多目标决策-理想点法综合评价淮北市地下水环境质量

运用多目标决策-理想点法对淮北市地下水质量进行评价,结果表明淮北市地下水质量达到了Ⅱ类水质标准以上,能够达到当地地下水环境功能区划要求.评价结果与实际情况一致,评价方法较精确,具有一定科学性.     

多目标决策-理想点法综合评价淮北市环境空气质量

运用多目标决策-理想点法对淮北市环境空气质量进行评价,评价结果表明淮北市环境空气质量达到了2级标准以上,能够达到淮北市环境空气功能区划要求。     

灰色关联法在淮安市地下水水质评价中的应用

为了掌握淮安市地下水质量的现状,在灰色关联方法原理的基础上,选择6个指标作为评价因子,构建了评价模型,对19个水质样品进行了评价.结果表明,淮安市大部分地区地下水质量优良,达到了Ⅰ类水,适用于各种用途,评价结果符合水质实际状况,具有较高的可信度,为淮安市地下水资源的科学管理提供了依据.     

关于淮北市饮用水环境安全的思考

随着城市的发展和经济持续稳步的增长,淮北市不可避免地出现一系列的环境问题,其中以水污染问题最为突出。淮北市许多地表水均受到较严重的有机污染和无机污染,其中的有害成分可以渗入地下,污染地下水,而淮北市是安徽省唯一依赖地下水生存的城市,淮北市饮用水环境安全问题不容忽视。     

莆田市地下水质量现状评价与分析

为掌握地下水质量现状,服务国家级地下水监测工程建设,通过现场调查和采集测试枯水期地下水样品,并采用单因子标准指数法和地下水综合评价法进行评价分析:莆田市境内木兰溪两岸流域和闽东南沿海诸河流域地下水质量现状总体良好,符合地下水质量Ⅲ类标准。     

佳木斯市地下水饮用水源水质现状研究

佳木斯市是以地下水作为唯一生活饮用水水源的城市.本文对佳木斯市区及郊区各县市的主要地下水饮用水源进行了23项水质指标的分析检测,结果表明:①2009年-2013年间,佳木斯市区八水源除铁、锰2项指标外,其余21项指标年均值均达到《地下水质量标准》Ⅲ类水质要求;②采用22项和20项指标进行F值法评价,八水源地下水质量级别分别为“较差”和“良好”级别;③2013年佳木斯市郊区中1个县级水源地达到《地下水质量标准》Ⅲ类水质要求;4个县级水源地除铁、锰2项超标外,其余各项指标均达到Ⅲ类水质要求.     

涪陵焦石镇页岩气开发区地下水质量评价

页岩气开发存在潜在污染源,在开采、运输、处理及处置不当的情况下,会对页岩气井场附近地下水造成污染。因此需要对页岩气开发区地下水质量进行评价,以确保用水安全。以涪陵焦石镇页岩气开发区一带为研究区,利用研究区内的地下水调查资料,采用单因子指数法对比分析了污染来源,并利用模糊数学法对该页岩气开发区浅层地下水质量进行了综合评价。结果表明:研究区浅层地下水中仅硬度和浊度2项评价因子超标,其他评价因子均达标,浅层地下水点未受到深部钻井液及钻屑、返排液等高矿化度液体及甲烷气体的污染;研究区浅层地下水质量总体较好,所取水样达到《地下水水质标准》(Ⅰ~Ⅲ类)的占96.23%,两个岩溶水点因井漏受到污染,不建议作为饮用水点。     

基于灰色关联聚类的地下水评价指标优化研究

地下水环境指标间既有联系又有差异,在保证评价指标能够全面、准确反映区域地下水质量的前提下,可对其进行分类、筛选和优化,简化评价指标,进而减轻监测工作量。本研究采用灰色关联聚类法,对研究区域地下水指标进行优化,并且优化前后水质综合评价结果一致,表明地下水评价指标的灰色关联聚类优化是合理可行的。     

安徽合肥地区浅层地下水质量评价

对合肥地区浅层地下水取样分析,采用单因子评价法、分类指标评价法和综合评价法对浅层地下水质量进行评价。结果显示:可以直接饮用的地下水资源(Ⅰ类水、Ⅱ类水和Ⅲ类水)占59. 3%,经过适当处理可以饮用的地下水资源(Ⅳ类水)占30. 5%,不能直接饮用的地下水资源(Ⅴ类水)占10. 2%。在地下水评价指标中,挥发性有机指标较好,毒性重金属指标和半挥发性有机指标次之,无机毒理指标和一般化学指标较差。影响地下水质量的化学组分主要为铁、锰、总硬度、溶解性总固体、氟、硫酸盐和钠+钾等无机组分,与人类活动相关的化学组分主要为氨氮、硝酸盐、亚硝酸盐、六价铬、砷、铝、碘、氯化物等无机组分和苯并(a)芘等有机组分。影响地下水质量的原因主要为城市和乡镇工业污水、生活污水排放,农村农药、化肥使用及生活垃圾污染。     

淮北市地下水污染初步研究

淮北市是一个新兴的中等工业城市,是我国重要的煤炭基地之一,近几年来发展较快,随着城市工业的迅速发展和人口增加,对地下水的需求愈加迫切。因此,查明淮北市地下水污染状况以及污染原因,探讨北方型岩溶裂隙水污染机制,为该市地下水污染治理提供依据具有重要意义。     

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.     

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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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.     

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.     

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.     

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.     

Sorption of 1-naphthol by plant cuticular fractions

The contribution of aliphatic-rich plant biopolymer to sorption of hydrophobic organic compounds is significantly important because of their preservation and accumulation in the soil environment,but sorption mechanism is still not fully understood.In this study, sorption of 1-naphthol by plant cuticular fractions was examined to better understand the contributions of respective fraction.Toward this end,cuticular materials were isolated from the fruits of tomato by chemical method.The tomato cuticle sheet consisted of waxes (6.5 wt%),cuticular monomer (69.5 wt%),and polysaccharide (24.0 wt%).Isotherms of l-naphthol to the cuticular fractions were nonlinear (N value (0.82-0.90)) at the whole tested concentration ranges.The KodKow ratios for bulk cuticle (TC1),dewaxed cuticle (TC2),cutin (TC4),and desugared cuticle (TC5) were larger than unity,suggested that tomato bulk cuticle and cutin are much powerful solption medium.Sorption capability of cutin (TC4) was 2.4 times higher than the nonsaponifiable fraction (TC3).The 1-naphthol interactions with tomato cuticular materials were governed by both hydrophobic-type interactions and polar (H-bonding) interactions. Removal of the wax and polysaccharide materials from the bulk tomato cuticle caused a significant increase in the sorption ability of the cuticular material.There was a linear negative trend between K_(oc) values and the amount of polysaccharides or fraction's polarities ((N O)/C);while a linear positive relationship between K_(oc) values and the content of cutin monomer (linear R~2=0.993) was observed for present in the cuticular fractions.Predominant sorbent of the hydrophobic organic compounds (HOCs) in the plant cuticular fraction was the cutin monomer,contributing to 91.7% of the total sorption of tomato bulk cuticle.     

Seed selections for crystallization of calcium phosphate for phosphorus recovery

Seed induces and promotes the crystallization of calcium phosphate, and acts as carrier of the recovered phosphorus （P）. In order to select suitable seed for P recovery from wastewater, three seeds including Apatite （AP）, Juraperle （JP） and phosphate-modified Juraperle （M-JP） were tested and compared. Batch and fixed-bed column experiments of seeded crystallization of calcium phosphate were undertaken by using synthetic wastewater with 10 mg/L P phosphate. It shows that AP has bad enduring property in the crystallization process, while JP has better performance for multiple uses, and M-JP is a hopeful seed for P recovery by crystallization of calcium phosphate.