工业企业搬迁污染场地的管理与对策

概述了我国工业企业搬迁污染场地在法律法规、标准体系、及目前政府相关部门对工业企业搬迁污染场地实施监督管理的现状,指出了目前我国在法律法规、土壤环境标准体系及污染场地管理体系中存在的主要问题,以及通过健全法律法规、完善标准体系、明晰管理体系以及提高环境管理者业务水平等措施,解决工业企业搬迁污染场地管理中的问题,保障工业企业搬迁污染场地的环境安全。     

北京市工业污染场地修复现状、问题及对策

工业企业搬迁遗留的大量污染场地,是城市土地开发的重要来源。我国污染场地修复工作起步较晚,污染场地风险管理与修复体系尚不健全。通过北京市污染场地案例调研,分析了北京市污染场地调查评估、修复以及监管概况,探讨北京市污染场地修复工作中目前存在的标准缺失、原位绿色修复技术缺乏和监管内容不完整等问题,并从技术标准支撑体系、绿色可持续修复理念和全过程监管框架等方面提出对策,以期为北京市污染场地管理与修复体系的建立提供参考。     

RAG-C和RBCA模型中场地特征参数的差异及其启示

近年来,我国大中城市陆续开展污染企业搬迁,这些搬迁企业遗留场地都存在着不同程度的环境与健康风险。开展定量评估人体健康风险是我国工业污染场地管理体系不可缺少的技术手段,也是适合我国国情并走向可持续性土壤与地下水修复及综合环境管理的必然发展方向。污染场地特征参数在风险评估模型中起着重要作用,其对风险评估结果具有显著影响,研究对比了我国污染场地风险评估技术导则(RAG-C)与美国RBCA模型中场地特征参数的区别,并对完善我国污染场地风险评估技术提供了建议。     

中国污染场地管理面临的问题及对策

概述了欧美国家污染场地管理现状,分析了中国污染场地管理面临的突出问题:中国在污染土壤管理的法律法规和标准、污染土壤的修复技术、污染土壤治理投入等方面同欧美国家有一定的差距.结合污染场地管理和场地风险评估、场地修复条件以及土地利用功能,提出了基于风险评估基础上污染场地管理程序和污染场地管理亟待开展的工作.指出了土壤环境标准体系,污染场地管理体系和污染场地修复技术体系的三元结构的完善是破解中国污染场地管理和修复的难题的根本.     

中国污染场地修复与再开发

污染场地的存在带来了环境和健康的风险,阻碍了城市建设和地方经济发展。加强和完善有关污染场地修复与再开发的法律法规体系非常必要。此外,国家的污染场地修复标准和技术导则对于建立全国统一的污染场地管理体系也十分关键。     

我国POPs污染场地的环境管理基础与完善对策研究

固体废物不恰当处理处置是造成场地污染的原因之一,也是今后需要引起关注的环境问题.在POPs公约中,POPs污染场地和POPs废物一样有着明确的无害化管理要求,作为该公约的缔约国,我国将认真履行公约的义务,消除POPs引起的污染.根据调查,我国POPs引起的场地污染比较严重,现有的环境管理法律法规、标准和制度政策是POPs污染场地管理的基础,但这种基础还比较薄弱,尚不能完全满足环境无害化管理的要求.因此,我们在充分利用现有环境管理体系的基础上,还应该继续改进和完善现有法规和标准体系,建立相关的环境风险评价程序和资金筹集机制,加强污染场地环境管理和监督管理能力建设.     

我国污染场地管理技术标准体系探讨

随着工业化发展,我国的污染场地数量不断增多,环境问题日益突出.为规范污染场地管理,国家及地方层面陆续颁布了系列污染场地管理标准文件,但我国的污染场地标准体系建设尚处在初期阶段,存在调查评估导则缺乏支撑性技术标准、修复过程标准严重缺失、风险评估方法过于保守以及后期风险管理忽视等问题.本文在分析我国污染场地标准体系现状基础上,提出建立进一步开展场地高精度调查、层次化风险评估、修复全过程管理及后期风险管理等技术标准体系,以期推进污染场地管理技术标准体系的完善和发展.     

关于老工业区污染场地管理的探讨

根据在某老工业区第1批28块场地环境调查的实践,对污染场地管理中存在的问题进行了分析并提出了相应改进建议：①获取准确的场地资料难度很大,建议研究制定场地全过程档案管理制度;②工业企业关闭搬迁会产生新的环境污染风险,工业企业关闭搬迁应该成为污染场地管理的重要环节,环保部门应该在工业企业搬迁前介入,严格监管整个过程中的环境污染;③大量区域由于其中污染严重、风险高的场地缺乏修复资金而难以再开发利用,建议结合规划优先启动资金投入低的污染较轻区域修复,并同时对风险较高的污染场地进行风险管控,当区域开发取得一定规模、成就和收益后,可以整合资金力量和资源开展污染较重区域的修复。     

污染场地风险管控环境经济政策作用路径与体系构建

随着“退二进三”和“退城进园”等政策的实施,我国工业企业搬迁、污染场地修复及再开发等问题逐步凸显,遗留了大量存在潜在污染隐患的场地,亟须加快污染场地风险管控的环境经济政策探索与创新。本文从对环境经济政策的作用机制分析入手,提出从全生命周期的视角出发,按照“防、控、治、管”的思路,在场地污染预防与调查、污染场地风险管控与效果评估、污染场地治理修复、污染场地监管和再利用四个阶段纳入多样化、差异化的经济激励政策工具,形成税费、补贴、价格、交易等多种手段组合的污染场地风险管控环境经济政策体系。     

试论我国工业类建设项目地下水污染防控管理体系

本文分析了国内外地下水污染防控管理体系的特点,我国工业类建设项目场地地下水污染的原因,在此基础上,从环境管理手段、差异化管理、地下水污染防控管理的法规和标准方面提出了工业类建设项目地下水污染防控管理体系构建的建议。     

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.     

基于综合水质标识指数和对应分析法的校园河道水质评价

以三峡大学的校园河道求索溪为研究对象,利用综合水质标识指数法确定求索溪水质类别,分析其水质时空变化规律,并利用对应分析法得出求索溪中不同监测点的主要污染因子.研究结果表明:求索溪整体的综合水质标识指数为7.423,整体水质为劣V类(地表水环境质量标准GB 3838-2002)且黑臭.从时间变化来看,求索溪4月份的水质最差,5月份次之,4、5月份所有监测点的水质都劣于V类且黑臭;8月份水质最好,水质为Ⅳ类;从空间分布来看,8个监测点综合水质标识指数均超过6.0,水质为劣V类,其中6号监测点的水质相对最好,监测点3号的水质相对最差;对应分析法得出求索溪的整体水体污染程度受总氮因子的影响最大,其次为总磷.该研究拟为求索溪及类似校园河道的水环境治理研究提供基础依据和参考.     

Effects of chitosan on growth of an aquatic plant (Hydrilla verticillata) in polluted waters with different chemical oxygen demands

Effects of chitosan on a submersed plant, Hydrilla verticillata, were investigated. Results indicated that H. venicillata could prevent ultrastructure phytotoxicities and oxidativereaction from polluted water with high chemical oxygen demand (COD). Superoxide dismutase (SOD) activity and malondialdehyde (MDA) contents in H. verticillata treated with 0.1% chitosan in wastewater increased with high COD (980 mg/L) and decreased with low COD (63 mg/L), respectively. Ultrastructural analysis showed that the stroma and grana of chloroplast basically remained normal. However, plant cells from the control experiment (untreated with chitosan) were vacuolated and the cell interval increased. The relict of protoplast moved to the center, with cells tending to disjoint. Our findings indicate that wastewater with high COD concentration can cause a substantial damage to submersed plant, nevertheless, chitosan probably could alleviate the membrane lipid peroxidization and ultrastructure phytotoxicities, and protect plant cells from stress of high COD concentration polluted water.     

Removal of cadmium using MnO2 loaded D301 resin

MnO2 loaded weak basic anion exchange resin D301 （Anion exchange resin, macroreticular weak basic styrene） as adsorbent has been prepared and applied to the removal of cadmium. The adsorption characteristics have been investigated with respect to effect of pH, equilibrium isotherms, removal kinetic data, and interference of the coexisting ions. The results indicated that the Cd^2＋ could be efficiently removed using MnO2 loaded D301 resin in the pH range of 3-8 from aqueous solutions with the co-existence of high concentration of alkali and alkaline-earth metals ions. The saturate adsorption capacity of the Cd^2＋ was 77.88 mg/g. The adsorption process followed the pseudo first-order kinetics. The equilibrium data obtained in this study accorded excellently with the Langmuir adsorption isotherm.     

Evaluation of phytoextracting cadmium and lead by sunflower, ricinus, alfalfa and mustard in hydroponic culture

Soil contaminated with heavy metals cadmium(Cd)and lead(Pb)is hard to be remediated.Phytoremediation may be a feasible method to remove toxic metals from soil,but there are few suitable plants which can hyperaccumulate metals.In this study,Cd and Pb accumulation by four plants including sunflower(Helianthus annuus L.),mustard(Brassica juncea L.),alfalfa(Medicago sativa L.), ricinus(Ricinus communis L.)in hydroponic cultures was compared.Results showed that these plants could phytocxtract heavy metals, the ability of accumulation differed with species,concentrations and categories of heavy metals.Values of BCF(bioconcentration factor)and TF(translocation factor)indicated that four species had dissimilar abilities of phytoextraction and transportation of heavy metals.Changes on the biomass of plants,pH and Eh at different treatments revealed that these four plants had distinct responses to Cd and Pb in cultures.Measurements should be taken to improve the phytoremediation of sites contaminated with heavy metals,such as pH and Eh regulations,and so forth.     

Effect of coagulation pretreatment on the fouling of ultrafiltration membrane

The purpose of this study is to understand the effect and mechanism of preventing membrane fouling, by coagulation pretreatment, in terms of fractional component and molecular weight of natural organic matter （NOM）. A relatively higher molecular weight （MW） of hydrophobic compounds was responsible for a rapid decline in the ultrafiltration flux. Coagulation could effectively remove the hydrophobic organics, resulting in the increase of flux. It was found that a lower MW of neutral hydrophilic compounds, which could remove inadequately by coagulation, was responsible for the slow declining flux. The fluxes in the filtration of coagulated water and supernatant water were compared and the results showed that a lower MW of neutral hydrophilic compounds remained in the supernatant water after coagulation could be rejected by a membrane, resulting in fouling. It was also found that the coagulated flocs could absorb neutral hydrophilic compounds effectively. Therefore, with the coagulated flocs formed on the membrane surface, the flux decline could be improved.     

Penetration analysis of elements and bioleaching treatment of spent refractory for recycling

Acidithiobacillus ferrooxidans ATCC23270 and Acidithiobacillus thiooxidans TM-32 were used for bioleaching of spent refractories of aluminium and copper melting furnaces for their recycling.Firstly,penetration of elements into aluminium melting furnace refractory was investigated and it was found that up to 7 cm from surface was contaminated.Comparison on leaching efficiency by the strains ATCC23270 and TM-32 found that the strain ATCC23270 could treat larger amount of the refractories than the strain TM-32 could do.In the experiment of bioleaching of spent refractory aluminium melting furnace by the strain ATCC23270,high leaching efficiency were obtained on Al,Si,and Ca,and extremely low leaching performance was,however,shown on the rest of elements i.e.,Na,Mn,and Zn.Under the strain TM-32 use,relatively high leaching performance was recognized on Al,Si,Ca,Na,Mn,and Zn.In the experiment of bioleaching for spent refractory copper melting furnace,almost the same leaching trends were shown on Cu,Zn,Al,and Si under the strains ACTT23270 and TM-32 uses.