石灰石与SO_2直接硫酸化反应宏观动力学的研究

温度、ＳＯ＿２浓度、颗粒大小、石灰石类型和样品的微观结构影响着直接硫酸化反应过程。这一反应过程能用缩芯模型来描述，并对ＳＯ＿２具有一级反应特征。本征反应和产物层扩散控制反应的活化能分别是８５．２ｋＪ／ｍｏｌ和４１．５ｋＪ／ｍｏｌ。在８００℃、２０００ｐｐｍＳＯ＿２和反应１０１ｍｉｎ的条件下，Ｉｇｚｌａｂｅｒｇａ和Ｆｏｒｓｂｙ石灰石的ＣａＣＯ＿３转化率分别可达８４％和７２％。在初始２ｍｉｎ内已煅烧石灰石（ＣａＯ）的硫酸化反应速率与石灰石的反应速率稍高，随后二者基本相同。     

催化光度法测定环境样品中微量He的研究

在酸性介质中，痕量Ｈｅ能显著催化空气中的Ｏ２氧化Ｋ４「Ｆｅ（ＣＮ）６」，生成蓝色化合物，反应对Ｈｇ为一级，催化反应的表以观活化能为６２．９５ｋＪ．ｍｏｌ＾－１，据此建立了测定痕量Ｈｇ的动力学分析法，测定条件为Ｋ４「Ｆｅ（ＣＮ）６」；１．４×１０＾－３ｍｏｌ．Ｌ＾－１，「ＣＨ３ＣＯＯＨ」：０．１４ｍｏｌ．Ｌ＾－１，７５⒈。     

石灰石与SO2直接硫酸化应宏观动力学的研究

温度，ＳＯ２浓度，颗粒大小，石灰石类型和样品的微观结构影响着直接硫酸化反应过程。这一反应过程能用缩芯模型来描述，并对ＳＯ２具有一级反应特征。本征反应和产物层扩散控制反应的活化能分别是８５．２ｋｊ／ｍｏｌ和４１．５ｋｊ／ｍｏｌ。在８００℃、２０００ｐｐｍＳＯ２和反应１０ｍｉｎ的条件下，Ｉｇｎａｂｅｒｇａ和Ｆｏｒｓｂｙ石灰石的ＣａＣＯ３转化率分别可达８４％和７２％。在初始２ｍｉｎ内已煅烧石灰石（ＣａＯ     

三氯乙烯和四氯乙烯与羟基自由基加成反应的理论研究

用从头计算法在ＵＨＦ／６－３１Ｇ水平上研究了三氯乙烯和四氯乙烯与羟基自由基的加成反应，通过振动分析确认了过渡态，计算了内禀反应坐标（ＩＲＣ）。研究表明，该反应能生成较稳定的加成中间体，活化势垒分别为５０．８７ｋＪ·ｍｏｌ＾－１和６３．８３ｋＪ·ｍｏｌ＾－１，且二者反应在常温下均为熵减、放热、吉布斯自由能变化小于零，能自发进行的过程。     

催化光度法测定环境样品中微量Hg的研究

在酸性介质中,痕量Ｈｇ（Ⅱ）能显著催化空气中的Ｏ２氧化Ｋ４［Ｆｅ（ＣＮ）６］,生成蓝色化合物,反应对Ｈｇ（Ⅱ）为一级,催化反应的表观活化能为６２．９５ｋＪ·ｍｏｌ－１．据此建立了测定痕量Ｈｇ（Ⅱ）的动力学分析法,测定条件为Ｋ４［Ｆｅ（ＣＮ）６］：１．４×１０－３ｍｏｌ·Ｌ－１,［ＣＨ３ＣＯＯＨ］：０．１４ｍｏｌ·Ｌ－１,７５℃．在此条件下,线性测定范围为０．０２—０．７０μｇ·ｍｌ－１．本法重现性好,常见共存离子中除Ａｇ（Ｉ）严重干扰外,其余离子不影响测定．测定了水样及污泥样品中的Ｈｇ含量,结果满意     

单甲脒水解动力学研究

报道了单甲脒水解反应动力学与单甲脒在模拟水生生态系统中降解的研究。结果表明，单甲脒属在水中不稳定的化合物，在ｐＨ≤５时稳定，在ｐＨ≥６时则发生明显的水解反应，水解反应速率随反应介质ｐＨ值的增大而加速。单甲脒水解反应半衰期可从１５．９２ｄ（ｐＨ６）缩短至１．４０ｄ（ｐＨ９）。实验获得单甲脒水解反应温度效应系数为２．９，活化能为７８．７４ｋＪ／ｍｏｌ．单甲脒在模拟水生生态系统中的实验结果与在缓冲溶液体     

UV/H2O2/草酸铁络合物光降解水中氯仿的研究

以４００Ｗ高压汞灯为紫外光源，Ｈ２Ｏ２－草酸铁络合物为光氧化剂，对氯仿水溶液进行了光降解反应实验研究．结果表明，ＵＶ／Ｈ２Ｏ２草酸铁络合物体系能有效地使水溶液中氧仿迅速光解脱氯；在等摩尔系列溶液中,Ｆｅ３＋／草酸根的摩尔比为１：３时，氯仿光解效果最好：溶液ｐＨ值对氯仿光解有显著影响，ｐＨ值在３－４时光解速率最快；随着Ｈ２ｏ２浓度的增加，氯仿大解速率提高，但Ｈ２Ｏ２浓度较大时，Ｈ２Ｏ２的有效利用率降低；温度对氯仿光解反应有一定影响，反应的表观活化能为７．６ｋＪ／ｍｏｌ.     

2，4－二氯苯基荧光酮与铬显色反应的研究及其应用

研究了铬（Ⅵ）－２，４－二氯苯基荧光酮（ＤＣＩＰＦ）－溴化十六烷基三甲铵（ＣＴＭＡＢ）体系的显色条件。试验结果表明，在ｐＨ５．２～７．０范围内，铬与ＤＣＩＰＦ及ＣＴＭＡＢ形成红色三元胶束配合物，其最大吸收波长为５７８ｎｍ，表观摩尔吸光系数为１．４０×１０５ｌ·ｍｏｌ（－１）·ｃｍ（－１），铬（Ⅵ）含量在０～９．０μｇ／２５ｍｌ范围内符合比耳定律，配合物的组成为Ｃｒ（Ⅵ）：ＤＣＩＰＦ＝１：２。拟定方法用于水中铬的测定，结果满意。     

酸溶──磷锑钼光度法测定污泥中的磷

本文报道了以硝酸－硫酸－高氯酸分解试样，钼酸铵－酒名酸锑钾－抗坏血酸混合显色剂测定污泥中磷的方法。在硫酸浓度０．４－０．６Ｎ和三价锑离子存在下，磷酸与钼酸铵反应形成磷锑钼杂多酸，该杂多酸在常温下被抗坏血酸还原为磷钼蓝络合物，它的最大吸收波长位于７００ｎｍ处．摩尔吸光系数ε值为１．４９×１０￣４Ｌ·ｍｏｌ￣（－１）·ｃｍ￣（－１），磷量在０－６０μｇ／５０ｍｌ范围内服从比尔定律，检出限为０．０１５μｇ／ｍｌ。本法用于四种不同污泥样品测定的相对标准偏差为０．１９－１．３１％，标准回收率在９９－１０５％之间，结果准确、可靠。     

2,4—二氯苯基荧光酮与铬显色反应的研究与其应用

研究了铬（Ⅳ）－２，４－二氯苯基荧光酮（ＤＣＩＰＥ）－溴化十六烷基三甲胺（ＣＴＭＡＢ）体系的显色条件，试验结果表明，在ｐＨ５．２～７．０范围内，铬与ＤＣＩＰＦ及ＣＴＭＡＢ形成红色三元胶束配合物，其最大吸收波长为５７８ｎｍ，表现摩尔吸光系数为１．４０×１０＾５Ｉ．ｍｏｌ＾－１．ｃｍ＾－１，铬（Ⅵ）含量在０～９．０μｇ／２５ｍｌ范围内符合比耳定律，配合物的组成为Ｃｒ（Ⅵ）：ＤＣＩＰＦ＝１：２，拟定方法     

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.     

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.