突发污染应急调控处置启动判别技术:以南水北调中线工程为例

针对突发水污染灾害的特点,把应急处置工程决策纳入应急预警范畴,构建了拓展后的应急预警新框架,为应急处置小组等利益相关者提供系统化的信息支持。综合考虑污染物水溶性、挥发性、持久性和污染性等污染物自身属性及污染发生季节、发生位置和迁移特征等水环境属性,进行污染威胁度评估;进一步结合事故现场及河道沿岸等工况条件生成应急调控处置工程的启动准则。在南水北调中线工程"放水河节制闸-蒲阳河节制闸"典型渠段,以甲苯运输泄漏为事故情景,依托调水工程实际参数和实地调控处置设施,进行案例分析。该预警模式(突发污染应急调控启动判别模型)链接了污染输移、水力调控措施与应急调控处置措施,在传统以水质预测为主的污染预警基础上向减灾过程推进了一步,提供了更为完整的预警信息和决策建议。     

环境污染应急处置技术的CBR-MADM两步筛选法模型

突发环境污染事件进行应急处置时,需要在历史案例库和处置技术库的基础上通过筛选模型筛选出最适宜的应急处置技术.其中筛选的效率和准确性是构建技术筛选模型的首要因素,目前尚无较为满意的解决方案.本文结合案例推理技术(CBR)和模糊多属性群决策模型(MADM)的优势,建立了环境污染应急处置技术的CBR-MADM两步筛选法模型:第1步,先利用基于熵权G1法的CBR推理从案例库中匹配案例,再从相似度最高的几个案例中提取应急处置技术作为备选技术;第2步,利用MADM对备选技术进行筛选和决策.CBR-MADM两步筛选法既充分利用了历史处置经验,又极大地提高了应急处置技术的筛选速度和效率.将该方法应用于2012年底山西长治浊漳河苯胺泄漏污染事件中,成功筛选出“投加混凝剂-活性炭坝拦截”技术,同实际情况吻合,验证了其适用性和可行性.     

水污染预警DSS系统框架下的白河水质预警模型研究

为了应对频发的水环境污染事故,在污染事故发生后快速有效地制定应急响应措施,保护水环境,有必要在水源保护区建立水污染预警DSS系统,重点对系统建立的核心与难点——水质预警模型进行研究.密云水库是北京市最重要的地表水源地,以密云水库上游的白河为研究区域建立水污染预警DSS系统,设计水污染预警DSS系统的三层结构框架,将控制端、核心预警模型、GIS空间数据库紧密联合起来;在此基础上对核心预警模型的建模过程、参数取值等进行研究;最后以典型污染物氰化钠为例,设置水污染事故情景以及应急措施预案情景,进行了情景模拟分析.实例研究表明,此水质预警模型能够较准确地对污染发展趋势进行分析预测,并对不同的应急处理方案的实施效果进行模拟分析,模拟结果能够支持应急方案的制定与优选决策,达到了DSS系统的功能需求.     

我国突发水污染事件应急处置技术与对策研究

当前,我国突发水污染事件仍处于高发态势,对应急处置的要求高、挑战大,主要表现为事件成因多样、污染物类型复杂、情景差异明显,而与之相应的是应急处置技术体系尚不健全。本文针对我国突发水污染事件应急处置技术面临的突出问题,提出了提升我国突发水污染事件应急处置技术水平的基本思路,以解决制约我国环境应急处置的突出问题为出发点,统筹全面布局与重点突破,针对重点污染物、重点环节、重点区域,按照"夯实基础、突出重点、加强融合、优化决策"的应急处置技术研发与应用各项任务,构建健全高效的突发水污染事件应急处置技术体系,全面提高我国水环境安全保障水平。     

如何做好突发环境事件应急监测的快速响应

应急监测是突发性环境污染事故处置中的首要环节,是对污染事故及时、正确地进行应急处理、减轻事故危害和制定恢复措施的根本依据。文章从制定应急监测预案、加强应急监测能力建设、摸清污染源状况、加强应急培训和应急演练等方面对做好突发环境事件应急监测的快速响应作了简要的阐述,供大家探讨。     

有毒气体重大突发泄漏情景设计及仿真分析

某石化企业生产过程中会产生大量有毒气体硫化氢,而且厂区内人员较多,距周边社区较近,如果突发重大泄漏事故,应急响应不及时或处置不当,后果将不堪设想。通过对厂区内可能发生的硫化氢重大突发泄漏情景进行设计及仿真分析,呈现重大突发事件发生、发展过程,分析事故影响区域及规律,可为企业应对有毒气体泄漏的重大突发事件应急准备及应急响应提供依据,同时可用于检验现有应急预案存在的不足并进行针对性完善。     

基于IAHP-DS的流域突发化学品污染事故应急处理技术动态优选体系研究

因化学品造成的突发性水污染事故时有发生,为了在最短时间内降低污染物对水环境的影响,如何结合事故现场情况科学高效地选择最适宜的应急处理技术方案是当前应急响应的关键问题。基于改进层次分析法(IAHP)和Dempster-Shafer(D-S)证据理论构建了流域突发化学品污染事故应急处理技术动态优选体系。首先在利用IAHP确定指标权重的过程中,结合D-S证据理论引入专家权重,可客观地综合不同专家的意见,解决专家意见间的冲突性;然后采用加权秩和比(WRSR)法对应急处理技术进行综合评估,最终确定出最佳的应急处理技术方案;最后以浙江建德苯酚水污染事故为案例进行了验证分析,成功筛选出活性炭筑坝拦截技术,与本案例实际采用的应急处理技术方案一致,表明该优选体系具有较强的适用性和可行性,能够快速实现应急处理技术的优选。     

两阶段评估体系筛选水源突发污染应急最优技术方案

为预判突发污染对水源的威胁程度,进而筛选适宜污染情景的最优应急处置技术,本研究构建了包含10个评价指标的水源突发污染威胁度判别指标体系,依据威胁度等级判定,确定与不同威胁度对应的应急处置技术评估指标体系的指标权重.同时,为合理体现群决策过程中专家差异对权重的影响,提出了基于循环修正的群组G1指标赋权法.以Spearman等级相关系数作为检验标准,应用平均值法、Board法、Copeland法3种组合评价方法对单一专家评价结果进行循环迭代修正,最终得到评价指标的一致性排序和各位专家的权重,使各项指标的权重赋值更为准确.将综合评估模型应用于2012年广西龙江镉污染事故中,成功筛选出“调水稀释—絮凝沉降—水厂强化混凝”的组合应急技术方案,同实际情况吻合,验证了评估模型的可行性.     

突发性水体重金属污染应急处理处置技术研究进展

近年来突发性水体重金属污染事件频发,严重威胁流域水资源安全,制约国民经济和社会的可持续发展。尽管突发性水体重金属污染应急处理处置技术备受关注,但现有的技术储备仍十分薄弱。本文基于文献调研和已有的案例总结,系统评述了现有的应急处理处置技术的优缺点,并简要介绍了这些应急技术在已报道的国内历次突发性重金属水污染事件中的实践应用,指出了突发性重金属水污染应急处理处置技术的发展趋势,对于未来应对突发性重金属水污染事件快速选择经济、有效、绿色的应急处理处置技术和应对策略具有重要的参考价值。     

上海世博会突发环境事故应急预案系统研究探讨

针对中国2010年上海世博会可能发生的各类突发环境事故,提出应集成运用数据库、GIS、数学模型、专家系统等多种技术手段,特别是提出采用CBR技术,开发世博会突发环境事故应急预案系统。以提高世博会运行管理时期对各类突发环境事故的预防和处理处置能力;指出环境事故应急预案的主要研究工作应包括应急预案的种类、内容、支撑技术体系,以及应急预案系统的规划、建设与运行管理等;给出了需要解决的关键技术问题和系统开发方案。     

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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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.     

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.     

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.     

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.     

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.