化学修饰电极预富集—石墨炉原子吸收法测定土壤中可溶性铅

研究了用Ｎａｆｉｏｎ化学修饰电极预富集－石墨炉原子吸收法测定土壤中可溶性铅的方法。土壤经０．１ｍｏｌ／Ｌ ＨＣｌ处理，以Ｎａｆｉｏｎ修饰的钨丝电极富集可溶性痕量铅后，放入石墨杯中进行原子吸收法测定。实验结果，在ｐＨ３．５的ＨＣｌ介质中，测定的线性范围为０～４．５μｇ／Ｌ，检测限为０．０４μｇ／Ｌ；对浓度为２μｇ／Ｌ的铅标准溶液平行测定１０次，相对标准偏差为２．６％；１０多种离子不干扰测定，样品回收     

石墨炉原子吸收分光光度法测定饮用水中的锑

用石墨炉原子吸收分光光度法测定较清洁和低矿化度饮用水中的锑，铁，铝含量分别为３００μｇ／和２００μｇ／ｌ时均无干扰。以Ｍｇ（ＮＯ３）２作基体改进剂，线性范围为０．５－１００μｇ／ｌ，若进样量为２０μｌ最低检测浓度为５．０μｇ／ｌ，则最低检出率为０．５μｇ／ｌ。     

分子扩散法捕集环境中SO2的研究

吸收膜容量研究表明，用１０％（Ｖ／Ｖ）三乙醇胺十丙酮或１０％（Ｗ／Ｖ）ＮＯ２ＣＯ３作吸收剂，在１５℃，绝对干燥空气条件下测得两种采样器的感受（α），１＾采样器α１（ＴＥＡ）０．３０４３ＰＰｍ．ｈ．μｇ＾－１（ＳＯ＾２－４），α２（Ｎａ２ＣＯ３）０．２９６３ｐｐｍ．ｈ．μｇ＾－１（ＳＯ＾２－４），２＃采样器α２（ＴＥＡ）０．７８９３ＰＰｍ．ｈ．μｇ＾－１（ＳＯ＾２－４）α２（Ｎａ２ＣＯ３）０．８６６     

流动注射分光光度法测定水中的氯离子

本文采用流动注射分析（ＦＩＡ）技术．载流中含有Ｈｇ（ＳＣＨ）２和Ｆｅ２＋，注入试样中的氯离子与Ｈｇ（ＳＣＨ），反应，释放出ＳＣＨ－，后者与Ｆｅ２＋形成红色Ｆｅ（ＳＣＨ）给离子，其强度用分光光度法在４８０ｎｍ处测定．记录的吸收峰高度与试样中氯离子浓度成正比．线性范围６．０—１８μｍ／ｍＬＣｌ，检出限达０．１２μｇ／ｍＬＣｌ－．对６．０μｇ／ｍＬＣｌ－连续测定１１次，其ＲＳＤ为３．９％．出样频率为９０样／小时．方法已用于水样中氯离子的测定．     

新银盐分光光度法测定地表不中痕量砷

在酒石酸介质中，以硼氢化钾为还原剂，使砷离子转变为砷化氢，以乙醇－－硝酸银－聚乙烯醇为吸收液进行显色，在４００纳米处以原吸收液为参比进行测定。方法的检出限为０．２０微克／升，对含砷为０．６５－１．２７μｇ／ｌ的天然水进行测定，回收率为９２－１１６％，相对标准偏差７．４－１２．２％。     

聚乙烯吡咯烷酮修饰碳糊电极溶出伏安法测定水中硝基酚

提出用聚乙烯吡咯烷酮（ＰＶＴｒ）修饰碳糊电极同时测定水中对硝酚和２，４－二硝基酚的方法。在０．１ｍｏｌ／ＬＫｃｌ的酚工液中开始路富集，然后在磷酸盐缓冲液介质中溶出，以微分脉冲伏安法测定，检测奶分别为０．５０μｇ／Ｌ和１．８０μｇ／Ｌ。讨论了测定的影响因素以及２种硝基酚在民极上的反应机理。测定了地面水中对硝基酚和２，４－二硝基酚的含量，回收率分别为９０±６％和８６±５％     

HPLC法测定废水中苯胺类化合物

用乙醚为提取有机相，提取前先经碱化，提取后加酸使苯胺成盐，吹去乙醚，用ＨＰＬＣ法测定苯胺类化合物。方法适用于测定废水中苯胺类化合物。检出限：苯胺３．０ｎｇ，邻硝基苯胺０．５ｎｇ，对硝基苯胺１．０ｎｇ。线性范围：苯胺０．８１７－１３．０７２μｇ／ｍｌ，邻硝基苯胺０．１４６４－２．３４２４μｇ／ｍｌ，对硝基苯胺０．２５３－４．０４８μｇ／ｍｌ。精密度（ＣＶ）：苯胺２．３８％，邻硝基苯胺１．０９％，对硝     

氯化物发生—原子荧光法测定海水中痕量铅

以过硫酸铵为氧化剂将Ｐｂ氧化成亚稳四价态，与ＫＢＨ４作用生成ＰｂＨ４，应用氢化物发生－原子荧光法测定海水痕量Ｐｂ。本法灵敏度较高，检测限为０．６３μｇ／Ｌ；其回收率在９０％－１０５％之间；变异系数为２．１％－４．２％。     

汽车尾气和大气中C1—C4烃类分析方法研究

采用熔融性Ａｌ２Ｏ３／ＫＣｌ大孔径毛细管柱，用气相色谱直接进样方式，对汽车尾气中的低碳烃类化合物进行了分析监测。在汽车尾气中检出了３２个色谱峰，对其中的１０种烃类化合物进行了定量测定。浓度在２５μｇ／Ｌ－２０ｍｇ／Ｌ范围内与峰面积有良好的线性关系，方法的相对标准偏差小于１０％；样品的回收率为８５．０％－１１５．０％；最低检出浓度为２５μｇ／Ｌ。     

水中微量铝的间接原子吸收法测定

在ＨＡｃ－ＮａＡｃ缓冲溶液（ｐＨ４．５）体系中，利用（１－（２－萘酚（ＰＡＮ），Ａｌ＾３＾＋与Ｃｕ＾２＾＋－ＥＤＴＡ发生定量交换反应，用氯仿萃取出Ｃｕ＾２＾＋－ＰＡＮ，用原子吸收法测定水中的Ｃｕ＾２＾＋，以间接测定ＡＬ＾３＾＋。方法的最佳线性范围为０．１－１．０ｍｇ／Ｌ，最低检出浓度为０．１ｍｇ／Ｌ；测定河水，饮用水，地下水中的Ａｌ＾３＾＋，其回收率在８５．０％－１０９％之间，变异系数为１．５％－     

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.