淀粉聚乙烯膜在受控条件下的好氧生物降解

采用土埋、真菌生长和 CO₂ 释放试验分别测定了几种淀粉聚乙烯膜的生物降解性 .试验结果表明 ,膜的生物降解性与膜中的淀粉含量正相关 ,并受膜比面积大小的影响 .在受控条件下 ,含淀粉 6%～ 30 %的膜经 28d降解后 ,降解质量变化率在0.6%～ 12.4%范围内 ,其 CO₂ 释放量为 0.02～ 0.15mg/mg膜 .膜中的聚乙烯组分不仅本身难被生物降解 ,而且还抑制微生物对其淀粉组分的降解 .CO₂ 是淀粉聚乙烯膜好氧生物降解的终产物 ,可以作为评估膜生物降解性的一个可靠指标 .     

西湖底泥不同供氧条件下有机质降解及CO2与CH4释放速率的模拟研究

采用密闭培养实验装置于室温（２５℃左右）及ｐＨ为７５条件下，对西湖底泥中有机质完全降解及转化为ＣＯ２和ＣＨ４的速率进行了模拟研究．结果表明，在西湖湖水现有供氧水平（５０—８６ｍｇ（Ｏ２）／Ｌ）条件下，底泥中有机质完全降解的速率最为缓慢，培养期间（４２天）平均只有０７２ｍｇ（Ｃ）／（ｋｇ·ｄ）．当湖水供氧水平进一步上升（８６→１２０→１６０ｍｇ（Ｏ２）／Ｌ），ＣＯ２释放速率增加，最大值可达到８７ｍｇ（Ｃ）／（ｋｇ·周）；当湖水供氧水平下降（８６→０ｍｇ（Ｏ２）／Ｌ），ＣＨ４释放速率加快，最大值可达到４６ｍｇ（Ｃ）／（ｋｇ·周）．     

再生纤维素膜的微生物降解

采用田间掩埋、平皿培养和ＣＯ２释放试验分别测试了再生纤维素膜的生物降解性。试验结果表明：膜的失重随掩埋时间而增加;不同试验菌株对膜有不贩降解活性,其顺序为木霉Ｔ－３１１〉黑曲霉Ａ－３０５〉青霉Ｐ－３０７;掩埋或用菌株Ｔ－３１１接种４２ｄ后,膜的生物降解率可超过７０％;在膜的微生物降解过程中,失重、菌株在膜表面的可见生长和ＣＯ２释放分别是膜不同降解程度的表征,彼此既相关又有区别。     

Ni,Fe氧化物对吐氏酸废水催化臭氧化研究

用浸渍法和附着沉淀法制备了６种以Ｎｉ、Ｆｅ为活性组分，γＡｌ２Ｏ３载体的国型催化剂，催化臭经处理难生物降解的典型染料中间体废水－吐氏酸废水。初始ＣＯＤｃ浓度为１５００ｍｇ／Ｌ左右的废水，当臭氧投加量为０．８ｇ／Ｌ时，在活性最高的催化剂作用下，ＣＯＤＣｒ去除率大于５０％，而没有催化剂作用时小于３０％。     

A／O~2工艺处理化纤废水

采用Ａ／Ｏ２工艺处理化纤废水，试验结果表明：当进水ＣＯＤ：９９０．０～１７００ｍｇ／Ｌ，：５５０～１８８ｍｇ／Ｌ，ＴＮ：１５１～３８６ｍｇ／Ｌ，∑ＣＮ－：４．５０～２８．０ｍｇ／Ｌ，ＳＣＮ－：５５０～３８０ｍｇ／Ｌ，ＡＮ：１０５～３３６ｍｇ／Ｌ时，各项指标的去除率分别为ＣＯＤ：８７．２％左右，－Ｎ：９７．８％左右，ＴＮ：７６４％左右，∑ＣＮ：９８．１％左右，ＳＣＮ：１００％，ＡＮ：１００％。本文还考查了不同浓度的∑ＣＮ－及ＣＯＤ对Ａ／Ｏ２系统的影响。     

柠檬酸废水的厌氧－兼氧－好氧处理

采用厌氧－兼氧－好氧工艺处理柠檬酸废水。管道厌氧消化器在进水ＰＨ３．４４～４．３８．ＣＯＤ１４１８７．５ｍｇ／Ｌ，处理水量为２００ｔ／ｄ，有机负荷率７．０９ｋｇＣＯＤ／（ｍ３·ｄ）条件下，出水ＰＨ７．０～７．５，ＣＯＤ去除率为用８１．１％，产气率为０．４３ｍ３／ｋｇＣＯＤ。兼氧－好氧处理进水ｐＨ３．２～４．６，ＣＯＤ１９２９ｍｇ，／Ｌ．处理水量１０８０ｔ／ｄ，停留时间为兼氧６ｈ、好氧１３ｈ，出水ｐＨ７．４～８．１，ＣＯＤ１０７．６ｍｇ／Ｌ，达到ＧＢ８９７８－８８二级标准。     

海带生物吸附含铜废水的试验

利用海带作为生物吸附材料对含Ｃｕ＾２＋废水处理进行了研究。０．２ｇ颗粒直径为０．１８～０．４２ｍｍ的海带粉末，在１００ｍＬ Ｃｕ＾２＋浓度为１００ｍｇ／Ｌ、ｐＨ为３．０～６．０溶液，吸附容量Ｑｍａｘ为４１．５～６０．０ｍｇ／ｇ，Ｃｕ＾２＋的去除率为８３．９％～８９．３％。ｐＨ值是影响吸附的主要因素，最佳吸附ｐＨ值为３．０～６．０。     

臭氧—活性炭C2法处理印染废水

本文介绍了臭氧－活性炭Ｃ２法在印染水处理中的应用，在进水ＣＯＤ〈８００ｍｇ／ｌ，ＢＯＤ〈３００ｍｇ／ｌ，ＢＯＤ３／ＣＯＤ～０．３～０．４时，处理后出水ＣＯＤ〈１２０ｍｇ／ｌ，ＢＯＤ３〈６０ｍｇ／ｌ。     

饱和带有机污染物的厌氧反硝化微生物降解

以卤代烃和芳香烃为代表,通过室内实验模拟饱和带厌氧反硝化环境,对地下饱和带中有机污染物的厌氧反硝化可生物降解性,降解机理,降解动力学方程等进行了研究。实验结果表明,芳香烃较卤代烃易被微生物降解,在有低学葡萄糖存在时有 机物的最大生物降解速率Ｃ６Ｈ６：Ｌｍａｘ＝１７ｍｇ／（ｍ＾２．ｄ）,Ｃ７Ｈ８：Ｌｍａｘ＝４６ｍｇ／（ｍ＾２．ｄ）,ＣＣｌ４;Ｌｍａｘ＝７ｍｇ／（ｍ＾２．ｄ）,ＣＨＣｌ３：Ｌｍａｘ＝６     

柠檬酸废水的厌氧—兼氧—好氧处理

采用厌氧－兼氧－好氧工艺处理柠檬酸废水，管理厌氧消化器在进水ｐＨ３．４４～４．３８，ＣＯＤ１４１８７．５ｍｇ／Ｌ，处理水量为２００ｔ／ｄ，有机负荷经７．０９ｋｇＣＯＤ／（ｍ＾３．ｄ）条件下，出水ｐＨ７．０～７．５，ＣＯＤ去除率为８１．１％，产气率为０．４３ｍ＾３／ｋｇＣＯＤ，兼氧－好氧处理进水ｐＨ３．２～４．６，ＣＯＤ１９２９ｍｇ／Ｌ，处理水量１０８０ｔ／ｄ，停留时间为兼氧６ｈ，好氧１３ｈ，出水ｐ     

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.     

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.     

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.     

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

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

Isolation and preliminary characterization of a 3-chlorobenzoate degrading bacteria

A study was conducted to compare the diversity of 2-, 3-, and 4-chlorobenzoate degraders in two pristine soils and one contaminated sewage sludge. These samples contained strikingly different populations of mono-chlorobenzoate degraders. Although fewer cultures were isolated in the uncontaminated soils than contaminated one, the ability of microbial populations to mineralize chlorobenzoate was widespread. The 3- and 4-chlorobenzoate degraders were more diverse than the 2-chlorobenzoate degraders. One of the strains isolated from the sewage sludge was obtained. Based on its phenotype, chemotaxonomic properties and 16S rRNA gene, the organism S-7 was classified as Rhodococcus erythropolis. The strain can grow at temperature from 4 to 37℃. It can utilize several （halo）aromatic compounds. Moreover, strain S-7 can grow and use 3-chlorobenzoate as sole carbon source in a temperatures range of 10-30℃ with stoichiometric release of chloride ions. The psychrotolerant ability was significant for bioremediation in low temperature regions. Catechol and chlorocatechol 1,2-dioxygenase activities were present in cell free extracts of the strain, but no （chloro）catechol 2,3- dioxygenase activities was detected. Spectral conversion assays with extracts from R. erythropolis S-7 showed accumulation of a compound with a similar UV spectrum as chloro-cis,cis-muconate from 3-chlorobenzoate. On the basis of these results, we proposed that S-7 degraded 3-chlorobenzoate through the modified ortho-cleave pathway.     

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.