广州市乌涌综合治理总体设计方案探讨

结合乌涌流域排水规划与排水现状,制定了排污口截污、截污管网完善、初雨调蓄、河道整治和水生态修复与保持的综合治理总体设计方案,方案实施后可达到"旱季污水100%截流,雨季溢流污染削减70%"的治水目标。     

三河三湖水污染防治“十五”计划出台

据报道 ,按照国务院的要求 ,国家环保总局会同国家发展与改革委员会等部门和相关省、自治区、直辖市政府编制了“三河”、“三湖”水污染防治“十五”计划 ,并已经国务院批复实施。“计划”共确定了 15 90个项目 ,总投资 12 34亿元。主要包括城市污水处理、截污导流工程、农业面源污染治理、流域综合治理、引水工程等。“计划”的总目标是 ,到 2 0 0 5年 ,在淮河干流和主要支流不断流的情况下 ,淮河干流水质进一步好转 ,南水北调东线工程水质达标。海河干流及主要支流水质明显改善 ,饮用水源地控制断面水质达到饮用水标准。辽河全流域水体水…     

小清河引黄补水冲污必要性与可行性分析

小清河污染日趋严重，污染治理刻不容缓。引黄补水冲污是小清河污染综合治理的重要组成部分，本文从水质污染的严重性、规划治理目标要求，增大环境容量等方面论述补水冲污的必要性，从黄河较好的引水条件、补水口门的选择及补水工程措施等方面分析了引黄补水的可行性。     

奎河水资源化工程采用水质指标的讨论

1　引　言　　奎河是徐州市一条纳污和排洪河流 ,目前河水黑臭 ,鱼虾绝迹。徐州市政府为了治理奎河 ,已经投巨资前后进行两次工程治理。　　但是 ,奎河一、二期工程仅仅是形成了奎河污染控制系统的基本框架 ,系统内的一些工程还没有发挥作用 ,如一期截污工程 ;一些工程运行了 ,还没有充分发挥效益 ,如污水处理厂 ;特别是系统目前还不完善 ,整个系统还无法正常运行。　　为此 ,徐州市政府提出了奎河治理三期方案 ,该方案是以要达到河道水质要求和使处理后的奎河水能够实现多途径资源化目标 ,决定采取的工程和管理措施。合理确定要达到的水质…     

基于MIKE11模型入河水污染源处理措施的控制效能分析

为分析入河水污染源不同处理措施的控制效能,以中国多闸坝重污染河流的典型代表—涡河为例,针对"引江济淮"工程涡河段的水质改善需求,以涡河主要污染物COD、氨氮为指标,应用MIKE 11模型建立能客观反映模拟河段水动力、水质时空演变规律的模型;结合情景分析方法对涡河流域入河水污染源不同处理措施的控制效能进行量化评估.模拟结果表明:截污是改善"引江济淮"工程涡河段水质的关键,可降低约18.9%~36.8%的COD入河负荷,以及13.9%~26.3%的氨氮入河负荷;提高污水厂的处理量是改善"引江济淮"工程涡河段水质的有效措施,可削减15.0%的COD和10.8%的氨氮污染;综合处理措施优于单一措施,通过截污、提高污水厂的处理量和排放标准可以使86%以上的河段达到IV类水体要求.本研究结果可为"引江济淮"工程沿线的水污染防治提供技术支持,同时为河流综合治理工程决策提供借鉴和依据.     

饮用水水源保护区上游支流污染评估与控制方案研究

河流水体污染严重威胁着水库型饮用水水源保护区的水质安全.通过对碧流河水库饮用水水源保护区上游支流入河污染源的初步估算,对入库河流水质进行评估和污染源解析,对典型污染入库河流提出"四层生态控制"工程方案,采用污染防治与水土流失治理、生态经济发展兼顾的修复技术,包括截污工程、人工生态湿地系统、生态护坡、前置库技术等以削减入...     

城市河流截污与人工湿地净化实例

针对受上游村庄、城镇、农田等点源、面源污染的城市河道,采用截污与人工湿地净化协同的处理方法改善水质。其中,截污环节根据地形与开发时序,合理设置截污区域,设计了配套所需的截污设施;人工湿地净化环节合理利用自然地形,采用多级潜流人工湿地与阶梯多级表面流人工湿地复合的湿地水净化系统,并选取合适的湿地植物,保障人工湿地正常代谢。设计截污能力为1.02×104m3d,人工湿地处理能力为3.5×104m3d,人工湿地面积为45 hm2。经过截污与人工湿地净化协同作用,可基本实现水质净化目标,使其水质达到GB 3838—2002的Ⅳ类标准,不仅有效保障处理水质,更可营造城市水景,充分发挥河流与人工湿地生态服务功能,改善研究区所在地的生态环境。     

滇池水污染治理的分析及思考

通过调查分析,滇池水污染成因主要为城市点源直排、污水处理厂尾水及面源污染。重点介绍了近年来已经实施的控源截污、外流域调水、污水处理厂尾水外排、农业面源治理、生态清淤、生态修复等截污、治污工程,结合这些工程建设及运行中存在的问题,对今后的滇池治理思路提出了建议。     

浅谈城市河道水环境综合整治

随着水环境整治理念的创新及治理技术的进步,城市河道水环境综合整治逐步发展为防洪固堤、水质提升、水环境改善、生态环保相统一的工程体系。工程以全面规划、统筹兼顾、因地制宜、生态优先为原则,实施管道截污、河堤建设、生态修复、内源污染治理等措施。通过河道生态建设以及点源、内源污染的清除,综合改善河道防洪能力、水质及水环境状况,修复河道生态系统,提高河道内水体自净能力与生态稳定性。     

塘西河生态补水和再生水厂尾水补给工程对水环境的影响

随着水环境整治理念的创新及治理技术的进步,城市河道水环境综合整治逐步发展为防洪固堤、水质提升、水环境改善、生态环保相统一的工程体系。工程以全面规划、统筹兼顾、因地制宜、生态优先为原则,实施管道截污、河堤建设、生态修复、内源污染治理等措施。通过河道生态建设以及点源、内源污染的清除,综合改善河道防洪能力、水质及水环境状况,修复河道生态系统,提高河道内水体自净能力与生态稳定性。     

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.     

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

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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.     

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.     

Alterations of organ histopathology and metallolhionein mRNA expression in silver barb, Puntius gonionotus during subchronic cadmium exposure

Common silver barb,Puntius gonionotus,exposed to the nominal concentration of 0.06 mg/L Cd for 60 d,were assessed for histopathological alterations(gills,liver and kidney),metal accumulation,and metallothionein(MT)mRNA expression.Fish exhibited pathological symptoms such as hypertrophy and hyperplasia of primary and secondary gill lamellae,vacuolization in hepatocytes,and prominent tubular and glomerular damage in the kidney.In addition,kidney accumulated the highest content of cadmium,more than gills and liver.Expression of MT mRNA was increased in both liver and kidney of treated fish.Hepatic MT levels remained high after fish were removed to Cd-free water.In contrast,MT expression in kidney was peaked after 28 d of treatment and drastically dropped when fish were removed to Cd-free water.The high concentrations of Cd in hepatic tissues indicated an accumulation site or permanent damage on this tissue.