Ce_(0.65-x)Co_xK_(0.15)Zr_(0.2)O_2催化碳烟燃烧活性研究

采用柠檬酸络合燃烧法制备了不同铈钴摩尔比的Ce_(0.65-x)Co_xK_(0.15)Zr_(0.2)O_2(x=0,0.15,0.23,0.30,0.38,0.45,0.65)催化剂,采用XRD、SEM、FT-IR与H_2-TPR等技术对催化剂进行表征,并通过程序升温氧化反应(TPO)考察了催化剂不同Ce/Co比对碳烟颗粒物催化燃烧活性的影响。研究结果表明:在松散接触条件下,该系列催化剂催化碳烟颗粒物燃烧活性较高,T_m均小于400℃,当x=0.23时活性最高,T_i与T_m分别为321℃与355℃,催化剂所表现出的高活性受益于样品表面具有大量高活性的细小Co_3O_4颗粒物。     

复合氧化物催化材料上碳颗粒物的催化燃烧

针对柴油车排放碳颗粒物的控制 ,研制可应用于柴油车排放碳颗粒物催化再生复合氧化物催化材料 .通过运用热分析仪 (TGA)和程序升温氧化反应装置 (TPO)对复合氧化物催化材料的活性进行评价 ,研究了催化材料的组成、原子配比、催化材料与碳颗粒物质量比、H₂O的加入、焙烧温度对催化活性的影响 .实验结果表明 :双组分金属氧化物催化剂中 ,Cu-Mo-O有较好的活性 ;多组分金属氧化物催化剂中 ,Cu-K-Mo-O在原子比Cu∶K∶Mo =1∶1∶2 ,催化剂与碳颗粒物质量比为 5∶1时活性最好 ,其碳颗粒物起燃温度为 32.7℃ ,同时H₂O和焙烧温度对该催化剂的影响较小 ,是能够应用于柴油车排放碳颗粒物控制催化再生的良好催化材料 .     

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。     

新型汽车尾气净化催化剂的研究

研究Ｌａ－Ｃｏ－Ｃｕ－Ｍｎ－Ｃｅ－Ｐｄ催化剂的活性和热稳定性,结果表明,该催化剂具有低温活性良好、活性高以及热稳定性好的性能特点,对ＣＯ、ＨＣ氧化的Ｔ５０％和Ｔ１００％分别约为１８２℃,２３８℃和２４０℃、２６５℃,催化剂表面组分发生强相互作用形成３种活性中心,是催化剂低的起燃温度,高活性的原因。催化剂高温处理后未发生烧结,活性未下降,热稳定性良好。     

呼和浩特市大气气态和颗粒物上正构烷烃的研究

采用聚氨基甲酸乙酯和玻璃纤维滤膜采集样品并测定。大气中总正构烷烃的浓度分布、气／固分布比与季节变化、污染源有关。在呼市大气中总正构烷烃（Ｃ１５－Ｃ３３），夏季主要存在气态中（７８％），而冬季主要存在于颗粒物上（８３％）。内蒙古草原大气对照样品中，气态中总正构烷烃在冬夏两季所占百分比都约为５０％。市区冬季大气颗粒物上的总正构烷烃浓度比其它城市结果高出１－２个数量级。     

催化氧化CS2的催化剂及其性能研究

以ＣＳ２作为含硫废气的处理对象，研究了Ｐｔ－Ｍｏ负载，在改性天然丝光沸石上对ＣＳ２的催化氧化活性，以及添加Ｖ对催化剂活性的影响。研究表明，Ｐｔ－Ｍｏ－Ｖ和改性载体之间存在着共催化作用，在Ｐｔ－Ｍｏ－Ｈ＾＋Ｍ催化剂上由于Ｖ的添加，使催化剂处理ＣＳ２的浓度和ＳＤＹ值明显提高。在反应温度３１０℃，空速５００ｈｒ＾－１和ＣＳ２浓度为３７０ｍｇ／ｍ＾３转化率达到１００％，ＳＯｘ放出率接近９５％－１００％。     

地表水中总有机碳的测定

该文提出了燃烧氧化－非分光红外吸收法测定地表水中总有机碳含量。水样连同净化空气分别导入高温燃烧管和低温反应管内，样品中的总碳和无机碳氧化分解ＣＯ２。定量试样中的总碳和无机碳之差即为样品总有机碳。     

南宁市区交通环境空气颗粒物中碳组分的污染特征分析研究

含碳颗粒物是大气颗粒物的重要组成部分,对人体健康产生很大的威胁.分别于2012年夏季及2013年冬季在南宁市选取六条主要交通干道采集了PM10、PM2.5样品,分析测定了其中的碳组分.结果表明,碳组分浓度季节变化明显.碳组分在细颗粒物中占有比重比在可吸入颗粒物中大.存在二次有机碳污染.对8种碳组分丰度分析说明南宁市大气颗粒物中碳组分的主要来源是燃煤、机动车尾气及生物质样品燃烧.     

氢氟烃HFC－134a的分解实验研究

该研究进行了氢氟烃ＨＦＣ－１３４ａ的催化分解和化学分解实验。实验结果表明无催化剂时ＨＦＣ－１３４ａ很稳定，即使升温至５００℃时也下会分解：在空气和水蒸汽存在下ＨＦＣ－１３４ａ催化分解成ＣＯ和ＣＯ＿２。ＣＦＣ－１２比ＨＦＣ－１３４ａ易分解，反应产物只有ＣＯ＿２。分解产物ＨＦ对催化剂有强烈的失活作用；超氧离子（Ｏ＿２￣－）对液相中的ＨＦＣ－１３４ａ具有很强的氧化分解能力。在常温下几乎可完全分解高浓度的ＨＦＣ－１３４ａ。     

[Cu—γ—Al2O3]催化剂处理染料废水工艺条件研究

采用「Ｃｕ－γ－Ａｌ２Ｏ３」催化剂对由活性艳红Ｘ－３Ｂ配制的ＣＯＤｃｒ为５７００ｍｇ／Ｌ色度３１００倍的实际染料废水进行了催化氧化试验，试验表明，在控制ｐＨ＝４－５，Ｈ２Ｏ２用量为５．０ｍｇ／Ｌ，催化剂用量为３．０ｇ／Ｌ，ｔ＝７０℃和反应时间为２ｈ条件下，可获得ＣＯＤｃｒ去除率为７７％－７８％，脱色率为９９％的良好效果，且催化剂可再生使用。     

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.     

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.     

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.     

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

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

Organochlorine pesticides in soils under different land usage in the Taihu Lake region, China

A field study was conducted in the Taihu Lake region, China in 2004 to reveal the organochlorine pesticide concentrations in soils after the ban of these substances in the year 1983. Thirteen organochlorine pesticides (OCPs) were analyzed in soils from paddy field, tree land and fallow land. Total organochlorine pesticide residues were higher in agricultural soils than in uncultivated fallow land soils. Among all the pesticides, ΣDDX (DDD, DDE and DDT) had the highest concentration for all the soil samples, ranging from 3.10 ng/g to 166.55 ng/g with a mean value of 57.04 ng/g and followed by ΣHCH, ranging from 0.73 ng/g to 60.97 ng/g with a mean value of 24.06 ng/g. Dieldrin, endrin, HCB and α-endosulfan were also found in soils with less than 15 ng/g. Ratios of p,p'-(DDD DDE)/DDT in soils under three land usages were: paddy field ＞ tree land ＞ fallow land, indicating that land usage inlfuenced the degradation of DDT in soils. Ratios of p,p'-(DDD DDE)/DDT ＞1, showing aged residues of DDTs in soils of the Taihu Lake region. The results were discussed with data from a former study that showed very low actual concentrations of HCH and DDT in soils in the Taihu Lake region, but according to the chemical half-lives and their concentrations in soils in 1980s, the concentration of DDT in soils seemed to be underestimated. In any case our data show that the ban on the use of HCH and DDT resulted in a tremendous reduction of these pesticide residues in soils, but there are still high amounts of pesticide residues in soils, which need more remediation processes.     

Single and joint effects of pesticides and mercury on soil urease

The influence of two pesticides including chlorimuron-ethyl and furadan and mercury （Hg） on urease activity in 4 soils （meadow burozem and phaeozem） was investigated. The soils were exposed to various concentrations of the two pesticides and Hg individually and simultaneously. Results showed that there was a close relationship between urease activity and organic matter content in soil. Chlorimuron-ethyl and furadan could both activate urease in the 4 soils. The maximum increment of urease activity by chlorimuronethyl was up to 14%-18%. There was almost an equal increase （up to 13%-21%） in the urease activity by furadan. On the contrary, Hg markedly inhibited soil urease activity. A logarithmic equation was used to describe the relationship （P〈0.05） between the concentration of Hg and the activity of soil urease in the 4 tested soils. Semi-effect dose （ED50） values by the stress of Hg based on the inhibition of soil urease in the 4 soils were 88, 5.5, 24 and 20 mg/kg, respectively, according to the calculation of the corresponding equations. The interactive effect of chlorimuron-ethyl or furadan with metal Hg on soil urease was mainly synergic at the highest tested concentrations.