混凝-臭氧/吸附-超滤-反渗透组合工艺对页岩气返排液水质净化效能分析

页岩气返排液中部分小分子有机物如二甲基苄胺（DMBA）、吲哚啉和6-甲基喹啉较难去除,采用混凝-臭氧/吸附-超滤-反渗透组合工艺处理页岩气返排液,探究了其有机、无机组分的去除规律。结果表明:混凝-臭氧-超滤-反渗透组合工艺对离子的去除率为96.7%~99.86%,对DOC和UV₂₅₄的去除率分别为98.7%和99.13%,对DMBA、吲哚啉和6-甲基喹啉去除率分别为82.02%、98.02%和97.67%;混凝-吸附-超滤-反渗透组合工艺对离子的去除率为95.99%~99.86%,对DOC和UV₂₅₄的去除率分别为95.31%和97.54%,对DMBA、吲哚啉和6-甲基喹啉去除率分别为70.19%、94.70%和87.93%。混凝-臭氧/吸附-超滤-反渗透工艺可有效去除返排液中的离子、DOC和UV₂₅₄,对DMBA、吲哚啉和6-甲基喹啉的去除效果显著,有利于返排液的外部回用。     

部分亚硝化-厌氧氨氧化处理磁混凝生活污水

以磁混凝预处理后的生活污水为处理对象,构建了部分亚硝化-厌氧氨氧化分体式反应器,通过曝气调控与生物强化促进部分亚硝化反应的稳定进行,并耦合厌氧氨氧化反应进行深度脱氮.近100d的运行结果表明,在生物强化和间歇曝气的控制条件下,亚硝酸盐积累率达到了89.93%;提高亚硝化反应器中曝气阶段溶解氧浓度（从0.6~0.8mg/L升高至1.0~1.2mg/L）有利于氨氮与总氮去除.该系统最高能够去除95.45%的氨氮和86.28%的总氮,实现了稳定、高效脱氮;磁混凝预处理后的生活污水在亚硝化反应器中,间歇曝气条件促进了残留的溶解性有机物为反硝化提供碳源,COD总去除率达到64.65%~74.42%,并且亚硝化反应器出水与系统最终出水的有机物组分相似,主要为难降解有机物.     

焦化废水中有机物在A1-A2-O生物膜系统中的降解机理研究

对焦化废水中有机物在A1 A2 O生物膜系统各段的降解进行了研究 .结果表明 ,废水中主要有机组份为苯酚类和含氮杂环类化合物 ,它们所占比例分别为 5 0 %和 4 0 % .经过厌氧酸化处理后 ,苯酚类中简单酚得到了较大程度的降解 ,随着苯酚甲基取代基数目的增加 ,降解率逐渐降低 ,对三甲酚则没有降解 ;简单的含氮杂环化合物如喹啉、异喹啉、吲哚、吡啶在厌氧过程中也得到了较大的降解 ,而有取代基的含氮杂环化合物则有所增加 ;喹啉和甲基喹啉的降解可生成羟基喹啉和甲基 2(1H)喹啉酮中间产物 .经过厌氧酸化段处理后 ,废水的BOD5 COD有较大提高 .厌氧出水的大部分有机物可在缺氧段得到降解 .最终出水中有机物基本上为大分子难降解物质 .     

焦化废水中有机物在A1-A2-O系统各段的降解与转化

在厌氧酸化－缺氧－好氧（A1－A2－O）生物膜系统小试装置中处理焦化废水，以探讨有机物在各阶段的降解与转化情况。通过UV吸收光谱及GC／MS分析发现，上海焦化厂废水中的有机组分主要为：甲酚、苯酚、二甲酚等酚类化合物，及以喹啉、吲哚为代表的含氮杂环化合物，约占有机物总量的90％。经A1－A2－O生物膜系统处理后，大部分有毒有害难降解有机物得到了降解和转化。厌氧段中原有物质浓度的增加和新物质的生成，是厌氧酸化使部分有机物降解产生中间产物而造成；缺氧段使大部分有机物被完全降解或转化，还产生一些新的简单有机物，如卤代烃、酯类、醛类等；经好氧段反应后，有机物进一步降解和转化，部分被完全去除，在降解转化过程中又产生了一些中间产物和衍生物，如苯酚、羟基喹啉等。     

部分亚硝化-厌氧氨氧化处理磁混凝生活污水

以磁混凝预处理后的生活污水为处理对象,构建了部分亚硝化-厌氧氨氧化分体式反应器,通过曝气调控与生物强化促进部分亚硝化反应的稳定进行,并耦合厌氧氨氧化反应进行深度脱氮.近100d的运行结果表明,在生物强化和间歇曝气的控制条件下,亚硝酸盐积累率达到了89.93%;提高亚硝化反应器中曝气阶段溶解氧浓度（从0.6~0.8mg/L升高至1.0~1.2mg/L）有利于氨氮与总氮去除.该系统最高能够去除95.45%的氨氮和86.28%的总氮,实现了稳定、高效脱氮;磁混凝预处理后的生活污水在亚硝化反应器中,间歇曝气条件促进了残留的溶解性有机物为反硝化提供碳源,COD总去除率达到64.65%~74.42%,并且亚硝化反应器出水与系统最终出水的有机物组分相似,主要为难降解有机物.     

后置短程反硝化AOA-SBR工艺实现低C/N城市污水的脱氮除磷

为了解厌氧/好氧/缺氧(A/O/A)运行的序批式反应器(SBR)中,强化生物除磷(EBPR)与同步短程硝化反硝化(SPND)耦合,并后置短程反硝化的脱氮除磷特性,以低C/N(≤4)城市污水为处理对象,通过优化曝气量和缺氧时间,实现了低C/N城市污水的深度脱氮除磷.结果表明,当好氧段曝气量由1.0 L·min-1降至0.6 L·min-1,缺氧时间为180 min时,出水PO3-4-P浓度由0.06 mg·L~(-1)降至0,出水NH+4-N、NO-2-N和NO-3-N浓度分别由0.18、18.79和0.08 mg·L~(-1)逐渐降低至0、16.46和0.05 mg·L~(-1),TN去除率由72.69%提高至77.97%;随着曝气量的降低,SPND现象愈加明显,SND率由19.18%提高至31.20%;此后,当缺氧段时间由180 min逐渐延长至420 min,出水PO3-4-P、NH+4-N和NO-3-N浓度分别维持在0、0和0.03 mg·L~(-1)左右,出水NO-2-N低至3.06 mg·L~(-1),SND率达32.21%,TN去除性能逐渐提高,TN去除率高达99.42%,实现了系统的深度脱氮除磷.     

焦化废水中有机物对厌氧微生物抑制作用的研究

本文探讨焦化废水在厌氧生物处理过程中,有机物对厌氧微生物的抑制怍用。结果表明,焦化废水中对厌氧微生物有抑制作用的有机物主要有邻甲酚、间甲酚、3,4—二甲酚和间苯二酚等。     

后置短程反硝化AOA-SBR工艺实现低C/N城市污水的脱氮除磷

为了解厌氧/好氧/缺氧(A/O/A)运行的序批式反应器(SBR)中,强化生物除磷(EBPR)与同步短程硝化反硝化(SPND)耦合,并后置短程反硝化的脱氮除磷特性,以低C/N(≤4)城市污水为处理对象,通过优化曝气量和缺氧时间,实现了低C/N城市污水的深度脱氮除磷。结果表明,当好氧段曝气量由1.0L·min-1降至0.6L·min-1,缺氧时间为180min时,出水PO43--P浓度由0.06mg·L-1降至0,出水NH4+-N、NO2--N和NO3--N浓度分别由0.18、18.79和0.08mg·L-1逐渐降低至0、16.46和0.05mg·L-1,TN去除率由72.69%提高至77.97%;随着曝气量的降低,SPND现象愈加明显,SND率由19.18%提高至31.20%;此后,当缺氧段时间由180min逐渐延长至420min,出水PO43--P、NH4+-N和NO3--N浓度分别维持在0、0和0.03mg·L-1左右,出水NO2--N低至3.06mg·L-1,SND率达32.21%,TN去除性能逐渐提高,TN去除率高达99.42%,实现了系统的深度脱氮除磷。     

PD-DPR系统处理城市污水与高硝酸盐废水实现稳定亚硝酸盐积累和磷去除的特性

本研究以模拟城市污水和高硝酸盐废水为处理对象,在一个厌氧-缺氧-微曝气运行的SBR反应器内,将短程反硝化工艺(PD,NO_3~-→NO_2~--N)与反硝化除磷工艺(DPR)耦合,并通过联合调控进水C/N比、厌氧排水率和缺氧时间,考察了PD-DPR系统的亚硝酸盐积累特性和除磷性能.结果表明,经过140d,NO_3~-→NO_2~--N转化率(NTR)为80.1%,PO~(3-)_4-P去除率高达97.64%.在厌氧段(180 min),聚糖菌(GAOs)和聚磷菌(PAOs)对污水有机碳源进行充分利用,将其转化为内碳源;缺氧段(150 min),反硝化聚糖菌(DGAOs)和异养反硝化菌(DOHOs)分别进行内源和外源短程反硝化实现NO~-_2-N稳定积累,同时反硝化聚磷菌(DPAOs)进行高效反硝化吸磷;微曝气段(10 min),在不发生硝化反应的前提下,PAOs超量吸磷,提高了系统的除磷性能.系统出水NO~-_2-N/NH~+_4-N为1.31∶1(接近厌氧氨氧化工艺理论值1.32∶1),PO~(3-)_4-P浓度为0.30 mg·L~(-1),COD浓度为12.94 mg·L~(-1).其出水水质可满足与厌氧氨氧化(ANAMMOX)工艺耦合进行深度脱氮的需求.     

AAO-生物膜工艺处理电镀废水的脱氮除磷性能

为提高电镀废水的污染物去除效率,探讨厌氧-缺氧-好氧(AAO)-生物膜耦合工艺的有机物去除和脱氮除磷效能。结果表明:AAO-生物膜工艺处理电镀难降解有机废水运行效果良好,COD去除率稳定在89%左右;脱氮主要途径是好氧硝化,缺氧反硝化,60 d运行中系统脱氮率达到70%~80%;难降解有机物影响NH₄+-N和COD的去除效率,且存在时间差距,在其影响下,NH₄+-N的变化稍滞后于COD。AAO-生物膜工艺的除磷效果经50 d运行后趋于稳定,出水TP浓度低于1 mg/L,去除率>65%,除磷主要依靠厌氧释磷和好氧吸磷过程。     

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.     

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.     

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.     

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 heavy metals from sewage sludge by low costing chemical method and recycling in agriculture

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