土壤中4-溴苯胺降解动力学及其生态毒性追踪

秀谷隆是一种被广泛应用的取代脲类除草剂，其主要降解产物为４－溴苯胺（４－ＢＡ），研究４－溴苯胺在不同土壤中的降解动力学规律，并用土壤环境指示动物弹尾目跳虫Ｃｏｌｌｅｍｂｏｌａ（Ｆｏｌｓｏｍｉａ ｃａｎｄｉｄａ）跟踪指示该化合物在进一步降解过程中的毒性，结果表明：４－溴苯胺在土壤中的降解行为可用一级反应动力学方程来较好地描述，其生态毒性明显高于母体化合物秀谷隆，该化合物在粘土中的残留量低于砂土，但毒     

保护性耕作对玉米田土壤中除草剂残留的影响

保护性耕作能够显著提高土壤有机质,改善土壤质量,但是关于保护性耕作如何影响农药等污染物在土壤中残留的研究却较为匮乏,而土壤污染又与粮食安全息息相关.因此,选择7个实验地点,针对传统耕作与保护性耕作两种耕作方式下土壤中3种除草剂(乙草胺、阿特拉津和二甲四氯钠)残留特征进行了分析.结果表明,保护性耕作显著影响土壤的总有机碳含量、土壤含水率和土壤团聚体平均粒径等性质[使(2.1±0.1)%、(19.1±1.2)%和(82.2±3.0)μm分别增加至(2.9±0.3)%、(22.3±1.5)%和(97.2±4.2)μm].研究进一步发现,保护性耕作对不同除草剂在土壤中残留的影响存在差异性.例如,保护性耕作通过影响土壤总有机碳含量显著增加东丰试验田土壤中阿特拉津的含量[使(3.8±0.3)ng·g^-1增加至(17.7±3.0)ng·g^-1],通过影响土壤团聚体平均粒径显著降低德惠试验田土壤中乙草胺的含量[使(50.6±10.3)ng·g^-1降低至(9.2±2.5)ng·g^-1].然而,由于不同土壤性质对土壤中...     

高级氧化技术降解含氮除草剂的研究进展

目前,含氮除草剂已在全球范围内得到广泛使用,随着其不断的排入水体,会对水体生态环境和人体健康造成严重危害。介绍了几种主要的高级氧化技术降解含氮除草剂的机理,并综述了国内外利用高级氧化技术在降解含氮除草剂领域所取得的研究进展,为开发新的降解含氮除草剂技术提供参考。     

用Symmetry^TM色谱柱分析除草剂

百草枯(Paraquat)及杀草快(Diquat)是一类全世界广泛使用的除草剂,从各种谷物、水果、豆类到蔗糖及橡胶,都使用这类除草剂.它们都是以二氯或二溴盐形式存在的离子.检测水中的Paraquat及Diquat有标准的EPA方法(EPA方法549),该方法用配备光电二极管矩阵检测器的液相色谱(HPLC)来检测并进行色谱峰的鉴别.     

生物降解阿特拉津的研究进展

综述了近年来国外微生物降解转化阿特拉津的新研究进展，研究表明，选择适当的微生物，创造和保持必要的环境条件，能够降解与转化阿特拉津。     

Photodegradation of acetochlor in water and UV photoproducts identified by mass spectrometry

The sunlight photodegradation half-lives of 20 mg/L acetochlor were 151, 154 and 169 days in de-ionized water, river water and paddy water, respectively. When exposed to ultraviolet (UV) light, acetochlor in aqueous solution was rapidly degraded. The half-lives were7.1, 10.1, and 11.5 min in de-ionized water, river water and paddy water, respectively. Photopreduets of acetochlor were identified by gas chromatography/mass spectrometry(GC/MS) and found at least twelve photoproducts resulted from dechlorination with subsequent hydrtrxylation and cyclization processes. The chemical structures of ten photoproducts were presumed on the basis of mass spectrum interpretation and literature data. Photoproducts are identified as 2-ethyl-6-methylaniline; N, N-diethylaniline ; 4, 8-dimethyl-2-oxo- 1,2,3,4- tetrahydroquino-line; 2-oxo-N-(2-ethyl-6-methylphenyl)-N-(ethoxymethyl) acetamide; N-(ethoxymethyl)-2‘-ethyl-6‘-methylformanilide; 1-hydroxyaeetyl-2-ethoxyl-7-ethylind ole; 8-ethyl-l-ethoxymethyl-2-oxo-1, 2, 3, 4-tetrahydroquinoline; 4, 8-dimethyl-l-ethoxymethyl-2-oxo-1, 2, 3, 4-tetrahydroquinoline; 2-hydroxy-2‘-ethyl-6‘-methyl-N-(ethoxymethyl) acetanilide and a compound related to acetochlor. The other two photoproducts were detected by GC/MS although their chemical structure was unknown.     

Rapid treatment of atrazine-contaminated water by nickel/iron bimetallic system

The utility of nickel/iron in the remediation of atraz.ine-contaminated water was investigated. The experimental results showed that nickel/iron had effective catalytic activity in dechlorinating atraz.ine under acidic conditions. The dechlonnation reaction approximately followed the first-order kinetics under the experimental conditions( nickel/iron: 1.0 g/250 ml: Ca~r~ = 20.0 mg/L), the reaction rate increased with decreasing pH value of the reaction solution and increasing the proportion of Ni: Fe within 2.95 %. For condition with 2.95% nickel/iron, the reaction rate constants were 0.07518( R = 0.9927), 0.06212( R = 0.9846) and 0.00131 min^-1 ( R = 0.9.565) at pH = 2.0, 3.0 and 4.0, respectively. HPLC analysis was used to monitor the decline of atraz.ine concentration.     

磺酰脲类除草剂在硅胶G表面的光解

应用高效薄层析方法研究了苄嘧磺隆，甲磺隆，氯磺隆，氯嘧磺隆4种磺酰脲类除草剂在氙灯与太阳光下的光解动力学，以及8种有机色素对苄嘧磺隆光降解的影响。结果表明4种除草剂在硅胶G表面的降解呈一级动力学反应；有机色素对除草剂的降解均表现显著的猝灭效应。其中以姜黄素的猝灭作用最强，色素剂量与光解中的猝灭效应存在着显著的相关性。色素剂量加大，猝灭效应加强。     

Sorption of dissolved organic matter and its effects on the atrazine sorption on soils

IntroductionApplication of organic amendments, such as sewagesludge to agricultural soils, has been considered as aneffective way to improve the soil physico chemical propertiesand organic matter compositions. Dissolved organic matter(D…