超临界水氧化法降解甲胺磷的研究

实验研究了典型有机磷农药甲胺磷在超临界水中的氧化降解.结果表明,超临界水氧化技术能有效地降解甲胺磷,COD去除率最高可达97%以上.随着反应温度的升高、压力的增大、停留时间的延长和初始废水浓度的增大,COD去除率也随之提高.甲胺磷在超临界水中氧化降解的动力学方程为:-d[COD]/dτ=8.69×105exp(-9.61×104/RT)1.09[O2]0-0.38.     

厌氧－缺氧－好氧处理城市废水系统缺氧相中的脱氮硫杆菌

利用厌氧－缺氧－好氧处理城市废水的中试规模系统,对其缺氧相中的脱氮硫杆菌进行了研究。结果表明,脱氮硫杆菌的最高脱氮作用率、氧化Na₂S的最高浓度、S^2-的最高污泥负荷率和污泥中脱氮硫杆菌的最高含量（MPN）分别为3.6mg－NO^－₃/gVSS·h、1750mg/L、25mg－S^2-/gVSS·d和1.1×10⁸/gVSS。脱氮硫杆菌在氧化二价硫成硫酸并还原硝酸为氮气的过程中起着相当有意义的作用。     

好氧颗粒污泥和絮状污泥脱氮性能及细菌种群分析

比较了SBR反应器中好氧颗粒污泥和絮状污泥对不同浓度氨氮废水的去除情况,并采用定量PCR(RT-PCR)和末端限制性酶切片段长度多态性(T-RFLP)技术研究了2种污泥中氨氧化细菌数量和细菌组成的变化.结果表明,100～500mg/L的氨氮对2种污泥去除COD的影响不大,而氨氮的去除率随着其浓度的上升而下降,絮状污泥的氨氮去除率略高于颗粒污泥(10%～16%).絮状污泥和颗粒污泥中氨氧化细菌的数量分别为2.80×10⁴～3.44×10⁴,7.83×10⁴～1.18×10⁵个/g干污泥.絮状污泥中细菌种群数量高于颗粒污泥,且两者的变化趋势与氨氮去除率的变化基本一致.     

厌氧流化床反应器处理含硫废水毒性的实验

采用多孔聚合物载体固定化微生物在厌氧流化床（AFB）反应器中处理含硫废水,研究反应器抗硫化物（S^2－）毒性抑制和抗硫酸盐毒性抑制的能力;探索解除 S^2－毒性的方法．研究表明,当进料基质 COD浓度为 5000mg/L,HRT为5.2－5.4h,S^2－＜200mg/L时,反应器去除 COD效果不受影响,S^2－350mg/L时,厌氧消化受到明显抑制,反应器可容忍530mg/L S^2－浓度而未造成消化系统的破坏;SO₄^2－浓度高达3521mg/L,COD去除率仍可达77％－80％,但SO₄^2－去除率明显下降;当COD/SO₄^2－的比值大于1.45时,硫酸盐还原菌和产甲烷菌的生长未受到明显抑制,此时容积负荷为22－24kgCOD/（m³>·d）,COD去除率为80％,SO₄^2－去除率为58.8％;向反应器投加适量FeCl₂可很好地解除S^2－的抑制．     

缺氧－好氧生物膜法脱氮技术的研究

为了防止氮污染对水体造成的危害,我国对氨氮排放实行严格的控制。采用缺氧－好氧淹没式生物膜脱氮方法研究其处理效果与工艺参数,并着重研究氮负荷和碳源对硝化、反硝化的影响;微生物在膜上的分布特性及其对底质变化的影响。研究结果表明：缺氧段（A段）停留时间为7.3h,好氧段（0段）为15.7h好氧段容积负荷：COD0.36kg/m³·d,NH₃－N0.35kg/m³·d;缺氧段硝态氮负荷0.65kg/m³·d,COD负荷1.7kg/m³·d。这一水处理技术工艺稳定,NH₃－N与NO_x－N的去除率均在90％以上,而且生物活性强,分布较均匀,是目前控制氮污染的有效方法。     

六种重金属对大肠杆菌体内质粒DNA一级结构的影响

将质粒ｐＢＲ３２２、ｃ－Ｍｙｃ、ｐＣ５３－ＳＮ_３、ｐＴＢ２９转入大肠杆菌（Ｅｓｃｈｅｒｉｃｈｉａｃｏｌｉ）ＨＢ１０１中使其各自分别在含亚致死浓度Ｐｂ²⁺、Ｃｄ^2-、Ｚｎ²⁺、Ｃｕ²⁺、Ｍｎ²⁺、Ｈｇ²⁺的液体氨苄ＬＢ培养基中,振荡培养２４ｈ后,再将这些质粒抽提出来,通过限制性内切酶分析,研究了这些重金属离子对大肠杆菌体内质粒ＤＮＡ分子一级结构的影响。结果表明,在供试的６种重金属离子中只有Ｈｇ^２＋处理可明显导致质粒ＤＮＡ序列的改变。此外,供试６种重金属离子连续处理２４ｈ未发现可明显导致大肠杆菌体内质粒ＤＮＡ链的随机断裂。     

湿式空气氧化过程中氧气、二氧化碳和水蒸气分压的理论

介绍了亨利常数随温度、压力变化的经验公式,并采用湿式空气氧化（WAO） 工艺处理城市污水厂活性污泥,验证了湿式氧化过程中亨利常数经验估算公式,以期为湿式氧化工艺设计和运行实践提供依据．结果表明,在180 ℃时,氧气的初始分压为0.98MPa,氧气和二氧化碳的亨利常数分别为2.5778×10⁹、5.9894 ×10⁹N/mF²．     

江苏省丰、沛、铜重氟病区动物体中氟的含量及其与环境的关系

丰、沛、铜重氟病区,禽、畜体内氟主要积聚在骨骼中（羊骨1096×10^－6～2001.9×10^－6,鸡骨335×10^－6～378×10^－6）及生理功能强的内脏（肝、心、肾等）器官中,氟的含量3.3×10^－6～7.17×10^－6,肌肉和蛋、奶品中氟的含量大多接近或低于氟的卫生标准,显然肉、蛋、奶食品不是该区地氟病的致病因子。研究表明,动物体内氟含量与环境水氟及叶菜和树叶（含水分高）中的氟含量呈明显的正相关。因而造成食草动物比以食粮食为主的家禽体内的氟含量明显偏高。说明水是氟的传播媒界,为该区地氟病的主要致病因子。     

厌氧－缺氧－好氧工艺去除废水中COD、氮和磷的研究

为了减少废水中营养盐的排放量,采用实验室规模的厌氧─缺氧─好氧工艺处理豆制品废水。结果表明,TCOD、SCOD、NH⁺₄-N、NO^-₃－N、TN、TP、SP（可溶性磷）、SS、细菌总数和大肠菌群数的去除率分别为96%、94％、93％、89％、82％、88％、78％、98.0％、99.9％以上。厌氧相产气率平均0.4L/L·d,上所产气体中平均甲烷含量69.8％,CO₂3.8％,N226.4%。缺氧相产气率平均为0.2L/L·d,平均甲烷含量59.5％,CO₂12％,N₂39.2％。好氧相中亚硝酸细菌含量为1.1×10⁵/mL,硝酸细菌含量为1.4×10³/mL。     

含硫酸盐高浓度有机废水生物处理技术

采用硫酸盐还原一硫化物生物氧化一产甲烷-接触氧化工艺处理青霉素废水,硫酸盐还原与有机物甲烷化分别在两个反应器中进行,有效地避免了硫酸盐还原菌对产甲烷菌的竞争抑制;利用无色硫细菌将硫酸盐还原产物一硫化物氧化成s,消除了硫化物对产甲烷菌的毒害作用研究结果表明,当系统进水COD为4500～5000mg/L,SO₄^2-浓度为1500－1600g/L时,系统出水中COD为310～348mg/L,COD平均去除率为93．2％,SO^2-平均去除率为91．2％     

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.     

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.     

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.     

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

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