Estrogenic activities of two synthetic pyrethroids and their metabolites

Synthetic pyrethroids(SPs) are among the most common pesticides in current use,and so far,several SPs have been assessed for their potential estrogenicities by various methods.Previous studies have shown that the estrogenicities partly come from their metabolites.Although considerable information is available with respect to the metabolism and environmental degradation of SPs,little is known about the estrogenicities of the metabolites.In this study,permethrin(PM) and β-cypermethrin(CP),as well as their metabolites(3-phenoxybenzoic alcohol(PBCOH),3-phenoxybenzaldehyde(PBCHO) and 3-phenoxybenzoic acid(PBCOOH) were evaluated for their estrogenic activities in the MCF-7 human breast carcinoma cell line.In the MCF-7 cell proliferation assay,PM and CP exhibited significant estrogenic activities at 10-7 mol/L,comparable to 17β-estradiol(E2 ) of 10-9 mol/L,with the relative proliferative effect ratios of 55.4% and 56.3%,respectively.The real-time quantitative polymerase chain reaction(qRT-PCR) results confirmed the estrogenicities of PM and CP with significant alteration of pS2 and ERα mRNA levels observed at 10-6 mol/L.For the three major metabolites,PBCOH and PBCOOH exhibited estrogenic activities in all assays,while no significant estrogenic responses was observed for PBCHO compared to the vehicle control.In particular,PBCOH had even slightly stronger estrogenic activity than its parent compounds,indicating that metabolism may be one of the reasons for the estrogenicities of the SPs.Given the widespread use of SPs,the toxicological effects of parent compounds and their metabolites should be taken into consideration in the risk assessment of SPs.     

胞外聚合物与溶解性微生物产物的关系

通过活性污泥内源呼吸试验,发现胞外聚合物与溶解性微生物产物之间存在相互转化、吸附与被吸附的关系。内源呼吸初期(0~19h),bound EPS水解生成BAP,细胞自溶过程也释放部分SMP。19~43h,微生物利用SMP中易降解部分生成bound EPS和UAP,大分子量的SMP被bound EPS吸附,并存在一定程度的细胞水解。43~162h为SMP分泌、溶出阶段,内源呼吸加强,微生物脱氢酶活性几乎丧失,细胞水解、自溶。bound EPS表面出现SMP解吸-吸附的交替过程。162~210h期间bound EPS水解及细胞自溶为主要过程。并且产出的SMP可生物降解性较差,对微生物表现出毒性作用,抑制其脱氢酶活性,而在毒性环境下,微生物又产出更多的SMP。     

模糊数学方法在矿山环境综合评价中的应用

环境质量是一个涉及多因素多层级的模糊概念，用经典数学进行环境质量评价，评判环境质量的等级只能用一个绝对判据来划分，无法处理模糊因素边界不清晰、中间过渡不分明的问题。本文应用模糊数学方法，在单环境因素模糊综合评价的基础上，进行了总体环境质量模糊综合评价的探讨，结合某区域环境实例，对其总体环境质量进行了模糊综合评价，并将评价结果与用经典数学评价结果进行了比较，比较表明，环境质量模糊评价方法较经典数学评价方法更客观更准确。     

头孢拉定及光降产物对藻类生长影响的研究

文章研究头孢拉定和经紫外光降解不同时间的头孢拉定产物对铜绿微囊藻和斜生栅藻生长及叶绿素a含量的影响.结果表明,头孢拉定对两种藻均有抑制作用,且随着浓度的增加抑制作用加强,但两者的抑制效果不同;3 mg/L的头孢拉定能显著抑制铜绿微囊藻的生长以及叶绿素a含量的增加,但对斜生栅藻只有微弱的抑制作用,即便是10 mg/L的头...     

Characterization of disinfection byproduct formation potential in 13 source waters in China

The formation potential of four trihalomethanes (THMFP) and seven haloacetic acids (HAA7FP) in 13 source waters taken from four major water basin areas in China was evaluated using the simulated distribution system (SDS) chlorination method. The specific ultraviolet absorbance (SUVA254: the ratio of UV254 to dissolved organic carbon (DOC)), which ranged between 0.9 and 5.0 L/(mg m), showed that the organic compounds in di erent source waters exhibited di erent reactivities with chlorine. The HAA7FP of source waters ranged from 20 to 448 g/L and the THMFP ranged from 29 to 259 g/L. The HAA7FP concentrations were higher than the THMFP concentrations in all but one of the samples. Therefore, the risks of haloacetic acids (HAAs) should be of concern in some source waters. TCM (chloroform) and BDCM (bromodichloromethane) were the major THM constituents, while TCAA (trichloroacetic acid) and DCAA (dichloroacetic acid) were the major HAA species. Br-THM (brominated THM species) were much higher than Br- HAA (brominated HAA species), and the formation of Br-DBP (Br-THM and Br-HAA) should be of concern when the bromide concentration is over 100 g/L.     

Biodegradation of acetanilide herbicides acetochlor and butachlor in soil

The biodegradation of two acetanilide herbicides, acetochlor and butachlor in soil after other environmental organic matters addition were measured during 35 days lal)oratory incubations. The herbicides were applied to soil alone, soiI-SDBS (sodium dodecylbenzene sulfonate) mixtures and soil-HA (humic acid) mixtures. Herbicide biodegradation kinetics were compared in the different treatment. Biodegradation products of herbicides in soil alone samples were identified by GC/MS at the end of incubation. Addition of SDBS and HA to soil decreased acetochlor biodegradation, but increased butachlor biodegradation. The biodegradation half-life of acetochlor and butachlor in soil alone, soilSDBS mixtures and soil-HA mixtures were 4.6d, 6, ld and 5.4d and 5.3d, 4.9d and 5.3d respectively. The biodegradation products were hydroxyacetochlor and 2-melhvl-6-ethvlaniline for acetochlor, and hvdroxvbutachlor and 2,6-diethvlaniline for butachlor.     

水体中几种无机离子对硝酸根敏化甲芬那酸光降解影响研究

以中压汞灯为光源,研究环境浓度范围内硝酸根对甲芬那酸(MEF)光降解的影响机制.结果表明,甲芬那酸在不同浓度硝酸根溶液中的光解反应符合准一级动力学规律,其降解速率常数随硝酸根离子浓度增大而增大,当硝酸根离子浓度由0增至1 mmol·L-1时其速率常数由0.00627 min-1增至0.0232 min-1;以异丙醇为分子探针检测到羟基自由基存在于MEF光解过程中;光解过程中产生亚硝酸根,其浓度随着反应的进行而不断增大;碱性水环境对硝酸根敏化甲芬那酸的光解反应有利;碳酸盐、氯离子、三价铁对硝酸根敏化甲芬那酸光解产生抑制作用.采用UPLC/MS/MS对硝酸根敏化MEF光降解产物进行鉴定,并提出3条可能的光解路径.毒性研究表明,在硝酸根敏化甲芬那酸光降解过程中,生成了具有较甲芬那酸而言更高风险的中间产物.     

蒽醌-2-磺酸钠促进Klebsiella oxytocaGS-4-08脱色产氢机制与产能分析

采用0~0.5 mmol·L~(-1)蒽醌-2-磺酸钠(AQS)研究其对Klebsiella oxytoca GS-4-08厌氧降解甲基橙(MO)的影响,对比细菌产氢、降解碳源及生成产物等情况,得出最佳浓度为0.1 mmol·L~(-1).在该浓度下,Klebsiella oxytoca GS-4-08可在10 h内完全脱色MO,25 h内降解蔗糖达到92%,同时产生0.117 mol·mol~(-1)乙醇和0.116 mol·mol~(-1)乙酸,2.25 mol·mol~(-1)氢气;将实验结果与已有研究进行对比,分析了AQS促进Klebsiella oxytoca GS-4-08厌氧脱色MO与产氢的机制.通过将细菌降解过程中的物质转换为COD进行对比,对降解过程中电子转移进行了分析,得到0.1 mmol·L~(-1)AQS浓度时电子得率最高,其为87.98%;并将细菌降解过程中的能源转换进行对比,得到0.1 mmol·L~(-1)AQS浓度时能源产量最高,其为802 k J·mol~(-1);同时得出Klebsiella oxytoca GS-4-08发酵过程可产生两种以上生物燃料,表明了其在工业生产应用上的前景.     

沼泽红假单胞菌W12对活性黑5的厌氧脱色和降解作用

从处理印染废水的厌氧移动床生物膜反应器（moving bed biofilm reactor,MBBR）中分离到一株具有高效脱色活性的沼泽红假单胞菌W12。经实验确定W12对活性黑5（reactive black 5,RB5）脱色的适宜条件为：pH〈10;有光照;谷氨酸盐或乳酸盐作为碳源,当乳酸钠为碳源时浓度应〉500 mg/L;盐度不超过5%;RB5浓度不大于700 mg/L。紫外-可见光谱扫描结果表明,RB5的脱色和降解过程生成芳香胺类化合物,这些中间产物可进一步降解。此外发现,RB5诱导生成的胞外代谢物能提高W12的脱色活性。     

腐殖酸在氯离子体系中的电解氧化特性

通过小型实验对腐殖酸模拟废水进行了电解氧化处理,考察了阳极材料、氯离子初始浓度对腐殖酸电解氧化处理效果的影响,探讨了腐殖酸在电解处理过程中分子量分布的变化及电解产生的低分子量产物组成.研究结果表明,PbO2阳极的电解处理效果比 Ru-Ir/Ti阳极的处理效果好,当废水在氯离子体系中电解时.可缩小2种阳极对CODCr去除效果的差距;电解后溶液中溶解性有机物的分子量分布向小分子量方向转变;当溶液中有氯离子存在时,电解过程产生的 ClO-的间接氧化作用可有效地将大分子有机物降解为小分子有机物.腐殖酸在氯离子体系中电解生成的低分子量化合物主要有 CO2、氯仿、乙酸、苯酚、苯乙醇、2H-1,4 氯苯基双氮杂卓-2-1,1-(1,1-二甲基乙基)-萘酚、3-(3-羧基-4-羟基-5-硝基酚)-D-丙氨酸等.