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1.
药物和个人护理品简称(PPCPs)是一类具有潜在累积效果的环境污染物,其广泛分布于水体与土壤环境中.在土壤/沉积物中,PPCPs将发生一系列的物理、化学和生物作用,其中吸附是PPCPs在土壤/沉积物中极为关键的环境行为,将影响PPCPs在环境中的迁移转化及其对生物体的危害程度.重金属作为一类常见的无机污染物,它们的存在会影响PPCPs在土壤/沉积物表面的吸附行为,对土壤/沉积物吸附PPCPs的吸附效果造成不同影响.本文归纳总结了重金属存在时,PPCPs在土壤/沉积物中的吸附机理,综合探讨了PPCPs官能团组成、重金属离子类型、pH、离子强度和有机质等因素对PPCPs吸附的影响,并针对以往研究存在的问题进行了展望.  相似文献   

2.
依据沉积学原理和水体沉积物重金属的环境地球化学特征,将地积累指数与改进的多变量Chernoff脸谱图相结合,选择江西德兴铜矿附近的乐安江表层沉积物以及德国西南部Mannheim和Worms周围若干湖泊的表层沉积物作为研究对象,开展不同地域、不同类型水体沉积物中重金属积累的对比分析和污染状况的综合性定量评价.多变量脸谱图能清晰地反映出两区域沉积物中重金属的污染特征和空间分布模式.  相似文献   

3.
羟基磷灰石对沉积物中重金属释放特性的影响   总被引:1,自引:0,他引:1  
以羟基磷灰石掺杂前后模拟重金属污染沉积物为研究对象,利用混匀释放实验及化学连续萃取法分析沉积物中重金属的释放特征及形态分布特性,考察了羟基磷灰石对重会属污染沉积物中Cu、zn、Pb、Cd稳定性的影响.结果表明不同来源模拟污染沉积物中松花江沉积物中的重金属最易重新释放,而伊通河沉积物中的重金属释放量最小;同时伊通河沉积物中残渣态重金属的比例较其它沉积物高很多,而可交换态和碳酸盐结合态的重金属比例较其它沉积物低很多,说明同时进入沉积物中的重金属,伊通河沉积物中的重金属相对稳定一些.羟基磷灰石的掺杂不同程度降低了沉积物中重金属的释放能力,促使沉积物中的重金属由较不稳定结合态向较稳定结合态转化,减小了沉积物中重金属的生物可利用性,增强了重金属的稳定性.  相似文献   

4.
依据沉积学原理和水体沉积物重金属的环境地球化学特征,将地积累指数与改进的多变量hernoff脸谱图相结合,选择江西德兴铜矿附近的乐安江表层沉积物以及德国西南部Mannheim和Worms周围若干湖泊的表层沉积物作为研究对象开展不同地域、不同类型水体沉积物中重金属积累的对比分析和污染状况的综合性定量评介,多变量脸谱图能清晰地反映出两区域沉积物中重金属的污染特征和空间分布模式。  相似文献   

5.
土壤中重金属污染现状与防治方法   总被引:20,自引:0,他引:20  
文章阐明了土壤重金属污染物来源与分布,同时对国内外土壤重金属污染治理的研究工作做了系统的综述,提出了土壤中重金属污染物防治的环境矿物学新方法,利用环境矿物材料治理土壤重金属污染物的方法,具有成本低、效果好、无二次污染及有用金属可回收利用等优点,展现出广阔的环境矿物学研究与应用前景。并提醒人们要提高土壤质量意识,保护生态环境。  相似文献   

6.
为充分了解三峡库区香溪河沉积物中重金属分布特征及其对环境风险的影响,于2017年5月和2018年5月在香溪河汛期采集了表层和柱状沉积物样品,通过电感耦合等离子体发射光谱仪(Inductively Coupled Plasma Optical Emission Spectrometer,ICP-OES)测定样品中的锌(Zn)、锰(Mn)、钡(Ba)、铬(Cr)、铜(Cu)和镍(Ni)等重金属元素的含量,同时使用地累积指数法(Igeo)和潜在生态危害指数法(RI)两种评价方法对沉积物中重金属的污染水平进行评估。结果发现:三峡库区表层沉积物在采样点各处Zn、Mn、Cr、Cu和Ni的含量变化并不明显,柱状沉积物中Ba和Zn在沉积过程中有累计作用,而Ni变化不大。重金属变异系数分析表明,表层沉积物中Cu受人类活动的影响最大,各采样点的含量变化较大,人为活动带入的污染占主导地位;柱状沉积物中Zn的垂直分布变化最明显,受到人类活动影响比其他重金属严重,根据相关性分析表明不同重金属之间可能来源相同。地累积指数法(I_(geo))和潜在生态危害指数法(RI)评价结果表明,沉积物的重金属属于无污染至轻度污染类别,处于低生态危害等级,不会对环境造成过大的危害。总体而言,三峡库区香溪河沉积物的生态危害程度较低,未发生重大重金属污染,且不同重金属之间存在相同来源。  相似文献   

7.
对珠三角两个代表性乡镇工业区的土壤(沉积物)重金属污染现状和来源进行了评价。结果表明,两工业区在主要污染元素类型和综合污染程度上很相似,表层土壤(沉积物)均以Hg、As、Cu的污染为主,且均以Hg的污染最严重;但在某些次要污染元素种类以及某些主要、次要污染元素的单个元素污染程度上存在一些差异。柱样沉积物中重金属的变化特征进一步说明,两工业区土壤(沉积物)中重金属的累积与我国尤其是本地区的工农业发展阶段和发展水平密切相关。文章最后提出了乡镇工业区土壤(沉积物)重金属污染的几点建设性防治对策。  相似文献   

8.
《环境化学》2013,(1):176
渭河流域微量元素地球化学特征及污染评价工业革命以来,随着人类活动的不断加强,大气、土壤和水环境等都受到了不同程度的污染.其中河流沉积物既接受来自大气污染物的直接沉降,又受当地工业活动、生活污水和农田灌溉等直接污染,它们可以通过食物链影响人体健康.最近10年,随着西部  相似文献   

9.
水体沉积物中的重金属会对生态系统构成直接和间接的威胁.为了研究工业化、城市化过程中城市湖泊沉积物重金属污染程度,以武汉市墨水湖为研究对象,测定了5种重金属Zn、Cu、Ni、Pb及Cr在表层沉积物中的含量,分析了其污染程度、分布特征,并对其稳定度进行了分析.结果表明,墨水湖表层沉积物重金属污染程度较重,在所有采样点5种重金属含量均高于最低效应阈值(LEL),多数采样点甚至超过了严重效应阈值(SEL);该湖泊沉积物中重金属分布具有比较明显的空间差异性:排污口区>湖中心水域>城区岸边带>林田岸边带;其稳定程度依次为:Zn相似文献   

10.
滇池及其河口沉积物中重金属污染评价   总被引:6,自引:0,他引:6  
本文对滇池及其入湖河口表层沉积物中As、Pb、Cd、Cr、Cu、Zn和Hg等重金属含量进行了分析,并采用地质累积指数法和潜在生态风险指数法评价了其污染程度和生态危害.结果表明,滇池草海北部重金属含量最高,草海及其河口重金属污染强度明显高于外海及其河口;以"全国土壤环境质量标准"为依据,As和Cd是沉积物中主要的超标污染物.地质累积指数法评价结果表明,草海及其河口沉积物中Cd达到了"严重"污染程度,是主要重金属污染物,其他金属总体处于"中度"以下污染程度;外海及其河口所有重金属基本处于"清洁"到"偏中度"污染程度.潜在生态风险评价结果表明,草海及其河口沉积物总体上达到了"很强"的潜在生态危害程度,而外海及其河口大部分区域总体属于"低度"危害程度.Cd是最主要的潜在生态危害重金属污染物,其次是Hg、As、Pb和Cu,而Zn和Cr对潜在生态危害指数的贡献率很小,在整个研究区域产生的潜在生态风险均为"轻微".相关性和主成分分析结果表明,滇池表层沉积物中Cu、Pb、Zn、Cd、Hg和As可能有相似的污染来源,而Cr主要受地球化学成分影响.  相似文献   

11.
重金属进入土壤后难以被降解,并通过食物链在生物体内富集,长此以往会导致中毒、癌症、畸形、突变,严重影响了人类生产活动及地球生态系统的稳定。植物修复技术是一种经济有效的重金属污染修复技术,其依靠超富集植物强大的自身抗性机制,从土壤中提取或稳定重金属,达到污染治理的目的。然而修复土壤重金属污染的超富集植物通常生长缓慢、生物量低,其抗性机制也会受到植物本身对重金属胁迫的阈值限制,当胁迫超过这个阈值,植物修复的效率就会大大降低甚至失去修复功能。文章在解析植物重金属相互作用机制的基础上,综述了添加外源物质对重金属毒害植物的缓解效应以及其在强化植物修复土壤重金属污染中的应用研究进展;介绍了应用外源物质调控植物吸收转运重金属的3种途径,分别为提高土壤重金属生物利用度、促进植物生长以及增强植物耐性。提出了应用外源物质作为强化植物修复措施的潜力及今后的研究方向,其未来的研究应着重于以下方面:明确外源物质的应用浓度、时期、方式与植物吸收转运重金属之间的关系;从植物内源激素及信号分子间的互作、抗逆基因表达、内生及根际微生物等不同层面上揭示外源物质对植物积累重金属的调控机理;开展外源物质与其他植物修复强化技术的联合应用研究。这些研究可为土壤重金属污染的植物修复技术及其强化措施研究提供科学依据,同时也对植物修复工程技术的发展实践具有一定的指导意义。  相似文献   

12.
黔西北土法炼锌及铅锌选矿厂对河流造成严重的重金属污染。河流沉积物中重金属的化学形态研究表明,同一采样点中不同重金属的形态分布和同一重金属在不同采样点中的形态分布均有较大差异。这可能与沉积物组分的不同亲和力,不同河段沉积物中粘土矿物、有机质、Fe Mn氧化物含量的不同以及人为活动(生活污水、选矿剂、矿渣等)的加入等有关,而碳酸盐岩地质背景的河床本身可能也有较大影响。潜在生态危害指数法研究表明,沉积物中重金属表现出强生态风险性,产生生态危害的主要重金属污染物是Pb,其后依次是Cd、Cu和Zn。  相似文献   

13.
• Metal pollution was studied in riverine sediments from different land-use areas. • Cd was the most serious heavy metal contaminant in riverine sediment cores. • Riverine sediment cores from industrial area were most polluted by heavy metals. • B1 fraction determined metal pollution, risk and toxicity in riverine sediments. Anthropogenic activities are regarded as the main sources of heavy metal pollution, yet few studies have investigated the effects of land-use setting on heavy metal accumulation in riverine sediments. Based on both total contents and geochemical fractions, heavy metal pollution, risk and toxicity were determined in riverine sediment cores from different land-use areas (mountain area- MA, farm area- FA, city area- CA, and industrial area- IA) of the Yang River Basin in North China. The results showed that FA had higher contents of riverine sedimentary Cu; CA had higher contents of Cd; IA had higher contents of both Cd and Zn. Most riverine sediments from FA and IA were contaminated with the investigated metals, although these concentrations were evaluated to have low potential ecological risk and no toxicity to benthic organisms. However, a high proportion of Cd in the B1 fraction of riverine sediments in IA indicating high risk should receive more attention. The B1 fraction largely determined the contamination, risk and toxicity levels associated with heavy metals in the riverine sediments of the Yang River Basin.  相似文献   

14.
Although Lebanon has abundant water, its rivers are polluted and aquifer water mismanaged. Effective river water usage requires an understanding of the geochemistry of polluting metals in catchments. Climate is “Mediterranean”: wet winters and dry summers. Active sediment flushing is restricted to winter high discharge episodes. Except in winter, water column pollutants are removed by precipitation or sorption to the surface of static bed sediments. Hence (1) does winter flushing of contaminated sediment and replacement by clean sediment favour self purification? (2) does the distribution of metals between extractable fractions change seasonally and thereby affect metal bioavailability ? Results on the distribution of metals are reported for Fe, Pb, Zn, Cu and Cd in bed sediments from Nahr Ibrahim (a karstic river) for summer and winter. A Tessier-like sequential extraction scheme was applied to samples (< 75 μm) for five locations along a 13 km stretch to the sea. Water pH was above 8.2 at all locations implying a very low solubility for Fe. Sediment was derived from catchment soils and limestone. Total sediment Fe increased in winter at all sites following deposition of eroded soil from upstream. Cadmium, Cu and Pb derived from polluting sources; the sources of Zn were more complex. Dilution by clean sediment explained winter reductions in total Cd, Cu and Pb; Zn changes were less consistent. Iron occurred mostly (> 77 sum of fractions) in the residual fraction compared with 6– 31 for pollutants; residual Cu and Zn showed a small increase in winter whereas Cd and Pb did not change. All readily exchangeable metals decreased in winter and the carbonate bound forms predominated in both seasons. Nahr Ibrahim has a high capacity for self purification and metal resolubilisation from sediment will be limited by the solubility of carbonate forms.  相似文献   

15.
Trace metals accumulation in soil irrigated with polluted water and human health risk from vegetable consumption was assessed based on the data available in the literature on metals pollution of water, soil, sediment and vegetables from the cites of Bangladesh. The quantitative data on metal concentrations, their contamination levels and their pollution sources have not been systematically gathered and studied so far. The data on metal concentrations, sources, contamination levels, sample collection and analytical tools used were collected, compared and discussed. The USEPA-recommended method for health risk assessment was used to estimate human risk from vegetable consumption. Concentrations of metals in water were highly variable, and the mean concentrations of Cd, Cr, Cu and As in water were found to be higher than the FAO irrigation water quality standard. In most cases, mean concentrations of metals in soil were higher than the Bangladesh background value. Based on geoaccumulation index (I geo) values, soils of Dhaka city are considered as highly contaminated. The I geo shows Cd, As, Cu, Ni, Pb and Cr contamination of agricultural soils and sediments of the cities all over the Bangladesh. Polluted water irrigation and agrochemicals are identified as dominant sources of metals in agricultural soils. Vegetable contamination by metals poses both non-carcinogenic and carcinogenic risks to the public. Based on the results of the pollution and health risk assessments, Cd, As, Cr, Cu, Pb and Ni are identified as the priority control metals and the Dhaka city is recommended as the priority control city. This study provides quantitative evidence demonstrating the critical need for strengthened wastewater discharge regulations in order to protect residents from heavy metal discharges into the environment.  相似文献   

16.
Heavy metal pollution in orchard soils is of increasing concern owing to the potential health risk via the food chain. The evaluations of the degree of heavy metal contamination and the potential sources in soils from navel orange orchards in the Ganzhou district were investigated in the present study with the geoaccumulation index and hierarchical cluster analysis. The soil samples were collected from 280 navel orange orchards located in the 18 counties of the Ganzhou district. The concentrations of heavy metals in the samples were determined using atomic fluorescence spectrometry and inductively coupled plasma atomic emission spectrometry with sample preparation by microwave digestion system. The results of the geoaccumulation index showed that the Ganzhou navel orange orchards were practically uncontaminated with Hg, As, Pb, Cd, Cr, Zn, and Cu, while uncontaminated to moderately contaminated with Ni. The results of cluster analysis indicated that four distinct clusters emerged for 18 sampling counties, and the considerable differences between clusters were derived from the different kinds of polluted substances. Results of the assessment of geoaccumulation index of heavy metals in soils will be helpful for the formulation of strategic sustainable agriculture in Ganzhou navel orchards and improvement of the navel orange yield and quality.  相似文献   

17.
通过现场采样及室内培养分析,研究了西藏当雄拉屋矿区污染土壤微生物区系组成、主要生理类群及其活性。结果表明:矿区土壤受重金属Cu、Zn、Pb、Cd不同程度污染,矿区污染土壤几种重金属质量分数比非矿区土壤有明显的增加。矿区土壤微生物区系组成和各生理类群发生了明显变化,土壤细菌、真菌、放线菌以及各生理类群数量均显著降低,且3大微生物以及各生理类群对矿区污染的敏感性大小分别表现为放线菌〉细菌〉真菌,硝化细菌〉氨化细菌〉纤维分解菌。矿区土壤酶活性较低,对照土壤的各种酶活性最高,而矿区土壤基础呼吸和代谢商则受到刺激明显提高,其中土壤脱氢酶的活性变化最大,作为矿区重金属污染的指标更灵敏。可见,土壤中微生物区系组成及参与物质转化的生理类群种类、数量及土壤酶活和微生物活性在一定程度上可反映该矿区污染生境的重金属污染特征及其生态功能的演变规律。  相似文献   

18.
通过对浙江东部沿海某典型固体废物拆解区污染土壤的调查与分析,评价了其土壤重金属的污染程度。结果表明,与土壤环境背景值相比,研究区土壤污染较为严重,Cd、Cu中等程度以上污染土壤均在50%以上。在此基础上,重点对重金属污染土壤的划定进行了探讨,提出了适合土地质量差别化管护的污染土壤表达方法。  相似文献   

19.
针对天津市景观河道底泥重金属污染进行了调研,分析了各采样点Zn、Cr、Pb、Cu、Cd 5种重金属的污染情况,采用美国NOAA标准对底泥重金属污染进行生物安全性评估和模糊综合评价,以及采用地积累指数法(排除背景值的影响)对重金属的富集程度进行了评价。结果显示:除子牙河外,天津市景观河道重金属污染都比较严重;重金属Zn、Cu、Cd对河道底泥污染的贡献较大,而Pb、Cr对河道底泥污染的贡献较小;城市工业化和开发是造成河道重金属污染的一个重要原因;"城市水环境改善与水源保护示范工程研究"的工程示范对河道水体改善作用有明显的效果,建议政府大力推广。  相似文献   

20.
为探讨深圳市农林土壤重金属的污染现状,分菜地、果园、林地和荒地等4种不同的土地利用类型,共采集了52个表层土壤样品,采用原子吸收法测定了其重金属Cu、Pb、Zn、Cd、Cr和Ni全量,单项污染指数法和内梅罗综合指数法评价了6种重金属在土壤中的污染现状.评价结果显示,部分土壤样点存在较为严重的重金属污染,Cd的污染最为严重,Cu的污染最轻;不同用地类型下的污染等级不同,荒地处于尚清洁(警戒限)水平,菜地和林地处于轻度污染水平,果园处于中度污染水平,全市农用地土壤处于轻度污染水平.  相似文献   

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