改进BCR法在活性污泥样品重金属形态分析中的应用

利用改进的BCR三步顺序提取法研究了活性污泥中重金属的形态分布。所研究的可提取态包括可交换态,还原态-铁锰氧化物结合态和氧化态-有机物和硫化物结合态。这三态的含量之和加上残渣态的含量与各重金属的总量进行了比较。利用ICP-MS测定了活性污泥提取液以及残渣态中Cr,Mn,Co,Ni,Cu,Zn,As,Cd,Pb的含量。实验表明,采用改进的BCR法可以用来分析活性污泥样品中的金属形态。     

原子吸收光谱法测定烟叶中的重金属总量及形态分析

采用火焰原子吸收光谱法测定烟叶中Mn,Cu,Zn元素,石墨炉原子吸收光谱法测定Cd,Cr,Pb元素,以HNO3-H2O2微波消解法获取烟叶中的重金属总量,以超声水提取法获取水溶态重金属进行初级形态分析,以Tessier逐级提取法获取5种形态的重金属进行次级形态分析。实验结果表明,原子吸收光谱法检测6种重金属线性良好,相关系数(r2)不低于0.998 8,检出限为0.16~3.1μg·L-1。烟叶样品中Mn,Cu,Zn,Cd元素主要以可交换态和碳酸盐结合态的形式存在;Cr主要以残渣态的形式存在;而Pb主要以碳酸盐结合态和残渣态的形式存在。     

污水厂污泥堆肥后重金属形态变化分析

采用高温好氧静态强制通风堆肥工艺,研究了污水厂污泥与稻草、锯末、粉煤灰、磷矿粉、石灰按不同比例混合堆肥前后重金属在交换态、碳酸盐结合态、铁锰氧化物结合态3种不稳定态和包括有机结合态、残渣态的稳定态含量的变化。结果表明,该试验可以显著降低污泥中交换态Cu、Pb、Zn、Cd和As的含量,提高其它形态的含量。由此可见,堆肥处理可以在一定程度上降低重金属活性并保持养分,从而达到农业利用的目的。     

锦州市大气颗粒物中重金属形态分析及生物有效性评价

研究了锦州市秋冬季大气颗粒物中重金属元素Al、Cd、Cr、Cu、Zn、Pb的化学形态和生物有效性。结果表明锦州市主要商业街和交通主干道的PM10和PM2.5污染比较严重,冬季取暖期间PM2.5平均超标3.4倍,最高超标达8.1倍。PM10和PM2.5中重金属Zn、Pb和Cu的含量较高,在PM10中最大值分别为0.903、0.392、0.272μg·m-3。Cd、Cu、Pb、Zn在大气颗粒物中主要以酸可提取态(F1)和氧化物结合态(F2)存在,这两种形态在环境中易迁移和转化,特别是Cd的F1和F2形态含量之和占总量的95%,其毒性较大。Cd的含量较低(0.006~0.018μg·m-3),但富集因子高(1880~2819),表明Cd人为污染严重;Cu、Zn和Pb的富集因子较高(100),表明其受人类活动影响较大。Cd和Zn在PM2.5中生物有效性系数分别为0.56和0.58,对大气环境和人体健康危害较大。     

重庆都市圈土壤重金属元素形态分析

选取重庆市表层土壤样品,采用Tessier A连续提取法研究了土壤中Hg、Cd、Cr、Cu、Zn、Ni等6种重金属元素进行形态分析。结果表明,在该区域表层土壤中Cd以离子交换态为主,其余的重金属元素均以残渣态为主,说明Cd较活泼,对环境有潜在的影响力,Hg、Cu、Zn、Ni、Cr相对比较稳定。     

煎煮对几种特色南药中重金属元素含量和形态影响

考察了几种特色南药中重金属(Cd,Cr,Cu,Fe,Mn,Ni,Pb,Sr,Zn)的含量状况,并采用形态连续萃取法分析重金属在药材中的形态分布,研究了药材煎煮时药材中重金属的释放及煎煮过程对药材中重金属形态分布的影响。结果表明,几种南药中Cr,Pb,Zn的含量较高,且巴戟天中的重金属总量高于限量标准;原药材中Cr,Cu,Mn,Ni,Pb和Zn主要存在于有机态和残留态,Fe和Sr主要存在于残留态。煎煮使南药中大量重金属迁移到药汤中;药汤中Cu,Mn,Cr,Pb和Zn主要来自于其在药材中的可交换态、碳酸盐结合态和有机态,而药汤中Sr,Ni和Fe不仅包含其非残留态,更多来自于它们的残留态。为减少药汤中重金属,对于Cu,Mn,Cr,Pb和Zn既要控制在药材中的总量,且需降低它们在药材中的非残留态含量;对于Fe,Ni和Sr则主要是控制其在药材中的总量。     

六种微山湖湿地植物重金属富集能力分析

利用火焰原子吸收分光光度法测定了微山湖6种湿地植物（拉拉秧、黄花、红柳、芦苇、香蒲、三菱草）中重金属Cu、Pb、Zn、Cd的含量,并探讨了湿地植物对水环境中重金属的吸收与富集能力以及土壤和水体的绿色植物修复技术。结果表明,这些植物中Zn、Cu、Pb含量较高,黄花对Cu富集能力最强,香蒲对Pb富集能力最强,红柳对Zn富集能力最强。     

延安市污水处理厂污泥中6种重金属元素的形态分析

采用Tessier连续提取法对延安市污水处理厂污泥中的Zn、Cu、Cr、Cd、Pb和Mn六种重金属元素进行形态提取,并用电感耦合等离子体发射光谱(ICP-AES)法对其中各元素的总量及其形态进行测定。结果表明： Pb、Cd多以可交换态、碳酸盐结合态存在,分别占总量的76.84%和78.59%, 对生物具有潜在有效性。Zn、Cu、Cr多以稳定的硫化物及有机结合态和残渣态存在,不易迁移到环境中去。     

新疆喀什市农田土壤重金属特征分析

目的对新疆喀什市农田土壤重金属特征进行分析,方法采用火焰原子分光光度计测定土壤中的重金属Cu、Zn、Pb、Cr、Cd、Ni。结果农田土壤在不同深度土层的重金属Cr、Cd、Cu、Ni、Pb、Zn含量分布规律均为0~20 cm土层20~40 cm土层40~60 cm土层,即在土壤表层聚集。结论棉田土壤的Cd、Cu、Ni、Pb、Zn的含量均高于小麦土壤,且Cd含量略高于土壤背景值。     

杭州不同功能区道路灰尘中污染物的分布和有效性

比较研究了杭州城市的工业区、商业区、居民区、公园和附近农村道路灰尘中重金属(Pb、Cu、Cd、Zn、Hg)、P和有机物的积累情况,测定了灰尘分散到水中后污染物在溶液、悬浮物和沉积物中的分配情况。结果表明,不同功能区城市灰尘中污染物含量有较大的变异:重金属一般以工业区和商业区为最高;P以居民区和商业区为最高,而有机物以公园和居民区最高;灰尘中污染物含量随粒径减小而增加。当灰尘分散至水中后,重金属等污染物大部分以沉积相形式存在,少量以溶解相和悬浮相存在;溶解态重金属的比例均较低,平均在0.5%以下,其中ρ(Hg)、ρ(Cd)>ρ(Zn)、ρ(Cu)>ρ(Pb)。而生物有效态(双酸提取)重金属占其总量的比例平均在12%~29%之间,由高到低顺序为Zn,Cd,Cu,Hg,Pb。     

Assessing spatial distribution,sources, and potential ecological risk of heavy metals in surface sediments of the Nansi Lake,Eastern China

The study is conducted to investigate the spatial distribution, sources and ecological risk of seven heavy metals in surface sediments of Nansi Lake, Eastern China. A total of 29 samples were collected in surface sediments of Nansi Lake, and were analyzed for three nutrients (TN, TOC and TP), two major metals (Al and Fe), as well as seven trace metals (As, Cd, Cr, Cu, Hg, Pb and Zn). The mean concentrations of As, Cd, Cr, Cu, Hg, Pb, Zn, Fe and Al were 14.41, 0.22, 71.10, 30.1, 0.048, 29.14, 90.2, 30,816 and 70,653 mg kg^?1, respectively, and the mean contents of these metals were higher than the background values with the exception of Cu and Fe. The spatial distribution indicated that the contents of all seven heavy metals were characterized by relatively higher contents in the upper lake than the lower lake. The hotspots with high values of As, Cd and Hg were associated with the river mouths, and the hotspots of Pb were mainly located around the dam in the central part, while no significant associations were displayed between spatial distribution of Cr, Cu, Zn and the river mouths. The mean enrichment factor (EF) values of As, Cd, Hg and Pb were 2.03, 2.93, 3.21 and 2.18, respectively, showing their moderate enrichment, while Cr, Cu and Zn with mean EF values of 1.19, 0.89 and 1.01 were deficiency to minimal enrichment. Multivariate and geostatistical analyses suggested that PC1 controlled by Cr, Cu and Zn was a lithogenic component, and come from parent rocks leaching. PC2 including Cd and partially Hg represented the factor from industrial wastewater discharge. PC3 showed elevated loadings of As and partially Cd, and could be attributed to the agricultural practices. While PC4 including Pb and partially Hg, was dominated by coal combustion. The results of potential ecological risk suggested that sediment environment of Nansi Lake suffered from high ecological risk.     

贵阳污灌区菜地土壤团聚体中有机碳和重金属的含量特征及相关性分析

以贵阳某污灌区菜地土壤为研究对象,分别采用微波消解-电感耦合等离子体质谱(ICP-MS)法和水合热重铬酸钾氧化分光光度法分析不同粒径土壤团聚体中重金属和有机碳的含量特征,并对有机碳和重金属的相关性进行分析。结果表明,以2mm粒径团聚体的含量为最高,约占75%。Cu、Zn、Cd和Pb在0.25～0.5mm粒径团聚体中含量最高,Cr在5～8mm粒径团聚体中含量最高,As在不同粒径团聚体中的含量变化不大,重金属含量随土层深度增大而减小。土壤重金属富集因子表现为CuPbCdZnCrAs,Cu、Zn、Cd和Pb在0.25～0.5mm粒径团聚体中分布因子最高,而在5～8mm粒径团聚体中重金属的质量负载因子最大。土壤有机碳含量随团聚体粒径的增大表现为先增大后减小,不同粒径团聚体中Cu、Cd、Pb和As含量与有机碳含量均呈显著正相关(p0.05)。污灌区菜地土壤Cr、As在5～8mm粒径团聚体中富集现象显著,Cu、Zn、Cd、Pb在0.25～0.5mm粒径团聚体中均表现出显著的富集特征。6种重金属在5～8mm粒径团聚体中的质量负载因子均为最高,表明6种重金属在5～8mm粒径团聚体中的贡献最大。     

黔产市售绿茶重金属的含量特征及健康风险评估

为研究黔产市售绿茶中重金属的含量分布特征及健康风险,以五个生产加工地的黔产市售绿茶为研究对象,分析其9种重金属(Pb、Cr、Cd、Hg、Cu、Zn、Mn、Ni和As)含量,利用美国环境保护署(USEPA)推荐的健康风险评价模型进行人体重金属的健康风险评价。结果表明,五种茶叶中Cr、Cd、Pb、Hg、Cu和As含量均低于国家限量标准。黔产市售绿茶的重金属浸出率大小次序为Zn>Mn>Hg>As>Cd>Pb>Cr>Cu>Ni。健康风险评价结果表明,五个产地的绿茶中重金属通过饮茶途径所产生的健康危害个人年风险大小次序为Cd>As>Mn>Ni>Cr>Hg>Pb>Zn>Cu,茶叶中重金属通过饮茶途径所产生的个人健康危害年风险总和为4.33×10-6~5.73×10-6 a-1,均低于USEPA和ICRP推荐的最大可接受风险水平,表明重金属引起的健康危害极小,其对暴露人群造成的健康危害可忽略不计,绿茶中重金属均处于安全范围内。     

耐高盐碱蓬对湿地土壤中金属元素的富集特征研究

基于秦皇岛滨海湿地人工种植耐高盐碱蓬修复工程试验,通过分析湿地土壤沉积物及耐高盐碱蓬中不同金属元素的含量与变化,研究了耐高盐碱蓬对金属元素的富集特征。结果显示:湿地沉积物中Fe、Mn、Cr、Pb和Zn的浓度较高,分别为8 210. 94、110. 04、8. 78、8. 25、10. 95 mg/kg,Cd的浓度最低,平均值为0. 022 mg/kg,湿地试验区土壤中同一金属元素变异程度较小,分布较均匀。碱蓬体内重金属含量根据采集地点的不同有差异,但与各站位中土壤的重金属分布特征存在正相关性;其中碱蓬内Fe、Mn、Zn、Cu的平均含量相对较高,且Fe、Mn、Ni、Cu、As、Cd、Pb元素在碱蓬根中的平均含量高于茎叶,而Cr在茎中的平均含量最高,Zn和Mo在叶中的含量最高。碱蓬的根、茎、叶对Cd的富集效果最好,其次为Mo、Cu,对Fe、Mn、Zn、As和Pb的富集效果相对较差,说明碱蓬对沉积物中不同金属元素的富集移出率存在差异。金属元素在碱蓬中的转移系数研究表明,Mo、Zn、Cd和Mn等元素可由根部转移到叶中,而Fe、Ni、Pb、As和Cu等金属元素固定在根部,该研究可为利用碱蓬修复湿地重金属污染提供理论基础。     

Distribution of heavy metals of agricultural soils of central Greece using the modified BCR sequential extraction method

The state of heavy metal (Cd, Cu, Ni, Zn, Pb, and Cr) pollution was studied, in 440 texturally different soil profiles in Thessaly, an intensely cultivated region in Central Greece. The study was carried out in 2004 and 2005 on 220 soil samples for each year. Soil samples were classified in three soil orders: Endisols, Alfisols, and Vertisols according to the Soil Taxonomy System. The pseudo-total concentrations of heavy metals were determined by the aqua regia procedure. Heavy metals were also determined after division into four fractions by sequential extraction with (a) acetic acid (exchangeable and specifically adsorbed metals), (b) a reducing agent (bound to Fe/Mn hydroxides), (c) an oxidizing agent (bound to soil organic matter), and (d) aqua regia (bound to mineral structures, residual). The concentrations of all the metals studied were higher in the topsoil (0–30?cm) and lower in the second soil layer (30–60?cm). Concentrations of 70–82% of Cd, 39–64% of Cu, 41–69% of Ni, 29–51% of Zn, 75–89% of Pb, and 52–87% of Cr were found in the first two fractions. Cd appeared to be the most mobile of the metals studied, while Cu and Zn were found in forms associated with soil organic matter. The chemical partitioning patterns of Pb and Cr indicated that these metals are largely associated with the Fe–Mn hydroxides, while Cr was also found in the residual fractions. Significant correlations between heavy metals fractions and soil physicochemical parameters were obtained and discussed.     

生活垃圾流化床热处置中重金属迁移分布研究

在流化床实验装置上研究模拟生活垃圾热解、气化、焚烧等热处置过程中重金属Cd、Pb、Zn及Cu的迁移转化,分析氧化还原气氛及温度对重金属挥发特性的影响。结果表明,高温及还原性条件促进了Cd、Pb及Zn的挥发;而氧化性气氛有利于Cu的迁移。热力学平衡模拟结果表明,金属在氧化和还原气氛下的转化途径不同。在还原性气氛下,金属主要以元素态单质或硫化物的形式存在,其熔沸点高低决定了金属挥发程度。反之,CuCl_3等氯化物的生成促进了Cu在氧化性气氛下的挥发。金属基反应在氧化性气氛下得到加强,提高了Cd、Pb及Zn向气相产物转化的起始温度。进一步考察重金属在不同组分的分布及富集规律,大部分以气相形式挥发的重金属易在降温过程中冷凝并富集于飞灰。气流夹带亦是导致重金属迁移的重要原因,流化床的高气速特性对重金属分布有显著影响。     

Evaluation of heavy metal bioavailability in soil amended with poultry manure using single and BCR sequential extractions

In the present study, three-step Community Bureau of Reference sequential extraction scheme (BCR-SES) and single extraction methods were performed to assess the mobility and availability of heavy metals (Cd, Cu, Pb, Fe and Zn) in an agricultural soil before and after amendment with poultry waste (PW).The PW samples were collected from poultry farms, situated in Hyderabad Sindh, Pakistan. The extractable heavy metals were measured by flame and electrothermal atomic absorption spectrometry. The validation of the method was carried out by analysis of a certified reference material of soil amended with sewage sludge (BCR-483). The single extractions using calcium chloride and EDTA, separately, while BCR-SESs were developed to evaluate the available heavy metals to plants and their environmental accessibility for control soil (CS), PW and soil amended with PW (SPW).The pH of the PW and SPW were found to be < 6.0, which may enhance the leaching of heavy metals to agricultural soil. The results from the partitioning study indicated that easily mobilised forms (acid exchangeable) of Cd were higher than other heavy metals. The oxidisable fractions of all heavy metals were dominant in PW and SPW as compared to found in CS samples. The EDTA- and CaCl₂-extractable heavy metals correspond to 5.0 to 10 and 0.5 to 3.0%, respectively of total contents in all three solid samples. Contamination factors revealed that the retention of Pb and Zn were higher compared with Cu, Cd and Fe in CS, PW and SPW samples.     

湛江湾红树林湿地土壤重金属含量分析及污染评价

采用电感耦合等离子体发射光谱仪(ICP-AES)和电感耦合等离子体质谱仪(ICP-MS)对湛江湾红树林湿地土壤中8种重金属(As、Cu、Cd、Cr、Hg、Ni、Pb、Zn)含量进行测定,采用单因子污染指数法、内梅罗综合污染指数法和地累积指数法进行污染评价,并结合相关性分析和因子分析方法探讨重金属来源。结果表明:除Ni外,其余7种重金属元素含量平均值均未超过国家土壤环境质量标准(GB15618-2018);但Ni、Zn、Cu、Hg、As和Cd元素均超过广东砖红壤环境背景值,其中As、Ni、Hg和Zn元素超标情况严重。8种重金属元素内梅罗综合污染指数评价结果为0.373~22.576,平均值为3.378,整体处于重度污染;单因子污染指数依次为Ni>Hg>Zn>Cd>As>Cu>Pb>Cr。单个重金属元素地累积指数评价结果与内梅罗综合污染评价相一致,均显示红树林土壤中Hg、Zn和Ni元素污染严重,是影响研究区土壤环境质量的重要因素。从站位看,位于湾内北部的北涯村、观海长廊以及西部的世乔村站位污染较严重,高污染站位约占总站位数的33%,主要为Cd、Hg和Zn。统计分析结果显示,除Ni外,湛江湾红树林土壤中7种重金属元素之间显著相关;结合实地调查结果推测重金属污染主要来自工业污染、船舶排污、养殖排污、生活排污及农业面源污染等人为活动的输入,其次为自然因子的输入。     

用植物叶片中重金属元素含量指示大气污染的研究

通过对潮州市区交通繁忙路段和对照区 (红山森林公园 )不同植物叶片重金属元素 (Pb、Cd、Cu、Zn)的含量研究 ,探讨了重金属含量与城市大气污染之间的关系。结果表明 ,植物叶片中的重金属元素富积量和大气中污染指数正相关。植物叶片的重金属元素富积量可较好和客观地指示市区大气的重金属污染状况。该研究为城市规划和环境保护提供了科学依据