国际协商控制12种难降解有机污染物

今春将有 1 1 0个国家的代表在斯德歌尔摩签署一项关于 1 2种难降解有机污染物的停用或减少排放的条约。该项活动由联合国环境规划署发起。有关国家曾于 1 999年 9月在日内瓦 ,2 0 0 0年 3月在波恩 ,2 0 0 0年1 2月在南非 ,先后三次就停用农药氯甲桥萘、毒杀酚和异狄氏剂 ,严格限制农药氯丹、狄氏剂、七氯、灭蚊灵和工业化学品六氯苯、多氯联苯、以及二英和呋喃类物质的排放等进行协商。所有代表同意 DDT农业使用 ,但对用于疟疾控制何时停止有争论国际协商控制12种难降解有机污染物@谢先德…     

载银TiO2半导体催化剂对印染废水的光降解研究

以新型载银ＴｉＯ２为催化剂，采用高压汞灯为光源对实际印染废水进行了光催化降解的研究。研究结果表明，用新型载银催化剂（简称ＴＳＡ）对印染废水和精炼废水进行深度处理的效果比用ＴｉＯ２为好。在光照１２０分钟条件下，用ＴＳＡ催化剂对印染和精炼废水生化处理出水进行光催化降解，废水的ＣＯＤｃｒ去除率分别达到７５．３％和８３．４％，比同样光降解条件下用单一ＴｉＯ２催化剂时废水的ＣＯＤｃｒ去除率提高２２．９％和２     

白洋淀几种不同食性鱼类对六六六、DDT的富集

对白洋淀几种不同食性鱼体内六六六和ＤＤＴ残留量分析表明，草食性鱼体内农药残留量最少，六六六含量为５９．３μｇ／ｋｇ，ＤＤＴ含量为２９．６μｇ／ｋｇ；其次是杂食性鱼类，六六六含量为９０．４μｇ／ｋｇ，ＤＤＴ含量为１０８．５μｇ／ｋｇ；肉食性鱼体内农药残留量最高，六六六含量为１１０．７μｇ／ｋｇ，ＤＤＴ含量为１２４．４μｇ／ｋｇ。鱼体对ＤＤＴ的浓缩因子为３１１～１２４４，明显高于六六六的１７７～３６８。鱼体内ＢＨＣ４种异构体的残留顺序为δ＞α＞γ＞β，与其在水体中的比例α＞γ＞δ＞β略有不同。鱼体内ＤＤＴ主要以代谢物ｐ，ｐ＇－ＤＤＥ的形式存在，但个别样品中少量的ｐ，ｐ＇－ＤＤＤ及ｏ，ｐ＇－ＤＤＴ的检出，表明白洋淀水生生态系统最近受到ＤＤＴ的轻度污染。本项研果与１９７５～１９７７年检测结果进行比较；白洋淀鱼体内六六六残留量显著下降，下降率为１５．８％～７９．２％；ＤＤＴ残留量却明显增加（草食性鱼类除外），增加率约为４７．８％～９７．８％。     

A^2／O生物膜法在油脂厂废水处理中的应用

Ａ＾２／Ｏ生物膜法是一种高浓度易降解有机废水处理的新工艺。用于油脂厂废水的处理,经过半年多的试运行,处理效果良好,在进水ＣＯＤ、超过设计水质时,出水ＣＯＤｃｒ超过设计水质时,出水ＣＯＤｃｒ仍能达到排放标准,ＮＨ４＾＋－Ｎ的去除率可达９０％以上,基本无污染冰生。     

超声波和零价铁联用对氯代苯酚脱氯降解作用的研究

采用超声波和零价铁联用对氯代有机物3氯苯酚(CP)、2,4-二氯苯酚(DCP)和2,4,6-三氯苯酚(TCP)模拟废水进行了脱氯处理研究。以单因素法, 考察了铁粉初始投加量、溶液的初始浓度、超声波功率和溶液的pH值等因素对氯代酚降解的影响，并探讨了降解反应动力学。结果表明，超声波和零价铁联用对氯酚具有显著的降解效果，当水样初始浓度为25 mg/L，溶液pH呈弱酸性，超声波功率为200 W时，氯代酚的脱氯效率达到最大值。降解反应符合准一级反应，CP、DCP和TCP的反应速率常数分别0.0613 h^-1、0.374 h^-1和0.197 h^-1。     

1，4-二氯苯降解菌的分离及其降解特性研究

从某污水处理曝气池的活性污泥中分离出一株能够以1，4-二氯苯为唯一碳源和能源生长的菌株DEB-1，通过形态特征和生理生化试验初步鉴定为黄杆菌属（Flavobacterium sp.）。实验结果表明，该菌株最适降解温度为32℃、最适降解pH为7.8，24 h对100 mg/L的1，4-二氯苯的降解率达94.5%。菌株DEB-1的降解谱较广，对5种氯苯类物质具有较高的降解率。并进一步研究了DEB-1的1，4-二氯苯降解酶粗酶液的性质，其最适反应温度和pH分别为30℃和8.5。对处理含氯代芳香化合物的有机废水具有一定的意义。     

碱解─A/A/0─生物炭处理有机磷农药废水

通过对有机磷农药废水成份及其机理的分析，提出了碱解－Ａ／Ａ／０－生物炭处理工艺。在适当的污泥回流比、混合液回流比条件下，控制曝气池中Ｎ_（ＴＯＣ）≤０．１０ ｋｇ·ＢＯＤ_５／ｋｇＭＬＳＳ·ｄ、ＮＨ_３≤０．０８ ｋｇＮＨ_３－Ｎ／ｋｇＭＬＳＳ·ｄ，厌氧池中Ｎ_（Ｔｏｃ）≤（０．１０．２５）ｋｇ ＢＯＤ_5／ｋｇＭＬＳＳ·ｄ及兼氧池中Ｎ_（ＮＤ）_３≤０．０８ ｋｇＮＯ_３－Ｎ／ ｋｇＭＬＬＳＳ·ｄ时，可同时获得最高的ＴＮ、ＴＰ及ＴＯＣ的去除效果，并使出水达一级排入标准。     

厌氧菌降解四氯乙烯的研究

报道了洳气污泥富集培养物中厌氧菌降解四氯乙烯的特征。研究结果表明，沼气污泥在甲醇、甲酸盐、乙酸盐、乙醇和Ｈ２／ＣＯ２等不同碳源基质中的富集培养物，以利用甲醇为碳源的富信培养物降解四氯乙烯（Ｔｅｔｒａｃｈｌｏｒｏｅ－ｔｈｙｌｅｎｅ，简称ＰＣＥ，下同）活性最高，平均每升培养液每天降解ＰＣＥ１４００ｎｍｏｌ。经对该富集培养物的分离培养，已分离出４株厌氧细菌，其中一株为甲烷八叠球菌，两株为弧菌，一株为杆菌     

光和O3降解偶氮染料水溶液的研究

以３００Ｗ中压汞灯为光源，研究了直接耐晒大红４ＢＳ、活性艳红Ｘ－３Ｂ、活性黑ＫＮ－Ｂ三种偶氮染料（以下分别简称为４ＢＳ、Ｘ－３Ｂ、ＫＮ－Ｂ）水溶液在有Ｏ３和无Ｏ３条件下的光降解情况。同时还做了仅用Ｏ３处理染料溶液的对比试验，结果表明：光照和Ｏ３联用时，它们的降解速率常数分别比仅用光处理时快２６、２７和１５倍；比仅用Ｏ３处理时快１．２、１．１和１．１倍；它们的降解均遵循一级反应动力学。另外还测定了它     

ZSM—5分子筛负载Pt,Pd催化剂上甲烷选择还原一氧化氮反应性？…

研究了ＺＳＭ－５分子筛负载Ｐｔ、Ｐｄ催化剂对ＣＨ４还原ＮＯ催化反应的性能。实现表明，Ｐｔ催化剂在３００－５０℃温度下，显示出较高的反应活性和Ｎ２选择性，ｄ和Ｐｔ－Ｐｄ催化剂在４００－５００℃温度下具有较好的反应性能。其活性选择性大小次序为：Ｐｔ〉Ｐｔ－Ｐｄ〉Ｐｄ。用铂氨络离子制备的催化剂反应性能优于用氯铂酸制备的催化剂。     

固定化降解菌Q5去除喹啉的性能研究

为了研究固定化微生物在土壤生物修复中的应用,以实验室筛选出来的高效降解菌 Q5 为生物活性物质,利用生物大分子仿生合成出的纳米多孔氧化硅为载体,通过表面吸附同定化方法将其固定,制备出固定化微生物.考察固定化微牛物初始 pH 值、温度、摇床转速和菌种的接种量对喹啉去除的影响,得到适宜的去除条件,在相同条件下比较固定化微生物与游离菌种对底物的去除情况,研究单一固定化菌种对不同浓度的喹啉的去除情况,考察固定化微生物的稳定性.实验结果表明,菌株 Q5 经固定化后,对喹啉的去除能力大大增强,在 500 mg/L 浓度下,40 h 固定化 Q5 对底物去除率达96.6%,远高于未固定化 Q5 的去除率 56.1%;对于高底物浓度,固定化微生物的去除效果明显,初始底物浓度为1 500 mg/L,反应 70 h 后去除率为 91.6%,且这种固定化微生物的重复使用性能良好.     

Novel approaches for remediation of pesticide pollutants

The use of synthetic pesticides has become an indispensable tool in agriculture for the control of pests. Therefore, the search for remedies and techniques for decontamination and detoxification of a pesticide-contaminated environment has become an important part of the research. Currently, bioremediation seems to be one of the most environmentally safe and cost-effective methods. In nature, the existence of abundant material resources can be used to degrade the environmental pesticide pollutants. At present, a number of microorganisms, capable of degrading pesticides, have been isolated and characterised. For insects, insecticide resistance-associated esterases have been purified and characterised from several insect species, and a new family of cytochrome P450 apparently associated with insecticide resistance in the tobacco budworm, was discovered. Generally, two bioremediation approaches have been used one directly based on microorganisms, and the other involved in isolated enzymes. For the former, in addition to using natural microorganism strains, with genetic techniques certain desirable biodegradation pathways from different organisms are brought together in a single host. However, because of their own limits, especially problems associated with releasing genetically altered microorganisms into the environment, the strategy based on enzymes seems more feasible. In the long term, collaborations between microbiologists, biochemists, and engineers will become increasingly important to efficiently dispose of the pesticide pollutants.     

多相催化-臭氧氧化法处理模拟有机磷农药废水

实验通过臭氧氧化法来降解模拟废水中的有机磷农药，将其转化为无害物质，并试验研究了在废水中加入2种自制的催化剂对降解结果的影响。采用气相色谱法测定水中有机磷农药的量。结果表明，只用臭氧处理的情况下1周后有机磷的去除率为78．03％；在催化剂A存在下，去除率可达93．85％；在催化剂B存在下，去除率可达为88．35％。结果表明，臭氧氧化法对此类污水：具有较好的降解作用，尤其在有催化剂存在的情况下处理效果更好，在室温和中性介质中均属于一级反应。     

多相催化-臭氧氧化法处理模拟有机磷农药废水

实验通过臭氧氧化法来降解模拟废水中的有机磷农药,将其转化为无害物质,并试验研究了在废水中加入2种自制的催化剂对降解结果的影响。采用气相色谱法测定水中有机磷农药的量。结果表明,只用臭氧处理的情况下1周后有机磷的去除率为78.03%;在催化剂A存在下,去除率可达93.85%;在催化剂B存在下,去除率可达为88.35%。结果表明,臭氧氧化法对此类污水具有较好的降解作用,尤其在有催化剂存在的情况下处理效果更好,在室温和中性介质中均属于一级反应。     

农药对藻类的生态毒理学研究Ⅱ:毒性机理及其富集和降解

随着对农药污染认识的深入,农药对生态系统的初级生产者———藻类毒性以及毒性机制的研究不断增多。农药对藻类的毒性在于破坏藻类生物膜的结构和功能、影响藻类的光合作用、改变呼吸作用以及固氮作用,影响藻类的生理进程并改变其生化组分。开展农药对藻类毒性机理的研究,揭示农药结构—活性关系,对农药的研制和应用,评价农药的生态风险,减少农药对藻类的毒害是重要的。在自然环境中还发现藻能富集和降解农药。因此,对于这些藻来说,农药对藻类的毒害作用和藻类对农药的富集和降解作用可能同时存在。本文综述了农药对藻类的毒性机理以及藻类对农药的富集和降解作用。     

Photocatalytic degradation of pesticides in pure water and a commercial agricultural solution on TiO2 coated media

Heterogeneous photocatalysis of pesticides is an effective process for removing pesticides from pure water. With a view to treating real agricultural effluents, this paper deals with the degradation of the chlortoluron and cyproconazole pesticides in pure water and the treatment of commercial solutions by photocatalysis on TiO2 coated media. The process was effective in degrading and mineralizing the pesticides. The changes of the fate of heteroatoms showed that during irradiation of the chlortoluron and cyproconazole, NH4+ and NO3(-) ions were produced. A release of chloride ions was observed from the beginning of the irradiation and stoichiometry was achieved. The photodegradation of chlortoluton and cyproconazole in commercial solutions was studied. For the degradation of chlortoluton in a commercial solution, the mineralization was completely achieved whereas in the case of the commercial cyproconazole solution, the degradation kinetic was lower. These results highlight the fact that the chemical nature of the additives in the commercial pesticide solutions does significantly affect the degradation yield of the target compound by photocatalysis.     

Characterizing pesticide sorption and degradation in macro scale biopurification systems using column displacement experiments

The efficiency of biopurification systems to treat pesticide-contaminated water was previously studied in microcosms. To validate the obtained results, macrocosm systems were set-up. Four pesticides (linuron, isoproturon, bentazone, and metalaxyl) were continuously applied to ten different organic substrate mixes. Retention of the pesticides was similar and in some cases slightly lower in the macrocosms compared to the microcosms. Differences in retention between the different mixes were however minimal. Moreover, the classification of the retention strength of the pesticides was identical to that observed in microcosms: linuron > isoproturon > metalaxyl > bentazone. Monod kinetics were used to describe delayed degradation, which occurred for isoproturon, metalaxyl and bentazone. No breakthrough of linuron was observed, thus, this pesticide was appointed as the most retained and/or degraded pesticide, followed by isoproturon, metalaxyl and bentazone. Finally, most of the matrix mixes efficient in degrading or retaining pesticides were mixes containing dried cow manure.     

Pesticides removal in the process of drinking water production

The aim of this research work was to study the effectiveness of the treatments commonly used in drinking water plants in Spain to degrade 44 pesticides systematically detected in the Ebro River Basin. The pesticides studied are: alachlor, aldrin, ametryn, atrazine, chlorfenvinfos, chlorpyrifos, pp'-DDD, op'-DDE, op'-DDT, pp'-DDT, desethylatrazine, 3,4-dichloroaniline, 4,4'-dichlorobenzophenone, dicofol, dieldrin, dimethoate, diuron, alpha-endosulphan, endosulphan-sulphate, endrin, alpha-HCH, beta-HCH, gamma-HCH, delta-HCH, heptachlor, heptachlor epoxide A, heptachlor epoxide B, hexachlorobenzene, isodrin, 4-isopropylaniline, isoproturon, metholachlor, methoxychlor, molinate, parathion methyl, parathion ethyl, prometon, prometryn, propazine, simazine, terbuthylazine, terbutryn, tetradifon and trifluralin. The techniques applied are: preoxidation by chlorine or ozone, chemical precipitation with aluminium sulphate and activated carbon adsorption. Oxidation by chlorine removes 60% of the studied pesticides, although combining this technique with a coagulation-flocculation-decantation process is more effective. The disadvantage of this treatment is the formation of trihalomethanes. Oxidation by ozone removes 70% of the studied pesticides. Although combination with a subsequent coagulation-flocculation-decantation process does not improve the efficiency of the process, combination with an activated-carbon absorption process gives rise to 90% removal of the studied pesticides. This technique was found to be the most efficient among the techniques studied for degrading the majority of the studied pesticides.     

Biosurfactants and chemotaxis interplay in microbial consortium-based hydrocarbons degradation

Environmental Science and Pollution Research - Hydrocarbons are routinely detected at low concentrations, despite the degrading metabolic potential of ubiquitous microorganisms. The potential...     

微生物在含染料废水处理中的应用

印染和染料废水属于难处理工业废水.常规的物化方法费用大,产生污泥多,使用不普遍.生物法克服了这些缺点,正受到越来越多的关注,其中关于微生物的脱色能力有不少研究报告.利用微生物进行染料脱色和降解被认为是去除这些污染物的经济有效的方法.真菌,细菌和藻类均可以降解部分染料,特别是白腐真菌P.chrysosporium的脱色能力有了大量的研究结果.本文综合了最近几年真菌,细菌和藻类在染料废水脱色降解中作用的研究成果,并据此初步分析了染料降解机理和部分影响因素.