一株解磷菌ID-a修复重金属污染土壤效应分析

采用一株解磷成团肠杆菌ID-a修复陕北某工业园区长柄扁桃种植地土壤,评价了该地区土壤重金属的污染状况,分析了修复前后土壤中重金属元素Cu,Pb,Zn,Cd存在形态的变化以及解磷菌修复对长柄扁桃叶子及果实中重金属Cu,Pb,Zn,Cd的质量分数的影响。由结果可知:工业园区土壤与未污染的对照组相比Pb,Cd,Cu和Zn质量分数分别增加了24.92,4.45,18.13,77.99 mg/kg;解磷菌修复组与对照组相比土壤中可交换态Cd,Pb,Cu的质量分数显著降低,其相应的残渣态的质量分数增加。长柄扁桃叶子中Pb,Cd和Zn质量分数分别降低了95.14%,40.63%和43.87%,果实中Cu,Zn质量分数分别降低了54.06%和35.91%,长柄扁桃果实中未检测出重金属Pb和Cd。因此,该菌剂能够修复该污染区种植地土壤,提高长柄扁桃的安全性。     

铜污泥中重金属形态分布及浸出毒性分析

结合目前有色冶金工业上普遍采用的石灰铁盐法工艺特点,首次采用改进的BCR连续提取法与毒性浸出实验相结合的方法对铜污泥（中和渣与铁砷渣污泥）的重金属形态分布与浸出毒性进行了系统的研究。结果表明：采用改进的BCR方法对铜冶炼污泥重金属元素形态进行提取,形态提取具有较高的回收率;As、Zn、Pb与Cd为中和渣与铁砷渣污泥中主要的重金属元素（质量含量As＞Zn＞Pb＞Cd）,其中中和渣含As高达58 566 mg/kg（折合5.85%）,铁砷渣含As为12 582 mg/kg（折合1.26%）;两种重金属形态分布差异主要体现在As的形态分布上,铁砷渣污泥中重金属稳定性较好,特别是砷的稳定性较中和渣高;中和渣污泥中,As主要以弱酸态形式存在（占68.01%）,Zn、Pb与Cd主要以残渣态存在;铁砷渣污泥中,As、Zn、Pb与Cd主要以残渣态存在,其中残渣态As占59.21%;浸出毒性结果显示两种污泥中砷的浸出毒性都远远超过国标GB 5085.3-2007规定值,因此铜冶炼厂污泥属于含高砷危险废弃物,而以弱酸态As为主的中和渣污泥浸出毒性较高,而主要以残渣态As存在的铁砷渣污泥浸出毒性较低。     

典型铅锌冶炼渣场及其影响区土壤重金属分布及影响因素

以某省级工业园区及周边土壤为研究对象,对土壤重金属元素Pb、Cd、Cu、Zn、As、Cr、Ni的总量以及赋存形态特征进行了分析,并基于地理探测器、污染负荷指数法和风险编码法(RAC)对土壤重金属的生态风险进行评估,铅锌冶炼渣场及周围区域总污染负荷指数PLIZONE为1.82,属轻度污染水平。土壤中Cd以弱酸态为主,Cu以残渣态和可氧化态为主,Pb以可还原态为主,As和Cr以残渣态为主。风险评估编码法评价表明,Cd的酸提取态占比较高,可能存在风险,Cr无风险,其余重金属为低风险。地理探测器的因子探测表明高程、土壤有机质(SOM)、阳离子交换量(CEC)对7种重金属含量的解释力最显著,地势和土壤理化性质是重金属分布差异的重要影响因素。这些土壤环境因素可作为重金属含量空间预测模型的辅助变量,为土壤重金属污染防治提供科学依据。     

抚顺市郊农田土壤重金属元素形态分析

选取抚顺市郊农田土壤样品,采用Tessier顺序提取法研究土壤中重金属的化学赋存形态。研究结果表明:在该区域土壤中,As、Cr、Cu、Hg和Zn的形态分布以残渣态为主,Pb的形态分布以铁锰氧化态和残渣态为主,而Cd的主要赋存形态是离子交换态、腐殖酸结合态和碳酸盐结合态。研究区域土壤中除As以外其他各元素总量的平均值均高于全国土壤背景值,其重金属的形态分布主要以化学行为稳定的残渣态和化学行为相对稳定的铁锰氧化态、腐殖酸结合态为主,而Cd以化学行为较为活跃的离子交换态为主,这应当引起关注。     

某铀尾矿周边农田土壤重金属分布特征及评价

选取某铀尾矿农田周边土壤为研究对象,通过对研究区的实地调查,以重金属元素含量实测值为基础数据分析了土壤重金属Pb、Cu、Zn、Cd的纵向分布特征,并应用单因子污染指数法、内梅罗综合污染指数法相结合对该区域的重金属污染状况进行了综合全面的评价分析。结果表明:Pb、Cu、Zn、Cd这四种重金属在农田土壤纵向分布上具有较好的规律性,其中Pb的含量大多呈现递减的趋势;Cu、Zn、Cd在大多数剖面的分布则呈现出先增加后减少的趋势。采样点中重金属含量异常分布可能与当地对农田土壤施加磷肥,靠近公路遭受汽车尾气排放、灌溉水渠等人为因素以及与尾矿库横向距离有关。以单因子污染指数法评价,该地区农田土壤未受Pb、Zn的污染;Cu、Cd污染属于轻度污染。内梅罗污染指数为3.09,说明综合污染等级为重度污染,且污染程度的强弱顺序为:CuCdZnPb。     

城市典型金属加工土壤污染特征及植物毒性研究

研究了金属冷、热加工工艺对Cu、Zn、Pb、As土壤粒径分布规律、种子萌发毒性及植物富集特征影响。结果表明,金属热加工造成的土壤重金属污染浓度较高,重金属在细颗粒土壤中的浓度显著高于粗颗粒土壤。金属热加工土壤Cu、Zn、Pb主要以铁锰氧化物结合态存在,As的主要形态为残渣态;金属冷加工土壤Cu的主要形态为残渣态和有机结合态,Zn、Pb主要形态为铁锰氧化物结合态,As主要形态为残渣态。冷热加工工艺不同粒径土壤培养的小麦种子发芽势和发芽率均大于80%,对种子萌发毒性较小。重金属富集量为：Zn>Cu>Pb>As,植物富集作用和重金属总量、形态分布相关。     

石煤尾矿区土壤重金属污染风险评价

以某石煤尾矿库及周边农田表层土壤为研究对象,采用TCLP法对土壤中Pb,Cd,Cu,Zn的生物可利用态风险进行评价,并运用Hakanson潜在生态风险指数法综合评价其潜在生态危害程度。结果表明:研究区土壤中Pb,Cd,Cu,Zn的平均质量分数均高于陕西省土壤元素背景值标准;TCLP法提取的重金属质量分数与国际标准值相比较,除Cu和Zn之外,Cd和Pb元素均超标;相关性分析表明,研究区土壤中除Pb和Cu之间呈显著正相关关系,其余元素两两之间呈极显著正相关关系;潜在生态风险评价结果表明,研究区土壤中Pb,Cd,Cu,Zn潜在生态风险综合指数均值为491.71,属强生态危害程度,Cd元素是构成潜在生态风险的主要因子。石煤尾矿库已对周围土壤造成重金属污染危害。     

织金县燃煤区土壤重金属含量及其结合形态

通过Tessier和Shuman法探究了织金县燃煤区土壤中水溶态、离子交换态、碳酸盐结合态、腐殖酸结合态、铁锰氧化物结合态、强有机结合态、残渣态七种形态Zn、Pb、Cd、Ni、Cu、As、Hg等几种重金属的含量,同时测定了其土壤中各种重金属的总含量。结果显示,Zn、Pb、Cd、Ni、Cu、As、Hg等重金属在织金县燃煤区土壤中的结合形态主要以残渣态含量最高,可高达84.15%。     

鄱阳湖湿地重金属污染地质累积指数与潜在生态危害指数评价

本文用地质累积指数和潜在生态危害指数对鄱阳湖重金属污染进行评价,结果表明：（1）评价结果表明鄱阳湖区重金属污染主要为Cu污染。鄱阳湖重金属污染的主要来源是德兴铜矿,其中Cu当然是主要污染物,因此,评价结果与实际情况是吻合的。（2）Cu、Zn、Cd污染源相同且来源于德兴铜矿,Pb表现为面源污染。湖区Cu、Zn、Cd分布均表现出从饶河段至湖口逐步降低的趋势,且Cu、Zn、Cd在土壤中的含量呈现显著的相关性和偏相关性,可以推论Cu、Zn、Cd污染源相同且来源于德兴铜矿。Pb在湖区均匀分布表现为面源污染,这可能与湖区Pb污染来源于船舶燃油有关。     

改进BCR法在猪粪堆肥菜园土和果园土中重金属形态分析中的应用

利用改进的BCR四步提取法研究了猪粪堆肥下菜园土和果园土土壤中重金属的形态分布。重金属提取态包括弱酸提取态、可还原态、可氧化态及残渣态,对这四种形态的含量之和与各重金属的全量进行了比较。利用火焰原子吸收分别测定了土壤样品各提取液中Cu、Zn的含量。结果显示:改进的BCR法测得各个提取态之和回收率在94.9%~108.4%之间;猪粪堆肥下土壤中Cu、Zn主要以残渣态和可还原态为主;菜园土中Cu、Zn有效态远大于稳定态含量,果园土中Cu的有效态与稳定态变化幅度较大,Zn的有效态所占比例随土层深度基本呈递增趋势。该方法可以用以来分析土壤样品中的金属形态,且实验数据重现性好、回收率高。     

广州河涌底泥重金属污染及潜在生态风险评价

通过对广州市区六条河涌底泥样品重金属总量的实验分析,探讨河涌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:除Cu之外,Ni、Cr、Cd、Pb、Zn、Fe的平均含量远高于广东省土壤重金属环境背景值;从富集系数看,Zn的富集程度最高,其次是Cd、Pb、Cr、Cu。;由潜在生态危害系数i r E的平均值可知各重金属元素对生态风险的影响程度大小依次为Cd>Pb>Zn>Cr>Cu。     

碱熔法消解一火焰原子吸收法测定云南红壤中的铜、铅、锌、镉

采用碱熔法对云南红壤进行消解,再用火焰原子吸收法测定其中铜、铅、锌、镉的含量。结果表明,铜、铅、锌、镉的加标回收率分别为91．32％、93．OO％、120．56％、90．80％。该方法操作条件易于控制,精密度高,适用于土壤重金属元素的分析测定。     

碱熔法消解—火焰原子吸收法测定云南红壤中的铜、铅、锌、镉

采用碱熔法对云南红壤进行消解,再用火焰原子吸收法测定其中铜、铅、锌、镉的含量.结果表明,铜、铅、锌、镉的加标回收率分别为91.32％、93.00％、120.56％、90.80％.该方法操作条件易于控制,精密度高,适用于土壤重金属元素的分析测定.     

Heavy metal uptake by wheat from a sewage sludge-amended calcareous soil

The objective of this 4-year study was to determine single and repetitive effects of sewage sludge applications on the accumulation of lead (Pb), cadmium (Cd), zinc (Zn) and copper (Cu) in soil and wheat (Triticum aestivum). A single sludge application at a rate of 100 Mg ha⁻¹ (for all the metals) and at a rate of 50 Mg ha⁻¹ (for Cu) significantly increased DTPA-extractable metal concentrations 4 years later. DTPA-extractable concentrations of Pb, Zn and Cu were closely correlated with the total concentrations in soil. Their relationships between metal uptake in stalks and DTPA-extractable metal concentrations in soil were approximately linear for Pb, Cd and Cu, but better described by a quadratic equation for Cd and Zn. TF for Pb, Zn and Cu, BF for all metals and BCF for Pb, Cd and Zn were lower in wheat grown on sludge-treated than control plots.     

Concentration of trace elements in arable soil after long-term application of organic and inorganic fertilizers

The Ruzyně Fertilizer Experiment (RFE, the Czech Republic) was established on a permanent arable field (illimerized Luvisol) in 1955. The effects of long-term application of several organic fertilizers (dung water, farmyard manure, poultry litter) and mineral N, P and K fertilizers on plant-available (extracted by CaCl₂), easily mobilizable (extracted by EDTA), potentially mobilizable (extracted by HNO₃) and total concentrations of trace elements were investigated in 2008. Concentrations of all analyzed trace elements in the applied fertilizers did not exceed the limits permitted by Czech national legislation. Concentrations of As, Cd and Cr were highest in single superphosphate, those of Cu, Mn and Ni were highest in poultry litter and those of Pb and Zn were highest in dung water. Poultry litter had the second highest concentration of As and Zn. Poultry litter supplied the soils with considerable amounts of Cu, Mn and Zn and increased their concentrations in the soil. There was also a significant increase in plant availability of Mn, Ni and Zn and a decrease in soil pH. Although all fertilizers were applied for five decades, total concentrations of As, Cr, Cu, Ni, Pb and Zn in soil remained far below Czech legislation limits. For Cu and Zn this was probably due to the relatively low mean annual application rates of poultry litter. Total Cd concentrations in soil exceeded the legislative limit even in the control (without any fertilizer inputs) and the effect of treatment was not significant. This indicates that fertilizers were not the main source of Cd in the experimental area. Therefore, common cropping practices do not induce soil contamination by trace elements even if they have been applied for more than 50 years.     

ICP-AES测定土壤中的重金属

样品经加热酸消解,以ICP-AES测定其中的铜、锌、镍、铅、镉、铬。采用该方法测定土壤样品中的铜、锌、镍、铅、镉、铬,前处理操作过程简便,设备简单,成本低廉。实验结果表明,采用该法测定土壤中的重金属时,测定结果准确可靠,重复性好。     

The availability and binding of heavy metals in compost derived from household waste

Organic waste can be recycled as compost which has traditionally been used as a soil improver. As more waste is recycled as compost, it is becoming increasingly important to find alternative uses for compost. Leachability data are used to determine the environmental availability of Cd, Cu, Pb, and Zn contained in natural compost. Batch sorption data are used to determine uptake of additional Cd, Cu, Pb, and Zn by compost and assess its potential use in remediation work, as an alternative to natural materials such as peat. The relative binding of these additional metals to compost is found to be in the order Pb > Cd ≈ Cu > Zn. The sorption of metals on compost takes place, at least in part, by exchange of calcium bound to the compost and there is evidence that the sorption occurs in both humic and non‐humic sites in the compost. The use of compost to bind metals in remediation work is discussed. © 1999 Society of Chemical Industry     

Vacuum Separation Behavior of Pb from Copper-Rich Particles of Crushed E-Wastes

Due to lack of proper treatment methods, Pb pollution caused by improper treatment of electronic wastes (e-waste) has been attracting increasing attention. This paper investigates the separation behavior of Pb in the presence of Cu and other metallic particles (Cd, Bi, and Zn), in order to separate and recover various metals effectively from the copper-rich particles of crushed e-wastes. Vacuum metallurgy separation method is adopted to separate and recover Pb from the copper-rich particles of crushed e-wastes. Due to the variety and complexity of metals in copper-rich particles, this paper studies the effects of Cu, Cd, Bi, and Zn on vacuum separating and recycling of Pb. It is found that Cu particles have both a positive dispersing and a negative blocking effect on Pb evaporation. Cd can be evaporated preferentially, and then Pb can be subsequently separated for their huge vapor pressure gap. The formation of Pb-Bi alloy with a low vapor pressure makes the separation of Pb more difficult. As a result of different condensation characteristics, Pb and Zn can be evaporated together from Cu particles, and then be respectively condensed on different positions as pure Pb and Zn.     

水泥窑铅镉等重金属的污染及防治

利用原子吸收分光光度法、振荡溶出等方法,研究了水泥窑铅镉等重金属污染的防治.氟会促进Pb,Cd,Zn和Cu的逸放.无论何种水泥窑,Hg逸放率高达89%～96%.Pb,Cd,Zn和Cu在不同类型水泥窑中其逸放率有明显差别,立窑的逸放率较高,Pb和Cd为84%～90%,Zn和Cu为36%～47%;湿法回转窑次之;新型干法窑的逸放率最低.使用高效的除尘设备,不仅可减少粉尘的污染,还可减少Pb等重金属的逸放.把Pb等重金属含量较高的窑灰用作水泥混合材既可使Pb等重金属被固封于水泥混凝土中不会产生二次污染,又能减少因窑灰循环入窑而导致Pb等重金属的再次逸放.