呋喃丹与稻田土壤生物活性的相互影响

呋喃丹(Carbofuran,2,3-二氢-2,2-二甲基-7-苯骈呋喃甲基氨基甲酸酯)是一种高效、广谱杀虫、杀线虫剂。自1982年国务院决     

农药涕灭威对金鱼(Garassius anralus L.)的毒性试验

农药涕灭威(Temik或Aldicarb)属氨基甲酸酯类,其化学名称为0-(甲基氨基甲酰基)-2-甲基-2-甲硫基丙醛肟。它是一种高效、具内吸作用的广谱性杀虫、杀螨、杀线虫剂。涕灭威毒性较大,据国外文献报道,涕灭威对红鳟鱼(Rainbow trout)的半数致死浓     

土壤中涕灭威及其有毒代谢物的分析

涕灭威通用名Aldicarb,并有Temik等商品名称,其化学名称为0-(甲基氨基甲酰基)-2-甲基-2-(甲硫基)丙醛肟。它是一种具有内吸作用的高效杀虫、杀螨剂及土壤杀线虫剂,也是一种高度抗胆碱酯酶的剧毒药物,对大鼠的急性口服毒性LD_(50)为0.93mg/kg。 涕灭威在土壤中的半衰期小于7d,两天后即开始被代谢为剧毒的涕灭威亚砜及涕     

速灭杀丁在苹果上的残留动态

速灭杀丁(Sumicidin)又称Fenvalerate,国内名称为氰戊菊酯,是日本住友化学工业公司开发的一种不具三碳环的合成拟除虫菊酯,化学名称为(R,S)α-氰基-3-苯氧基苄基(R,S)-2-(4-氯苯基)-3-甲基丁酸酯,结构式为:     

一株嗜盐菌的分离鉴定及其降解甲基绿的实验

从舟山双峰盐场的盐田中分离筛选得到一株可降解碱性染料甲基绿细菌Salinivibrio kushneri DD-1。研究了该菌株最佳的生长盐浓度以及在不同NaCl浓度、甲基绿浓度、pH值以及O_2浓度对该菌株降解甲基绿的影响,并对其降解产物进行分析。结果表明:该菌株为一株嗜盐菌,最佳生长盐浓度为50 g/L。脱色实验中,Salinivibrio kushneri DD-1在ρ(NaCl)为50 g/L时脱色率最高,达到95%;对低浓度甲基绿(25 mg/L)的脱色效果较好;脱色率随pH升高而增大,该菌株在碱性条件下对甲基绿的脱色效果更佳; Salinivibrio kushneri DD-1在厌氧条件下无法降解甲基绿,随着O_2浓度升高,脱色效果逐渐增强。甲基绿降解产物主要为4-(N,N-二甲基氨基)-4'-(N',N'-二甲基氨基)二苯甲酮、4-(N-乙基-N,N-二甲基氨基)-4'-(N',N'-二甲基氨基)二苯甲酮、[4-(N-乙基-N,N-二甲基氨基)][4'-(N',N'-二甲基氨基)][4″(N″,N″-二甲基氨基)]三苯基甲醇。     

(艹屈)和5-甲基(艹屈)的ab initio计算

湾区非角环上的甲基取代能大大增加多环芳烃的致癌性,量子化学的从头计算(ab initio)指出,5-甲基(艹屈)C1-C2键的电子性质有利于在此健发生亲电反应,电子密度分布图说明5-甲基(艹屈)在C1—C2键周围的电子密度明显大于(艹屈)相应部分的电子密度,这也有利于亲电试剂的进攻,因而在代谢过程中,5-甲基(艹屈)容易在此位置发生亲电氧化形成环氧化物,进而形成终致癌剂,这就使5-甲基(艹屈)的致癌性比(艹屈)大大增强。     

溴氰菊酯(Decis)在柑桔上的残留及其消解动态研究

溴氰菊酯(Deltamethrin),又名Decis,NRDC 161,RU22950,FMC—45498,是一种高效拟除虫菊酯类农药.化学名称为:δ-氰基-(3-苯氧苄基)(1R、3R)-3-(2,2-二溴乙烯基)-2,2-二甲基环丙烷羧酸酯.其化学结构式为:     

磺胺二甲基嘧啶(SM2)高效降解菌J2的分离筛选及降解特性研究

从城市污水处理厂活性污泥中分离得到一株能以磺胺二甲基嘧啶(SM2)为唯一碳源的菌株,经生理生化鉴定和16S rRNA基因序列同源性分析,将此菌鉴定为蜡样芽孢杆菌(Bacillus cereus),命名为J2.不同条件下的降解特性研究结果表明,J2菌株具有极高的SM2耐受性(100 mg·L~(-1))、较广的温度(20～30℃)和pH(6～8)适用范围;在温度30℃、pH=8.0、初始OD_(600)=0.1、SM2起始浓度为50 mg·L~(-1)的条件下,J2菌株在36 h内对SM2的降解率可达100%,降解效率远超目前已报道的其他SM2降解菌株,展现出了良好的应用潜力.J2菌株降解SM2过程中产生了5种主要中间代谢产物,分析推断其降解SM2的途径分为两条:①磺胺二甲基嘧啶分子首先在酶促反应作用下脱除SO_2,生成嘧啶环和苯胺环自由基,这两种自由基再经过环间耦合生成N-(4,6-二甲基嘧啶-2基)-1,4-二苯胺,该分子中的C—N键在活性氧物种的作用下断开生成苯胺和2-氨基-4,6-二甲基嘧啶;②在漆酶的作用下N~4键断裂,产生N-(3,5-二甲基嘧啶)-苯磺酰胺,之后N-(3,5-二甲基嘧啶)-苯磺酰胺的N—S键断裂,进一步形成2-氨基-4,6-二甲基嘧啶和苯亚砜.     

2,6-二甲基-β-环糊精螯合强化葎草对Pb吸收的影响和机理

采用盆栽试验研究了EDTA、2,6-二甲基-β-环糊精对Pb污染土壤上葎草生长及Pb积累特性的影响.土壤中硝酸铅含量分别为0、600和1200 mg·kg~(-1),螯合剂的含量为硝酸铅含量的0.5倍和1.0倍.结果表明:EDTA和2,6-二甲基-β-环糊精对Pb离子均有显著増溶作用,且二者之间没有差异;EDTA对葎草的生长有轻微抑制作用,而2,6-二甲基-β-环糊精与对照没有差异,原因可能是形成了Pb-2,6-二甲基-β-环糊精络合物降低了Pb的毒性;EDTA和2,6-二甲基-β-环糊精都显著促进了葎草根、茎、叶部对Pb离子的吸收.EDTA处理的葎草在硝酸铅含量为600mg·kg~(-1),螯合剂浓度为0.9 mmol·L~(-1)时,转移率达到最大值1.34,而2,6-二甲基-β-环糊精的转移率最大值为0.36.虽然2,6-二甲基-β-环糊精的转移率较低,但由于葎草的生物量大,2,6-二甲基-β-环糊精可以作为葎草提取修复的一种新型螯合剂,葎草也可用作植物提取修复的参考植物.由于2,6-二甲基-β-环糊精具有独特的“内疏水,外亲水”结构,推测其促进葎草吸收转移Pb的机理可能是会以Pb-2,6-二甲基-β-环糊精络合物的溶解物形式在葎草的质外体通道中移动,进入木质部,最终通过蒸腾流的驱动转运至地上部.     

叔戊基甲醚的毒性及环境影响初探

叔戊基甲醚(Tertiary amyl-methyl ether,TAME),又名甲基叔戊基醚,2-甲氧基-2-甲基丁烷,甲基-1,1-二甲基丙基醚,化学式:CH3CH3C(CH3)2OCH3,相对分子质量102,20,和甲基叔丁基醚(MIBE)同为汽油添加剂,配成氧化燃料.关于MIBE,本刊2001年第1期曾有专文介绍,现将搜集到的有关TAME的毒性与环境影响方面的研究资料作一初步介绍.     

Temporal trends in organophosphorus pesticides use and concentrations in river water in Japan, and risk assessment

We reviewed organophosphorus pesticide use in Japan between 1982 and 2016 using data from the National Institute of Environmental Studies. Organophosphorus pesticide concentrations in river water throughout Japan were taken from the literature, and risk assessments were performed for some organophosphorus pesticides based on risk quotients and hazard quotients. Assessments were performed for 20 common pesticides, including insecticides, fungicides, and herbicides. The amounts used decreased in the order: insecticides?>?herbicides?>?fungicides. Organophosphorus insecticide and fungicide use have decreased over the last four decades, but organophosphorus herbicide use has increased. During this period, annual organophosphorus pesticide use was the highest for chlorpyrifos (105,263?tons/year) and the lowest for glyphosate-sodium (8?tons/year). The ecotoxicological risk assessment indicated that diazinon and fenitrothion posed strong risks to the Japanese aquatic environment, and chlorpyrifos and malathion have moderate risks. None of the pesticides that were assessed posed significant risks to humans. Continued use of organophosphorus pesticides in Japan may cause strong risks to aquatic environments. These risks should be reassessed periodically.     

我国东南地区饮用水源地多种农药的赋存特征及健康风险评估

为阐明我国东南地区典型饮用水源地农药类微污染物的污染特征及生态风险,检测评估了某省7个水库的苯并咪唑类、酰胺类、三唑类和有机磷类等19类共55种常用农药的检出频率、检出浓度以及每种农药对于绿藻、水蚤和鱼类这3种不同营养级生物的风险商.在分析的55种农药中,多菌灵和乙草胺的检出频率为100%,12种农药的检出频率在80%以上.多菌灵的检出浓度最高(77.7 ng·L^-1),其次是乙草胺(51.6 ng·L^-1).风险评估结果显示,大部分农药在目标区域都处于低风险状态.对于3种生物来说,乙草胺是绿藻的风险主导型农药,而多菌灵是鱼类和水蚤的风险主导型农药.     

溴氰菊酯混配农药--大地西对稻田-鱼塘水生生态系的安全评价研究

研究了在自然条件下施用溴氰菊酯混配农药——大地西对稻田-鱼塘水生生态系的影响。结果表明,在稻田中施用时,由于实际用量低,加上作物的沾附、土壤与水体中悬浮物的吸附及其存在形态的变化,其实际浓度与毒性已降低到对稻田养鱼及邻近鱼塘的水生生物不再有危害的程度。描述了溴氰菊酯在整个模拟生态系中的迁移与消减规律。研究了溴氰菊酯在不同加工剂型中的存在形态,以及在鱼体内的吸收与分布特点及其与毒性的关系。     

Endosulfan is toxic to the reproductive health of male freshwater fish, <Emphasis Type="Italic">Cyprinion watsoni</Emphasis>

Endosulfan is an organochlorine pesticide that is toxic to aquatic life. Endosulfan might hamper the reproductive health of indigenous fish in agricultural areas of Pakistan where this pesticide is sprayed widely. The aim of the current study is to investigate the toxic effects of endosulfan on selected reproductive parameters of male freshwater fish, Cyprinion watsoni. Two concentrations of endosulfan (0.5 and 1 ppb for 30 days exposure) were tested for their effects on body weight, body length, and testicular weight, length, and width. Testicular testosterone was assayed from tissue extracts using enzyme immunoassay (EIA). A significant increase in the mortality rate was observed in both treated groups during both spawning and quiescent seasons. The overall behavior of fish in the aquarium was normal in all control and treated groups. However, the treated fish exhibited anxiety after treatment with endosulfan. The body weight and length, and testicular weight, length and width were not significantly different to the control group. The testicular testosterone concentrations were significantly lower in both endosulfan-treated groups compared to the control. The decrease was dose-dependent, with a significant difference between the two treated groups. The histomorphological results demonstrated various testicular alterations in the treated groups. These alterations included an increase in interlobular areas and clumping patterns in spermatocytes/spermatids. Because spermatids eventually differentiate into sperms, their low count will directly result in lower sperm count. Taken together, these results suggest that endosulfan is a toxicant that at least disturbs testosterone levels (possibly others) and negatively impacts the reproductive health of male freshwater fish.     

辛硫磷降解菌XSP-1的分离、鉴定及其降解特性研究

从农药厂污泥中分离到1株能以辛硫磷为唯一碳源生长的细菌, 命名为XSP-1.根据其生理生化特征和16S rRNA基因序列相似性分析, 将该菌株初步鉴定为戴尔福特菌属(Delftia sp.). 该菌株能在7 h内完全降解100　mg/L的辛硫磷. XSP-1降解辛硫磷的最适pH为7.0, 最适温度为35℃, 降解速率与初始接种量呈正相关, 该菌株对甲基对硫磷、毒死蜱、杀螟硫磷也有较好的降解能力. 根据已报道有机磷农药降解基因mpd的保守序列设计引物, 未从该菌株中扩增到目标条带, 但是该菌株是否带有新的有机磷农药降解基因仍需要进一步研究.     

农药微生物降解性与农药疏水性参数间的相关性

在纯培养条件下，产碱菌属广说性降解菌ＹＦ１１对对硫磷，甲基对硫磷，杀螟松，氰戊菊酯，溴氰菊酯，甲氰菊酯，氯氰菊酯，三氟氯氰菊酯，氯菊酯的降解速率的差异主要是由各杀虫剂的疏水性参数的不同引起的，两之间存在较好的相关性：ｌｏｇＫ＝２．２１－０．２６ｌｏｇＫｏｗ，ｒ＝０．９７３９。     

杀螟硫磷对褶皱臂尾轮虫毒性效应研究

运用生态毒理学方法,研究了农药杀螟硫磷对褶皱臂尾轮虫急性和慢性毒性影响.结果表明:杀螟硫磷对轮虫24 h急性毒性半致死浓度为9.57 mg/L;慢性毒性中,除浓度为0.5 mg/L外,一般随着浓度升高,幼体期延长,生殖期缩短,寿命缩短,生殖量下降;种群增长随浓度增加而减缓,但低浓度没有影响;除0.5 mg/L实验组所产休眠卵数量比对照组略增外,其它各实验组随浓度增加其休眠卵数量和孵化率明显下降,这表明杀螟硫磷毒性监测休眠卵孵化率可作为重要的监测指标.     

Photoelectrocatalytic degradation of high COD dipterex pesticide by using TiO2/Ni photo electrode

A TiO₂ thin film electrode deposited on porous nickel net (TiO₂/Ni) was prepared by the sol-gel method, and the surface morphology, crystal structure features and the grain size were characterized by Field emission scan electron microscopy (FESEM) and X-ray diffraction (XRD). The photoelectrocatalytic system was set up using a UV high-pressure mercury lamp as the light source, TiO₂ coated on foamed nickel as photo anode, Pt sheet as counter electrode and the pesticide dipterex in synthetic wastewater. Various factors that influence the photoelectrocatalytic decomposition of dipterex pesticide have been studied, such as degradation time, the type of electrolyte, current density, original pH value and different degradation methods. The prepared catalysts were employed to photoelectrocatalytically degrade the pesticide dipterex under UV irradiation, comparing the results with photocatalytic degradation and electrochemical oxidation. The results indicated that under the optimal conditions of 0.02 mol/L NaCl as the supporting electrolyte, current density = 2.5 mA/cm², pH 6.0 and dipterex pesticide 40 mg/L, and reaction time 2 hr, dipterex chemical oxygen demand (COD) removal rate and organophosphorous conversion of up to 82.6% and 83.5% were achieved, respectively. The method of photoelectrocatalytic degradation is more efficient than photocatalysis and electrochemical oxidation. The possible roles of the electrolytes on the reactions and probable mechanisms were also discussed.     

Predicting the aquatic risk of realistic pesticide mixtures to species assemblages in Portuguese river basins

Although pesticide regulatory tools are mainly based on individual substances, aquatic ecosystems are usually exposed to multiple pesticides from their use on the variety of crops within the catchment of a river. This study estimated the impact of measured pesticide mixtures in surface waters from 2002 and 2008 within three important Portuguese river basins (‘Mondego’, ‘Sado’ and ‘Tejo’) on primary producers, arthropods and fish by toxic pressure calculation. Species sensitivity distributions (SSDs), in combination with mixture toxicity models, were applied. Considering the differences in the responses of the taxonomic groups as well as in the pesticide exposures that these organisms experience, variable acute multi-substance potentially affected fractions (msPAFs) were obtained. The median msPAF for primary producers and arthropods in surface waters of all river basins exceeded 5%, the cut-off value used in the prospective SSD approach for deriving individual environmental quality standards. A ranking procedure identified various photosystem II inhibiting herbicides, with oxadiazon having the relatively largest toxic effects on primary producers, while the organophosphorus insecticides, chlorfenvinphos and chlorpyrifos, and the organochloride endosulfan had the largest effects on arthropods and fish, respectively. These results ensure compliance with European legislation with regard to ecological risk assessment and management of pesticides in surface waters.     

Predicting the aquatic risk of realistic pesticide mixtures to species assemblages in Portuguese river basins

Although pesticide regulatory tools are mainly based on individual substances, aquatic ecosystems are usually exposed to multiple pesticides from their use on the variety of crops within the catchment of a river. This study estimated the impact of measured pesticide mixtures in surface waters from 2002 and 2008 within three important Portuguese river basins(‘Mondego', ‘Sado' and ‘Tejo') on primary producers, arthropods and fish by toxic pressure calculation. Species sensitivity distributions(SSDs), in combination with mixture toxicity models, were applied. Considering the differences in the responses of the taxonomic groups as well as in the pesticide exposures that these organisms experience, variable acute multi-substance potentially affected fractions(ms PAFs) were obtained. The median msP AF for primary producers and arthropods in surface waters of all river basins exceeded 5%, the cut-off value used in the prospective SSD approach for deriving individual environmental quality standards. A ranking procedure identified various photosystem II inhibiting herbicides, with oxadiazon having the relatively largest toxic effects on primary producers, while the organophosphorus insecticides, chlorfenvinphos and chlorpyrifos, and the organochloride endosulfan had the largest effects on arthropods and fish, respectively. These results ensure compliance with European legislation with regard to ecological risk assessment and management of pesticides in surface waters.