacturing base, were analyzed to assess the impact of urbanization and industrialization on soil pollution. A total of 227 surface soil samples were collected and analyzed for major heavy metals (As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, and Zn) by using microwave-assisted acid digestion and inductively coupled plasma–mass spectrometry (ICP-MS). Multivariate analysis combined with enrichment factors showed that surface soils from the region (>7.2?×?10⁴ km²) had mean Cd, Cu, Zn, and As concentrations that were over two times higher than the background values, with Cd, Cu, and Zn clearly contributed by anthropogenic sources. Soil pollution by Pb was more widespread than the other heavy metals, which was contributed mostly by anthropogenic sources. The results also indicate that Mn, Co, Fe, Cr, and Ni in the surface soils were primarily derived from lithogenic sources, while Hg and As contents in the surface soils were controlled by both natural and anthropogenic sources. The pollution level and potential ecological risk of the surface soils both decreased in the order of: urban areas?>?waste disposal/treatment sites?～?industrial areas?>?agricultural lands?～?forest lands?>?water source protection areas. These results indicate the significant need for the development of pollution prevention and reduction strategies to reduce heavy metal pollution for regions undergoing fast industrialization and urbanization.     

Health risk assessment of heavy metals in soil-plant system amended with biogas slurry in Taihu basin,China

Biogas slurry is a product of anaerobic digestion of manure that has been widely used as a soil fertilizer. Although the use for soil fertilizer is a cost-effective solution, it has been found that repeated use of biogas slurry that contains high heavy metal contents can cause pollution to the soil-plant system and risk to human health. The objective of this study was to investigate effects of biogas slurry on the soil-plant system and the human health. We analyzed the heavy metal concentrations (including As, Pb, Cu, Zn, Cr and Cd) in 106 soil samples and 58 plant samples in a farmland amended with biogas slurry in Taihu basin, China. Based on the test results, we assessed the potential human health risk when biogas slurry containing heavy metals was used as a soil fertilizer. The test results indicated that the Cd and Pb concentrations in soils exceeded the contamination limits and Cd exhibited the highest soil-to-root migration potential. Among the 11 plants analyzed, Kalimeris indica had the highest heavy metal absorption capacity. The leafy vegetables showed higher uptake of heavy metals than non-leafy vegetables. The non-carcinogenic risks mainly resulted from As, Pb, Cd, Cu and Zn through plant ingestion exposure. The integrated carcinogenic risks were associated with Cr, As and Cd in which Cr showed the highest risk while Cd showed the lowest risk. Among all the heavy metals analyzed, As and Cd appeared to have a lifetime health threat, which thus should be attenuated during production of biogas slurry to mitigate the heavy metal contamination.     

Assessing heavy metal sources in agricultural soils of an European Mediterranean area by multivariate analysis

According to the European Thematic Strategy for Soil Protection, the characterization of the content and source of heavy metals in soils are necessary to establish quality standards on a regional level that allow the detection of sampling sites affected by pollution. In relation to this, the surface horizons of 54 agricultural soils under vegetable crops in the Alicante province (Spain), a representative area of the European Mediterranean region, were sampled to determine the content of Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn. Analytical determinations were performed by atomic absorption spectroscopy after microwave sample digestion in acid solution. Results indicated that heavy metal levels were similar to those reported by authors working on agricultural soils from other parts of the Mediterranean region, with the exception of Cu and Pb in some samples. Multivariate analysis (principal component analysis and cluster analysis) was performed to identify a common source for heavy metals. Moreover, soil properties were determined in order to characterize agricultural soils and to analyze relationships between heavy metal contents and soil properties. The content of Co, Cr, Fe, Mn, Ni and Zn were associated with parent rocks and corresponded to the first principal component called the lithogenic component. A significant correlation was found between lithogenic metals and some soil properties such as soil organic matter, clay content, and carbonates, indicating an important interaction among them. On the other hand, elements such as Cd, Cu and Pb were related to anthropic activities and comprised the second (Cu and Pb) and third principal components (Cd), designated the anthropogenic components. Generally, Cd, Cu and Pb showed a lower correlation with soil properties due to the fact that they remain in available forms in these agricultural soils. Taking into account these results and other achieved in other parts of the European Mediterranean region, it can be concluded that soil quality standards are highly needed to declare soils affected by human induced pollution. This is particularly relevant for anthropogenic metals (Cd, Cu and Pb, and in some areas also Zn). Further research in other agricultural areas of the region would improve the basis for proposing such soil quality standards.     

巢湖合肥地区洗衣粉排磷占入湖磷贡献率的研究

合肥地区人均洗衣粉用量为3．12kg/a,洗衣粉总用量为8345t/a,洗衣粉带入水体的总磷量为256．08t/a,占入湖总磷负荷量的13．62％。因此,实行“禁磷”措施后,可削减该地区入湖总磷负荷量的13．62％,对改善巢湖水质将会起到一定的积极作用。