辽河流域水污染治理历程与“十四五”控制策略

为明晰辽河流域水污染治理“十四五”需求,进一步科学合理地推进辽河流域治理与保护进程,通过调研历史监测数据、统计年鉴等资料,回顾辽河流域水环境演化和治理历程.将辽河流域的治理分为3个阶段:第1阶段（1991—1999年）,该阶段流域水环境呈重度污染并持续恶化,环境治理逐渐起步;第2阶段（2000—2006年）,该阶段辽河流域水质恶化趋势基本得到遏制,控源治污初显成效;第3阶段（2007—2019年）,该阶段辽河流域水质优良比例整体持续提升,国家水体污染控制与治理科技重大专项有力支撑流域综合调控.辽河流域水污染治理颇显成效,但仍存在以下主要问题:①辽河流域水污染治理经历了从单一的控源治污向河流综合治理转变,污染程度由重度转为轻度,但流域水污染控制依然不容乐观;②辽河流域属寒冷地区缺水型河流,生态流量不足;③水质改善及水生态恢复成果不稳定;④流域管理机制体制有待完善.“十四五”应针对性增设分水期考核方式和水生态考核指标,完善水环境标准;坚持水资源、水环境、水生态“三水”统筹科学施治,构建减排和增容相结合的水污染控制模式,推动水量、水质、水功能良性循环发展;建立流域统筹管理、垂直领导的管理体制,制定辽河流域河流空间管控的长效机制,促进环保技术产业化,发展流域循环经济,缓解经济社会发展与水环境保护矛盾,最终实现流域经济社会可持续健康发展.      

太湖流域水环境监测预警系统建设对策研究

太湖流域水环境监测预警系统是加大太湖水污染防治力度、切实改善水环境质量的重要基础性工程,被视为掌握流域水质规律、预警太湖蓝藻暴发的必要系统.本文概述了太湖流域水环境,介绍了系统建设框架,结合实践从历史经验回顾、管理需求辨析、系统要素联接和预警技术评估等角度出发,提出建设中的难点问题与对策.     

东莞:加快治理黑臭河涌

正为补齐生态环境短板,改善水环境质量,从2016年起,东莞全面打响水污染治理攻坚战。通过不断完善管理机制,高效推进次支管网建设,积极创新治水模式,开展重污染河涌综合整治示范项目,水污染治理工作不断迈上新台阶,百姓环境获得感、幸福感得到提升。目前,全市40条重污染河涌整治示范项目水质均已基本消除黑臭,全市共建成截污管网超过     

农村水环境问题及治理对策

本文通过对农村地区水环境现状的分析,指出农村水环境存在问题,如水土流失,旱涝灾害对水环境的污染等问题,同时提出了保护农村水环境、改善农村水环境的主要措施.提出了各级政府应重视农村水污染的治理、积极改善农村的水环境.     

基于生态视角下的太湖一级保护区水污染防治研究

江苏省太湖流域一级保护区综合整治是治理太湖的重点工作,直接关系太湖湖体水环境质量.通过现场调查、遥感、访问专家等生态学调查方法,对一级保护区存在的生态问题进行全面分析,并提出了严格控制建设用地规模、调整工业结构、优化城乡布局、调整人口结构等减小生态压力的途径,为全面治理太湖水污染提供理论依据.     

辽河铁岭段水环境质量分析及银州段污染治理对策

本文概述了辽河铁岭段水环境质量状况,查清影响水质污染的原因,对重点污染源进行了水质预测,并依据水环境质量控制目标,提出了行之有效的水污染治理规划和对策.     

“十二五”太湖富营养化控制与治理研究思路及重点

在总结“十一五”太湖富营养化治理成效、存在问题的基础上,提出“十二五”期间水体污染控制与治理科技重大专项太湖富营养化控制与治理项目的总体设计思路. 项目以综合示范区水质改善为目标,重点研发园区化乡镇企业工业废水中难降解含氮、磷有机物的深度削减技术,农田种植业和农村分散式生活污水的控源减排技术,“湖荡湿地-入湖河流-湖滨缓冲带”为一体的生态拦截与修复技术;以湖泊水生态安全保障为目标,研发湖泛与水华灾害应急处置技术及建立水资源优化调度决策平台. 选择太湖流域重污染型竺山湾小流域、面源污染主控型苕溪小流域和城市化型太湖新城三大典型综合示范区,通过控源减排和生态修复关键技术的研发、集成和综合实施,实现综合示范区污染负荷得到有效控制、示范区水环境质量得到改善和规模化蓝藻水华发生得到有效控制的目标.      

太湖西岸典型控制单元污染物排放核定研究

文章现以宜兴市为例,进行太湖西岸典型控制单元污染物排放核定的研究.结合水污染管理现状,完成了可操作的、面向排污许可证实施的宜兴流域控制单元划分、污染物排放量核定、水质响应关系建立和水环境容量测算与分配等水质目标管理体系,为宜兴市及整个太湖流域的水污染控制与治理方案提供方法论的指导.     

江苏省太湖污染防治概述

太湖水源是整个太湖流域国民经济与社会发展的命脉，近年来太湖水质恶化已影响太湖流域的经济与社会发展，分析了太湖污染来源及污染状况探讨了太湖污染的发展原因，指出了太湖水污染防治的措施，如污染物总量控制，重点治理，综合防治等。     

南水北调湖北库区水环境现状及问题分析

本文调查了南水北调中线工程水源地──丹江口水库湖北库区水环境现状，分析了污染源排放与治理以及水环境质量存在的问题。认为库区水环境问题较多，有半数支流水质不能满足中线工程要求，主要问题是COD_(Mn)与富营养化物质污染严重，个别河流还存在着重金属汞污染问题；污染防治的重点在于抓住轻工行业重点污染源与生活污水治理，从管理上推行总量控制排污许可证制度，切实改善水环境质量。     

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.