湖北省农村环境调查与分析

文章调查分析了湖北省江汉平原、鄂北岗地等部分地区农村的环境状况,并对农民环境意识进行了问卷调查.调查表明,湖北省农村化肥、农药等过量施用十分突出;除鄂西山区外,地表水污染相当严重,塘堰已基本丧失饮用功能;垃圾污染不显著,但秸秆乱垛、垃圾乱倒、粪肥乱堆、畜禽乱跑等现象相当普遍;乡镇企业污染不突出,但应密切关注;农民已有一定的环境意识和要求,也有一定的环境知识;农民最关心的实事是修水泥路,其次为建水厂;农民不仅有改善环境的愿望,也有为之支付部分费用和劳动力的意愿.最后,提出了保护农村环境的建议和对策.     

我国农村垃圾污染防治立法研究

受城乡二元结构影响,我国城乡环境保护存在重大差异,由此导致农村环境不断恶化,其中垃圾污染尤为突出。农村垃圾污染已严重损害了农民环境权利,成为我国新农村建设和生态文明建设过程中亟需解决的环境问题。从立法角度看,我国农村垃圾污染防治在立法指导思想、立法体系以及立法内容等方面都存在严重的立法缺陷。因此,在环境正义理论的指导下,我国立法应该从立法理念、立法模式、立法程序和法律制度等方面对农村垃圾污染防治作进一步的思考。     

我国农村环境管理体制探析

<正>近年来,在城市环境日益改善的同时,农村环境污染问题越来越凸显,在工业化、城镇化程度较高的东部发达地区的农村尤为突出。点源污染与面源污染共存,生活污染和工业污染叠加,各种新旧污染相互交织,工业及城市污染向农村转移,农村环境污染问题对农村社会发展和农民福利改善的阻碍也将日趋明显。具体污染现状是:农村生活污水和垃圾排放量大,目前全国农村每年产生生活污水约90亿吨,生活垃圾约2.8亿吨,而且处理率较低。     

我国农村生态环境令人担忧

水利部副部长翟浩辉日前表示，目前中国农村化肥、农药、除草剂、农膜的大量使用已造成严重污染，许多河道发黑，河岸杂草丛生，垃圾成堆；不少农田土壤层有害元素含量超标、板结硬化，农村水环境的恶化不仅危及农民的身体健康，也影响了农产品的安全。在很多农村的沟渠河道正遭受着工业废弃水和生活垃圾污染的同时，水土流失尚未得到有效控制，     

浅谈望花区的农村连片整治工作

由于农村环境污染越来越严重,农村的生活垃圾和生活污水无序排放,水质受到了严重污染。概述了望花区通过连片整治,使该区域的农村环境污染得到有效控制,农村饮用水水源地环境质量有所改善,农业面源污染防治取得一定进展,村庄环境基础设施建设逐步完善,农村环境管理制度和监管能力及公众环保意识明显提高,农村环境与经济、社会协调发展。     

东北严寒地区村镇环境现状调查研究

在城乡一体化发展背景下,农村内部现代化进程不断加快,而与之配套的社会公共服务设施与管理体制尚不健全,使得农村环境污染不断加剧.经问卷调研,东北严寒地区村镇环境突出的问题是水体和空气污染严重,垃圾围村现象普遍,工业企业生产及道路交通使得噪声污染加剧,工业企业污染较重.探究环境污染形成机制包括:农村粗放的经济发展模式、农民生活形式现代化和模式传统化的矛盾、农民环保意识薄弱以及城乡二元化体制结构使得东北严寒地区村镇环境不断恶化.文章最后提出了针对性的对策建议.     

河源农村垃圾污染现状调查及其处理对策

随着社会的进步和发展,农村生活方式也呈现多样化和现代化,然而,产生越来越多的生活垃圾却不容小视。农村生活垃圾污染着人们赖以生存的环境,影响了社会主义新农村的建设步伐,威胁着人们的身体健康。本文通过对河源市广大农村垃圾污染现状进行调查与分析,探讨有效处理的对策,从而使得农村垃圾的管理走向规范化和现代化。     

构建农村环保保障体系

随着社会经济发展,农村环境问题已十分突出,畜禽养殖污染、农药化肥污染、生活垃圾污染、生活污水等问题严重影响了农村经济的持续健康发展。由于农村环境问题在短期内很难根治,已经成为环保部门的新课题。为此,必须采取一些有效的措施以尽快扭转局面。     

农村水环境面源污染的思考与几点对策

农村面源污染主要是指农业生产活动过程中,农村的生活、生产垃圾、污水、化肥农药等污染物,伴随着径流、泥砂的搬运而造成的面源污染导致水资源和土地资源的破坏,针对农村面源污染的严峻形势,加大面源污染防治宣传力度,提高农民的环保意识,加大对广大农民的科普教育和政策引导,提高农民参与面源污染防治工作的主动性、积极性和自觉性。以科学发展观为指导,树立可持续发展的观念,高度重视并切实解决农村面源污染问题。     

新农村建设中的环境问题初探

在介绍了新农村建设中的环境问题的研究背景和意义的基础上,阐述了新农村建设的环境现状及存在的主要环境问题：农村生态环境破坏、农业面源污染、畜禽养殖造成的污染、生活垃圾污染、新农村水环境问题突出、农村的工业污染加剧等问题;分析了新农村建设中环境问题的成因,提出了新农村建设环境保护的战略对策。     

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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