苯胺降解菌的分离和特性研究

从活性污泥中分离到一株细菌ＡＮ３，能以苯胺为唯一碳源、氮源和能源生长．经鉴定为食酸丛毛胞菌（Ｃｏｍａｍｏｎａｓａｃｉｄｏｖｏｒａｎｓ）．该菌株可以在高达５０００ｍｇ／Ｌ以上的苯胺中生长．当苯胺浓度为２０００ｍｇ／Ｌ左右时，经３天培养即可全部被降解．该菌株还可以利用乙酰苯胺，但不能利用其他取代类苯胺化合物．ＡＮ３菌的生长和降解苯胺的最适温度为３０℃和ｐＨ为７０．９种金属离子对该菌的生长和苯胺的降解均有不同程度抑制作用，尤以Ａｇ＋和Ｈｇ２＋为明显．该菌与苯胺降解代谢有关酶类的测定结果表明，该菌含有的邻苯二酚－２，３加双氧酶是诱导酶．     

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）．     

染料脱色菌的筛选及固定化脱色试验

从印染厂污水中筛选到７株高效脱色菌,其中Ｐｓｅ４、Ｐｓｅ２９两菌在非固定化条件下,分别对１０ｍｇ／Ｌ阳离子桃红ＦＧ、活性艳红Ｋ－２ＢＰ溶液３在染料为唯一碳源、能源时、１２ｄ脱以８０％以上,这２菌都属于公章民菌属,将各菌等量混合进行脱色,没有协同作用,采用凹凸棒粘土颗粒或塑料环为载体固定化脱色菌,能大大缩短反应时间,提高脱色率,凹凸棒颗粒固定化柱在６ｈ即对６０ｍｇ／Ｌ混合染料脱色９１％,是一种具有较     

硝基苯降解菌生长特性及其降解活性

从一些下水道底泥中筛选分离、驯化得到２株厌氧降解硝基苯高效菌吉氏拟杆菌（Ｂａｃｔｅｒｏｉｄｅｓ ｄｉｓｔａｓｏｎｉｓ）和屎拟杆菌（Ｂａｃｔｅｒｏｉｄｅｓ ｍｅｒｄａｅ）,能与葡萄糖共代谢还原硝基苯。实验确定了吉氏拟杆菌和屎拟杆菌的最适生长条件为：温度２８～３５℃;ｐＨ６．５～７．２;ＮａＣｌ浓度为０．４％～０．５％。该菌最大降解硝基苯的速率为９５ｍｇ／（Ｌ·ｄ）,ｌｇ葡萄糖能共代谢还原２００ｍｇ～     

沼泽红假单胞菌对活性紫KBR脱色的研究

研究了驯化后的沼泽红假单胞菌(Rhodopseudomonaspalustris)N菌株的生长细胞在不同条件下对活性紫KBR的脱色效果.结果表明,该菌株生长细胞脱色的最佳条件为温度25～30℃,pH值为7,厌氧条件下的脱色率远远高于好氧条件下的脱色率.染料作为该菌株唯一的碳源和能源脱色时,脱色率与细胞浓度呈极显著相关,细菌脱色比活率保持在较恒定的水平.此外,生长细胞脱色过程中对菌体生长的测定表明,该菌株生长的指数期明显滞后于染料脱色的指数期.     

一株酸性大红3R脱色菌的分离、鉴定及其脱色性能研究

通过浓度梯度驯化,从厌氧污泥中分离到一株酸性大红3R脱色菌M3,根据其形态学特征及16S rRNA基因序列分析,鉴定该厌氧菌株为阴沟肠杆菌(Enterobacter cloacae).同时,研究了该菌株在厌氧静置条件下对酸性大红3R的最适脱色条件.结果表明,菌株脱色的最佳营养源为酵母粉,最适宜脱色条件为酵母粉浓度1％、pH =6.5、温度35 ℃、盐度小于4％,在此条件下,对浓度为100 mg·L-1酸性大红3R溶液厌氧静置培养72 h,脱色率达到98％以上.菌株耐盐性良好,在6％ ～8％的盐度下具有较好的脱色效果.分光光谱表明,菌株脱色机制主要为生物降解脱色.毒性试验表明,脱色后的酸性大红3R毒性明显降低.     

杀灭菊酯的微生物降解及酶促降解

测定了降解菌ＹＦ１１及其胞内酶对杀灭菊酯的降解特性,在纯培养系统中,菌量为ＯＤ４１５ｎｍ０．２０时,ＹＦ１１对大于３０ｍｇ／Ｌ的杀灭菊酯的降解呈零级动力学特征,浓度为３０￣１００ｍｇ／Ｌ时,降解速率为１．８７６－２．１２４ｍｇ／（Ｌ·ｈ）;浓度大于２００ｍｇ／Ｌ的杀灭菊酯对降解菌ＹＦ１１的降解产生抑制作用,降解速率与菌量近似成正比关系,１０ｍｇ／Ｌ杀灭菊酯的降解曲线呈一级动力学特征。从ＹＦ１１提取     

一株苯胺降解菌的研究

报道了从自然界分离的一株能以苯胺为唯一氮源和碳源，同时降解苯胺的细菌４＾＃。该菌鉴定为节杆菌４＾＃（Ａｒｔｈｒｏｂａｃｔｅｒ．４＾＃）。该菌降解苯胺的最高浓度为２０４４ｍｇ／Ｌ。４＾＃菌株降解苯胺的最适ｐＨ值和温度分别为７．０和３０℃，最适苯胺浓度为１０２２ｍｇ／Ｌ。在此条件下，４８ｈ苯胺的降解率可达９４．７％。试验结果表明，重金属离子对４＾＃菌株降解苯胺都有不同程度的抑制作用，以Ｈｇ＾２＋、Ａｇ     

水泥负载TiO2光催化降解染料水溶液的研究

研究了以ＴｉＯ２为催化剂，且将ＴｉＯ２涂布在模拟工业水处理浅池的水泥质池底表面，以直管高压汞灯为光源，对有机染料酸性玫瑰红Ｂ和晒化绿Ｂ进行光催化降解的可行性。结果表明，在实验条件下，本系统对以上染料有显著的光降解作用，浓度为２５ｍｇ／Ｌ的上述二种染料溶液，经３０ｍｉｎ光照，其降解率分别达８８．２％，此外，还探讨了染料浓度，染料体积、染料溶液ＰＨ值等因素对光降解的影响。     

氧化还原介体厌氧催化酸性红B生物脱色研究

研究了筛选出的四种结构相似的醌类氧化还原介体对酸性红B厌氧脱色的促进作用,并以催化效果最佳的蒽醌-2-磺酸钠为醌介体模型,探讨了醌介体催化酸性红B厌氧生物降解路径。在35℃中温厌氧条件下,采用间歇批量实验法,测定不同体系中醌介体催化酸性红B脱色效果。结果表明:①在酸性红B浓度为150mg·L-1,醌介体浓度为0.16mmol/L,反应时间为4h时,结构相似的四种醌介体均可促进酸性红B脱色,反应效率提高了1.6².4倍,其大小顺序为AQS>2,7-AQDS>AQDS>α-AQS;②AQS在催化酸性红B降解过程中与传统厌氧微生物降解路径保持一致。     

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.