Carbonaceous particles in the atmosphere and precipitation of the Nam Co region, central Tibet

A continuous air and precipitation sampling for carbonaceous particles was conducted in a field observatory beside Nam Co, Central Tibetan Plateau during July of 2006 through January of 2007. Organic carbon (OC) was the dominant composition of the carbonaceous particles both in the atmosphere (1660 ng/m³) and precipitation (476 ng/g) in this area, while the average elemental carbon (BC) concentrations in the atmosphere and precipitation were only 82 ng/m³ and 8 ng/g, respectively. Very high OC/BC ratio suggested local secondary organic carbon could be a dominant contribution to OC over the Nam Co region, while BC could be mainly originated from Southern Asia, as indicated by trajectory analysis and aerosol optical depth. Comparison between the BC concentrations measured in Lhasa, those at “Nepal Climate Observatory at Pyramid (NCO-P)” site on the southern slope of the Himalayas, and Nam Co suggested BC in the Nam Co region reflected a background with weak anthropogenic disturbances and the emissions from Lhasa might have little impact on the atmospheric environment here, while the pollutants from the Indo-Gangetic Basin of Southern Asia could be transported to the Nam Co region by both the summer monsoon and the westerly.     

Compound pollution of Cd,Pb,Cu,Zn,As in plant-soil system and its prevention

ＣｏｍｐｏｕｎｄｐｏｌｌｕｔｉｏｎｏｆＣｄ，Ｐｂ，Ｃｕ，Ｚｎ，Ａｓｉｎｐｌａｎｔ－ｓｏｉｌｓｙｓｔｅｍａｎｄｉｔｓｐｒｅｖｅｎｔｉｏｎ￥ＷｕＹａｎｙｕ；ＷａｎｇＸｉｎ；ＬｉＹｉｎｇ（ＩｎｓｔｉｔｕｔｅｏｆＡｐｐｌｉｅｄＥｃｏｌｏｇｙ，ＣｈｉｎｅｓｅＡ...     

潮滩植物翅碱蓬对Cu、Zn、Pb和Cd累积及其重金属耐性

以辽宁盘锦双台子河口潮滩湿地生态系统一种常见土著植物翅碱蓬(Suaedaheteroptera)作为研究对象,分析了Cu、Zn、Pb和Cd在该植物体内的累积分布、迁移规律并对其重金属的耐性进行了初步的探讨。结果表明,其对Cu、Zn、Pb和Cd四种重金属在不同潮滩均有比较明显的累积效应,累积量均表现为Zn >Pb >Cu >Cd ,而累积吸收系数分别达到4.7、4.6、3 .1和4.9,生物富集吸收系数分别为0 .97、1.73、0 .41和2 .2 3 ;研究结果还表明,由于该植物对上述四种重金属有一定的选择吸收耐性,其累积在植物的不同部位存在明显的差异,其中Cu表现为根>茎>叶,Zn表现为叶>根>茎,Pb表现为根>叶>茎,Cd表现为根>茎≈叶,而迁移效率表现为Zn >Cu >Cd >Pb。     

Pb、Zn、Cu、Cd的超富集植物研究进展

我国矿产资源丰富,矿区重金属污染十分严重,Pb、Zn、Cu、Cd四种重金属的污染在我国极其严重。利用超富集植物修复矿区重金属污染土壤,较传统方法而言是一种可靠经济安全的技术。综述了Pb、Zn、Cu、Cd四种重金属超富集植物,分析了可用于的我国重金属超富集植物的分布情况和生活环境,为土壤重金属污染的生态恢复提供参考。     

矿山不同片区土壤中Zn、Pb、Cd、Cu和As的污染特征

根据某典型有色金属矿山生产过程的污染状况,将受污染的矿区土壤分为尾矿污染区、坑道废水污染区、污风降尘污染区和精矿运输污染区4种类型.选择该矿区受污染土壤样本28个,用等离子体原子发射光谱仪(ICP-AES)等方法分析了土壤重金属含量和形态特征.结果表明,该矿区土壤重金属Zn、Pb、Cd、Cu和As污染较为严重,土壤Zn、Pb、Cd、Cu和As平均含量分别达508.6mg·kg^-1、384.8mg·kg^-1、7.53mg·kg^-1、356mg·kg^-1 和44.6mg·kg^-1.不同片区间存在明显差别,污染强度以尾矿污染区最高,内梅罗综合指数为173,其次是精矿运输污染区和坑道废水污染区,污风降尘污染区污染较轻;各片区土壤的重金属元素以残余态为主,有机结合态比例最小,不同元素之间、不同片区土壤之间各形态所占比例差别不大.     

Zn、Cu和Pb在无齿相手蟹体内的积累和分布

以长江河口湿地生态系统中一种习见的大型底栖动物无齿相手蟹Sesarm dehaani为研究对象，分析了Zn、Cu和Pb在该动物体内的积累和分布特性。结果表明，无齿相手蟹对这3种重金属的积累在不同部位间均存在着显著的差异，而在不同样点间差异都不显著。动物对Zn和Cu积累能力最强的部位都是鳃，最弱的部位分别是内脏和螯肢。无齿相手蟹各部位对和Pb的积累均很低，且对Pb的排泄明显大于吸收。污染评价表明，本研究所有样点的无齿相手蟹均还没有受到Zn、Cu和Pb的污染。     

几种大型底栖生物对Cd,Zn,Cu的积累实验研究

参照国家海水水质标准,在一系列低浓度Cd,Zn,Cu的海水中,对几种大型底栖生物进行了长约5个月的积累实验研究。结果表明,在实验浓度范围内,紫贻贝、魁蚶、褶牡蛎》、菲律宾蛤和刺海参对Cd都有一定程度的积累,且其体内Cd浓度与环境海水Cd浓度间有一定的相关关系,可比较好地指示海水Cd污染。褶牡蛎对Zn有很强的累积能力,其体内Zn浓度与环境海水Zn浓度之间有一定相关关系;紫贻贝对Zn的积累能力较褶牡蛎弱,在一定浓度范围内表现为调节;其他实验生物积累Zn能力很小。研究还表明,紫贻贝、魁蚶、菲律宾蛤、褶牡蛎和栉孔扇贝只有在Cu浓度低于0.02mg/L的海水中,存活才超过50天,其中紫贻贝与褶牡蛎对Cu有一定的积累。     

海水中铜铅锌镉的分析方法研究

海水中铜铅锌镉金属元素的测定方法主要分为原子吸收法和阳极溶出伏安法.经过实验分析,比较两种分析方法的优缺点.结果表明：原子吸收法分析,海水样品需要经过前处理富集浓缩,灵敏度较高,方法稳定性强;阳极溶出伏安法可以直接进样,同时测定海水中铜铅锌镉四种金属元素,但是该方法检出限较高,测定低浓度样品,结果的重复性较差.通过优化实验条件,可以提高两种方法的适用性.     

重金属Zn和Cd对翅碱蓬生长及抗氧化酶系统的影响

通过测定翅碱蓬生长和生理指标,研究了不同含量Zn和Cd对翅碱蓬的发芽率、苗高、苗重、体内超氧阴离子自由基(O-2)、过氧化氢(H2O2)的产生及对抗氧化酶(超氧化物歧化酶SOD、过氧化氢酶CAT、过氧化物酶POD)活性的影响,以探讨盐生植物翅碱蓬对重金属胁迫的反应.结果表明,两种重金属均不同程度地加快了超氧阴离子自由基的产生速率;翅碱蓬对Zn胁迫的耐受阈值为100 mg·kg-1,Zn含量低于100 mg·kg-1时,发芽率和苗高、苗重保持良好;含量高于100 mg·kg-1实验组,翅碱蓬生长及体内酶活性机制受到不同程度抑制,SOD 、POD反应迅速,CAT相对缓慢.翅碱蓬对Cd污染抵御能力差,含量高于0.4 mg·kg-l即可造成严重伤害,阻碍翅碱蓬生长,降低抗氧化酶活性.Zn和Cd共同作用(200 mg·kg-1 +0.2 mg·kg-1)时,表现为协同作用,发芽率仅为对照组的50.5％、苗重仅为49.2％,实验50 d后,SOD、CAT均失活,影响极显著.     

Speciation and fractionation of heavy metals in soil experimentally contaminated with Pb,Cd, Cu and Zn together and effects on soil negative surface charge

Speciation and fractionation of heavy metals in soil subsamples experimentally loaded with Pb, Cd, Cu and Zn in orthogonal design was investigated by sequential extraction, and operationally defined as water-soluble and exchangeable(SE), weakly specific adsorbed( WSA),Fe and Mn oxides-bound(OX) and organic-bound( ORG). The results showed that fractions of heavy metals in the soil subsamples depended on their speciation. About 90% of Cd and 75% of Zn existed in soil subsamples in the SE fraction. Lead and Cu existed in soil subsamples as SE, WSA and OX fractions simultaneously, although SE was still the major fraction. Organic-bound heavy metals were not clearly apparent in all the soil subsamples. The concentration of some heavy metal fractions in soil subsamples showed the good correlation with ionic impulsion of soil, especially for the SE fraction. Continuous saturation of soil subsamples with 0.20 mol/L NH4CI, which is the first step for determination of the negative surface charge of soil by the ion retention method, resulted in desorption of certain heavy metals from the soil. It was found that the percentage desorption of heavy metals from soil subsamples depended greatly on pH, the composition and original heavy metal content of the soil subsamples. However, most of the heavy metals in the soil subsamples were still be retained after multiple saturation. Compared with the parent soil, the negative surface charge of soil subsamples loaded with heavy metals did not show difference significantly from that of the parent one by statistical analysis. Heavy metals existed in the soil subsamples mainly as exchangeable and precipitated simultaneously.     

重金属铜、锌、镉、铅复合污染对土壤环境微生物群落的影响

以铜锌冶炼厂附近的水稻土为例 ,研究了重金属复合污染对土壤微生物群落的影响 .结果表明 ,有效铜、锌、镉、铅与微生物生物量碳、微生物生物量氮、微生物商、微生物生物量氮 全氮均呈显著负相关 .重金属污染均能降低细菌、真菌和放线菌的数量 .用BIOLOG生态盘研究了重金属污染对微生物群落结构的影响 ,发现重金属污染明显影响了微生物群落结构 ,反映在典型变量 1(CV1)与重金属元素含量呈极显著正相关 ,因此认为典型变量 1是反映重金属污染程度的有效指标 .经逐步回归分析发现 ,有效铜是影响典型变量 1最主要的因素 .     

南京市不同功能城区土壤中重金属Cu、Zn、Pb和Cd的污染特征

将南京城市建成区分为矿冶区、开发区、商业区、城市广场、风景区、老居民区等6大功能区,选择采集土壤样本56个,用原子吸收光谱仪选择分析了土壤中重金属元素的全量和活性形态含量.结果表明,南京城市土壤中Pb、Cu、Zn和Cd的总量分别为:117.1±103.7mg·kg^-1,39.86±39.9mg·kg^-1,273.3±131.6mg·kg^-1和1.13±0.7mg·kg^-1.矿冶区、老居民区、商业区、新开发区、城市广场和风景区的内梅罗重金属综合污染指数分别为:5.4、4.9、3.4、1.6、2.4和2.3.矿冶区以Pb、Cd的强度积累为特征,但活性形态的比重较小.而城市中心的居民区和商业区Zn的积累最显著,并且所测定的重金属的醋酸盐浸提态含量明显较高.除了风景区和城市市民广场外,城市中心区的重金属均表现出较明显的表聚性.城市活动区土壤Pb、Cd的强烈积累可能已经对人类健康构成了威胁.     

两种外生菌根真菌对重金属Zn、Cd和Pb耐性的研究

纯培养条件下研究菌根真菌对重金属耐性的前提是选择合适的培养方式且保持重金属的有效性，比较了液体静置、液体摇床和琼脂固体培养3种方式下Cd对点柄粘盖牛肝菌(Suillus granulatus)生长的影响，筛选后确定液体静置培养是一种比较合适的方法，运用液体静置培养方法，研究了重金属Zn、Cd和Pb对点柄粘盖牛肝菌和卷缘桩菇(Paxillus involutus)生长的影响，并利用EC50值评价真菌对Zn、Cd和Pb的耐性。结果表明卷缘桩菇的CdEC50值低于点柄粘盖牛肝菌，但Zn和Pb的EC50值均高于点柄粘盖牛肝菌，表明卷缘桩菇比点柄粘盖牛肝菌更耐Zn和Ph，对Cd却比较敏感。     

Responses of Sesbania rostrata and S. cannabina to Pb, Zn, Cu and Cd toxicities

Responses of Sesbania rostrata and S. cannabina to Pb, Zn, Cu and Cd toxicities were assessed by a seed-suspending seedbed(SSS) approach. The results showed that the SSS approach was suitable for testing the tolerance of a plant to the stress of toxic metals. The endpoints include seed germination success, straightened radicle and hypocotyl of the seedlings from the seeds. The measurements could be done easily and accurately. It was found that the elongation of radicle was the most sensitive indicator to the stress of heavy metals among the endpoints. When exposure to lower or medium concentrations of Pb, Zn, and Cd, the development of the lateral roots were favorable. Species of S. rostrata was more tolerant than S. cannabina to the heavy metals, especially to Zn and Cd. The ED50 of Pb, Zn, Cu and Cd were 32.90, .5.32, 4.40 and 12.00 μg/ml for S. rostrata,respectively, and they were 30.11, 2.87, 4.0.5 and 4.94 μg/ml respectively for S. cannabina.     

Mobility and speciation of Cd,Cu,and Zn in two acidic soils affected by simulated acid rain

Through a batch experiment, the mobility and speciation of heavy metals(Cd, Cu, Zn) in two acidic forest soils from Hunan Province were studied. The results showed that the release and potential active speciation of Cd, Cu, and Zn in the tested contaminated red soil(CRS) and yellow red soil(CYRS) increased significantly with pH decreasing and ion concentrations increasing of simulated acid rain, and these effects were mainly decided by the pH value of simulated acid rain. Cd had the highest potential nsk on the environment compared with Cu and Zn. Cd existed mainly in exchangeable form in residual CRS and CYRS, Cu in organically bound and Mn-oxide occluded forms, and Zn in mineral forms due to the high background values.     

孔石莼（Ulva pertusa）对铅、铜、镉的吸收

研究了大型藻孔石莼对铅、铜和镉的吸收动力学和热力学过程。结果表明,暴露于不同浓度的重金属体系中的孔石莼对铅、铜和镉的积累量随着水相中的游离态浓度的增加而增加,可以用Langmuir吸附等温式从热力学平衡角度加以描述,铅和镉饱和结合量分别为：0．715mg/g干重,Cd^2＋为0．037mg／g干重;在孔石莼对铜（0．056mg／L）吸收动力学浓度的实验中,第4天达到了吸收平衡,蓄积量为对照组的9．01倍;在镉暴露浓度为0．028mg／L的实验中,第5天达吸收平衡,蓄积量为对照组的5．06倍。     

组配改良剂对污染稻田中Pb、Cd、Cu和Zn钝化效果持续性比较

为研究组配改良剂碳酸钙+海泡石(LS)对稻田土壤重金属Pb、Cd、Cu、Zn钝化效果的持久性,通过一次性施用0、2、4、8 g·kg-1的LS,并分别于2012年(第一季)、2013年(第二季)和2014年(第三季)连续种植水稻,在湘南某矿区附近污染稻田进行了一个3 a的大田修复试验.结果表明:1LS能显著提高三季土壤p H值,且LS对土壤p H值提高效果为:第一季第二季第三季.2LS能显著降低三季水稻土壤中Pb、Cd、Zn的交换态含量,且第三季水稻土壤中Pb、Cd、Zn的交换态含量分别降低32.6%~97.7%、8.3%~71.4%和10.9%~83.5%,但对降低三季土壤中Cu的交换态含量无显著影响;LS降低三季土壤中Pb、Cd、Cu、Zn交换态含量的效果均为:PbZnCdCu.3LS使第三季水稻糙米中Pb和Cd含量分别降低26.7%~66.7%、59.1%~80.3%,这种降低效果均随着改良剂LS添加量的增加而增大,但对糙米中Cu和Zn含量无明显影响.LS降低糙米中Pb、Cd、Cu、Zn含量的效果为:第一季,PbCdCuZn;第二季,PbCdCuZn;第三季,CdPbZnCu.LS降低三季水稻糙米中重金属含量的整体效果为PbCdCuZn.4随着时间的延长,LS对土壤中Pb和Cd具有更稳定的钝化效果.因此,LS对治理Pb和Cd污染的土壤具有良好的持久性.     

三亚湾和榆林湾海水溶解态Cu、Pb、Zn、Cd、Cr的分布

研究了三亚湾和榆林湾海区溶解态重金属（ Ｃｕ 、 Ｐｂ 、 Ｚｎ 、 Ｃｄ 、 Ｃｒ） 的浓度和分布。结果发现表层重金属 Ｃｕ 、 Ｐｂ 、 Ｚｎ 、 Ｃｄ 、 Ｃｒ 的平均浓度分别为０９７ 、２１０ 、１１４７ 、００８７ 、０２９ μｇ／ Ｌ，符合一类海水水质标准，表明此海区还没受到重金属的污染。表层海水中 Ｃｕ 和 Ｚｎ 与盐度呈负相关，有较大的河流输入； Ｃｒ 与盐度有正相关，浓度从河流到远岸有增高的趋势，这和三亚湾外海高盐水的涌入有关； Ｐｂ 、 Ｃｄ 与盐度无显著相关性，表明还存在其他过程如： 悬浮颗粒物的清除，大气沉降和不同水团间的混合等过程影响着它们的含量。调查发现除 Ｃｒ 外其他重金属浓度在远岸站位底层有明显增加，这种分布可能和海区底部存在较大的沉积物向上覆水的输入有关。因此海区重金属分布不但受本身物化性质的影响，还与其他环境因子有关     

Investigation on Fe, Mn, Zn, Cu, Pb and Cd fractions in the natural surface coating samples and surficial sediments in the Songhua River, China

Natural surface coating samples （NSCSs） from the surface of shingles and surficial sediments （SSs） in the Songhua River, China were employed to investigate the relationship between NSCSs and SSs in fractions of heavy metals （Fe, Mn, Zn, Cu, Pb, and Cd） using the modified sequential extraction procedure （MSEP）. The results show that the differences between NSCSs and SSs in Fe fi＇actions were insignificant and Fe was dominantly present as residual phase （76.22% for NSCSs and 80.88% for SSs） and Fe-oxides phase （20.33% for NSCSs and 16.15% for SSs）. Significant variation of Mn distribution patterns between NSCSs and SSs was observed with Mn in NSCSs mainly present in Mn-oxides phase （48.27%） and that in SSs present as residual phase （45.44%）. Zn, Cu, Pb and Cd were found dominantly in residual fractions （〉48%）, and next in solid oxides/hydroxides for Zn, Pb and Cd and in easily oxidizable solids/compounds form for Cu, respectively. The heavy metal distribution patterns implied that Fe/Mn oxides both in NSCSs and SSs were more important sinks for binding and adsorption of Zn, Pb and Cd than organic matter （OM）, and inversely, higher affinity of Cu to OM than Fe/Mn oxides in NSCSs and SSs was obtained. Meanwhile, it was found that the distributions of heavy metals in NSCSs and SSs were similar to each other and the pseudo-total concentrations of Zn, Cu, Pb and Cd in NSCSs were greater than those in SSs, highlighting the more importance for NSCSs than SSs in controlling behaviours of heavy metals in aquatic environments.     

水稻籽实中蛋白质-Cd、Pb结合体及其稳定性

通过凝脱层析方法，对水稻籽实中的蛋白质－Cd,Pb结合形态特征及其稳定性进行了研究。结果表明；水稻籽实TrisHCl提取液经SephadexG-75分 离，洗脱液得到3个紫外吸收峰，在第1、3峰处出现了Cd、Pb浓度峰，其蛋白质－Cd、Pb结合体的表观分子量为54.5KD和5.5KD。在蒸煮加热处理后，水稻籽实中蛋白质－Cd、Pb结合体发生变性，使分子量为54.5KD的蛋白质－Cd,Pb结合体完全破坏，分子量为5.5KD的结合体也部分地被破坏，与蛋白质结合的Cd ,Pb被释放出来。胃蛋白酶和胰蛋白酶消化处理后，也能够破坏蛋白质－Cd,Pb结合体的形态，洗脱液中Cd,Pb的浓度分布也发生了变化，在第1、3紫外吸收峰处的Cd、Pb浓度也明显降低。另外，在第3峰以后的洗脱液中也检测到Cd、Pb的浓度。