CuO对贵金属/CeO2/Al2O3催化剂的作用

制备含少量贵金属Ｐｔ、Ｐｄ的不同Ｃｕ和Ｃｅ摩尔含量比（０：１０,１：９,２：８）的催化剂,实验条件十加入ＣｕＯ可以提高Ｐｔ催化剂的二效活性;加入Ｃｕ：Ｃｅ＝２：８的ＣｕＯ降低了Ｐｄ催化剂的顾效性能,然而Ｃｕ：Ｃｅ＝１：９时可以改善Ｐｄ催化剂的三效催化性能。通过结构分析,认为ＣｕＯ的存在可以提高ｄ催化剂的比表面积,ＰｄＯ的分散度。     

钯、铜、锰、铈三效催化剂性能研究

应用脉冲－火焰反应装置、ＸＲＤ、ＴＰＲ和氢氧滴定技术来研究Ｐｄ－Ｃｕ－Ｍｎ－Ｃｅ－Ｏ三效催化剂的性能。实验结果表明，不同的制备Ｐｄ－Ｃｕ－Ｍｎ－Ｃｅ－Ｏ催化剂的方法，则催化活性各不相同。在分层制备的催化剂中，催化性能主要以外层组分性能为主；以混合浸渍法制备的样品中，ＣｕＭｎ＿２Ｏ＿４相消失，Ｃｕ－Ｍｎ－Ｃｅ－Ｏ表面氧环境发生变化；表面活性剂的添加改变了Ｐｄ的分布，使催化剂表面易于还原；这些改变均对催化剂的三效性能发生影响。催化剂表面的有效贮氧量与三效活性没有明显的关系。     

汽车尾气净化剂的发展,现状及前景

催化净化是控制汽车尾气污染的主要手段。文章介绍了汽车尾气催化剂的发展过程：描了了当今普遍使用的三效转化催化剂“提出了未来尾气净化催化剂的发展趋势及需要解决的问题，ＴＷＣ催化剂是以贵金属Ｐｔ，Ｐｄ和Ｒｈ为适性组元，引入Ｃｅ，Ｌａ，Ｂａ和Ｚｒ等为助剂，担载在高比表面物质上制备面成一的类性能优虹的催化剂，它能对尾气中的３种主要有害物质ＮＯｘ，ＣＯ和ＨＣ同时进行转化。     

载体对负载钯催化剂的CO氧化活性的影响

采用ＣＯ－ＴＰＳＲ和ＣＯ氧化活性测试等方法考察了不同载体对Ｐｄ催化剂的ＣＯ表面氧化性能的影响，结果表明，载体对Ｐｄ催化剂的ＣＯ氧化性能、ＣＯ吸附能力影响很大，ＣＯ的吸附能力顺序为Ｐｄ／ＣｅＯ２（吸附量、０．５９ｍｌ／１００ｍｇ）〉Ｐｄ／Ａｌ２Ｏ３（吸附量：０．０５２ｍＬ／１００ｍｇ）〉Ｐｄ／ＴｉＯ２（吸附量：０．００１ｍＬ／１００ｍｇ），催化剂的ＣＯ氧化活性与ＣＯ吸附能力有很好的对应关系，尤其是Ｐ     

掺杂ZrO2、TiO2、γ－Al2O3对Pt、Pd／Al2O3燃烧

运用ＸＲＤ、ＢＥＴ、ＤＴＡ等测试技术，研究并考察了掺杂ＺｒＯ２，ＴｉＯ２，ｒ－Ａｌ２Ｏ３对Ｐｔ－Ｐｄ．Ａｌ２Ｏ３燃烧催化剂性能的影响，结果表明，ＺｒＯ２对Ａｌ２Ｏ３晶相的γ型转为α型有明显的抑制作用，而ＴｉＯ２的添入则起促进作用。     

CO2催化氢化研究--REY负载双金属催化剂的催化作用

用高压釜实验评价了用离子交换法制备的负载于ＲＥＹ和ＺＳＭ－５分子筛上的多种过渡金属对ＣＯ２加氢合成醇和甲烷化的催化活性。实验结果表明,双金属催化剂的活性按下列顺序降低,ＣＯ２甲烷化;Ｒｕ＞ＮｉＲｕ＞ＮｉＰｄ＞ＮｉＩｒ;合成醇：ＮｉＣｕ＞Ｎｉ＞ＮｉＭｎ＞ＮｉＣｏ。用２％Ｒｕ／ＲＥＹ催化剂,在４７３Ｋ,３．９ＭＰａ,ＣＯ２／Ｈ２＝１／５,反应时间２０ｈ条件下,７６％的ＣＯ２转化为甲烷。反应温度,压力和     

烟气中SO2/NOx同时吸收催化脱除的研究

根据同时脱硫脱硝的要求,对以ＣＵＯ为主要活性组分催化剂的制备和反应过程进行研究,活性测试的结果表明,催化剂的最佳活化温度和活化时间分别为４５０℃和２ｈ。当反应温度为４００℃,空间速度为２×１０＾４ｈ＾－１以及ＣｕＳＯ４／ＣｕＯ摩尔比和Ｃｕ／Ｓ分别保持在１．４６和０．８３以上时,ＳＯ２和ＮＯｘ的脱除率可达９０％以上。     

Ni/Fe/Cu氧化物的催化臭氧化作用研究

以吐氏酸的臭氧氧化为例,研究了过渡金属镍、铁、铜单组分和不同配比双组分氧化物的催化作用,附着沉淀法制备的Ｎｉ－Ｆｅ（１：４）和Ｎｉ－Ｃｕ（４：１）催化剂的臭氧利用率分别比γ－Ａｌ２Ｏ３载体提高了２８．９％和２４．３％,金属氧化催化臭氧化能显著改善吐氏酸溶液的可生化性,当溴氧消耗量为０．２５－０．３５ｇ／Ｌ时,ＢＯＤ５／ＣＯＤ达到最大值０．２８。     

催化加氢转化CO2的研究

研究催化加氢法转化ＣＯ２,在Ｆｅ／ＡＣ催化剂上采用不同的反应条件,可将ＣＯ２分别转化成低碳烯烃,液化石油气和液态烃,其转化率均在４０％－５０％之间。在Ｃｕ－Ｚｎ－分子筛催化剂上,３５％ＣＯ２可被转化成二甲醚;在Ｒｈ－Ｖ／ＳｉＯ２催化剂上,ＣＯ２可被转化成乙醇,其单程转化率在５％以上。     

催化剂对汽车发动机烟灰燃烧性能的影响

将汽车排气管中收集到的烟灰与不同催化剂混合组成干混试样。利用ＴＧ－ＤＴＡ技术,考察了不同催化剂对烟灰的助燃作用。发现催化剂存在时烟灰的燃烧特征温度Ｔｍａｘ有较大程度的降低。催化剂的助燃活性：ＮｉＯ／Ａｌ２Ｏ３〉ＣｕＯ／Ａｌ２Ｏ３〉Ｖ２Ｏ５／Ａｌ２Ｏ３〉Ｐｄ／Ａｌ２Ｏ３〉Ａｇ２Ｏ／Ａｌ２Ｏ３〉Ｃｒ２Ｏ３／Ａｌ２Ｏ３〉ＣｅＯ２／Ａｌ２Ｏ３,与金属氧化物的生成焓（－ΔＨ）有一定对应关系,随着－ΔＨ的增加     

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.     

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.     

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.     

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.