北京市PM2.5污染特征 、来源分析及其重金属健康风险评价

分析了2016年北京市的PM_(2.5)及其中的Zn、Pb、Mn、Cu、Cr、As、Ni、Cd、Sb、Co、V、Ba、Al、Fe、Mg、Ti、Ca、S 18种元素含量,并对重金属As、Cr、Pb、Cd、Ni、Mn、Cu和Zn进行了相应的健康风险评价。结果表明:PM_(2.5)质量浓度为14.63～206.35μg/m~3,年平均值为74.00μg/m~3,超过《环境空气质量标准》(GB 3095—2012)二级标准(35μg/m~3)1倍多;PM_(2.5)中S、Zn、Sb、Pb和Cd的富集程度较高,主要来源于机动车尾气排放、燃煤和工业活动;Mn、Pb、Cr、Zn、Cu、As、Cd、Ni 8种重金属对儿童、成人女性、成人男性的非致癌总风险均小于1,不存在非致癌风险;As、Cd、Cr和Ni 4种重金属的致癌风险为1.94×10~(-7)～6.04×10~(-5),均小于10~(-4),部分重金属可能存在潜在致癌风险,主要是As和Cr存在潜在致癌风险。     

合肥市污水处理厂污泥重金属分布特征及其生态风险评价

为了解污泥中重金属污染状况,分析了合肥市5家污水处理厂污泥中As、Cd、Cr、Cu、Pb和Zn的总量、形态特征与生物毒性,并采用内梅罗指数法和潜在生态危害指数法对污泥中重金属生态风险进行了评价。结果表明,污泥中各重金属元素总量为Zn(639.00~2 094.50mg/kg)Cu(107.22~415.86mg/kg)Cr(48.06~388.24mg/kg)Pb(4.50~35.40mg/kg)As(11.72~47.51mg/kg)Cd(2.02~16.68mg/kg)。形态分布特征分析结果显示,Cr、Cu和Pb较稳定,As的稳定性相对较差,Zn在污泥中稳定性最差,而Cd在不同污泥样品中的形态分布差异较大;水平振荡法和毒性特征沥滤方法对污泥中重金属浸出浓度较低,未超过相应限值。内梅罗综合污染指数法和潜在生态危害指数法对污泥中重金属总量评价结果表明,5家污水处理厂(分别命名为WT、WXY、JKQ、ZZJ、CTP)污泥样品表现为CTPJKQWXYZZJWT,各重金属元素污染顺序为CdCu(Zn)AsCrPb。     

镍、铬对活性污泥真实产率的影响

采用两个直流完全混合式反应器,研究了Ni(Ⅱ) 、Cr(Ⅵ) 对好氧活性污泥真实产率系数(YH)、COD去除率、MLSS和污泥呼吸作用的影响.结果表明,当Ni(Ⅱ) 、Cr(Ⅵ) 为3 mg/L时,YH(MMLSS/MCOD)从无重金属的0.388分别升高到Ni(Ⅱ) 的0.427和Cr(Ⅵ) 的0.408;COD的去除率不受影响,MLSS增加了7.5%;污泥呼吸作用增强了5%.随着Ni(Ⅱ) 、Cr(Ⅵ) 浓度的进一步增加,YH、COD去除率、MLSS和呼吸作用都迅速下降.当Ni(Ⅱ) 、Cr(Ⅵ) 为15 mg/L时,YH(MMLSS/MCOD)分别为0.289和0.218;而Ni(Ⅱ) 、Cr(Ⅵ) 为25 mg/L时,对污泥呼吸的抑制作用分别达43%和60%.总体来看,Cr(Ⅵ) 比Ni(Ⅱ) 对系统的毒性更大.     

电感耦合等离子体质谱法测定土壤中重金属有效态浓度

采用电感耦合等离子体质谱(ICP/MS)法,结合内标技术,高效、快速地测定了土壤中Cu、Zn、Pb、Cd、Ni、Cr、Hg、As和Se 9种元素的有效态浓度.Cu、Zn、Pb、Cd、Ni、Cr、Hg的有效态采用0.1 mol/L NaNO3浸提,所得浸提液上机前预先稀释10倍;As和Se的有效态采用稀HCl浸提.结果表明,在测定所有空白、标准溶液及样品时均在线加入500 靏/L 45Sc/72Ge/209Bi内标溶液,有效地克服了基体效应、接口效应和仪器波动所产生的影响;0.15%(质量分数)NaCl\|1.0%(体积分数)HCl作为Hg标准溶液固定液,可保证1 靏/L Hg标准溶液7 d有效期;9种元素有效态的仪器检出限均在靏/L级以下,方法检出限<0.030 mg/kg,平均加标回收率为81%～121%,相对标准偏差为0.02%～1.21%.     

焦化废水处理过程外排污泥中重金属形态特征及其潜在环境风险

焦化废水处理过程所排放污泥中重金属的含量及化学形态是否构成环境风险将直接影响污泥处置方法的选择,为此,实验采用BCR顺序提取法分析了焦化废水处理站外排污泥中重金属(Cd、Hg、Pb、Cr、As、Ni、Zn、Cu和Mn)的形态特征,并采用地累积指数(Igeo)和潜在生态危害指数(RI)评价了重金属对土壤的潜在环境风险。研究结果表明:除Ni主要以可氧化态存在外,焦化废水外排污泥中其他几种重金属元素主要存在于残渣态,重金属元素的含量低于《城镇污水处理厂污染物排放标准(GB18918—2002)》中的控制限值;与城市污泥相比,焦化废水外排污泥具有低Pb、Cr、Zn、Cu含量,而高Cd、Hg、Mn含量的特点;基于Igeo和RI的评价结果,Cd和Hg是外排污泥中具有一定环境风险的元素,需要考虑其下游去向。焦化废水处理外排污泥中主要存在残渣态重金属成分,不表现为很高的环境风险,其处置应重点考虑其中有机污染物特别是POPs。     

杭州西湖景区PM2.5中重金属来源及健康风险评价

研究了杭州西湖景区PM_(2.5)中12种重金属元素的污染特征、来源及健康风险。结果表明,2018年杭州西湖景区PM_(2.5)年均质量浓度为36.40μg/m~3,其中V、Cr、Mn、Fe、Ni、Cu、Zn、As、Nb、Ag、Sn、Pb的年均质量浓度分别为3.16、3.61、22.68、304.84、2.58、9.69、96.38、5.26、197.45、3.89、5.65、27.85ng/m~3,12种重金属元素合计占PM_(2.5)的质量分数为1.88%,总体上冬春季高于夏秋季。Cr、Mn、Fe、Cu、Zn、As、Pb主要来源于机动车尾气和交通二次扬尘,Sn主要来源于工业排放,V和Ni主要来源燃油,Nb和Ag来源未知。健康风险评价显示,杭州西湖景区PM_(2.5)中重金属的非致癌健康风险和致癌健康风险均处在安全范围内,表现出冬春季高于夏秋季的特征。     

危险废物焚烧灰渣熔融过程中重金属元素热力学平衡计算

熔融固化是目前危废焚烧灰渣处置的有效方法之一。为了能够有效地控制熔融过程中重金属元素的迁移,采用HSC Chemistry软件模拟研究了重金属元素As、Pb、Zn、Cu、Ni、Cr等在熔融过程中的物质变化历程,考察了不同气氛、温度、氯化物种类的影响。结果表明:在还原性气氛下,As、Pb几乎100%以As S(g)和Pb S(g)的形式挥发进入气相;Zn主要以气态金属挥发,1 500℃时90.8%的Zn进入气相;Cu、Ni、Cr与灰渣中的Fe2O3、Al2O3等形成不易挥发的化合物,几乎完全被熔渣固化。氧化性气氛有利于各重金属元素的固化,除46.47%的Pb以Pb Cl2(g)、Pb Cl(g)、Pb O(g)的形式挥发外,其余重金属元素均能被固溶在渣中。与灰渣中Na Cl相比,Ca Cl2不影响As、Cr的平衡形态分布,但能促进Pb、Zn、Cu、Ni以气态氯化物的形式挥发进入气相,不利于重金属元素的固化。     

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.     

纳米零价铁与黑曲霉发酵液联用对砷锑污染土壤的淋洗修复

土壤砷(As)、锑(Sb)污染对生态环境和人体健康有着潜在的风险,采用黑曲霉发酵液(FB)与纳米零价铁(nZVI)联用淋洗修复As、Sb污染土壤。通过振荡淋洗实验,探究nZVI强化FB淋洗去除As、Sb的效果及不同条件下对As、Sb淋洗效率的影响。结果表明,制备的FB对污染土壤中As和Sb有着较好的去除效果,去除率可达84.1%和71.8%;nZVI对FB去除As、Sb有强化作用,在nZVI质量浓度为0.1 g·L^-1、pH为1和淋洗时间为60 min的条件下,其淋洗效果最佳,对As、Sb淋洗效率可达96.6%和95.6%,修复后的土壤达到《土壤环境质量建设用地土壤污染风险管控标准(试行)》(GB 36600-2018)二类用地标准。nZVI-FB对土壤中As、Sb的解吸动力学符合拟二级动力学方程。nZVI-FB能够有效的提取土壤中As、Sb的铁铝氧化物结合态。本研究结果可为As、Sb复合污染土壤的淋洗修复提供参考。     

Fenton预处理对城市污泥重金属形态及生物淋滤溶出影响

针对生物淋滤处理城市污泥重金属Cr、As和Pd的溶出效率较低的问题,采用芬顿(Fenton)氧化法对城市污泥进行预处理,考察Fenton氧化对污泥中重金属Cr、As和Pd赋存形态转化及后继生物淋滤过程溶出率的影响。实验结果表明,经pH=4.00、Fe~(2+)=1.00 g·L~(-1)、H_2O_2=9 g·L~(-1)的条件下Fenton预处理后,重金属Cr、As和Pb的存在形态均由稳定性较强的可氧化态和残渣态向不稳定的弱酸提取态和可还原态转化,其不稳定态比重分别由15%、30%、9%提高到了24%、41%、11%;生物淋滤实验结果显示,由于重金属形态变化,重金属Cr、As和Pb溶出率分别由52.71%、11.15%、33.19%提升至60.76%、24.32%、45.96%。Fenton预处理联合生物淋滤法提高了对重金属Cr、As和Pb的去除效果,有助于实现污泥的无害化处理处置。     

Characteristics and impacts of trace elements in atmospheric deposition at a high-elevation site,southern China

To investigate the regional background trace element (TE) level in atmospheric deposition (dry and wet), TEs (Fe, Al, V, Cr, Mn, Ni, Cu, Zn, As, Se, Mo, Cd, Ba, and Pb) in 52 rainwater samples and 73 total suspended particles (TSP) samples collected in Mt. Lushan, Southern China, were analyzed using inductively coupled plasma-mass spectrometry (ICP-MS). The results showed that TEs in wet and dry deposition of the target area were significantly elevated compared within and outside China and the volume weight mean pH of rainwater was 4.43. The relative contributions of wet and dry depositions of TEs vary significantly among elements. The wet deposition fluxes of V, As, Cr, Se, Zn, and Cd exceeded considerably their dry deposition fluxes while dry deposition dominated the removal of pollution elements such as Mo, Cu, Ni, Mn, and Al. The summed dry deposition flux was four times higher than the summed wet deposition flux. Prediction results based on a simple accumulation model found that the content of seven toxic elements (Cr, Ni, Cu, Zn, As, Cd, and Pb) in soils could increase rapidly due to the impact of annual atmospheric deposition, and the increasing amounts of them reached 0.063, 0.012, 0.026, 0.459, 0.076, 0.004, and 0.145 mg kg^?1, respectively. In addition, the annual increasing rates ranged from 0.05% (Cr and Ni) to 2.08% (Cd). It was also predicted that atmospheric deposition induced the accumulation of Cr and Cd in surface soils. Cd was the critical element with the greatest potential ecological risk among all the elements in atmospheric deposition.     

Survey of heavy metal pollution and assessment of agricultural soil in Yangzhong district, Jiangsu Province, China

We investigated concentrations of Hg, Cd, Pb, Zn, Cu, As, Ni, and Cr in samples of soil, cereal, and vegetables from Yangzhong district, China. Compared to subsoils, the sampled topsoils are enriched in Hg, Cd, Cu, Pb, Zn, and As. High levels of Cd and Hg are observed in most agricultural soils. Concentrations of Cr and Ni show little spatial variation, and high Cu, Pb, and Zn contents correspond well to areas of urban development. High As contents are primarily recorded at the two ends of the sampled alluvion. The contents of Cd, Hg, and total organic carbon (TOC) increase gradually to maximum values in the upper parts of soil profiles, while Cr and Ni occur in low concentrations within sampled profiles. As, Pb, Cu, and Zn show patterns of slight enrichment within the surface layer. Compared to data obtained in 1990, Cd and Hg show increased concentrations in 2005; this is attributed to the long-term use of agrochemicals. Cr and Ni contents remained steady over this interval because they are derived from the weathering of parent material and subsequent pedogenesis. The measured As, Cu, Pb, and Zn contents show slight increases over time due to atmospheric deposition of material sourced from urban anthropogenic activity. Low concentrations of heavy metals are recorded in vegetables and cereals because the subalkaline environment of the soil limits their mobility. Although the heavy metal concentrations measured in this study do not pose a serious health risk, they do affect the quality of agricultural products.     

Comprehensive assessment of toxic metals in urban and suburban street deposited sediments (SDSs) in the biggest metropolitan area of China

A set of toxic metals, i.e. As, Hg, Pb, Cd, Cu, Zn, Ni and Cr, in urban and suburban SDSs were investigated comparatively in the biggest metropolitan area of China, Shanghai. Results showed that all of the metals except As were accumulated greatly, much higher than background values. Geo-accumulation index indicated that metal contamination in urban SDSs was generally heavier than that in suburban SDSs. Potential ecological risk index demonstrated that overall risks caused by metals were considerable. Cd contributed 52% to the overall risk. Multivariate statistical analysis revealed that in urban SDSs, Zn, Ni, Cd, Pb, Cu and Cr were related to traffic and industry; coal combustion led to elevated levels of Hg; soil parent materials controlled As contents. In suburban SDSs, Pb, Cu, As and Cd largely originated from traffic pollution; Zn, Ni and Cr were associated with industrial contaminants; Hg was mainly from domestic solid waste.     

中国商品有机肥重金属分析

测定了来自10个地区不同生产原料的118个商品有机肥样品的重金属含量.结果表明:(1)商品有机肥样品中的Cd、Hg、Pb、Cr、As、Zn、Cu、Ni的平均值分别为0.600、0.120、7.34、84.30、9.45、202.91、91.06、11.01 mg/kg.(2)河南、湖北、上海的商品有机肥中8种重金属平均值均较高;内蒙古的商品有机肥中Cr平均值为20.32 mg/kg,广西的商品有机肥中Zn平均值为51.36mg/kg,远低于所有样品中Cr和Zn平均值.(3)以猪粪为主要生产原料的商品有机肥中重金属平均值最高.(4)Cr超过中国商品有机肥重金属限量标准、欧盟生态标志法的重金属限量标准、加拿大堆肥重金属限量标准(A级)和加拿大堆肥重金属限量标准(B级);As、Cd超过中国商品有机肥重金属限量标准、欧盟生态标志法的重金属限量标准和加拿大堆肥重金属限量标准(A级);Cu、Zn超过欧盟生态标志法的重金属限量标准和加拿大堆肥重金属限量标准(A级);Hg超过加拿大堆肥重金属限量标准(A级);Pb超过中国商品有机肥重金属限量标准;Ni均未超标.     

Current and future emissions of selected heavy metals to the atmosphere from anthropogenic sources in Europe

Current atmospheric emissions of As, Cd, Cr, Ni, and Pb (reference year 2000) from major anthropogenic sources in Europe are presented in this paper. Combustion of fuels in stationary sources was the main emission source for As, Cd, Cr, and Ni (more than a half of the total anthropogenic emissions), while combustion of gasoline was the main source of for lead. There is a continuous reduction of heavy metal emissions in Europe during the last 40 years. Better knowledge of heavy metal sources, emissions, pathways, and fate in the environment, and progress in developing efficient emission control equipment has resulted in more efficient regulatory efforts to curb heavy metal emissions from anthropogenic sources very substantially. There is a potential for further reduction of these emissions until the year 2010 up to about 40% for As, Cd, Cr, and Ni and about 57% for Pb, as estimated within various emission scenarios presented in the paper.     

A comparative study on metal sorption by brown seaweed

This study compared the sorption of Ag, Cd, Co, Cd, Mn, Ni, Pb and Zn by a Ca-treated Sargassum biomass at pH 5.0, under low and high ionic strength (IS) conditions. The sorption isotherms of As [As(V)] and Cr [Cr(III) and Cr(VI)] were also determined at low IS. The isotherm data for the eight cationic metals and Cr(III) were well fitted by Langmuir equations. Generally, the maximum metal uptake (Umax) followed: Cr(III) > Pb approximately Cu > Ag approximately Zn approximately Cd > Ni approximately Mn approximately Co > Cr(VI) > As(V) at low IS and Pb > Cu > Co > Mn approximately Cd > Zn approximately Ag > Ni at high IS. As(V) did not bind to the seaweed at pH 5.0. The results indicated that sorption of Pb was not affected by the increasing IS, though the percentage of free Pb ions in the water was greatly reduced as predicted by the speciation model. High IS lowered Umax by 10-36% (except Co and Pb), and lowered the affinity constant of the metal by 33-91% for all cationic metals, as compared to low IS. Moreover, the removal efficiency of the cationic metals and Cr decreased exponentially with initial metal concentrations and was lower at high IS. Ion-exchange was the mechanism responsible for the cationic metal sorption onto the seaweed, and Na ion interfered with the cationic metal binding through electrostatic interaction. In conclusion, this study showed the differential binding capacity of the Sargassm biomass for different metals and oxidation states and the differential effects of IS. According to the present results, Sargassum may be considered a good biosorbent for cationic metals (especially Pb) in both low and high-salt containing wastewater.     

Concentration and health risk evaluation of heavy metals in market-sold vegetables and fishes based on questionnaires in Beijing,China

Concentrations of heavy metals (As, Cd, Pb, Cu, Ni, Fe, Mn, and Zn) in market vegetables and fishes in Beijing, China, are investigated, and their health risk to local consumers is evaluated by calculating the target hazard quotient (THQ). The heavy metal concentrations in vegetables and fishes ranged from not detectable (ND) to 0.21 mg/kg fresh weight (f.w.) (As), ND to 0.10 mg/kg f.w. (Cd), and n.d to 0.57 mg/kg f.w. (Pb), with average concentrations of 0.17, 0.04, and 0.24 mg/kg f.w., respectively. The measured concentrations of As, Cd, Pb, Cu, Ni, Fe, Mn, and Zn are generally lower than the safety limits given by the Chinese regulation safety and quality standards of agriculture products (GB2762-2012). As, Cd, and Pb contaminations are found in vegetables and fishes. The exceeding standard rates are 19 % for As, 3 % for Cd, and 25 % for Pb. Pb contaminations are found quite focused on the fish samples from traditional agri-product markets. The paper further analyzed the health risk of heavy metals in vegetables and fishes respectively from supermarkets and traditional agri-product markets; the results showed that the fishes of traditional agri-product markets have higher health risk, while the supermarkets have vegetables of higher heavy metal risk, and the supervision should be strengthened in the fish supply channels in traditional agri-product markets.     

赭石对模拟重金属废水的吸附效果研究

采用模拟重金属废水的正交试验设计,进行赭石对模拟重金属废水的吸附效果研究,探讨pH、赭石加入量和振荡时间等影响因素对吸附效果的影响。结果表明,在一定pH、赭石加入量和振荡时间条件下,赭石对6种重金属（Pb、Cd、Mn、Zn、Cr和Ni）均有较好吸附效果,对Pb、Cd、Mn、Zn和Cr的最大吸附率可达100%,对Ni的吸附率达8963%。处理后废水中重金属达到污水排放标准。各影响因素对Mn、Zn和Cr吸附效率的影响大小表现为：pH＞赭石加入量＞振荡时间,Ni和Cd表现为：赭石加入量＞pH＞振荡时间,Pb表现为：pH＞振荡时间＞赭石加入量。赭石对废水中重金属吸附的最佳条件为赭石加入量40 g/L,pH 10～10.5,振荡时间2 h。     

Evaluation of diffusive gradients in thin film (DGT) samplers for measuring contaminants in the Antarctic marine environment

This work has been the first application of DGT samplers for measuring metals in water and sediment porewater in the Antarctic environment, and whilst DGT water sampling was restricted to quantification of Cd, Fe and Ni, preconcentration using Empore chelating disks provided results for an additional nine elements (Sn, Pb, Al, Cr, Mn, Co, Cu, Zn, As). Although higher concentrations were measured for some metals (Cd, Ni, Pb) using the Empore technique, most likely due to particulate-bound or colloidal species becoming entrapped in the Empore chelating disks, heavy metal concentrations in the impacted Brown Bay were found to be comparable with the non-impacted O'Brien Bay. Sediment porewater sampling using DGT also indicated little difference between Brown Bay and O'Brien Bay for many metals (Cd, Al, Cr, Co, Ni, Cu), however, greater amounts of Pb, Mn, Fe and As were accumulated in DGT probes deployed in Brown Bay compared with O'Brien Bay, and a higher accumulation of Sn was observed in Brown Bay inner than any of the other three sites sampled. Comparison of DGT derived porewater concentrations with actual porewater concentrations showed limited resupply of Cd, Pb, Al, Cr, Mn, Co, Ni, Cu, Zn and As from the solid phase to porewater, with these metals appearing to be strongly bound to the sediment, however, resupply of Fe and Sn was apparent. Based upon our observations here, we suggest that Sn, and to a lesser extent Pb, are critical contaminants.     

Heavy metal contamination in the seaweeds of the Venice lagoon

The concentrations of heavy metals (Fe, Zn, Cu, Cd, Ni, Pb, Cr, As) were determined in seven seaweeds of environmental and commercial relevance (Ulva rigida C. Ag., Gracilaria gracilis (Stackhouse) Steentoft, L. Irvine and Farnham, Porphyra leucosticta Thuret, Grateloupia doryphora (Montagne) Howe., Undaria pinnatifida (Harv.) Suringar, Fucus virsoides J. Agardh, Cystoseira barbata (Good. et Wood.) Ag.) collected in four sampling sites in the lagoon of Venice, in spring and autumn 1999. Metals were extracted using hot concentrated acids in a Microwave Digestion Rotor and analysed by absorption spectrophotometry using a flame mode for Fe and Zn and a graphite furnace for Pb, Cr, Cd, Cu, Ni and As. High contamination levels, especially for Pb, were detected in Ulva and to a lesser extent in Gracilaria. Brown seaweeds, especially Cystoseira was highly contaminated by As. The least contaminated genera with all metals except As were Porphyra and Undaria. A concentration decrease for Zn and Cd was observed from the inner parts of the central lagoon, close to the industrial district, towards the lagoon openings to the sea.