3种氯酚化合物对大型溞的联合毒性

氯酚类化合物是我国水体中广泛存在的一类优先控制污染物,以大型溞(Daphnia magna)为试验生物,测定了2,4-二氯酚、2,4,6-三氯酚和五氯酚对大型溞的48 h致死的单一毒性和联合毒性.基于单一氯酚化合物的浓度-效应曲线,运用浓度加和(CA)与独立作用(IA)2个模型对2种等毒性浓度比的混合物(Mix-LC5...     

太湖流域3种氯酚类化合物水质基准的探讨

按照美国地面水水质基准制定的程序和规范,筛选了太湖流域广泛存在的水生生物物种并收集了相应的基础毒性数据,探讨了五氯酚(PCP)、2,4-二氯酚(2,4-DCP)和2,4,6-三氯酚(2,4,6-TCP)在我国太湖地区的水生态基准的定值.同时采用蒙特卡罗构建物种敏感度分布(SSD)曲线和生态毒理模型方法预测了3种氯酚类化合物对太湖水生生物的急性基准浓度(CMC)和慢性基准浓度(CCC).结果表明,基于EPA规范方法和急慢性毒性比率得到的PCP、2,4-DCP和2,4,6-TCP3种氯酚类化合物的CMC值分别为25、908和594μg·L-1,CCC值分别为12、176和162μg·L-1;基于SSD曲线得到的CMC值分别为25、818和648μg·L-1,CCC值分别为6、75和198μg·L-1;基于生态毒理模型得到的CCC值分别为4、15和67μg·L-1,显示出3种方法得到的氯酚类化合物的CMC或CCC在同一个数量级上,但在数值上由生态毒理模型得出的CCC要小于其它两种方法,并且除PCP的急慢性基准值与美国EPA推出的水生态基准值相近外,其它两种氯酚类化合物的急慢性基准值均低于美国EPA推出的急慢性基准值.研究结果希望能为我国水质基准的制定提供一些有用的线索.     

不同种类海产品中溴酚的含量及组织分布

溴酚类化合物(bromophenols,BrPs)可以在藻类等海洋生物中自然生成，是海洋风味物质，在海洋生物中广泛检出．同时，一些BrPs也是广为应用的溴代阻燃剂或溴代阻燃剂的合成前体化合物，不仅具有生物毒性且能与多溴二苯醚、四溴双酚A、甚至多溴代二苯并二噁英及多溴代二苯并呋喃等强毒性有机污染物发生相互转化．本研究利用HPLC-MS/MS分析了我国江苏省连云港市市场上销量较高的贝类、螺类和鱼类(各3种)中，19种BrPs的含量及组织分布．结果可见，样品中共检出4种BrPs，分别是4-一溴酚(4-monobromophenol,4-mBrP)、2,4-二溴酚(2,4-dibromophenol,2,4-diBrP)、2,6-二溴酚(2,6-dibromophenol,2,6-diBrP)和2,4,6-三溴酚(2,4,6-tribromophenol,2,4,6-triBrP)，其中2,4,6-triBrP含量水平和检出率最高，在9种海产品不同组织中的浓度范围为0.512—56.0 ng·g^-1 dw (干重)(平均值(14.1±13.8) ng·g^-1     

共价三嗪有机框架材料对水中氯酚类污染物的光催化脱氯降解

利用共价三嗪有机框架材料(CTF-1)对4-氯酚(4-CP)、2,4-二氯酚(2,4-DCP)、2,4,6-三氯酚(2,4,6-TCP)和五氯酚(PCP)等4种不同氯原子取代数目的氯酚类污染物进行光催化降解研究,探讨了底物结构对氯酚脱氯降解效率的影响及机制.结果表明,氯酚脱氯降解过程明显受苯环氯原子取代数目的影响,氯原子数目越多,脱氯降解效率越高,氯原子数目与表观速率常数呈显著正相关,氯酚降解及脱氯速率均为：PCP>2,4,6-TCP>2,4-DCP>4-CP.对CTF-1光催化降解氯酚机制研究表明,活性物种在反应中不起作用,体系反应机制为针对氯酚上取代氯位点进行水解脱氯过程.本研究结果为深入揭示氯酚脱氯降解机制提供了理论依据,也为光催化技术处理卤代酚类废水提供了技术参考.     

应用不同毒理学终点评估酚类物质的生态危害和风险

以我国典型湖泊、河流中检出率较高的五氯酚、2,4-二氯酚、2,4,6-三氯酚、4-硝基酚、2,4-二硝基酚以及列入美国优先监测污染物的2-甲基-4,6-二硝基酚为研究对象,分别应用急性毒性终点、慢性致死效应终点和/或慢性非致死效应终点开展基于物种敏感度分布法和评估因子法的生态危害评估;在此基础上结合我国典型湖泊、河流中酚类物质实测浓度计算五氯酚、2,4-二氯酚、2,4,6-三氯酚和4-硝基酚的长期风险商。结果表明,应用繁殖发育等慢性非致死效应终点得到的五氯酚、2,4-二硝基酚的5%物种危害浓度(HC5)明显低于其应用慢性致死效应终点得到的HC5。太湖、三江(松花江、长江、珠江)四河(辽河、海河、黄河、淮河)以及钱塘江水系中五氯酚、2,4-二氯酚、2,4,6-三氯酚和4-硝基酚的水生态风险是可接受的。但五氯酚对我国三江四河的长期危害风险亟需引起关注,特别是对水生生物繁殖、发育和生长等的非致死性危害。     

典型酚类化合物对土壤跳虫的慢性毒性

以跳虫Folsomia candida为受试物种,基于其28 d繁殖试验评价了12种典型酚类化合物的慢性毒性效应。结果表明,在所设浓度范围内,除间苯二酚外的其他酚类对跳虫繁殖均存在不同程度的抑制效应。氯酚类对跳虫慢性毒性最大,2,4-二氯酚、2-氯酚、2,4,6-三氯酚对跳虫繁殖毒性的EC50分别为5.94、10.2、19.7 mg·kg-1;其次为烷基酚类,2,4-二甲基酚、3-甲基酚、壬基酚对跳虫繁殖毒性的EC50分别为21.7、35.1、50.5 mg·kg-1。苯酚的毒性较上述烷基酚低,EC50值为71.7 mg·kg-1。其他取代酚—包括2-萘酚、4-硝基酚、邻苯二酚对跳虫繁殖的EC50分别为95.4、133、306 mg·kg-1。双酚A仅在最高浓度(500 mg·kg-1)处理下对跳虫繁殖有显著影响。     

3种氯酚类化合物对河蚬的毒性和氧化应激(Toxicity and Oxidative Stress of Three Chlorophenols to Freshwater Clam Corbicula fluminea)

以河蚬(Corbicula fluminea)为试验生物,研究了2,4-DCP、2,4,6-TCP和PCP的急性毒性和21d慢性毒性,并在同一条件下测试了这3种氯酚类化合物对河蚬软体组织抗氧化系统的影响.结果显示:2,4-DCP、2,4,6-TCP和PCP对河蚬96hLC50值分别为19.25(17.58～21.20)、41.98(35.48～58.24)和0.23(0.18～0.27)mg·L-1;以致死作为观察指标,其21d无观察效应浓度(NOEC)和最低观察效应浓度(LOEC)值分别为1.00、2.00、0.06mg·L-1和2.00、4.00、0.08mg·L-1.3种氯酚类化合物对河蚬软体组织抗氧化系统几种酶的活性均表现出了不同程度的影响,其中对SOD和GSH-Px的影响最为明显.2,4,6-TCP和PCP对SOD均表现为抑制作用,对GSH-Px表现为先诱导后抑制;2,4-DCP对SOD和GSH-Px表现为明显的诱导作用;3种氯酚类化合物对CAT均表现为明显的诱导作用;对GST活性也有一定影响,但与对照组相比变化范围不大(62.95%～137.04%).3种氯酚类化合物暴露后生物体抗氧化酶有不同的响应,表明不同氯酚类化合物所导致的氧化损伤及其应激机制不同.     

Fe0体系降解2,4-二氯酚的影响因素及其反应机理

采用铁屑、炉渣及河砂混合介质降解2,4-二氯酚(2,4 - DCP)模拟废水,研究铁屑粒径、铁屑投加量、铁屑与炉渣配比、pH值等因素对2,4- DCP脱氯效果的影响,探讨Feo体系降解2,4- DCP的反应机理.结果表明,铁屑粒径、铁屑投加量、铁屑与炉渣配比、pH对2,4- DCP脱氯效果均有显著影响,在铁屑粒径为2～5mm、不改变废水pH、铁屑与炉渣质量比为31:9条件下,Feo体系对2,4- DCP去除率高达97％.2,4- DCP经脱氯后主要产物为2-氯酚、4-氯酚和苯酚,反应后废水的可生化性明显提高,利于后续的生物处理.     

·OH自由基介导2,4-二氯酚光降解机理及产物毒性变化特征的理论研究

由于2,4-二氯酚(2,4-dichlorophenol,简称2,4-DCP)具有"三致"作用及潜在的生态风险,其光化学降解机理及产物的生态毒理效应目前成为人们关注的焦点。本研究采用理论化学计算手段,系统阐明了2,4-DCP在水环境中·OH介导的间接光化学转化机理、动力学和转化产物的生态毒性变化特征。结果表明2,4-DCP很容易被·OH氧化降解,其降解主要通过·OH-加成和H-迁移路径进行。在低温条件下·OH-加成路径将占主导,主要形成4,6-二氯苯-1,3-二酚;而当温度超过313 K时,·OH提取酚羟基上的氢原子为主要降解途径,主要形成2-氯苯-对苯醌。尤其在活性物种浓度较低的高温环境中,H-迁移路径有可能生成二噁英。计算毒理学结果表明:H-迁移产物的水生毒性超过·OH-加成产物,甚至超出母体2,4-DCP一个毒性等级。因此,我们建议在以后的环境监测以及风险评估过程中,关注2,4-DCP及其转化产物特别是H-迁移路径的转化产物的生态毒理学问题。     

驯化的活性污泥强化降解土壤中氯酚的研究

以接种驯化的活性污泥为生物强化手段,在小型生物泥浆反应器中,研究了受氯酚污染土壤的修复情况.考查了添加驯化活性污泥对土壤中氯酚降解的强化效果,并对土壤中邻氯苯酚(2-CP)、对氯苯酚(4-CP)和2,4-二氯酚(2,4-DCP)在单一污染体系中的降解情况进行了研究.结果表明,在生物泥浆反应器中添加用邻氯苯酚(2-CP)驯化的活性污泥可以明显地促进土壤泥浆中2-CP的降解,是一种有效的强化手段.该方法对土壤中的4-CP和2,4-DCP也有较好的降解效果,对三种氯酚的降解速率由大到小的顺序为2-CP,4-CP,2,4-DCP.反应结束时,泥浆体系中剩余的氯酚基本都残留在土壤中,固液分离后的水相可以直接排放或者在土壤修复过程中循环利用.     

环境空气中短链氯化石蜡研究进展

短链氯化石蜡(SCCPs)是碳链长度为10至13个碳原子的正构烷烃氯代衍生物。SCCPs具有持久性、生物累积性、长距离迁移能力、以及毒性作用。SCCPs已被《关于持久性有机污染物的斯德哥尔摩公约》增列为持久性有机污染物审查范围内,引起了全球关注。SCCPs在环境各介质及生物体内均有检出,近年来,在室内空气和灰尘中也检出了大量SCCPs,其已成为人体暴露的一个重要来源。本文就大气环境及室内空气与灰尘中氯化石蜡(CPs)的采样与分析方法、污染水平与来源,及人体暴露概况进行了综合阐释,以期为我国大气和室内环境中CPs的研究工作提供参考。     

Study of Fishes in the Chung-Kung Stream: Species Distribution and Organochlorine Pesticide Residues

Abstract

In this study, we investigated the potential for reductive dechlorination of 2,4-dichlorophenol (2,4-DCP), 2,4,6-trichlorophenol (2,4,6-TCP), and pentachlorophenol (PCP) by municipal sewage sludge adapted to 2,4-DCP at different concentrations. 2,4-DCP was completely dechlorinated within 4 weeks. After 18 weeks' incubation, 2,4,6-TCP was also completely dechlorinated and the residue of PCP was 0, 44.46, 51.96% at 0.5, 5, and 50 μg ml¹ respectively. the 2,4-DCP adapted communities initially removed the ortho-chlorine from PCP of 5.0, 50 μg ml¹, following an ortho < para < meta order of chlorine removal. Intermediate products were 3,4,5-TCP, 3,5-DCP, 3-CP (3-chlorophenol), phenol, benzoate and hexanoic acids, whereas PCP (0.5 μg ml¹) indicated a preference for meta-chlorine removal. the intermediate product of 2,4,6-TCP at three concentrations were 2,4-DCP, phenol, benzoate and hexanoic acid. These products were identified by GC-MASS spectrometry. the effects of supplements, including sodium citrate (0.08 mM), sodium pyruvate (0.18 mM), sodium sulphate (0.14 mM) had a direct stimulatory effect on the dechlorination of 2,4,6-TCP and PCP after treatment for 4 weeks, but dechlorination was inhibited after 8 weeks.     

Biotransformations of Chlorophenols in River Sediments

The accumulation of chlorophenols, including 2,4-dichlorophenol (2,4-DCP), 2,4,6-trichlorophenol (2,4,6-TCP) and pentachlorophenol (PCP), from river sediments from southern Taiwan were studied. Through simple or more exhaustive extractions, the results showed that 99% of the samples containing 2,4,6-TCP and PCP could be removed by simple extraction. the concentrations were found to range from non-detectable to 16.60 ngg¹ for 2,4,6-TCP and to 25.02 ngg¹ for PCP. Partition coefficients (K_p) were 0.71, 0.74 mlg¹ for 2,4,6-TCP, 1.35 and 1.41 mlg¹ for PCP. Biodegradation by DCP-adapted or unadapted anaerobes in sediment was carried out. During 21 days' incubation, the complete degradation time for 2,4,6-TCP in DCP-adapted anaerobic, unadapted anaerobic, and unadapted aerobic conditions were found to be 9, 10, 12 days for N3 sediment, and 8, 10, 11 days for N6 sediment, respectively; for PCP it was 19 days, without degradation, 14 days for N3 sediment, and 13, 17, 10 days for N6 sediment, respectively. the biodegradable products were identified as 2,3,4,5-tetrachlorophenol (2,3,4,5-TeCP), 3,4,5-TCP, 3,5-DCP, 3-MCP, phenol, methylphenol, and benzoate for PCP, and 2,4-DCP, 4-MCP, phenol, methylphenol, and benzoate for 2,4,6-TCP.     

6种硝基苯化合物对海洋生物的急性毒性研究（Study on the Acute Toxicity of Six Nitrobenzenes to Marine Organisms）

为研究硝基苯化合物对海洋生物的毒性,选择了6种代表性硝基苯化合物对小球藻(Chlorella vulgaris)、黑鲷(Sparus macrocep)幼鱼和螠蛏(Siliqua minima)幼体进行了急性毒性实验,获得了这些化合物对这些生物体的急性毒性数据及环境安全浓度.实验结果表明:2,4-二硝基甲苯、2,4-二硝基氯苯、2,4-二氯硝基苯和邻二硝基苯对小球藻48h半数抑制浓度(EC50)分别为0.50、0.21、2.44和0.10mg·L-1,毒性顺序为邻二硝基苯(剧毒)>2,4-二硝基氯苯(剧毒)>2,4-二硝基甲苯(剧毒)>2,4-二氯硝基苯(高毒).2,4-二硝基氯苯、邻二硝基苯、2,4-二硝基甲苯、2,4-二氯硝基苯、对硝基苯胺和硝基苯对黑鲷幼鱼的96h半数致死浓度(LC50)分别为0.14、0.15、4.45、1.37、11.52和5.71mg·L-1,其安全浓度分别为:0.001、0.002、0.04、0.01、0.12、0.06mg·L-1,毒性顺序为2,4-二硝基氯苯(剧毒)>邻二硝基苯(剧毒)>2,4-二氯硝基苯(高毒)>2,4-二硝基甲苯(高毒)>硝基苯(高毒)>对硝基苯胺(中毒).2,4-二硝基氯苯、2,4-二硝基甲苯、2,4-二氯硝基苯、邻二硝基苯、硝基苯和对硝基苯胺对幼蛏的96h LC50分别为0.39、13.20、3.45、15.56、86.90和148.87mg·L-1,安全浓度分别为:0.004、0.13、0.03、0.16、0.87、1.49mg·L-1,毒性顺序为2,4-二硝基氯苯(剧毒)>2,4-二氯硝基苯(高毒)>2,4-二硝基甲苯(中毒)>邻二硝基苯(中毒)>硝基苯(中毒)>对硝基苯胺(低毒).     

Biotransformations of Chlorophenols in River Sediments

Abstract

The accumulation of chlorophenols, including 2,4-dichlorophenol (2,4-DCP), 2,4,6-trichlorophenol (2,4,6-TCP) and pentachlorophenol (PCP), from river sediments from southern Taiwan were studied. Through simple or more exhaustive extractions, the results showed that 99% of the samples containing 2,4,6-TCP and PCP could be removed by simple extraction. the concentrations were found to range from non-detectable to 16.60 ngg¹ for 2,4,6-TCP and to 25.02 ngg¹ for PCP. Partition coefficients (K_p) were 0.71, 0.74 mlg¹ for 2,4,6-TCP, 1.35 and 1.41 mlg¹ for PCP. Biodegradation by DCP-adapted or unadapted anaerobes in sediment was carried out. During 21 days' incubation, the complete degradation time for 2,4,6-TCP in DCP-adapted anaerobic, unadapted anaerobic, and unadapted aerobic conditions were found to be 9, 10, 12 days for N3 sediment, and 8, 10, 11 days for N6 sediment, respectively; for PCP it was 19 days, without degradation, 14 days for N3 sediment, and 13, 17, 10 days for N6 sediment, respectively. the biodegradable products were identified as 2,3,4,5-tetrachlorophenol (2,3,4,5-TeCP), 3,4,5-TCP, 3,5-DCP, 3-MCP, phenol, methylphenol, and benzoate for PCP, and 2,4-DCP, 4-MCP, phenol, methylphenol, and benzoate for 2,4,6-TCP.     

Additive und synergistische Kombinationswirkungen von Xenobiotika in subtoxischen Konzentrationen auf menschliche Fibroblasten

The toxic combination effects of xenobiotics of different substance classes were investigated in human fibroblasts. Subtoxic concentrations of 4-chloroaniline enhanced the toxicity of 2,4-dichlorophenoxyacetic acid (2,4-D, dimethylammonium salt) in an additive manner. A mixture of 4-chloroaniline, dicofol and 4-chlorophenol increased the toxicity of 2,4-D synergistically. The concentrations of the components used in the mixture were one third of their ?no observed effect concentrations” (NOEC). The combination of 4-chloroaniline, dicofol and 4-chlorophenol (without 2,4-D) at subtoxic concentrations also showed synergistic effects. The great differences in the lipophilicity of the combined substances might be the cause of the synergistic action.