卫生填埋场的伊－灰复合上防渗技术实验研究

卫生填埋场防渗层设置工程通常需要筹集大量的优质粘土，这对于许多地区是十分困难的。本文提出了以廉价复合土取代优质粘土的观点，并以普通粘土、伊利土和粉煤灰为对象进行了复合防渗技术实验研究，结果表明：伊利土与粉煤灰复合后具有良好的抗渗性能，复合土在１．５ｇ／ｃｍ３的密实度下可获得５．４×１０－８ｍ／ｓ的渗透系数，粉煤灰在复合土中的最佳重量百分比范围是２０％～３０％。     

白泥复合衬层防渗稳定性的研究

为考察白泥复合防渗衬层的防渗稳定性和对污染物的阻滞去除能力,利用自制击实渗透仪对白泥和亚粘土防渗衬层进行了对比研究. 结果表明:白泥/亚粘土“夹层结构"复合衬层能保持低于国家防渗规范(10－7 cm/s)的防渗性,并对渗滤液中的重金属,COD_Cr和NH₄＋-N具有较强的阻滞去除能力,可以与常用的亚粘土防渗衬层相媲美,不过其淋滤出水ρ(Cl－)高,因此其长期防渗稳定性需进一步研究;60%白泥+40%亚粘土“混合式"复合衬层和白泥防渗衬层在渗滤液渗透作用下,其防渗性能不好,渗透系数超过国家防渗规范要求,因此不宜用于填埋场防渗.      

垃圾填埋场采用钠基膨润土防水毯防渗技术的探讨

目前内蒙古各城市生活垃圾的处置方式,大多采用卫生填埋法。防渗是卫生填埋处理技术的主要标志,它能防止垃圾在填埋过程中产生的渗滤液对水体污染。近几年钠基膨润土防水毯在卫生填埋场中得到快速发展,现已部分或全部取代粘土防渗层。本文主要从工程施工、质量、造价等分析膨润毯取代粘土防渗层的优势以及采用粘土防渗层对生态环境产生的不利影响。     

卫生填埋场水平防渗系统各结构单元设计深度探讨

结合《生活垃圾卫生填埋场防渗系统工程技术规范》（CJJ113－2007）和《生活垃圾填埋场污染控制标准》（GB16889－2008）,在此基础上进一步探讨卫生填埋场水平防渗系统各结构单元的组成详细设计。     

沸石改性天然粘土防渗层性能研究

用不同比例的沸石对天然粘土进行改性,对改性粘土防渗层的渗透性、去除主要污染物的有效性和控制渗滤液渗透的可行性进行研究。实验结果表明改性粘土防渗层的渗透系数随沸石比例的增加而增大,如果沸石的配比适当,其渗透系数可达到低于1×10-7cm/s的现行标准,而且提高了防渗层的污染物去除能力。因此,沸石改性粘土作为垃圾填埋场防渗材料是可行的。     

粉煤灰固结技术及应用研究

为防治火电厂贮灰扬尘污染对粉煤灰固结技术进行了试验研究，目前已研制出２个系列的粉煤灰固结剂，固结后的抗压强度都在１６ｋｇ／ｃｍ＾２以上，最高达７０ｋｇ／ｃｍ＾２，水稳系数和冻稳系数都在０．９０－１．００，该项技术具有抑尘效果好，保持时间长，治理成本低，原料来源广泛，施工工艺简单和易于推广等特点，它可用于正在使用的灰场（包括中转灰场，碾压灰场）和贮满灰的灰场治理扬尘，还可用于灰场防渗和灰坝加固。     

各国生活垃圾填埋场防渗结构标准研究

介绍美国、德国和欧盟等国的生活垃圾填埋污染控制标准中对于填埋场防渗结构包括防渗构造、防渗系数、防渗层厚度的有关规定。并对我国54家生活垃圾填埋场的防渗结构进行调查,调查结果表明,我国生活填埋场防渗结构设计不合理,容易发生渗滤液泄漏,这与现行《生活垃圾填埋污染控制标准》(GB16889-1997)中有关防渗结构的要求不足有关。建议我国的生活垃圾填埋场采用复合防渗结构,人工膜厚度至少为1.5mm,压实粘土层厚度至少为50cm。     

石灰在填埋场防渗层中的改性研究

渗滤液是城市固体废物填埋场污染环境的主要来源之一。防渗层可以减少其对环境的污染。鉴于天然防渗层中存在防渗性能差等问题,提出将石灰作为配比填料加入到填埋场底部防渗层中。实验表明,在天然防渗层中分别加入配比为0%、5%和10%的石灰后,配比为10%的防渗层防渗性能良好,对COD和锌离子去除能力较强,效果最佳。     

土工织物在废料填埋场污染防治中的应用

近年来应用土工合成材料作为填埋场的防渗反滤系统材料逐渐增多。土工合成材料化学性能稳定，可取代传统的砂石、粘土用作反滤、防渗层，具有造价低、施工简便等优点。1填埋场污染防治系统的组成填埋场底部和侧边须布置防渗系统以防止废物中有害物质进入地基影响地下水和周围环境，并将填埋场内的沥滤液收集导入污水处理装置中进行无害化处理；顶部布置防渗系统以减少雨水浸润而减少沥滤液的产生和扩散。近年来大型现代化填埋场中的顶部防渗系统还可收集利用垃圾发酵过程中产生的气体。填埋场防渗反滤系统一般由以下几部分组成：填埋场底部…     

干湿循环与垃圾渗滤液耦合作用下GCL防渗性能

开展膨胀指数和渗透系数测定试验,研究干湿循环与垃圾渗滤液渗透耦合作用下膨润土的膨胀性能和土工合成黏土衬垫（GCL）防渗性能变化规律.结果表明,干湿循环与垃圾渗滤液渗透耦合作用对膨润土的膨胀性能和GCL的防渗性能具有显著负面影响：在7次干湿循环后,垃圾渗滤液饱和的膨润土的膨胀指数从20mL/2g降低至7.5mL/2g,GCL的渗透系数从1.65×10^-11m/s增加到1.89×10^-7m/s.膨胀指数下降和渗透系数升高的根本原因是膨润土渗透膨胀性能的丧失.单纯的垃圾渗滤液渗透不会改变GCL的渗透系数.将有效应力从20kPa升高至150kPa,可以促使GCL的渗透系数降低4个数量级,满足填埋场防渗要求（< 5.0x10^-11m/s）.     

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.     

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.     

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.     

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.     

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.     

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.     

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.     

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.