涕灭威在土壤中的降解特性

用实验室模拟培养方法研究了土壤中涕灭威及其代谢物在不同条件下的降解规律，探讨了影响卫解的主要因素。结果表明，温度和土壤微生物活性是影响降解的重要因素，温度和蔼同，有机质含量增加均大大加快涕灭威残留物降解。     

单甲脒等农药的土壤薄层层析行为

用土壤薄层层析法研究单甲脒，单甲脒盐酸盐、灭幼脲和涕灭威等农药在不同土壤中的迁移行为，分别获得了这几种化合物的Ｒｆ值，它们分别为０．１４、０．１７，０．０８，０．７６，研究表明，单脒，单甲脒盐酸盐和灭幼脲不会污染地下水，而涕灭威则会对地下水污染构成严重的威胁。     

涕灭威等三种农药在土壤中的移动性

涕灭威、呋喃丹和拉索三种农药在土壤中的淋溶结果表明，经过３０ｃｍ土柱下渗到收集器中的涕灭威为８８．０％，呋喃丹为６９．１％，拉索为１．８４％；农药在四种土壤中的淋溶速度，砂土＞砂壤土＞粘壤土＞粘土；土壤性质对农药移动的影响比农药自身性质的影响要小。     

涕灭威淋溶动态的研究

本文介绍了涕灭威在不同类型土壤中的淋溶动态。以在砂土柱中垂直向下移动的速度最快,移动的量也最多。48h可穿透27cm砂土柱,渗透水中含量可达33.12％;而在粘土柱中,80％集中在柱顶部。涕灭威在水平方向移动量小于垂直向下的移动量。涕灭威在向下移动的同时产生降解作用,48h后,在砂土柱的4—8cm处出现降解产物——涕灭威亚矾,2d内呈线性增加,之后逐渐降解。涕灭威在不同类型土壤中降解遵循一级反应动力学规律,即ln(C/C_0)=-Kt。本试验条件下其半衰期为3d左右。     

单甲脒农药对土壤微生物种群和土壤酶活性的影响

研究了单甲脒（Ｎ＇－２，４－二甲苯基－Ｎ－甲基甲脒，简称ＤＭＡ）对土壤微生物种群和土壤酶活性的影响．田间试验表明，喷洒单甲脒盐酸盐（ＤＭＡＨ）于棉花植株对土壤微生物种群和土壤酶活性无明显影响．实验室试验表明，投加ＤＭＡＨ于土壤对土壤微生物种群有不同的抑制作用；当ＤＭＡＨ在土壤中的浓度为２０ｍｇ／ｇ时，好氧异养菌总量开始降低，硝化细菌和放线菌、真菌的土壤ＤＭＡＨ抑制浓度分别为０．５ｍｇ／ｇ和０．１ｍｇ／ｇ．ＤＭＡＨ对土壤酶活性的影响亦不相同，脱氢酶对土壤中ＤＭＡＨ含量为１０ｍｇ／ｇ时其活性即有明显的减弱，而过氧化氨酶对ＤＭＡ的耐受性相当高，其活性的抑制浓度达５００ｍｇ／ｇ．试验还证明了土壤中ＤＭＡ的微生物降解作用．当ＤＭＡ在土壤中的浓度为５０～５００ｇ／ｇ时，其消解速率可从８．７５ｍｍ·ｋｇ－１·ｄ－１提高到４８ｍｇ·ｋｇ－１·ｄ－１．     

九龙江口桐花树红树林对重金属的吸收与累积

探讨了福建九龙江口桐花树红树林对ＣＵ、Ｐｈ、Ｚｎ、Ｃｄ、Ｍｎ元素的吸收、累积及分布．结果表明：该林地土壤５种元素的储量关系为Ｍｎ＞Ｚｎ＞Ｐｈ＞ＣＵ≥Ｃｄ；植物体不同部位，各元素含量有着明显的差异，含量范围分别为Ｃｈ１．５１～５．７０、Ｐｂ１．３０～１０．７０、Ｚｎ１８．０～１００．１、Ｃｄ０．０４～０．２３和Ｍｎ１５．５～２３７．５（ｗ／１０－６）；植物对土壤元素的富集系数大小依次为Ｃｄ＞Ｚｎ＞Ｍｎ＞Ｃｕ＞Ｐｈ；群落现存生物量中，ＣＵ、Ｐｂ、Ｚｎ、Ｃｄ、Ｍｎ元素的现存累积量分别为１６．５６、６３．３０、４４５．０５、１．１４和１６５６．９３（ρＡ／ｍｇ·ｍ－２）．其中，地下部分别占７０．２％、８１．８％、７６．２％、７２．２％和８２．１％；林地残留物相应元素的储量分别为２１１．１１、１８４．００、１９４１．６９、６．１９和２２２４８．３１（ρＡ／μｇ·ｍ－２）．     

苏南某市春季蔬菜中农药残留调查

2003年3月对苏南某市蔬菜中有机氯、拟除虫菊酯及氨基甲酸酯类农药残留状况的调查结果表明:有机氯农药残留量较低,检出范围为ND～31.7μg·kg-1,蔬菜基地蔬菜中六六六类农药检出量高于传统菜地;蔬菜中滴滴涕类残留物主要组分为p,p′ DDE和p,p′ DDD。拟除虫菊酯类农药检出范围为ND～46.9μg·kg-1,检出量较高的是氯氰菊酯、氰戊菊酯、溴氰菊酯。氨基甲酸酯类农药检出范围为ND～111.9μg·kg-1,其中灭虫威和3-羟基克百威检出量和检出率最高,且蔬菜基地样品中的检出量低于传统菜地。蔬菜样品中克百威大部分已降解为3-羟基克百威,涕灭威、亚砜涕灭威与砜涕灭威检出量都很低,其中砜涕灭威平均检出量最低。供试区春季蔬菜中所检测的各种农药除克百威和涕灭威外,其余残留量均低于国家无公害蔬菜农药残留量标准。     

涕灭威及其有害代谢物水解的研究

本文报导了涕灭威及其有害代谢物亚砜和砜在水中的消失动态和水解动力学的研究,探讨影响其水解的主要因素,并预测它们在水环境中的化学行为与状态。结果表明,涕灭威及其亚砜和砜在呈中性的水介质中较为稳定,在碱性中容易分解,在15℃和pH7的水中,半衰期分别约为4.3、0.9和2.3年,水解速率的大小顺序为:涕灭威<涕灭威砜<涕灭威亚砜。水解速率随着介质中碱性和温度的提高而增加,并随着介质组成中盐离子的增加而减小。实验测得涕灭威及其亚砜和砜的温度效应系数分别为2.86、2.49和2.60,活化能分别为18.82±0.38、16.34±0.17和17.95±0.15kc/mol。     

重金属Cd污染土壤毒性的发光菌法评价

应用明亮发光杆菌 Ｔ３ 对重金属污染土壤的毒性评价方法进行探索;进行了土壤平衡、土壤浸提实验及土壤中人为添加 Ｃｄ 对明亮发光杆菌 Ｔ３ 的效应实验;确定了土壤最佳平衡时间、土壤浸提剂、土壤最佳浸提时间及草甸棕壤中 Ｃｄ 对明亮发光杆菌 Ｔ３ 的毒性响应水平．实验结果表明：在土壤浸出液的提取过程中,土壤最佳平衡时间为１ ｄ ,最佳浸提液为０ ．１ ｍｏｌ／ Ｌ 盐酸,最佳浸提时间为２ ｈ ;草甸棕壤中 Ｔ３ 菌的发光强度与投加的 Ｃｄ浓度呈显著负相关（ Ｐ＜ ０ ．０１） ,ρ（ Ｃｄ） 对 Ｔ３ 菌的 Ｅ Ｃ５０ 值为２６ ．２ ｍｇ／ｋｇ ．     

阿特拉津在土壤中的生物降解研究

运用恒温培养法研究了阿特拉津在河北省白洋淀地区农田土壤中的生物降解动力学，并从中分离鉴定了土壤中降解阿特拉津的优势菌种，研究结果表明，该土壤对阿特拉津具有一定的降解能力，非生物＋生物的降解、非生物降解和生物降解的速率分别为０．０２６２ｄ＾－１，０．００５５４８ｄ＾－１和０．００８１９４ｄ＾－１，半衰期分别为２６ｄ，１２５ｄ和８５ｄ，发现土壤中降解阿特拉津的优势菌种为蜡状芽孢杆菌（Ｂａｃｉｌｌｕｓ     

Microbial degradation of two carbamate insecticides and their main metabolites in soil

Degradation studies in soil of the insecticides aldicarb and carbofuran and their metabolites (aldicarb sulfoxide, aldicarb sulfone; 3-ketocarbofuran and 3-hydroxycarbofuran) were carried out using laboratory systems under controlled conditions (temperature, water content, light). The insecticides were added to soil samples and subsamples of the soil were analyzed at different times to assess both the bacterial abundance and the concentration of the different chemicals. The epifluorescence direct count method was applied to the subsamples to estimate microorganism numbers (N/g soil). Untreated samples of soil were used as controls for evaluating the effects of the application of the insecticides on microbial abundance. Subsamples treated with the pesticides were analyzed using HPLC and the DT 50 s of the different compounds studied were calculated. The DT 50 values show that neither the parent compounds nor the transformation products have a high persistence in soil and there is a general increase in the concentration of microorganisms as the pesticides diminish.     

MICROBIAL DEGRADATION OF TWO CARBAMATE INSECTICIDES AND THEIR MAIN METABOLITES IN SOIL

Degradation studies in soil of the insecticides aldicarb and carbofuran and their metabolites (aldicarb sulfoxide, aldicarb sulfone; 3-ketocarbofuran and 3-hydroxycarbofuran) were carried out using laboratory systems under controlled conditions (temperature, water content, light). The insecticides were added to soil samples and subsamples of the soil were analyzed at different times to assess both the bacterial abundance and the concentration of the different chemicals. The epifluorescence direct count method was applied to the subsamples to estimate microorganism numbers (N/g soil). Untreated samples of soil were used as controls for evaluating the effects of the application of the insecticides on microbial abundance. Subsamples treated with the pesticides were analyzed using HPLC and the DT 50 s of the different compounds studied were calculated.

The DT 50 values show that neither the parent compounds nor the transformation products have a high persistence in soil and there is a general increase in the concentration of microorganisms as the pesticides diminish.     

涕灭威及其有毒代谢产物对DNA潜在损伤研究

采用生物遗传监测系统,研究了涕灭威及其两个有毒代谢产物(涕灭威亚砜,涕灭威砜)对蚕豆及大蒜根尖细胞微核率的影响,以及对小牛胸腺DNA的加合作用．结果表明,两种植物根尖细胞微核试验测得的高浓度剂量诱导的微核率与对照组相比有显著性差异(p<0．05),说明涕灭威、涕灭威亚砜及涕灭威砜可能对蚕豆及大蒜根尖细胞有致突变性．并且配对资料差异的显著性检验表明,蚕豆根尖微核试验的敏感性明显高于大蒜根尖微核试验的敏感性．涕灭威及其两个有毒代谢产物与小牛胸腺DNA结合引起吸收光谱波峰的移位,而且存在着剂量关系,说明涕灭威、涕灭威亚砜及涕灭威砜可能对小牛胸腺DNA造成加合作用．     

Comparison of basal cytotoxicity of seven carbamates in CHO-K1 cells

The cytotoxic effects of seven carbamate pesticides, aldicarb, aldicarb sulfone, aldicarb sulfoxide, benfuracarb, pirimicarb, propoxur and thiobencarb, were compared in Chinese hamster ovary (CHO-K1) cell line of Circetulus griseus. The endpoints evaluated were lysosomal function by neutral red assay and mitochondrial integrity by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT assay). The carbamates tested were evaluated in both serum-free medium and in serum-containing medium. Results demonstrate that CHO-K1 lysosomes appeared more susceptible to propoxur, aldicarb and its metabolites than mitochondria. Aldicarb was the most toxic carbamate pesticide tested on CHO-K1 cells and aldicarb sulfoxide the least. The presence of foetal calf serum (FCS) diminished significantly the cytotoxicity of tested carbamates.     

固定化毛霉对工业和农田污染土壤中多环芳烃的降解和生物有效性评价

为了探讨微生物修复不同类型多环芳烃污染土壤的可行性,应用固定化毛霉对多环芳烃污染工业土壤及农田土壤进行微生物修复,用羟丙基-β-环糊精(HPCD)提取模拟评价多环芳烃的微生物可利用性,并分析多环芳烃微生物降解和生物可利用性的相关关系.焦化厂污染土壤中多环芳烃的30 d降解率为77.6%,沈抚灌区污染土壤中多环芳烃的30 d降解率为54.2%,焦化厂土壤和污灌区农田土壤中多环芳烃降解差异明显.焦化厂土壤和污灌区土壤中多环芳烃的30 d降解量和多环芳烃的环糊精可提取量具有相关性,各环数多环芳烃的环糊精可提取量变化解释了焦化厂和污灌区土壤中多环芳烃降解的差异机制,说明可用环糊精提取量预测微生物降解土壤多环芳烃的情况.     

哒嗪硫磷水解与土壤降解研究

采用室内模拟方法,研究了哒嗪硫磷在东北黑土、江西红壤和南京黄棕壤3种不同类型土壤中的降解特性及pH、温度和表面活性剂（SDS）浓度对水解的影响。结果表明,哒嗪硫磷水解速率随pH值与温度的升高而显著加快,在15℃、pH 5缓冲溶液中水解半衰期为216.56 d,在35℃、pH 9缓冲溶液中半衰期为3.47 d,平均温度效应系数为2.98。SDS能显著抑制哒嗪硫磷水解,且随着浓度的增大抑制作用增强。哒嗪硫磷在3种土壤中的降解速率依次为南京黄棕壤〉东北黑土〉江西红壤,半衰期分别为10.27、78.75、105.00 d,降解速率随土壤pH值的增大而增大。灭菌处理下,哒嗪硫磷在3种土壤中半衰期显著延长,其中在南京黄棕壤中半衰期延长近10倍,哒嗪硫磷在土壤中降解主要为微生物降解。     

阿特拉津在土壤中的降解途径及其对持留性的影响

通过田间和实验室试验，研究了除草剂阿特拉津在土壤中的降解代谢规律及其与土壤特性的关系。试验表明，阿特拉津施用后、在作物生长期内可降解９０％以上，土壤酸碱度对阿特拉津在土壤中的代谢有显著影响。在碱性土壤中阿特拉津主要经过微生物代谢而被降解；在酸性土壤中化学水解占优势地位。阿特拉津在强酸性土壤中的持留性（半衰期为６３ｄ）低于弱酸性土壤中的持留性（半衰期为８４ｄ），而在碱性土壤中由于较强的微生物降解作用，其持留性（半衰期为５１ｄ）最低。     

涕灭威农药的残留、毒性及其对生态环境的影响

本文描述了涕灭威农药在土壤、水体和生物中的残留、降解和归趋以及对生物的毒性。涕灭威是一种剧毒农药、在环境中虽能很快降解成亚砜,并能进一步降解成毒性更低的化合物,但它仍有可能造成对地下水的污染和对生物与人体的潜在危害。     

Photodegradation of fenamiphos on the surface of clays and soils

The photodegradation of the organophosphorus fenamiphos was studied in various clay matrices: montmorillonite, kaolin and the mineral components of two soils collected from two different sites: Settat (S) and Berrechid (B). The degradation was shown to be mainly due to the direct excitation of fenamiphos and was similar for all the matrices with a two-step kinetics : a fast and a slower one. The first step rate obtained at the surface of montmorillonite was slightly lower than that determined at the surface of kaolin. The fenamiphos degradation process clearly depended on the amount of humic substances and iron(III). The latter component accelerated the disappearance of fenamiphos, while humic substances clearly inhibited the process. The degradation rate increased in the presence of water and was mainly due to the involvement of the photohydrolysis process leading to the scission of the P–O bond. The formation of the main by-products, sulfoxide, sulfone and phenol derivatives, were elucidated by HPLC/MS.     

Chemical and photochemical transformation of fenamiphos—an organophosphorus nematicide

Fenamiphos, an organophosphorus nematicide and its hydrolysis product 4‐methylthio‐m‐cresol under dye‐sensitized photo‐oxidative conditions yielded the corresponding sulfoxide analogs. Under UV‐photolytic conditions, fenamiphos in methanol solution gave mainly the cleavage products. To obtain standards of the oxidative degradation products/metabolites in larger quantities, fenamiphos and fenamiphos phenol was chemically transformed to the corresponding sulfoxide and sulfone. Their structures were confirmed by ‘HNMR and mass spectra.