双硫腙－醋酸丁酯萃取石墨炉原子吸收法测定海水中痕量铜、铅和镉

用双硫腙－醋酸丁酯萃取石墨炉原子吸收法测定海水中痕量Ｃｕ、Ｐｈ、Ｃｄ．试验选定了最佳测定条件．结果表明，在弱碱性介质（ｐＨ８－１０）中，能同时定量萃取Ｃｕ、Ｐｂ、Ｃｄ．方法的相对标准偏差＜３％，加标回收率９２％－１０２％，检出限（μｇ／Ｌ）分别为Ｃｕ０．０６，Ｐｂ０．１４，Ｃｄ０．００２．本法操作简便、快速，已应用于海水中Ｃｕ、Ｐｂ、Ｃｄ的分析，取得了令人满意的结果．     

滇池、洱海水及沉积物中重金属元素的行为

洱海水中重金属元素的含量不同,平均值以１０＾－９计算：Ｃｕ１．６,Ｐｂ０．５９,Ｚｎ９．８,Ｃｄ０．００９,Ｃｒ０．２４,水质较好;沉积物中每一样品同一元素的含量一般均趋于平均值,以１０＾－６计算：Ｃｕ１１１,Ｐｂ６０,Ｚｎ１２７,Ｃｄ０．５９１,Ｃｒ１３０。因此,洱海至今仍是一个较清洁的湖泊。滇池水质较差,内草海段水中重金属元素含量明显上升,以１０＾－９计算：Ｃｕ５．８,Ｐｂ０．５５,Ｚｎ３２,     

滇池,洱海水及沉积物中重金属元素的行为

洱海水中重金属元素的含量不同，平均值以１０＾－９计算：Ｃｕ１．６，Ｐｂ０．５９，Ｚｎ９．８，Ｃｄ０．００９，Ｃｒ０．２４，水质较好；沉积物中每一样品同一元素的含量一般均趋于平均值，以１０＾－６计算：Ｃｕ１１１，Ｐｂ６０，Ｚｎ１２７，Ｃｄ０．５９１，Ｃｒ１３０。因此，洱海至今仍是一个较清洁的湖泊。滇池水质较差，内草海段水中重金属元素含量明显上升，以１０＾－９计算：Ｃｕ５．８，Ｐｂ０．５５，Ｚｎ３２，     

Zn等金属离子对栉孔稚贝成活的毒性影响

本文通过实验讨论了Ｚｎ，Ｃｄ，Ｐｂ，Ｃｕ金属离子对栉孔稚贝生长的毒性影响。提出了上述四种金属离子２４～９６ｈ的ＬＣ５０值及稚贝生长安全浓度。Ｚｎ，Ｃｄ，Ｐｂ，Ｃｕ离子对栉孔稚贝９６ｈＬＣ５０分别为０．０４７、０．００８、０．１００及０．００７ｍｇ／Ｌ。四种金属离子对稚贝生物毒性顺序是Ｃｕ＞Ｃｄ＞Ｚｎ＞Ｐｂ。     

长江口悬浮固体中重金属元素的形态研究

研究了长江口水体中微量金属元素Ｃｕ、Ｐｂ、Ｚｎ、Ｃｄ，在固－液两相中的分配，以及在悬浮固体中的形态分布。结果表明，元素Ｃｕ、Ｐｂ、Ｚｎ有９０％左右存在于悬浮固体中，并以固态形式输入河口，溶解态仅占１０％左右；元素Ｃｄ固态部分约占３５％，溶解态占优势。在悬浮固体中，元素Ｃｕ、Ｐｂ、Ｚｎ主要以残留态和铁锰结合态形式存在，这两种形态的比例，Ｃｕ为４０％和２９％，Ｐｂ各占４０％，Ｚｎ为３７％和３８％。元素     

菲律宾蛤仔Cu、Pb、Zn、Cd及遗传杂合度的相互关系研究

测定了中国北方５个群体（青岛、烟台、兴城、大连、丹东）菲律宾蛤仔体内Ｃｕ、Ｐｂ、Ｚｎ、Ｃｄ含量，研究了４种重金属之间的相互关系及与遗传杂合度的相互关系。结果表明，Ｃｕ和Ｚｎ、Ｃｕ和Ｃｄ、Ｚｎ和Ｃｄ具有显著的相关性；Ｃｕ和Ｚｎ相关系数最大为０．９８３２，线性方程为：Ｃｚｎ＝５．２０７Ｃｃｕ－７．５８１６；Ｃｕ、Ｚｎ、Ｃｄ与杂合度相关系数为正，ｂｐ与杂合度相关系数为负，相关性均不显著。     

辽东湾双台子河海区动物体内污染物含量及时空分布

１９９７年１１月对辽东湾双台子河海区部分鱼类、贝类及甲壳动物体内的Ｈｇ、Ｃｄ、Ｐｂ、Ａｓ、Ｃｕ、Ｚｎ和油的含量进行了调查，并对这些污染物的时空分布趋势进行了分析。结果表明：狼虾虎鱼体内的污染物的浓度分别为０．００８（Ｈｇ）、０．８８（Ｃｄ）、０．１７（ｐｂ）、１．７７（Ａｓ）、０．２５（Ｃｕ）、４７．３（Ｚｎ）和８．３６（油）；贝在体内污染物的浓度分别为０．００３－０．０３３（Ｈｇ）、１．１６－１     

模拟秋茄湿地系统中镍、铜的分布积累与迁移

温室中建立模拟湿地系统。对照组用１５‰的人工海水，污水处理组分别用正常、５倍和１０倍浓度的人工污水定时、定量对模拟系统污灌一年，用于研究Ｎｉ、Ｃｕ在系统中的分配与迁移。结果表明：污水中的Ｎｉ、Ｃｕ主要存留于土壤中，占８８．１３％－９４．１２％；留存于植物体中的占０．１０％－０．３４％；凋落物占０．０２％－０．０９％。由植物吸收的Ｎｉ、Ｃｕ主要分布于根部，分别占总量的３１．０８％－５６．１９％和７．     

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     

深圳福田红树林对重金属Cu,Pb,Zn,Cd的吸收,累积与循环

研究了污水处理下红树林对Ｃｕ、Ｂｐ、Ｚｎ、Ｃｄ４种重金属元素的吸收、累积、分布循环结果表明，林地表层土壤４种元素的储量关系为Ｚｎ〉Ｐｂ〉Ｃｕ〉Ｃｄ；对土壤中４种重金属富集能力的大小依次为桐花树〉秋茄〉白骨壤。该群落中Ｃｕ、Ｐｂ、Ｚｎ、Ｃｄ的现存累积量分别为１４１．７９６、４５５．９６７、１２２０．２２４和９．４９３ｍｇ／ｍ＾３，年吸收量分别２为１８．９８、１６．４３、８９．１９和０．３９ｍｇ／ｍ＾     

Effects of two sludge application on fractionation and phytotoxicity of zinc and copper in the soil

The potential harm of heavy metals is a primary concern in application of sludge to the agricultural land. A pot experiment was conducted to evaluate the effect of two sludges on fractionation of Zn and Cu in soil and their phytotoxicity to pakchoi. The loamy soil was mixed with 0%, 20%, 40%, 60% and 80% (by weight) of digested sewage sludge (SS) and composted sludge (SC). The additions of both sludges caused a significant raise in all fractions, resulting in that exchangeable (EXCH) and organic bound (OM) became predominance of Zn and organic bound Cu occupied the largest portion. There was more available amount of Zn and Cu in SS treatments than SC treatments. During the pot experiment, the concentration of Zn in EXCH, carbonate (CAR) and OM and Cu in EXCH and OM fractions decreased in all treatments, so their bioavailability reduced. Germination rate and plant biomass decreased when the addition rate was high and the best yield appeared in 20% mixtures at the harvest of pakchoi. The two sludges increased tissue contents of Zn and Cu especially in the SS treatments. Zn in pakchoi was not only in relationship to ΔEXCH and ΔCAR forms but also in ΔOM forms in the sludge-soil mixtures. Tissue content of Cu in pakchoi grown on SC-soils could not be predicted by ΔEXCH. These correlation rates between Zn and Cu accumulation in pakchoi and variation of different fractions increased with time, which might indicate that sludges represented stronger impacts on the plant in long-term land application.     

Intraspecific differences in effects of co-contamination of cadmium and

A hydroponic experiment was carried out to study intraspecific differences in the effects of different concentrations of cadmium (Cd)(0-10 mg/L) and arsenate (As(V)) (0-8 mg/L) on the growth parameters and accumulation of Cd and As in six wheat varieties Jing-9428, Duokang-1, Jingdong-11, Jing-411, Jingdong-8 and Zhongmai-8. The endpoints of wheat seedlings, including seed germination,biomass, root length and shoot height, decreased with increasing the Cd and As concentrations. Significant differences in seed germination, biomass, root length, shoot height and the accumulation of Cd and As were observed between the treatments and among the varieties (p ＜ 0.05). The lethal dosage 50% were about 20, 80, 60, 60, 80 and 20 mg As/L for Jing-9428, Duokang-1, Jingdong-11,Jing-411, Jingdong-8 and Zhongmai-8, respectively, and the corresponding values for Cd were about 30, 80, 20, 40, 60 and 10 mg Cd/L, respectively. Among the six varieties, Duokang-1 was found to be the most resistant to Cd and As toxicity, and Zhongmai-8 was the most sensitive to Cd and As co-contamination. The resistance of the six varieties was found dependant on the seedling uptake of Cd and As. Duokang-1 was the most suitable for cultivation in Cd and As co-contaminated soils.     

Toxic effects of acetochlor, methamidophos and their combination on nifH gene in soil

Toxic effects of two agrochemicals on nifH gene in agricultural black soil were investigated using denaturing gradient gel electrophoresis （DGGE） and sequencing approaches in a microcosm experiment. Changes of soil nifH gene diversity and composition were examined following the application of acetochlor, methamidophos and their combination. Acetochlor reduced the nifH gene diversity （both in gene richness and diversity index values） and caused changes in the nifH gene composition. The effects of acetochlor on nifH gene were strengthened as the concentration of acetochlor increased. Cluster analysis of DGGE banding patterns showed that nifH gene composition which had been affected by low concentration of acetochlor （50 mg/kg） recovered firstly. Methamidophos reduced nifH gene richness that except at 4 weeks. The medium concentration of methamidophos （150 mg/kg） caused the most apparent changes in nifH gene diversity at the first week while the high concentration of methamidophos （250 mg/kg） produced prominent effects on nifH gene diversity in the following weeks. Cluster analysis showed that minimal changes of nifH gene composition were found at 1 week and maximal changes at 4 weeks. Toxic effects of acetochlor and methamidophos combination on nifH gene were also apparent. Different nifH genes （bands） responded differently to the impact of agrochemicals： four individual bands were eliminated by the application of the agrochemicals, five bands became predominant by the stimulation of the agrochemicals, and four bands showed strong resistance to the influence of the agrochemicals. Fifteen prominent bands were partially sequenced, yielding 15 different nifH sequences, which were used for phylogenetic reconstructions. All sequences were affiliated with the alpha- and beta-proteobacteria, showing higher similarity to eight different diazotrophic genera.     

EDTA-enhanced phytoremediation of lead contaminated soil by Bidens maximowicziana

Phytoremediation is a potential cleanup technology for the removal of heavy metals from contaminated soils.Bidens maximowicziana is a new Pb hyperaccumulator,which not only has remarkable tolerance to Pb but also extraordinary accumulation capacity for Pb.The maximum Pb concentration was 1509.3 mg/kg in roots and 2164.7 mg/kg in overground tissues.The Pb distribution order in the B. maximowicziana was:leaf>stem>root.The effect of amendments on phytoremediation was also studied.The mobility of soil Pb and the Pb concentrations in plants were both increased by EDTA application.Compared with CK(control check),EDTA application promoted translocation of Pb to overground parts of the plant.The Pb concentrations in overground parts of plants was increased from 24.23-680.56 mg/kg to 29.07-1905.57 mg/kg.This research demonstrated that B.maximowicziana appeared to be suitable for phytoremediation of Pb contaminated soil,especially,combination with EDTA.     

Distribution and ecological effect of mercury in Laogang landfill, Shanghai, China

Laogang landfill near Shanghai is the largest landfill in China, and receives about 10000 t of daily garbage per day, Samples of topsoil and plants were analyzed to evaluate mercury pollution from the landfill. For topsoil samples, there were significant correlations among total mercury （HgT）, combinative mercury （Hgc） and gaseous mercury （HgG）, and content of total organic carbon （TOC）, but, no significantly relationship was found between Hg content and filling time. Hg content changes in vertical profiles with time showed that the average Hgv of profiles 1992, 1996, and 2000 was similar, but their average HgG was quite different. HgT was significantly correlated with Hgc in profile 1992 and 2000, and Hgv was significantly correlated with Hg6 in profile 1996. HgG/Hgv ratio in profile samples decreased in the order of （HgG,/HgT）1992〉（HgG/HgT）1996〉〉（HgG/HgT）2000. A simple outline of Hg release in landfill could be drawn： with increasing of filling time, degradation undergoes different biodegradation, accordingly, gaseous mercury goes through small, more, and small proportion to total mercury. Distribution of Hg in plants was inhomogeneous, following the order of leaf〉root〉stem. The highest value of leaf may be associated with higher atmospheric Hg from landfill. Ligneous plants （e.g. Phyllostachys glanca, Prunus salicina and Ligustrum lucidum） are capable of enriching more Hg than herbaceous plants.     

Arsenic uptake by arbuscular mycorrhizal maize （Zea mays L.） grown in an arsenic-contaminated soil with added phosphorus

The effects of arbuscular mycorrhizal (AM) fungus (Glomus mosseae) and phosphorus (P) addition (100 mg/kg soil) on arsenic (As) uptake by maize plants (Zea mays L.) from an As-contaminated soil were examined in a glasshouse experiment.Non-mycorrhizal and zero-P addition controls were included.Plant biomass and concentrations and uptake of As,P,and other nutrients,AM colonization,root lengths,and hyphal length densities were determined.The results indicated that addition of P significantly inhibited root colonization and development of extraradical mycelium.Root length and dry weight both increased markedly with mycorrhizal colonization under the zero-P treatments,but shoot and root biomass of AM plants was depressed by P application.AM fungal inoculation decreased shoot As concentrations when no P was added,and shoot and root As concentrations of AM plants increased 2.6 and 1.4 times with P addition,respectively.Shoot and root uptake of P,Mn,Cu,and Zn increased,but shoot Fe uptake decreased by 44.6%,with inoculation, when P was added.P addition reduced shoot P,Fe,Mn,Cu,and Zn uptake of AM plants,but increased root Fe and Mn uptake of the nonmycorrhizal ones.AM colonization therefore appeared to enhance plant tolerance to As in low P soil,and have some potential for the phytostabilization of As-contaminated soil,however,P application may introduce additional environmental risk by increasing soil As mobility.     

Enzymatic oxidation of aqueous pentachlorophenol

The influence of the nonionic surfactant Tween 80 on pentachlorophenol （PCP） oxidation catalyzed by horseradish peroxidase was studied. The surfactant was tested at concentrations below and above its critical micelle concentration （CMC）. Enhancement of PCP removal was observed at sub-CMCs. The presence of Tween 80 in the reaction mixture reduced enzyme inactivation which occurred through a combination of free radical attack and sorption by precipitated products. A simple first-order model was able to simulate time profiles for enzyme inactivation in the presence or absence of Tween 80. At supra-CMCs, the surfactant caused noticeable reductions in PCP removal, presumably through micelle partitioning of PCP which precluded the hydrophobic PCP molecule from interacting with the enzyme.     

Decomposition of alachlor by ozonation and its mechanism

Decomposition and corresponding mechanism of alachlor, an endocrine disruptor in water by ozonation were investigated. Results showed that alachlor could not be completely mineralized by ozone alone. Many intermediates and final products were formed during the process, including aromatic compounds, aliphatic carboxylic acids, and inorganic ions. In evoluting these products, some of them with weak polarity were qualitatively identified by GC-MS. The information of inorganic ions suggested that the dechlorination was the first and the fastest step in the ozonation of alachlor.     

基于综合水质标识指数和对应分析法的校园河道水质评价

以三峡大学的校园河道求索溪为研究对象,利用综合水质标识指数法确定求索溪水质类别,分析其水质时空变化规律,并利用对应分析法得出求索溪中不同监测点的主要污染因子.研究结果表明:求索溪整体的综合水质标识指数为7.423,整体水质为劣V类(地表水环境质量标准GB 3838-2002)且黑臭.从时间变化来看,求索溪4月份的水质最差,5月份次之,4、5月份所有监测点的水质都劣于V类且黑臭;8月份水质最好,水质为Ⅳ类;从空间分布来看,8个监测点综合水质标识指数均超过6.0,水质为劣V类,其中6号监测点的水质相对最好,监测点3号的水质相对最差;对应分析法得出求索溪的整体水体污染程度受总氮因子的影响最大,其次为总磷.该研究拟为求索溪及类似校园河道的水环境治理研究提供基础依据和参考.     

Potential of plant polyphenol oxidases in the decolorization and removal of textile and non-textile dyes

In this study an effort has been made to use plant polyphenol oxidases; potato （Solanum tuberosum） and brinjal （Solanum melongena）, for the treatment of various important dyes used in textile and other industries. The ammonium sulphate fractionated enzyme preparations were used to treat a number of dyes under various experimental conditions. Majority of the treated dyes were maximally decolorized at pH 3.0. Some of the dyes were quickly decolorized whereas others were marginally decolorized. The initial first hour was sufficient for the maximum decolorization of dyes. The rate of decolorization was quite slow on long treatment of dyes. Enhancement in the dye decolorization was noticed on increasing the concentration of enzymes. The complex mixtures of dyes were treated with both preparations of polyphenol oxidases in the buffers of varying pH values. Potato polyphenol oxidase was significantly more effective in decolorizing the dyes to higher extent as compared to the enzyme obtained from brinjal polyphenol oxidase. Decolorization of dyes and their mixtures, followed by the formation of an insoluble precipitate, which could be easily removed simply by centrifugation.