生活垃圾填埋场封场后种植植物中重金属迁移研究

在上海老港生活垃圾填埋场填埋单元封场的覆盖土中掺混了矿化垃圾种植植物,分析Cd、Pb、Cu、Zn 4种重金属在土壤和植物中的迁移变化,研究表明:(1)覆盖土土质从一般耕作土变成肥沃土壤;覆盖土和种植混合土重金属Cd、Pb、Cu、Zn中Cd、Pb含量相近,但种植土的Cu含量略大于覆盖原土,Zn含量远大于覆盖原土;(2)植物能富集土壤和垃圾中的重金属,木本植物的根部富集重金属的能力强于草本植物,但重金属在草本植物根、茎、叶中的迁移速度大于木本植物;(3)植物根、茎、叶的Cu、Zn含量均远大于未受污染土壤种植植物相应部位的Cu、Zn含量,种植的植物不能供家养动物食用,以免通过食物链作用危及人体安全.     

城市生活垃圾焚烧处理过程中重金属迁移规律研究

通过采集厦门2个垃圾焚烧发电厂进厂垃圾、渗滤液、飞灰、炉渣和烟气样品,分析垃圾组成成分及各组分的重金属含量,结果表明,垃圾中以厨余、橡塑类和纸类为主,共占到垃圾干基的78．08％,重金属含量大小次序为Zn〉Cu〉Pb〉Cr〉Ni〉Cd〉Hg;垃圾渗滤液中除Zn外,其他金属的含量都较低,一厂渗滤液中重金属Ni、Zn迁移量较大,分别达到24．46％和8．52％。二厂渗滤液中重金属的迁移有相同的趋势,但含量相对较高。垃圾焚烧后其重金属主要分布在飞灰和废渣中,烟气中的含量非常少,不同金属的含量均有差别,这与金属的性质有很大关系;通过浸出毒性分析,飞灰中重金属酸溶态含量多,容易浸出,属于危险废物。同时,不同烟气处理工艺产生的飞灰的重金属浸出量有很大差别。     

贵州某垃圾填埋场及其附近农田土壤中重金属形态分析和评价

对贵州某垃圾填埋场及其附近农田土壤中Cu、Zn、Cr、M n、Pb、Cd 6种重金属的总量和形态进行了分析,并计算了内梅罗综合污染指数,评价了健康风险和生态风险.结果表明:(1)贵州某垃圾填埋场及其附近农田土壤中Cd、Cr、Cu、Zn、Pb和Mn的质量浓度平均值分别为0.44、192.89、45.68、264.39、3...     

膜浓缩液淋滤飞灰后灰渣重金属热处理特性分析

垃圾焚烧飞灰与垃圾渗滤液膜浓缩液协同处理能够解决2种废物处置难的问题,但二者协同处理产生的灰渣往往仍需进一步无害化处理。在分析灰渣的物理化学性质基础上,研究灰渣中重金属在热处理过程中的迁移转化特性,进而探讨灰渣热处理无害化的可行性。实验考察了不同热处理温度(300、600、800、1 000和1 200℃)对灰渣中重金属(Pb、Zn、Cu和Cd)的挥发率的影响,并分析热处理后灰渣的矿物相转化及重金属浸出毒性变化。结果表明:随着热处理温度的升高,重金属Pb、Cd的挥发率显著增大,Zn、Cu挥发率的增幅相对较小。热处理过程中,Pb、Zn、Cu、Cd在1 200℃时挥发率最大,分别为94.6%、68.9%、69.4%和97.7%。浸出实验结果表明,当热处理温度高于800℃时,热处理后灰渣中重金属Pb、Zn、Cu、Cr、Cd的浸出浓度均达到GB 16889-2008相关限值要求。研究结果显示,对飞灰协同处理后的灰渣进行热处理实现其无害化具有一定的可行性。     

观赏植物与驯化污泥联合修复垃圾渗滤液污染土壤

垃圾填埋场渗滤液污染土壤具有重金属-有机物复合污染的特性。研究了观赏植物广东万年青、白掌、孔雀竹芋和经垃圾渗滤液驯化的污泥对该污染土壤的修复效果,结果表明：采用单一植物修复时,广东万年青较白掌和孔雀竹芋对土壤污染物具有更强耐性,能在污染土壤中生长良好,对重金属Cd和Pb的富集能力也更强;驯化污泥能明显提高污染土壤中有机污染物的降解率,并使重金属Cd和Pb稳定态比例分别提高了34.7%和36.6%,降低了重金属的生物有效性。当采用广东万年青和驯化污泥联合修复时,污泥能促进植物的生长,且当污泥添加量为480 mg·kg-1时,联合修复对土壤中Cd、Pb及有机污染物的去除率分别较不加污泥的对照提高了51.7%、25.5%和40.2%。     

城市污泥重金属在高级厌氧消化工艺系统中的迁移转化及风险评价

采用改进的BCR连续提取法,研究了4座再生水厂高级厌氧消化系统中热水解和厌氧消化对污泥所含重金属(As、Cd、Cr、Cu、Hg、Ni、Pb、Zn)赋存形态的影响,并利用风险评价指数法(RAC)和潜在生态风险指数法(PERI)评估了消化产物进行土地利用时的重金属迁移风险和潜在生态风险。结果显示,4座再生水厂热水解污泥中的Cr、Cu、Pb、Ni、Cd、Zn的不稳定态向稳定态转化了0.9%~24.9%;消化污泥中Cr、Cu、Pb、Ni、Cd、Zn重金属的残渣态增加了1.0%~19.2%。RAC评价结果表明,消化污泥中重金属Cu、Hg、Pb、Cr、Cd、Zn的迁移风险指数均小于5%,处于无迁移风险或低迁移风险水平。以北京市土壤背景值和北京市大兴区土壤实测值作为参比值进行PERI评价,结果表明,消化产物中生物可利用态与潜在可利用态重金属均处于较低风险水平。高级厌氧消化有利于污泥中其它形态重金属逐渐向残渣态转化,从而降低其迁移性与生态风险。     

模拟陈腐垃圾掺烧过程中P/Cl/S对6种重金属迁移特性的影响

通过管式炉焚烧实验,探究了在陈腐垃圾与城市生活垃圾(MSW)掺烧过程中,P/Cl/S对6种重金属(Cd、Zn、Ni、Cu、Cr、Pb)迁移规律的影响,并考察了陈腐垃圾掺混比例、含特征元素的添加剂种类及焚烧温度对6种重金属挥发率的影响。结果表明,当陈腐垃圾掺烧比例与温度相同时,NaH₂PO₄和Na₂SO₄的协同作用对Cd挥发有显著的抑制作用,但对Ni、Cu的挥发起促进作用;NaCl对Zn的挥发有明显的抑制作用,但对Cr的挥发起促进作用;而NaCl和Na₂SO₄的协同作用促进了Pb的挥发。随着焚烧温度在设定范围(600~800 ℃)内的增加,Cd、Ni、Cr和Pb的挥发率整体呈增加的趋势。相比添加剂种类,陈腐垃圾掺混比例对Cd、Cr、Cu挥发率的影响更显著。本研究结果可为制定有效的重金属控制策略提供参考。     

复合纳米材料对土壤重金属离子吸持固化的模拟研究

土壤中过量重金属离子可通过食物链和地表水系统危害人群健康。通过土柱淋溶模拟实验,研究了SiO2-Al2O3-Fe2O3等复合纳米材料对土壤溶液中Cu2+、Cd2+、Pb2+、Zn2+和Ni2+的吸持与固化特征。分别向重金属含量4倍于土壤二级标准(GB15618-1995)的土壤中添加0%、4%、6%和10%的复合纳米材料,分析不同深度土壤渗滤液以及土柱上栽培植物不同部位中重金属的含量。结果表明,碱性壤质土壤中重金属向下的迁移量很少;在含4%复合纳米材料土柱中,其吸持固化土壤溶液中63%的Cu、79%的Cd、68%的Pb、89%的Zn和76%的Ni;在含6%复合纳米材料土柱中,其吸持固化土壤溶液中82%的Cu、92%的Cd、76%的Pb、91%的Zn和88%的Ni;再增加土柱中复合纳米材料的含量,其吸持固化效果并不再显著增加。     

淮南潘集矿区农田土壤重金属污染特征及在小麦中累积特征研究

为探究淮南潘集矿区内农田土壤和小麦中重金属的污染状况,选取了16块研究样地,测定其农田土壤和小麦不同部位中Cu、Zn、Pb、Cd、As含量,利用生物富集系数(BCF)和转运系数(TCF)分析重金属在小麦中的迁运行为,并进行重金属化学形态分析和潜在生态风险指数分析。结果表明,矿区农田土壤Zn、Pb浓度平均值低于背景浓度,Cu、Cd、As浓度平均值分别是背景浓度的1.03、4.17、1.81倍。5种重金属的化学形态以残渣态为主,Cu、Zn、Pb、Cd、As的残渣态质量分数平均值分别为47.44%、50.33%、43.36%、46.84%、98.86%。矿区农田土壤重金属综合潜在生态风险指数处于轻度或中度等级,相对较轻,主要贡献重金属是Cd。Cu、Zn易于富集在小麦地上部分,Pb、Cd、As大部分富聚在地下部分。     

干湿交替对土壤DOM特性及重金属释放的影响

以典型Cu和Zn污染农田土壤为研究对象,利用土壤培养实验、光谱学方法以及流动搅拌实验,以阐明土壤干湿交替对重金属污染土壤中土壤溶解性有机质(DOM)特性及重金属释放动力学行为的影响。结果表明,土壤pH、DOM含量及其芳香性随着土壤含水率升高而增大,而干湿交替主要影响土壤中DOM的含量,对pH和SUVA₂₅₄值的影响很小。重金属释放动力学研究表明,土壤含水率越高越有利于Cu和Zn的稳定,干旱过程则会促进其释放,但仅在初次湿润到干旱过程中对其释放特性产生影响,后期干湿交替循环影响很小,且不同干湿交替频率和强度具有类似影响。在同等条件下,Zn的释放比Cu更快,受干湿交替影响更小。本研究结果可为重金属污染土壤修复工作提供参考。     

大气中二（口/恶）（口/英）研究进展

二（口/恶）（口/英）是世界公认的强致癌物质,对人体健康危害极大.近年来,大气中二（口/恶）（口/英）的研究已成为各国环境化学家研究的热点.本文总结了近年来国际上有关大气中二（口/恶）（口/英）研究的进展情况,以及所取得的主要研究成果,并在此基础上指出了我国目前研究中存在的问题及以后所应开展的工作.     

Bioaccessibility of arsenic in various types of rice in an in vitro gastrointestinal fluid system

Rice can be a major contributor to dietary arsenic exposure because of the relatively high total arsenic concentration compared to other grains, especially for people whose main staple is rice. This study employed in vitro gastrointestinal fluid digestion to determine bioaccessible or gastrointestinal fluid extractable arsenic concentration in rice. Thirty-one rice samples, of which 60 % were grown in the United States, were purchased from food stores in New York City. Total arsenic concentrations in these samples ranged from 0.090 ± 0.004 to 0.85 ± 0.03 mg/kg with a mean value of 0.275 ± 0.161 mg/kg (n = 31). Rice samples with relatively high total arsenic (>0.20 mg/kg, n = 18) were treated by in vitro artificial gastrointestinal fluid digestion, and the extractable arsenic ranged from 53 % to 102 %. The bioaccessibility of arsenic in rice decreases in the general order of extra long grain, long grain, long grain parboiled, to brown rices.     

Residues of organochlorine pesticides in fishes in Sudan

Abstract

Cotton‐producing areas of the Centrol Sudan, bordered by the Blue and the White Nile, have been subjected to repeated applications of pesticides. This region is irrigated by a series of canals, the Gezira canals, which hold large amounts of fresh water. Lake Nubia at the Sudan‐Egypt border is another important fresh water reservoir and fisheries ground. Fish from both the Gezira and Lake Nubia showed elevated concentrations of pesticides, suggesting that continued pesticides application would endanger the equatic fauna of this region and the proposed fresh water fishery.     

Bioaccumulation of decamethylcyclopentasiloxane in perch in Swedish lakes

Decamethylcyclopentasiloxane (D5), a high production volume chemical used in personal care products, enters the environment both via air and sewage treatment plant (STP) recipients. It has been found in fish, and there is concern that it may be a bioaccumulative substance. In this work D5 was analyzed in perch from six Swedish lakes that did not receive STP effluent, and in perch and sediment from six lakes that received STP effluent. In the lakes receiving the STP effluent, the D5 concentrations in sediment varied over three orders of magnitude and were correlated with the number of persons connected to the STP normalized to the surface area of the receiving body. In the lakes not receiving effluent, the D5 levels in perch were all below the LOQ, while D5 was above the LOQ in almost all perch from lakes that received effluent. The D5 concentrations in perch and sediment from the lakes receiving STP effluent were correlated. This shows that STP effluent is a much more important source of D5 to aquatic ecosystems than atmospheric deposition, and that the risk of adverse effects of D5 on aquatic life will be greatest in small recipients receiving large amounts of STP effluent. The bioaccumulation of D5 was compared to that of PCB 180 on the basis of multimedia bioaccumulation factors (mmBAFs), which describe the fraction of the contaminant present in the whole aquatic environment (i.e. water and surface sediment) that is transferred to the fish. In four of the six lakes the mmBAF of D5 was >0.3 of the mmBAF of PCB 180. Given that PCB 180 is a known highly bioaccumulative chemical, this indicates that the bioaccumulation of D5 in perch is considerable.     

饮用水中硝酸根的催化还原研究进展

由于化肥的过度使用 ,造成地下水中硝酸盐的污染日益严重。饮用水中高浓度的硝酸盐对人类健康会产生极大的威胁。本文综述了催化还原脱除水中硝酸根的研究进展和现状 ,并对其发展趋势进行了简单的论述。     

山地城市典型区域地表径流污染迁移空间特征

选取包括山体和城市活动区域等下垫面在内的典型区域,对山地城市地表径流污染迁移特征、降雨等级和降雨强度对污染迁移的影响进行了研究,并分析了从小雨到暴雨等5场典型降雨条件下污染物赋存形态的变化。结果表明,受迁移段人为活动区域的影响,污染物呈现先升高再降低的趋势,入湖前化学需氧量(COD)、总氮(TN)、总磷(TP)和氨氮(NH3-N)的浓度分别在26.6~87.1、0.87~6.96、0.08~0.28和0.52~1.48 mg/L之间。溶解性COD(DCOD)、溶解性TN(DTN)、溶解性TP(DTP)和溶解性NH3-N(DNH3-N)分别占总污染物的55%~79%、83%~98%、18%~61%和55%~79%。除DTN外,其他3种污染物溶解态浓度占总浓度的百分比随降雨等级和雨强的增大而增大。NH3-N、COD、TP浓度与TSS浓度呈正相关,DCOD、DTN、DTP浓度与总悬浮物(TSS)浓度无相关性。TSS与场降雨的最大雨强呈现正相关。     

Speciation of heavy metals in estuarine sediments in the northeast of Brazil

An analytical procedure involving a three-step sequential extraction was used to determine the chemical association of heavy metals (Zn, Cr, Mn and Fe) with the major phases (exchangable, reducible and oxidizable) in samples from a fishpond of estuarine sediments. The pond is located in the Capibaribe River estuary, within the boundaries of the city of Recife, in the State of Pernambuco in the northeast of Brazil. The total metal content was determined as well. All metals were extracted from the residual fraction at a percentage greater than 50%.     

北京西三环地区大气颗粒物中多环芳烃的分布

2012年3-8月对北京西三环地区大气颗粒物进行分级采样,利用气相色谱(GC)/质谱(MS)联用仪对颗粒物中多环芳烃(PAHs)含量进行测定.结果表明,检出的16种PAHs总质量浓度(∑16PAHs)平均为46.73ng/m3;苯并[a]蒽(BaA)等6种单体浓度与∑16PAHs呈良好线性关系;PAHs粒径分布特征表明,其更易富集在细颗粒物上;不同环数PAHs分布特征为:3环＞4环＞5环＞6环＞2环,随着颗粒粒径减小,高环数PAHs含量增加.温度、湿度和紫外线(UV)指数与∑16PAHs呈负相关.通过特征化合物比值分析法对PAHs进行源解析发现,采样期间PAHs主要来源为燃烧源,交通源影响微弱.     

Bioaccessibility of arsenic in various types of rice in an in vitro gastrointestinal fluid system

Rice can be a major contributor to dietary arsenic exposure because of the relatively high total arsenic concentration compared to other grains, especially for people whose main staple is rice. This study employed in vitro gastrointestinal fluid digestion to determine bioaccessible or gastrointestinal fluid extractable arsenic concentration in rice. Thirty-one rice samples, of which 60 % were grown in the United States, were purchased from food stores in New York City. Total arsenic concentrations in these samples ranged from 0.090 ± 0.004 to 0.85 ± 0.03 mg/kg with a mean value of 0.275 ± 0.161 mg/kg (n = 31). Rice samples with relatively high total arsenic (>0.20 mg/kg, n = 18) were treated by in vitro artificial gastrointestinal fluid digestion, and the extractable arsenic ranged from 53 % to 102 %. The bioaccessibility of arsenic in rice decreases in the general order of extra long grain, long grain, long grain parboiled, to brown rices.