建立河流水质污染预警体系 保护河流水质安全

建立河流水质预警体系对保障河流水质安全具有极其重要的作用,是保护河流水质安全的重要内容之一。本文针对国内河流潜存的环境污染及事故风险现状,提出建立流域污染预警系统、河流水环境风险评估体系以应对河流突发污染事件发生,确保河流水环境安全,实现河流水资源可持续利用。     

贵州省黔东南苗族侗族自治州水资源可持续利用策略

以黔东南苗族侗族自治州为研究区域,全面分析流域特征及水系特点、水资源时空分布特征以及水环境质量分异状况,从空间、时间、目标、风险等维度综合探析区域水资源冲突,使用系统动力学方法进行水资源系统仿真和动态模拟,探讨不同产业发展模式、水资源利用策略下的优化情景,从面向流域综合管理的水资源生态补偿、面向区域产业转型的水资源优化配置、面向多目标开发的河流生态系统管理、面向山区民族村寨的饮用水安全保障等角度提出了全州水资源可持续利用的主要策略。     

深圳市利用小(2)型水库进行河流生态补水研究

深圳市水环境质量改善迫在眉睫,亟需探寻新的解决思路和途径。借鉴香港、新加坡等城市经验,提出"抓大放小"思路,通过挖潜现有供水水库库容,科学调度水资源,逐步调整小(2)型水库供水功能,充分利用水库库容在旱季为下游河流实施生态补水。补水后可一定程度改善下游河流水质状况,为深圳市河流治理提供新的思路和解决方案。同时通过完善村镇供水网络,实现集中供水,保障了区域供水水量和水质的稳定。     

水环境与水资源流域综合管理体制研究

作为我国环境管理的重要构成内容,水环境与水资源为我国社会、经济的发展提供了基础资源,但是随着经济的发展,引发了很多水问题、生态问题,给生态环境造成严重影响的同时,在很大程度上限制了我国经济、社会的发展。所以,水环境与水资源流域的管理问题近些年来越来越受到我国重视,是我国一直致力于解决的一大难题。本文针对水环境和水资源的综合管理问题展开了探讨,并研究了综合管理水环境与水资源流域的体制。     

流域水环境综合治理技术体系研究:以兆河流域为例

采用中国电建集团已形成的"以水环境改善为核心,以水资源保障、水生态修复为重点的五位一体综合治理技术体系"研究成果,以环巢湖的兆河流域为例,基于污染物总量控制、生态基流和水生态系统平衡分别确定水环境改善方案、水资源保障方案和生态修复方案,并评价工程实施后水质达标状况。结果表明:兆河流域污染源贡献量最高的类型为城镇生活源,污染负荷最高的小流域为县河;流量在75%保证率下兆河流域COD、NH_3-N、TP和TN的水环境容量分别为5438. 61,370. 42,70. 76,367. 50 t/a;县河流域污染负荷削减分配量最高;水环境、水资源和水生态措施实施后,兆河流域污染负荷低于水环境容量限值。     

基于主成分分析的城市水环境管理综合评价--以京津冀为例

在我国城市可持续发展的进程中,城市水体面临着水资源不足、水质恶化等一系列的问题。文章以京津冀为例,依据城市统计年鉴等相关资料数据,利用相关性分析,筛选出8项代表性的评价因子,构建城市水管理综合评价指标体系,并运用主成分分析法对京津冀区域水环境管理进行综合评价。结果表明:城市水环境综合管理水平受供水总量、人均GDP、水质评分、工业废水排放量和人口密度等多种因素共同影响;京津冀区域可以划分为4大类,其中北京、天津的城市水环境综合管理表现为最好,承德、衡水、张家口最差。     

太湖湖泛高发区物联网监测技术与预警系统

针对太湖湖泛高发区,利用物联网水质环境监测技术,建立实时监测网络和应急管理预警系统框架.结合当前湖泛成因机理研究和历史数据资料,重点对水质监测子系统、预警子系统和基础数据管理子系统的功能实现进行阐述.同时,将网络技术、无线传感技术和生态感知技术融入到水环境监测预警中,构建具有生态感知、多网接入、智能处理和综合管理等功能的太湖湖泛预警系统.为进一步加强太湖湖泛水体的监控与预警系统的建立提供可操作的思路.     

海河流域水生态功能一级二级分区

水生态功能分区是实现流域水环境"分区、分级、分期和分类"管理的基础.通过分析海河流域的陆地和水生态系统特点,确定了一级二级分区的指标体系,一级分区指标包括地貌类型、径流深、年降水量、年蒸发量,反映水资源供给功能的空间格局特征,共划分了6个一级水生态功能区;二级分区利用植被类型和土壤类型的空间异质性,反映流域生态水文过程及水质净化功能的空间格局特征,共划分了16个二级水生态功能区.最后,通过野外调查各个分区的水生态系统结构和生境差异性(水量、水质、河流生境、水生动植物等),对一级和二级分区结果进行了评价.分区结果能够为海河流域的水质目标管理和区域生态环境建设提供支持,分区方法和指标体系也可以为国内其它类似流域的水生态功能分区提供参考.     

基流匮乏型城市黑臭河流的治理模式及其主要技术方法——以贾鲁河为例

基流匮乏的重污染城市黑臭河流治理是世界性难题。以郑州市贾鲁河为实例,针对城市黑臭河流天然径流少、河道补给水多为生活及工业废水、河流生态功能基本丧失等污染特征,本文提出了基于废水资源化再生利用与水质目标管理结合的基流匮乏型城市黑臭河流的"三级循环、三级控制、三级标准"治理模式;针对水体黑臭问题成因,研发经济有效的污染控制与治理新技术,实现流域排污总量与环境容量的科学衔接,为解决同类型河流水资源短缺与水质目标的达成提供了切实可行的治理模式与途径,并对我国今后黑臭河流治理提供了建议。     

蒲河水生态修复工程与功效评估

"十二五"期间,沈阳市蒲河的污染控制与水生态修复工程同步实施。通过污水处理设施建设、水资源调控、生态廊道建设和河道水质改善技术示范等工程建设,实现了水质改善和水生态功能修复的目标。文章对重点工程的实施和功效进行了解析,总结了同类河流整治的科学对策和途径。     

Effects of two sludge application on fractionation and phytotoxicity of zinc and copper in the soil

The potential harm of heavy metals is a primary concern in application of sludge to the agricultural land. A pot experiment was conducted to evaluate the effect of two sludges on fractionation of Zn and Cu in soil and their phytotoxicity to pakchoi. The loamy soil was mixed with 0%, 20%, 40%, 60% and 80% (by weight) of digested sewage sludge (SS) and composted sludge (SC). The additions of both sludges caused a significant raise in all fractions, resulting in that exchangeable (EXCH) and organic bound (OM) became predominance of Zn and organic bound Cu occupied the largest portion. There was more available amount of Zn and Cu in SS treatments than SC treatments. During the pot experiment, the concentration of Zn in EXCH, carbonate (CAR) and OM and Cu in EXCH and OM fractions decreased in all treatments, so their bioavailability reduced. Germination rate and plant biomass decreased when the addition rate was high and the best yield appeared in 20% mixtures at the harvest of pakchoi. The two sludges increased tissue contents of Zn and Cu especially in the SS treatments. Zn in pakchoi was not only in relationship to ΔEXCH and ΔCAR forms but also in ΔOM forms in the sludge-soil mixtures. Tissue content of Cu in pakchoi grown on SC-soils could not be predicted by ΔEXCH. These correlation rates between Zn and Cu accumulation in pakchoi and variation of different fractions increased with time, which might indicate that sludges represented stronger impacts on the plant in long-term land application.     

Intraspecific differences in effects of co-contamination of cadmium and

A hydroponic experiment was carried out to study intraspecific differences in the effects of different concentrations of cadmium (Cd)(0-10 mg/L) and arsenate (As(V)) (0-8 mg/L) on the growth parameters and accumulation of Cd and As in six wheat varieties Jing-9428, Duokang-1, Jingdong-11, Jing-411, Jingdong-8 and Zhongmai-8. The endpoints of wheat seedlings, including seed germination,biomass, root length and shoot height, decreased with increasing the Cd and As concentrations. Significant differences in seed germination, biomass, root length, shoot height and the accumulation of Cd and As were observed between the treatments and among the varieties (p ＜ 0.05). The lethal dosage 50% were about 20, 80, 60, 60, 80 and 20 mg As/L for Jing-9428, Duokang-1, Jingdong-11,Jing-411, Jingdong-8 and Zhongmai-8, respectively, and the corresponding values for Cd were about 30, 80, 20, 40, 60 and 10 mg Cd/L, respectively. Among the six varieties, Duokang-1 was found to be the most resistant to Cd and As toxicity, and Zhongmai-8 was the most sensitive to Cd and As co-contamination. The resistance of the six varieties was found dependant on the seedling uptake of Cd and As. Duokang-1 was the most suitable for cultivation in Cd and As co-contaminated soils.     

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.     

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.     

Effect of sorbed and desorbed Zn(Ⅱ) on the growth of a green alga (Chlorella pyrenoidosa)

Toxic effect of Zn(Ⅱ) on a green alga (Chlorella pyrenoidasa) in the presence of sepiolite and kaolinite was investigated.The Zn-free clays were found to have a negative impact on the growth of C.pyrenoidosa in comparison with control samples (without adding any clay or Zn(Ⅱ)).When Zn(Ⅱ) was added,the algae in the presence of clays could be better survived than the control samples,which was actually caused by a decrease in Zn(Ⅱ) concentration in the solution owing to the adsorption of Zn(Ⅱ) on the clays.When the solution system was diluted,the growth of algae could be further inhibited as compared to that in a system which had the same initial Zn(Ⅱ) concentration as in the diluted system.This in fact resulted from desorption of Zn(Ⅱ) from the zinc-contaminated clays,although the effect varied according to the different desorption capabilities of sepiolite and kaolinite.Therefore the adsorption and desorption processes of Zn(Ⅱ) played an important part in its toxicity,and adsorption and desorption of pollutants on soils/sediments should be well considered in natural eco-environmental systems before their risk of toxicity to aquatic organisms was assessed objectively.