膜生物反应器去除废水中阴离子表面活性剂的研究

阴离子表面活性剂是环境中分布广泛且具有代表性的一类有机污染物.采用分置式膜生物反应器(MBR)进行去除模拟废水中阴离子表面活性荆(LAS)的实验,结果表明:MBR对阴离子表面活性荆的去除率高于90%.同时考察了阴离子表面活性荆生物降解的影响因素,确定其适宜降解条件为:气体流量为0.3m3/h、活性污泥浓度为6948mg/L.初步探讨了降解动力学和降解机理,研究表明对阴离子表面活性剂的去除符合拟一级反应动力学过程,且生物降解对其去除起主要作用.     

表面活性剂增效微生物修复PAHs污染土壤的研究进展

生物降解是去除土壤环境中多环芳烃（PAHs）的重要途径,通过使用表面活性剂增效修复可显著提高PAHs降解速度和程度。本文系统评述了表面活性剂增效修复PAHs污染土壤的研究现状和存在的问题。     

双表面活性剂修饰下纳米零价铁对水中Cr(Ⅵ)污染去除研究

为解决纳米级零价铁（nZVI）在环境中易团聚、易氧化的问题,强化其去除水中Cr（VI）的能力,选择非离子型表面活性剂聚乙烯吡咯烷酮（PVP）和阴离子表面活性剂油酸钠（NaOA）同时对nZVI进行修饰.同时,通过对比不同pH值、材料干湿状态、初始浓度及共存离子条件下的反应效果,结合材料的XRD和XPS表征、动力学实验和25℃等温线的拟合进行机理分析.结果表明：酸性条件有利于Cr（VI）的去除;材料的干湿状态对去除效率影响较大;材料去除水中Cr（VI）可在3 h内达到反应平衡,去除效率在90%以上,实验条件下最大去除量为183.1 mg·g^-1,反应过程符合准二级动力学模型及Langmuir模型;反应过程中Cr（VI）大部分转化为Cr（Ⅲ）.     

表面活性剂（LAS＆NIS）的环境安全性评价

阴离子表面活性剂直链烷基苯磺酸盐(LAS)和非离子表面活性剂(NIS)是产量和消耗量都相当大的两类表面活性剂。文章从生物降解性、毒性及在环境和生物体内的累积性3个方面分析了它们的环境安全性，认为表面活性剂对环境会产生不同程度的影响。LAS对动植物有毒害，在环境中和生物体内有累积(尽管易降解)，应引起重视；NIS中脂肪醇聚氧乙烯醚(APEO)的降解产物毒性高、降解速度慢，对环境有很大的危害。     

孔雀绿萃取分光光度法测定水中痕量阴离子表面活性剂

研究了孔雀绿（ＭＧ）与阴离子表面活性剂（ＡＳ）形成的缔合物革取显色体系。在ｐＨ＝３．７的醋酸溶液中，ＭＧ与ＡＳ形成稳定的离子缔合物，可用苯苹取，其萃取液在６２２ｎｍ处有最大吸收，ε值为７．１×１０４～８．９×１０４Ｌ．ｍｏ１－１．ｃｍ－ｌ。从而提出了包括十二烷基苯磺酸钠（ＤＢＳＮａ）和十二烷基磷酸钠（ＤＳＮａ）等阴离子表面活性剂的新分析方法，ＤＢＳＮａ浓度在１～３５μｇ／１０ｍｌ，ＤＳＮａ浓度在０．５～２５μｇ／１０ｍｌ符合比耳定律，用等摩尔连续变化法和斜率比法测得缔合物的组成比为ｌ：１，用本法测定了环境水样中的痕量阴离子表面活性剂，结果满意。     

表面活性剂在环境中的生物降解

简述表面活性剂对环境的影响,讨论了表面活性剂生物降解性的测试方法、降解过程动力学及其影响因素,并对各类表面活性剂结构与降解能力之间的关系作了评价。     

含氮农药的好氧生物降解性能及废水治理对策

从动力学角度出发,利用长期驯化的菌种,对乙草胺,阿特拉津,西草净,赛克津等４种含氮农药的好氧生物降解性能进行了研究,并对含氮农药废水提出了治理对策,结果表明,４种含氮农药的好氧生物降解性能都很差,均属于难生物降解有机物,降解过程均符合一级降解动力学模式,它们的生物降解速率常数分别为０．００３５３Ｌ（ｇ．ｈ）,０．００５７７Ｌ／（ｇ．ｈ）,０．００１６０Ｌ／（ｇ．ｈ）,０。０４５６Ｌ／（ｇ．ｈ）进一     

饱和带有机污染物的厌氧反硝化微生物降解

以卤代烃和芳香烃为代表,通过室内实验模拟饱和带厌氧反硝化环境,对地下饱和带中有机污染物的厌氧反硝化可生物降解性,降解机理,降解动力学方程等进行了研究。实验结果表明,芳香烃较卤代烃易被微生物降解,在有低学葡萄糖存在时有 机物的最大生物降解速率Ｃ６Ｈ６：Ｌｍａｘ＝１７ｍｇ／（ｍ＾２．ｄ）,Ｃ７Ｈ８：Ｌｍａｘ＝４６ｍｇ／（ｍ＾２．ｄ）,ＣＣｌ４;Ｌｍａｘ＝７ｍｇ／（ｍ＾２．ｄ）,ＣＨＣｌ３：Ｌｍａｘ＝６     

表面活性剂(LAS & NIS)的环境安全性评价

阴离子表面活性剂直链烷基苯磺酸盐(LAS)和非离子表面活性剂(NIS)是产量和消耗量都相当大的两类表面活性剂.文章从生物降解性、毒性及在环境和生物体内的累积性3个方面分析了它们的环境安全性,认为表面活性剂对环境会产生不同程度的影响.LAS对动植物有毒害,在环境中和生物体内有累积(尽管易降解),应引起重视;NIS中脂肪醇聚氧乙烯醚(APEO)的降解产物毒性高、降解速度慢,对环境有很大的危害.     

渭河宝鸡市区段阴离子表面活性剂污染研究

本文采用改进的亚甲蓝分光光度法，对渭河宝鸡市区段阴离子表面活性剂进行监测分析。测定结果表明：渭河在进入宝鸡市至植物园断面时阴离子表面活性剂含量较低，日平均值为0．049mg／L，达到地面水环境质量I类标准(≤0．2mg／L)(GB3838-88．地面水环境质量标准)；在流经市区新世纪桥、渭河桥断面时，由于分别有清姜河和金陵河两个支流的汇入，污染越来越严重．在这两个断面阴离子表面活性剂含量日平均值分别为0．34mg／L和0．54mg／L；在即将流出宝鸡市的斗鸡断面阴离子表面活性剂含量日平均值为0．424mg／L，已远远超过地面水环境质量V类标准(≤0．3mg／L)(GB3838-88，地面水环境质量标准)。从监测结果看：双休日阴离子表面活性剂含量普遍高于工作日；清姜河、金陵河污染严重，这两条支流的汇入对渭河水质影响巨大，要治理好渭河，须先治理好清姜河和金陵河这两条支流。     

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.     

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.     

Simultaneous removal of ammonium and phosphate by zeolite synthesized from coal fly ash as influenced by acid treatment

Zeolite synthesized from fly ash （ZFA） without modification is not efficient for the purification of NH4＋ and phosphate at low concentrations that occur in real effluents, despite the high potential removal capacity. To develop an effective technique to enhance the removal efficiency of ammonium and phosphate at low concentrations, ZFA was modified with acid treatment and the simultaneous removal of ammonium and phosphate in a wide range of concentration was investigated. It was seen that when compared with untreated ZFA, only the treatment by 0.01 mol/L of H2SO4 significantly improved the removal efficiency of ammonium at low initial concentrations. The behavior was well explained by the pH effect. Treatment by more concentrated H2SO4 led to the deterioration of the ZFA structure and a decrease in the cation exchange capacity. Treatment by 0.01 mol/L H2SO4 improved the removal efficiency of phosphate by ZFA at all initial P concentrations, while the treatment by concentrated H2SO4 （≥0.9 mol/L） resulted in a limited maximum phosphate immobilization capacity （PIC）. It was concluded that through a previous mild acid treatment （e.g. 0.01 mol/L of H2SO4）, ZFA can be used in the simultaneous removal of NH4＋ and P at low concentrations simulating real effluent.