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     

分析饮用水中五种卤代烃的顶空／气相色谱法验证

本文采用顶空／程序升温气相谱法快速分析饮用水中１．１－二氯乙烯，１．１．１．－三氯乙烷，１．１．２．－三氯乙烷，三溴甲烷１．１．２．２－四氯乙烷五种挥发性卤代烃，分离效果好，其相关系数均在０．９９以上，检出限分别为０．５０μｇ／ｌ．０．１０μｇ／ｌ。０．９８μｇ／ｌ，０．５６μｇ／ｌ，１．２０μｇ／ｌ，其回收率在８１．８％－１０２．７％之间，精密度在０．６２％－１２．１％之间。     

阳极溶出伏安法测定水体中痕量Sb^5＋

在ｐＨ３．４，８－羟基喹啉、甲基橙的浓度分别为４３μｍｏｇ／Ｌ、１３μｍｏｌ／Ｌ的０．１ｍｏｌ／Ｌ（ＮＨ４）２ＳＯ４底液中，用阳极溶出伏安法直接测定水体中Ｓｂ＾５＋。其线性范围为０．２６～５．２ｎｍｏｌ／Ｌ，方法的检出限为０．１ｎｍｏｌ／Ｌ；９次重复测定的变异系数为０．８％；回收率为９５．６％～１０４％。大部分常见阳离子不干扰测定。     

一种新的阴离子表面活性剂电极的研制及应用

研制出一种新的阴离子表面活性电极,电极膜最佳组成：ＴＨＤＡ－ＤＢＳ５ｍｇ,ＤＢＰ０４ｍｌ,ＮＢ０．３ｍｌ,ＰＶＣ粉０．２ｇ,电极线性范围１×１０＾－３－８．１×１０＾－７ｍｏｌ／Ｌ,级差５８ｍＶ／ｄｅｃ,对ＤＢＳ和ＳＤＳ检测分别为５．６×１０＾－７ｍｏｌ／Ｌ和７．４×１０＾－７ｍｏｌ／Ｌ。     

聚乙烯毗咯烷酮修饰碳糊电极溶出伏安法测定水中硝基酚

提出用聚乙烯毗咯烷酮（ＰＶＰｒ）修饰碳糊电极同时测定水中对硝基酸和２,４－二硝基酚的方法。在０．１ｍｏｌ／ＬＫＣｌ的酚试液中开路富集,然后在磷酸盐缓冲液介质中溶出．以微分脉冲伏安法恻定,检测限分别为０．５０μｇ／Ｌ和１．８０μｇ／Ｌ。讨论了测定的影响因素以及２种硝基酚在该修饰电极上的反应机理。测定了地面水中对硝基酸和２,４－二硝基酸的含量,回收率分别为９０±６％和８６±５％。     

离子色谱法测定土壤中的可溶性盐分

以０．００３０ｍｏｌ／ＬＮａＨＣＯ－０．００２４ｍｏｌ／ＬＮａ２ＣＯ３为淋洗液，离子色谱法测定土壤浸提液中的组分，Ｃｌ＾－，ＮＯ＾－３，ＳＯ＾２－４三组分的相对标准偏差小于５％，加标回收率在９０％以上，可以做多组分的同时测定，具有比较高的测试效率。     

三元缔合物抑制分光光度法测定痕量氟

利用氟离子对锆－水杨基荧光酮－溴化十六烷基三甲基铵三元缔合物形成的竞争抑制作用,建立了测定痕量氟的抑制分光光度法,确定了测定的最佳条件为：「ＳＡＦ」＝６．０×１０＾－５ｍｏｌ．Ｌ＾－１「ＣＴＭＡＢ」＝８．０×１０＾－４ｍｏｌ．Ｌ＾－１,「Ｚｒ（ＩＶ）」＝１．０μｇ．ｍｌ＾－１,「ＨＣｌ」＝０．０８ｍｏＬ．Ｌ＾－１,２５℃。     

离子色谱法测定酸雨中6种阴离子

离子色谱法测定酸雨中６种阴离子，以流速为１．５１ｍＬ／ｍｉｎ，０．２４ｍｏｌ／Ｌ Ｎａ２ＣＯ３和０．３ｍｏｌ／Ｌ ＮａＨＣＯ３的混和液为淋洗液，在ＹＳＡ８型８００１Ａ－４阴离子交换柱上分离，ＹＳ－１抑制器，ＹＩＣ－８型离子色谱仪电导检测器检测，方法的线性范围均为１００倍，可达２００倍以上，以ＣＩ＾－为例，最小检出限为０．００１，重现性ＣＶ％为０．７６，空白检测偏差Ｓｗｂ＝０．００６８１，回收率为９     

水系沉积物中铅含量的快速荧光测定方法的研究

建立了简单、快速测定Ｐｂ＾２＋的荧光测定方法。在ｐＨ＜６．８的酸度条件下,Ｐｂ＾２＋与浓度为１．４－２．０ｍｏｌ／Ｌ的Ｃｌ＾－形成的铅氯配合物在２６２．５ｎｍ的紫外光激光下发射出４８５．０ｎｍ可用于痕量铅离子测定的荧光,在选定激发单色器通带１０．０ｎｍ,发射单色器通带２０．０ｎｍ的仪器条件下,荧光强度与１．０×１０＾－７－１．０×１０＾－５ｍｏｌ／Ｌ范围的Ｐｂ＾２＋的线性关系可用△Ｆ＝１．０１×１     

废水中含磷表面活性剂的测定

用罗丹明６Ｇ分光光度法能测定亚甲基蓝分光光度法不能测定的含磷阴离子表面活性剂．本法变异系数２．７％（ｎ＝１４），最小检出浓度８．２×１０－８ｍｏｌ／Ｌ（ｎ＝２１），加标回收率９１．８％～１０８．３％，测定ＰＫ、Ｅ５０２Ａ、昆山ＰＫ的摩尔吸光系数分别为１．１６８×１０５、１．１７５×１０５和１．１３３×１０５Ｌ／ｍｏｌ．ｃｍ，标准曲线的相关系数０．９９９４。方法准确、简单、方便，水中常见的ＮａＣｌ、硬度、蛋白质、非离子表面活性剂、磷酸盐等不干扰测定。     

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.     

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.     

Degradation of metabolites accumulated of benzo[a]pyrene by coupling Penicillium Chrysogenum with KMnO4

Several main metabolites of benzo[a]pyrene （BaP） formed by Penicillium chrysogenum, Benzo[a]pyrene-1,6-quinone （BP 1,6- quinone）, trans-7,8-dihydroxy-7,8-dihydrobenzo[a]pyrene （BP 7,8-diol）, 3-hydroxybenzo[a]pyrene （3-OHBP）, were identified by high-performance liquid chromatography （HPLC）. The three metabolites were liable to be accumulated and were hardly further metabolized because of their toxicity to microorganisms. However, their further degradation was essential for the complete degradation of BaP. To enhance their degradation, two methods, degradation by coupling Penicillium chrysogenum with KMnO4 and degradation only by Penicillium chrysogenum, were compared; Meanwhile, the parameters of degradation in the superior method were optimized. The results showed that （1） the method of coupling Penicillium chrysogenum with KMnO4 was better and was the first method to be used in the degradation of BaP and its metabolites; （2） the metabolite, BP 1,6-quinone was the most liable to be accumulated in pure cultures; （3） the effect of degradation was the best when the concentration of KMnO4 in the cultures was 0.01% （w/v）, concentration of the three compounds was 5 mg/L and pH was 6.2. Based on the experimental results, a novel concept with regard to the bioremediation of BaP-contaminated environment was discussed, considering the influence on environmental toxicity of the accumulated metabolites.     

Impact of atrazine and nitrogen fertilizers on the sorption of chlorotoluron in soil and model sorbents

Sorption of chlorotoluron in ammonium sulfate, urea and atrazine multi-solutes system was investigated by batch experiments. The results showed application of nitrogen fertilizers to the soil could affect the behavior of chlorotoluron. At the same concentration of N, sorption of chlorotoluron decreased as the concentration of atrazine increased on the day 0 and 6 in soil, respectively. The sorption of chlorotoluron increased from 0 to 6 d when soils were preincubated with deionized water, ammonium sulfate and urea solution for 6 d. That indicated incubation time was one of the most important factors for the sorption of chlorotoluron in nitrogen fertilizers treatments. The individual sorption isotherms of chlorotoluron in rubbery polymer and silica were strictly linear in single solute system, but there were competition sorption between pesticides or between pesticides and nitrogen fertilizers. That indicated the sorption taken place by concurrent solid-phase dissolution mechanism and sorption on the interface of water-organic matter or water-mineral matter.     

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.     

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.     

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.     

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.     

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.     

Removal of heavy metals from sewage sludge by low costing chemical method and recycling in agriculture

ＲｅｍｏｖａｌｏｆｈｅａｖｙｍｅｔａｌｓｆｒｏｍｓｅｗａｇｅｓｌｕｄｇｅｂｙｌｏｗｃｏｓｔｉｎｇｃｈｅｍｉｃａｌｍｅｔｈｏｄａｎｄｒｅｃｙｃｌｉｎｇｉｎａｇｒｉｃｕｌｔｕｒｅＷｕＱｉｔａｎｇ，ＮｙｉｒａｎｄｅｇｅＰａｓｃａｓｉｅ，ＭｏＣｅｈｕｉＦ...