污染土壤重金属检测标准样品在能力验证工作中的应用研究

标准样品在能力验证工作中的使用越来越广泛,但是由于能力验证对样品验证结果评价方式的不同,环境基体标准样品在能力验证工作中的应用还需进一步研究。考察了一种新研制的重金属污染地区土壤标准样品在能力验证工作中的应用。结果表明,能力验证的指定值与标准样品的标准值一致,说明能力验证统计数据无显著偏离;标准样品的均匀性和稳定性引入的不确定度小于0. 3σ(σ为能力评定标准差),不会对参加实验室的能力评定产生影响;该次能力验证参加实验室的满意率约为80%,与测试背景土壤的满意率接近,说明实验室检测污染土壤中铅、镉、镍、铜、铬的水平和检测背景土壤的能力水平相当。     

TCLP法对天津市农田重金属生态风险评价

TCLP法是用缓冲剂提取重金属的一种方法,该法评价重金属生态风险在美国已开展多年。利用TCLP法对天津市某农田土壤重金属进行生态风险评价,结果表明,在采集的23个样品中有效态铜、铅、锌、镉的含量范围为1.13~5.26、2.11~5.22、2.60~30.6、1.09×10-3~77.9×10-3mg/kg,普遍低于铜、铅、锌、镉在土壤中的总量(22.1~66.8、21.2~50.6、56.8~445、0.04~0.20 mg/kg)。镉的TCLP有效态与总量的差别最大。锌、铅存在轻微污染,污染率分别为21.7%、4.3%。     

土壤重金属监测过程及其质量控制

重点探讨了土壤中典型重金属含量监测过程中样品制备、含水率、预处理等因素对分析结果的影响。实验结果表明,充分风干土壤的含水率在2%～3%左右,200目土壤颗粒度可满足分析精度的要求。硝酸-氢氟酸-高氯酸的多元混酸消解体系可实现对土壤重金属的充分溶解,对标准土壤样品中各元素的回收率可达84%～98%。批次内平行样品以及批次间质控样品各元素的相对标准偏差大都小于10%,符合《土壤环境监测技术规范》的要求,表明该研究建立的系统土壤重金属检测方法结果准确可靠。     

西南某省14种尾矿重金属浸出量及总量分析

研究中国西南某省不同类型尾矿的重金属浸出量及总量,为尾矿的污染防范、环境管理和综合利用提供参考和建议。采集了14种类型共164个有代表性尾矿进行浸出毒性试验,并分析其中79个典型尾矿样品的9种重金属含量,以评估其污染风险和综合利用价值。结果表明,有5种类型共7个样品出现浸出毒性超标,分别为铅锌矿、镍矿、银矿、铁矿、锰矿,总体超标率为4.3%。超标元素分别为砷、镉、锌、铅、铜、镍等6种元素,最大超标倍数分别为砷18.3倍、锌4.8倍、镉3.0倍、铅0.56倍、铜0.32倍、镍0.16倍;尾矿含有较多重金属,其中砷、锌、铅、铜含量较高,最高分别达到11.75%、2.60%、1.01%、0.29%,不同类型尾矿其重金属含量各有不同,铅锌矿尾矿的重金属总量最高。总体上,该省绝大多数尾矿为普通固废,少部分为危险废物,砷、镉、锌、铅、铜、镍等6种元素存在污染风险,其中砷元素是最主要污染物;尾矿由于重金属含量较高而有一定的综合利用价值。     

污染场地土壤重金属检测能力验证结果分析

本文分析了污染场地土壤重金属检测能力验证计划的实施及结果评价,并与之前的同类能力验证计划的结果进行了比较,分析了实验室取得不满意结果的原因,为实验室提高土壤中砷和汞的检测能力提供借鉴。     

便携式XRF在污染地块土壤金属元素调查中的应用

研究了便携式X荧光光谱仪（PXRF）测定土壤中砷、铅、铬、铜、锌和镍的性能，评估其检出限、精密度和准确度，探索了土壤水分和粒径对测定结果的影响程度，并与常规实验室分析方法测定结果进行比对。结果表明，PXRF测定土壤中砷、铅、铬、铜、锌和镍的检出限为5~15mg/kg，标准物质测定结果的相对标准偏差（RSD）≤8.6%，相对误差在±15%以内。随着土壤水分含量的增加，各金属元素测定结果均呈下降趋势，而RSD有上升趋势。土壤粒径对测定结果的影响较小，随着土壤粒径减少，各金属元素测定结果的RSD略有下降趋势。PXRF可以简单、快速地测定多种重金属元素，适用于污染地块重金属元素的现场实时监测。     

铅冶炼区土壤重金属总量和有效态含量的函数分析

采集铅冶炼企业周边3 000 m范围内220个表层土壤样品,测定了有毒有害元素铅、镉、砷和汞的总量和有效态含量,探讨了它们之间的关系。结果表明:研究区土壤受到汞、砷、铅、镉的污染依次明显严重,土壤重金属的总量和有效态含量的变异系数均大于100%,土壤镉、铅、汞、砷的生物有效性系数平均值分别为25.9%、17.2%、0.58%、0.11%。土壤铅、镉和砷的总量与其有效态含量呈显著正相关(P0.001),而汞的总量与其有效态含量的相关性不显著(P0.05)。土壤铅和镉的总量和有效态含量可以用直线函数和幂函数表达,函数反推的有效态值和对应统计值的变异系数不大于10%。     

土壤中重金属可提取态(氯化钙法)分析质量控制样品的研制

为真实反映土壤中重金属的生态风险和环境效应,全国农用地土壤污染状况详查土壤检测要求测定土壤中重金属可提取态(氯化钙法)指标。针对农用地土壤污染状况详查分析质量控制工作要求,研制了土壤中重金属可提取态(氯化钙法)分析质量控制样品。土壤样品为采自江西省旱地农田的红壤,经除杂、干燥、球磨、筛分(0.250 mm)、混匀等加工处理后装瓶。采用重金属总量和重金属可提取态(氯化钙法)两大类指标评价土壤样品的均匀性,均匀性分析结果同时采用单因素方差分析法(F检验法)和相对标准偏差法(RSD法)评价。结果表明:土壤样品均匀性良好,样品最小取样量为4.0g。8家实验室对土壤中As、Cd、Cr、Cu、Hg、Ni、Pb和Zn等8种元素开展联合定值。标准值为联合定值结果的总平均值(X-),标准值上、下限值分别为(X-+3S)和(X--3S),S为联合测定平均值的标准偏差,低于《全国土壤污染状况详查土壤样品分析测试方法技术规定》中分析方法检出限的元素不做量值评定。As、Cd、Cu、Ni和Zn等5种元素评定了标准值,含量范围为0.190 ～ 13.6 mg/kg。Cr、Pb和Hg等3种元素分析结果低于分析方法检出限,未能定值。研制的土壤分析质量控制样品已应用于土壤详查工作,在保证土壤详查检测结果准确可比等方面发挥了重要作用。     

淋洗处理土壤的重金属冲刷量测定

利用人工淋洗的方法模拟自然径流对土壤的冲刷,测定城市不同区域的各类土壤中重金属的冲刷量。通过电感耦合等离子体发射光谱(ICP-OES)法对铜、锌、铅、铬、镍5种重金属元素进行连续测定,回收率为96%～103%,线性相关系数r均大于0.999,相对标准偏差(RSD)小于5%。该方法灵敏度、精密度、和准确度均能满足相关检测标准的质量控制要求,具有多元素同时分析、样品前处理简单、干扰少、测定快速、准确等优点。该方法可以提高工作效率,对于大批量或突发性土壤重金属污染的监测具有实际应用价值。     

三峡库区柑橘对土壤重金属吸收富集特征研究

研究区域柑橘果实重金属含量符合NY/T 426-2000<绿色食品柑橘>标准,果实品质达到一级产品.土壤中重金属的含量越高,柑橘叶片、果皮、果肉的重金属含量也越高.柑橘叶片对土壤重金属铜、锌、铅、镉、镍、汞、砷、铬的吸收富集能力显著大于果皮与果肉,果皮对土壤重金属铜、锌、铅、镉、汞的吸收富集能力显著大于果肉,果肉对土壤重金属铬的吸收富集能力显著大于果皮.柑橘同一部位对土壤中不同重金属元素的吸收富集能力也存在很大的差异,柑橘叶片对土壤中不同重金属元素的富集系数大小顺序为Hg＞Pb＞Cd＞Cu＞Zn＞Cr＞As＞Ni,柑橘果皮对土壤中不同重金属元素的富集系数大小顺序为Cd＞Hg＞Cu＞Zn＞Pb＞Cr＞Ni＞As,柑橘果肉对土壤中不同重金属元素的富集系数大小顺序为Hg＞Cu＞Cr＞Zn＞Cd＞Ni＞Pb＞As.     

Stabilize lead and cadmium in contaminated soils using hydroxyapatite and potassium chloride

Combination of hydroxyapatite (HAP) and potassium chloride (KCl) was used to stabilize lead and cadmium in contaminated mining soils. Pot experiments of chilli (Capsicum annuum) and rape (Brassica rapachinensis) were used to evaluate the stabilization efficiency. The results were the following: (1) the optimal combination decreased the leachable lead by 83.3 and 97.27 %, and decreased leachable cadmium by 57.82 and 35.96% for soil HF1 and soil HF2, respectively; (2) the total lead and cadmium concentrations in both plants decreased 69 and 44 %, respectively; (3) The total lead and cadmium concentrations in the edible parts of both vegetables also decreased significantly. This study reflected that potassium chloride can improve the stabilization efficiency of hydroxyapatite, and the combination of hydroxyapatite and potassium chloride can be effectively used to remediate lead and cadmium contaminated mining soil.     

火焰原子吸收法测定土壤中的铅

建立了一种以 HNO3-HCl-HCl O4 -HF对土壤样品进行消化 ,火焰原子吸收测定铅的方法。该法用于实际样品的测定时 ,相对标准偏差小于 2 .3 % ,加标回收率为 98%～ 1 0 2 %。     

Correlation between soil characteristics and lead and cadmium content in the aboveground biomass of Virginia tobacco

The study was conducted on alluvial-meadow, maroon-forest soils and vertisols with Virginia tobacco. The total content of lead and cadmium is measured through decomposition by HF, HClO₄, and HNO₃ acids. A solution of 0.005 M diethylentriaminepentaacetic acid + 0.1 M triethanolamine, pH 7.3 was used for extraction of the elements’ mobile forms from soils. The preparation of plant samples was made by means of dry ashing and dissolution in 3 M HCl. An atomic absorption spectrometer “Spektra AA 220” of the Australian company Varian was used for determination of Pb and Cd content in the soil and plant samples. Certified reference materials (three soils and tobacco leaves) were also analyzed for the verification of the accuracy of Pb and Cd determination. A correlation/regression analysis was conducted between pH, humus content, total and mobile forms of lead and cadmium in the soil, and the concentration of these elements in the aboveground biomass of Virginia tobacco. It was established that there are no statistically significant dependencies determined between soil pH and lead concentration in the plant organs of Virginia tobacco. Regressional dependencies of great significance were determined between the humus content, total and mobile lead and cadmium in the soil, and the element concentration in the leaves of the three harvesting zones.     

Characterisation of trace elements and methylmercury in an estuarine sediment reference material, IAEA-405

An estuarine sediment sample, IAEA-405, was recently characterised for trace elements and methylmercury (MeHg) for ultimate use as a marine reference material. The reference values were calculated using data sets from 120 laboratories that participated in a world-wide intercomparison exercise. The data evaluation is highlighted, and includes comparisons of different analytical methods, as well as the distribution of data. Overall laboratory performance for this exercise was encouraging: 86 laboratories (72%) reported data with <25% outliers. There was sufficient acceptable data to establish recommended values for 17 elements and information values for a further 15 elements. In addition, a recommended value was established for methylmercury. The estuarine sediment sample, IAEA-405, can be used as a reference material for quality control in the determination of trace elements and methylmercury in moderately polluted sediments.     

Seasonal and spatial distribution of trace elements in the water and sediments of the Tsurumi River in Japan

The Tsurumi, a class-one Japanese river, has a significant metal loading originating from urban environment. Water and sediment samples were collected from 20 sites in winter and summer, 2009 and were analyzed to determine and compare the extent of different trace element enrichment. A widely used five-step sequential extraction procedure was also employed for the fractionation of the trace elements. Concentrations of zinc, copper, lead, chromium, and cadmium were three to four times higher than that of reference values and downstream sediments are much more polluted than the upstream sites. Geochemical partitioning results suggest that the potential trace metal mobility in aquatic environment was in the order of: cadmium > zinc > lead > copper > cobalt > chromium > molybdenum > nickel. About 80.2% zinc, 77.9% molybdenum, 75.3% cobalt, 63.7% lead, 60.9% copper, 55.1% chromium, and 39.8% nickel in the sediment were contributed anthropogenically. According to intensity of pollution, Tsurumi river sediments are moderately to heavily contaminated by zinc, lead, and cobalt. Enrichment factor values demonstrated that zinc, lead, and molybdenum have minor enrichment in both the season. The pollution load index (PLI) has been used to access the pollution load of different sampling sites. The area load index and average PLI values of the river were 7.77 and 4.93 in winter and 7.72 and 4.89 in summer, respectively. If the magnitude of pollution with trace metal in the river system increases continuously, it may have a severe impact on the river’s aquatic ecology.     

某铀尾矿库周围农田土壤重金属污染潜在生态风险评价

为能够定量评价铀尾矿库周围农田土壤重金属污染程度及其潜在生态危害性,采用Hakanson潜在生态风险指数法对土壤中重金属进行综合污染评价。结果表明,铀尾矿库周围部分农田土壤中重金属Cd、Ni、As、Cu、Hg、Zn含量存在积累和超标情况,尤以Cd的污染最严重,Ni、As次之;Pb、Cr含量能够满足标准限值要求。潜在生态风险评价结果显示,铀尾矿库周围农田土壤重金属潜在生态风险较高,主要潜在生态风险因子为Cd,其次是Hg、As,Cr、Pb、Ni、Cu、Zn并不构成潜在生态风险。铀尾矿库周围农田土壤中较高水平的Cd在构成环境污染的同时,也构成了较严重的生态危害,应加强对重金属Cd、Hg的生态风险防治。     

Effects of lead and zinc mining contamination on bacterial community diversity and enzyme activities of vicinal cropland

In the process of mining activity, many kinds of heavy metals enter into soils with dust, causing serious contamination to the environment. In this study, six soils were sampled from cropland at different distances from a lead/zinc mine in Heilongjiang Province, China. The total contents of lead and zinc in the vicinal cropland exceeded the third level of environmental quality standard for soil in China, which indicated that soils in this area were moderately contaminated. Bacterial community diversity and population were greatly decreased when the concentrations of lead and zinc were beyond 1,500 and 995 mg kg(-1), respectively, as analyzed by plate counting and polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE). The bands of DGGE patterns varied with the degree of contamination. The activities of soil urease, phosphatase, and dehydrogenase were negatively correlated with the concentrations of lead and zinc. The highest inhibitory effect of heavy metals on soil enzyme activities was observed in urease. It was noted that PCR-DGGE patterns combined with soil enzyme activity analysis can be indices for the soil quality assessment by heavy metal contamination.     

Interpretation of standard leaching test BS EN 12457-2: is your sample hazardous or inert?

A slag sample from a lead refiner has been obtained and given to two analytical laboratories to determine the release of trace elements from the sample according to BS EN 12457-2. Samples analysed by one laboratory passed waste acceptance criteria, leading it to be classified as an inert material; samples of the same material analysed by the other laboratory failed waste acceptance criteria and were classified as hazardous. It was found that the sample preparation procedure is the critical step in the leaching analysis and that the effects of particle size on leachability should be taken into account when using this standard. The purpose of this paper is to open a debate on designing a better defined standard leaching test and making current waste acceptance criteria more flexible.     

Soil Contamination by Pb, Zn and Cn from a Lead Smeltery

In the environment of a lead smeltery contamination with lead, zinc and cadmium was measured over a 15-year period. Efficient bag filters were installed in order to remove dust from the flue gases. This measure of improvement resulted in a drastic reduction of lead, zinc and cadmium content in suspended particles (by 92, 94 and 89%), to a lesser extent in depositions (by 79, 75 and 68%), whereas in household dust the reduction was considerably lower (by 53, 55 and 70%). It can be assumed that household dust contains also redispersed soil particles on which the dust from the smeltery flue gases has deposited over years. To determine to what extent contaminated soil continues to cause increased population exposure directly or through plants or pastures, in the period 1981–1985 the content of metallic ions in the soil was measured at three depths. Selective solubility of soil metallic compounds was analysed in water, in 1 mol ammoniumacetate solution and in 0.05 mol ethylenediaminetetra-acetic acid (EDTA) solution in relation to their solubility in suspended particles, depositions and household dust. A considerably low portion of soluble metallic compounds was found in the soil and physico-chemical characteristics of the soil and portion of metallic ions bound to fulvice and humic acids were determined. The behaviour of metallic ions in contact with soil samples was studied in laboratory and it was found that approximately 50% of lead, 70% of zinc and 7% of cadmium ions change into non-soluble or poorly soluble compounds. By qualitative phase analysis in the non-soluble fraction PbO₂, Pb₃P₄O₁₃, Zn(OH)₂, ZnO, Fe₂O₃ and Cd(OH)₂ were identified.     

新标准方法实施后水中石油类检测实验室能力验证结果比对研究

为推进国际履约进程,我国自2019年1月1日起停止实验室用途使用四氯化碳,原针对水中石油类的分析方法《水质石油类和动植物油类的测定红外分光光度法》(HJ 637—2012)随之失效,新分析方法则在2018年10月正式发布。随着新分析方法的发布实施,有必要考察实验室采用新方法分析水中石油类的能力。通过汇总两次能力验证计划的统计结果,分析了实验室采用两种新方法分析水中石油类的能力。结果显示:采用紫外分光光度法(HJ 970—2018)和红外分光光度法(HJ 637—2018)测定水中石油类能力验证参加实验室的满意率分别为79.1%和86.6%,分别低于和高于新方法发布之前水中石油类检测能力验证参加实验室的满意率。实验室在操作时的样品空白、正己烷透光率以及器皿污染控制等因素对检测结果的影响较大。目前市场上用于水质检测的石油类标准样品的来源较广泛,原料来源的不同可能导致标准量值存在差异,从而导致不同实验室的分析结果偏差较大。