平菇漆酶的性质和应用研究

通过采用硫酸铵分级沉淀对平菇菌种831和予6两菌种所产生的漆酶进行了初步分离,并对酶的性质进行了初步研究,研究表明它们的最适反应温度都在60℃,最适反应pH都在3.0,对831漆酶进行除酚和固定化脱色的研究表明,在最佳除酚条件下50℃,pH5.0,反应3h,对25mg/L单宁酸的去除率可达24.4%,在所研究的不同固定化材料中,以尼龙网为材料的固定化效果最好,固定化酶对50mg/L的活性艳蓝脱色率可达游离酶脱色率的76%,重复应用4次脱色率没有降低趋势,之后逐渐下降。     

平菇漆酶的性质和应用研究

通过采用硫酸铵分级沉淀对平菇菌种831和予6两菌种所产生的漆酶进行了初步分离,并对酶的性质进行了初步研究,研究表明它们的最适反应温度都在60℃,最适反应pH都在3.0,对831漆酶进行除酚和固定化脱色的研究表明,在最佳除酚条件下50℃,pH5.0,反应3h,对25mg/L单宁酸的去除率可达24.4%,在所研究的不同固定化材料中,以尼龙网为材料的固定化效果最好,固定化酶对50mg/L的活性艳蓝脱色率可达游离酶脱色率的76%,重复应用4次脱色率没有降低趋势,之后逐渐下降。     

磁性壳聚糖微球吸附水中As(Ⅲ)的实验研究

文章主要考察实验室制得的乙二胺改性磁性壳聚糖微球对毒性高,迁移能力强的A(sⅢ)去除效果。通过单因素实验研究了pH值、吸附时间、A(sⅢ)溶液初始浓度和吸附剂投加量对磁性壳聚糖微球吸附除A(sⅢ)效果的影响。实验结果表明在pH值为2,吸附时间为90 min,磁性壳聚糖微球投加量为0.4 g时,对初始浓度为10 mg/L,体积为100 mL的A(sⅢ)溶液去除率达到96.96%,吸附后溶液中A(sⅢ)浓度仅为0.304 mg/L,低于我国污水综合排放标准中砷含量标准值。磁性壳聚糖微球的解吸实验表明,吸附剂解吸4次后,对A(sⅢ)的去除率仍达到95%以上,吸附性能稳定,具有较好的可重复利用性。因此,磁性壳聚糖微球是一种去除低浓度含砷废水非常有效的材料。     

海藻酸钠包埋固定化微生物处理含油废水研究

采用海藻酸钠固定化包埋活性炭与菌Brevibacillus parabrevis Bbai-1,制备海藻酸钠-活性炭固定化微球。通过活性炭吸附前后的菌浓变化,测定了25℃时活性炭对Bbai-1的最大吸附量。采用正交试验优化了影响海藻酸钠-活性炭固定化微球的物理性质和微生物活性的4个主要因素(海藻酸钠浓度,活性炭含量,种子菌液浓度和交联时间),确定了固定化微球的最佳制备条件:海藻酸钠浓度为3.5%,活性炭含量为0.7%,种子菌液浓度为6×107 cell/mL,交联时间为24 h。并在25℃,原油含量为0.2%,固定化微球与含油培养基的体积比为3:20时,以游离菌作对比,考察了固定化微球降解原油的最佳pH和盐度。结果表明,固定化菌在pH 6~9,盐度为1.5%~3.5%时,原油降解率可达50%以上,比游离菌提高了20%,且具有较高的盐度适应能力和较宽的pH适应范围。     

固定化紫色非硫化合细菌降解活性艳红X—3B的研究

采用聚集－交联法固定化紫色非硫光合细菌用于处理活性艳Ｘ－３Ｂ染液，比较紫色非硫光合物细菌和固定化细胞的某些性质。２种细胞的反应最适温度均为３０－４０℃，固定化细胞的反应最适ＰＨ值范围较宽，为７．５－９．４热稳定性较好。Ｃｕ＾２＋对２种细胞毒活力均有抑制作用；比较聚集－交联固定化细胞和海藻钠包埋固定化细胞的脱公能力，前者比后者酶活力较高，半衰期长，成本低，操作方法简单，易于工业化应用。     

高分子凝胶球去除废水中重金属离子的研究

用海藻酸钠（SA）、海藻酸钠-聚乙烯醇（SA—PVA）、海藻酸钠-聚氧化乙烯（SA—PEO）凝胶球作为吸附剂吸附溶液中的Pb^2＋。探讨了凝胶球固定化时间、吸附时间、溶液pH值、溶液初始浓度对Pb^2＋去除率的影响,并对吸附动力学方程进行了分析。结果表明：固定化时间对去除率的影响较小;反应速率较快,吸附时间在10min时,三种凝胶球对Pb^2＋的去除率就分剐达到了80％、82％和88％,吸附时间在2h后基本达到吸附平衡,三种凝胶球对Pb^2＋的吸附能力为：SA—PGE〉SA—PVA〉SA;三种凝胶球吸附铅离子的行为均符合一级反应动力学方程;溶液的pH在4～6时有较高的去除率;三种凝胶球对不同金属的吸附能力为Pb^2＋〉Cu^2＋〉Cd^2＋;饱和吸附后的三种凝胶球均可以再生利用。     

热带假丝酵母314号固定化细胞分解苯酚的研究

1.比较了三种生长培养基对热带假丝酵母314号细胞分解苯酚活力的影响。在以苯酚为碳源的培养基中生长的细胞酶活力较高,125mg湿细胞一小时可分解苯酚5425.8μg。用3.0%的琼脂固定化后,固定化细胞酶的相对活力为44.4%。诱导能显著地提高固定化细胞的酶活力,最适的诱导时间为12—18个小时。 2.比较了固定化细胞和自然细胞的某些性质。两种细胞反应的最适温度均为37℃;反应的pH范围均在3.5—11之间;固定化细胞热稳定性稍差;Cu~(2 )和Zn~(2 )对自然细胞的活性有一定抑制作用;CN-明显抑制两种细胞酶活力。 3.固定化细胞装柱后连续处理浓度约为150ppm的苯酚溶液,20天内的出水酚浓度平均为0.29ppm,在此条件下固定化细胞的半衰期为11天。 4.连续处理苯酚过程中,固定化细胞所丧失的酶活力可以通过再培养得到恢复。     

季铵盐改性土壤对水中苯酚的吸附及机理研究

采用十六烷基三甲基溴化铵（ＨＤＴＭＡ）对土壤进行了改性。结果表明，改必一时最适温度为５０￣５５℃，最适ＰＨ为中性最适ＨＤＴＭＡ浓度为１％，又考察了ＰＨ、改性土壤用量及振荡时间对吸附效果的影响，通过测定吸附等温线探讨了吸附机理。结果表明，ＰＨ＝３￣１０时，酚捐附去除率基本不变，当ＰＨ〉１０时，吸附效率随ＰＨ增大而提高。随着改性土壤用量的增加和振荡时间的延长。酚的去除率升高。改性土壤对苯酚的等温吸附规     

壳聚糖交联沸石小球对Cu2+、Ni2+及Cd2+的吸附特性

以壳聚糖和人造沸石为原料,采用滴加成球法制备了一种新型重金属吸附剂——壳聚糖交联沸石小球,通过吸附实验考察了pH值、时间及重金属离子浓度对吸附Cu2+、Ni2+、Cd2+的影响.结果表明,制得的壳聚糖交联沸石小球的平均粒径为3.2 mm,密度为1.08 g·cm-3,含水率为80％.在pH=5、温度25℃条件下,壳聚糖...     

芽孢杆菌H-1菌株的固定化及降解动力学研究

采用海藻酸钠-海藻酸钙法对芽孢杆菌H-1菌株进行包埋实验,测试各固定化因素对凝胶微球物理性能的影响,得到各因素合适的取值范围。以石油降解率为试验指标对固定化因素进行4因素3水平正交试验,结果显示菌株的最佳固定化条件为海藻酸钠浓度7%、菌悬液添加量75%、CaCl2浓度2%、交联时间24 h。对比固定化菌株与游离菌株的降解效果,结果显示固定化菌株的降解效率大于游离菌株。对固定化菌株的降解动力学进行研究,结果表明当石油浓度较低时,固定化菌株的降解动力学方程符合Monod方程的线性简化形式,方程的半饱和常数K S=52.33 mg/L,最大反应速率v max=44.05 d-1。当原油浓度较高时,其降解速率大于方程的v max。     

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.     

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

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