4种表面活性剂对水中土霉素光解的影响

为研究表面活性剂对抗生素光解的影响,采用模拟日光（氙灯,λ>290 nm）光解实验考察了土霉素在CTAB、SDS、SDBS和Tween80 4种表面活性剂溶液中的光解。在模拟日光下,土霉素在pH=7.5的纯水和4种表面活性剂溶液中的光解遵循一级反应动力学,4种表面活性剂均促进了土霉素的光解,其中CTAB的促进作用最明显。CTAB的作用受pH值和浓度影响,pH=5.5时抑制土霉素的光解;pH=7.5和pH=9.0时促进土霉素的光解,促进作用与CTAB浓度呈正相关。CTAB可以降低土霉素的pKa,增大其阴离子形态比例,这可能是CTAB促进土霉素光解的重要原因。在自然光照下,纯水和地表水中CTAB的存在分别使土霉素的光解加快了1.62和4.96倍。     

土壤中苯系物在表面活性剂溶液中的解吸研究

选用阴离子表面活性剂十二烷基苯磺酸钠和十二烷基硫酸钠(LAS和SDS)，阳离子表面活性剂十六烷基三甲基氯化铵(CTAB)和非离子表面活性剂(AEO-9和SA-20)对污染土壤进行解析试验。研究了用表面活性剂解吸土壤中的苯系物，从而为淋滤冲洗被石油污染的农田提供理论依据。试验表明，阴离子表面活性剂对苯系物的去除效率达95％，非离子表面活性剂对苯系物的去除率达85％，而阳离子表面活性剂无明显去除效果。     

过碳酰胺对土壤中三氯甲烷和四氯乙烯的降解作用

采用室内土培试验手段,研究了1种酸性土壤中施入过碳酰胺后对三氯甲烷(TCM)和四氯乙烯(PCE)的降解效果.试验结果表明:过碳酰胺对土壤中TCM和PCE都有一定的降解,且随着降解时间的延长,过碳酰胺对TCM和PCE的降解效果逐渐增加.8周后TCM和PCE的降解率分别为23.91%和87.83%,说明过碳酰胺对TCM的降解效果差于对PCE的降解.随着过碳酰胺质量浓度的增加,TCM和PCE的降解效率提高,但过碳酰胺质量浓度较大时,过碳酰胺的有效利用率会降低.100 mg·kg-1的Tween80的存在会抑制过碳酰胺对土壤中TCM和PCE的降解.     

Remediation of a Diesel Contaminated,Sandy-Loam Soil Using Low Concentrated Surfactant Solutions (5 pp)

Background, Aims and Scope   Surfactant enhanced ex-situ soil washing can be used to remediate diesel contaminated soils. Surfactants enhance the diesel removal from soils by two processes: mobilization and solubilization. Mobilization occurs at surfactant concentrations below the critical micelle concentration (CMC), while solubilization occurs at surfactant concentrations beyond the CMC of the surfactant. In this paper, the leaching of diesel from a self contaminated (10 000 mg diesel/kg) sandy-loam soil was studied using low concentrated non-ionic surfactant solutions of Tergitol NP-10 (10-6 to 10-3 mol/L). Methods   The surface tension of the supernatant solutions of soil suspensions in non-ionic surfactant (Tergitol NP-10) solutions (10-6 to 10-3 mol/L) was measured to determine the total surfactant concentration (surfactant sorbed onto the soil + surfactant in solution) at which micelles are present in the water phase of the soil suspension, or 'effective critical micelle concentration' (ECMC), and to calculate the sub-CMC sorption isotherm of Tergitol NP-10 onto the soil. The diesel removal was measured by soil leaching experiments with Tergitol solutions ranging from 10-6 to 10-3 mol/L. Results and Discussion   The sub-CMC sorption isotherm of Tergitol onto the soil could be described by the Freundlich equation. Even at very low surfactant concentrations (10-6 mol/L) the surfactant enhanced the diesel removal from the soil. Up to the surfactants' ECMC the diesel removal increased in a linear way with an increasing surfactant concentration in the wash water. A significant part (20%) of the diesel oil was removed in the presence of surfactant, but in absence of micelles. Beyond the surfactants' ECMC, the increase in diesel removal efficiency with increasing surfactant concentration was less pronounced. When the added surfactant concentration was increased to 10-3 mol/L, which corresponds to an equilibrium surfactant concentration in the supernatant solution (6.77.10-4 mol/L) above the CMC, the diesel oil removal was increased up to 50%. At this surfactant concentration emulsion formation was observed. Conclusion   Surfactant aided leaching of diesel from a self-contaminated, sandy-loam soil with surfactant solutions below their ECMC was able to remove in one step 20% of diesel from the soil by the mobilization mechanism. Succesive treatments or continuous leaching with surfactant solutions below their ECMC was not studied but is likely to reduce the diesel contamination further and at the same time avoid problems with emulsion formation.     

两种季铵盐阳离子表面活性剂对番茄灰霉病菌的毒理效应

为探讨季铵盐阳离子表面活性剂1227和C8-10对番茄灰霉病菌Botrytis cinerea的毒理效应,运用电子显微镜、氧电极、紫外-可见分光光度计等测定了1227、C8-10对番茄灰霉病菌分生孢子萌发、细胞壁结构、呼吸作用和三种细胞壁降解酶的影响,并在番茄叶片活体上接种经药剂处理的番茄灰霉病菌,观察药剂对其侵染活性的影响.结果显示,两种季铵盐阳离子表面活性剂5μg/mL处理可使分生孢子芽管变短变粗、基部明显膨大,显著抑制聚甲基半乳糖醛酸酶、多聚半乳糖醛酸酶和羧甲基纤维素酶的活性,并可显著影响番茄灰霉病菌在番茄活体叶片上的侵染活性;40μg/mL处理可导致菌体细胞壁表面出现多处破损、细胞内含物聚集等现象;100μg/mL处理显著抑制分生孢子的呼吸作用;250μg/mL和1 000μg/mL处理对病原菌菌丝呼吸产生破坏作用.说明两种季铵盐杀菌剂高剂量能够破坏菌体细胞壁结构,导致番茄灰霉病菌呼吸完全停止和死亡,而低剂量可以抑制细胞胞壁降解酶的活性,降低其致病力.     

影响烟嘧黄隆药效的因素

室内盆栽试验表明,烟嘧黄隆的药效受要草叶龄、助主施药与降不间隔时间的影响。从玉米田马唐防除的生态经济阈值和不同叶龄防产的综合结果看,以马唐３叶期后至５叶期前喷３６ｇ／ｈｍ＾２ 嘧黄隆效果最好。非离子型表面活性剂吐温２０、ＯＰ－１０、平平加１５和阴离子型表面活性剂洗衣粉都能显著提高烟嘧黄隆对马唐的防效,增效幅度在２８．６－５２．７％。渗透剂Ｔ和ＹＺ－９０１不能显著提高烟嘧黄隆的药效。施药后与降水的间     

Surfactant‐induced deposit structures in relation to the biological efficacy of glyphosate on easy‐ and difficult‐to‐wet weed species

BACKGROUND: Typical active ingredient (AI) residue patterns are formed during droplet drying on plant surfaces owing to the interaction of spray solution characteristics and leaf micromorphology. Currently, comparatively little is known about the influence of AI deposit patterns within a spray droplet residue area on the penetration and biological efficacy of glyphosate. A scanning electron microscope with energy dispersive X‐ray microanalysis has been used to characterise residue patterns and to quantify the area ultimately covered by glyphosate within the droplet spread area. RESULTS: The easy‐to‐wet weed species Stellaria media L. and Viola arvensis L., as well as the difficult‐to‐wet Chenopodium album L. and Setaria viridis L., differing in their surface micromorphology, have been used. Rapeseed oil ethoxylates (RSO 5 or RSO 60) were added to glyphosate solutions to provide different droplet spread areas. Addition of RSO 5 enhanced droplet spread area more than RSO 60, and both caused distinct glyphosate residue patterns. The biological efficacy of treatment solutions showed no significant correlation with the area ultimately covered by glyphosate. CONCLUSION: The results have implications on herbicide uptake models. This study shows that droplet spread area does not correspond to the area ultimately covered by glyphosate, and that the latter does not affect glyphosate phytotoxicity. Copyright © 2009 Society of Chemical Industry     

几种有机硅助剂对草甘膦在单子叶植物体内吸收、转移和分布的影响

采用14C-草甘膦同位素标记法研究了4种有机硅助剂Silwet L-77、Silwet 800 、Freeway 和Boost 在体积分数0.1%用量下对草甘膦在黑麦草( Lolium perenne L. cv. Grasslands Greenstone)体内吸收、转移和分布的影响。结果表明:与单用草甘膦相比，4 种助剂的加入显著地降低了草甘膦在黑麦草体内的吸收和转移量，助剂之间无显著性差异。 处理后24和72 h测定，草甘膦主要分布在幼嫩组织中，其次是根部，在老叶片中的转移量最 少。无论转移量高低，草甘膦在植物体内的分布总是表现为地上部的比例高于地下部。有机 硅助剂对草甘膦在各组织中的分布比例没有影响。     

农药微乳剂概念及其生产应用中存在问题辨析

对农药微乳剂的定义及其组成、性质和外观形态进行了论述,并对微乳剂目前存在的诸如药效、表面活性剂用量、添加极性溶剂以及微乳剂质量等一系列问题进行了详细的探讨,从药效、外观、配方组成及稳定性等方面全面比较了微乳剂和水乳剂的优缺点,认为微乳剂具有较好的市场发展前景。     

表面活性剂对水中乙草胺光解的影响

以高压汞灯为光源,研究了不同类型农用表面活性剂对水中乙草胺的光化学降解作用。结果表明,SDBS、农乳603、农乳404、0206B在低剂量下对乙草胺具有光敏化降解效应,高剂量下却有光猝灭降解效应;Tween80能促进乙草胺的光解;CTAB、农乳500、农乳601、农乳404和农乳603能延缓乙草胺的光解。然而,当具有光猝灭作用和光敏化作用的表面活性剂混合后,或两种均是光猝灭作用的表面活性剂混合后,其联合作用均表现为光猝灭效应。