Studies on the Fate of Nonionic Surfactant in the Soil Environment

非离子表面活性剂在土壤环境中的去向研究

• 批准号: 61580077
• 负责人: ABE Sachiko
• 金额: $ 1.41万
• 依托单位: Aoyama Gakuin Woman's Junior College
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1986
• 资助国家: 日本
• 起止时间: 1986 至 1987
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-61580077/
• 关键词: Adsorption isotherm on clay; Langmuir isotherm; Nonylphenol ethoxylate; Biodegradation of nonionic surfactant; 土壌環流法による生分解試験; 生分解; 非イオン界面活性剤の定量分折

In order to clarify the fate of such nonionic surfactants as alkyl ethoxylates,alkylphenol ethoxylates in the soil environment,the biodegradation test with soil perfusion method was carried out.In the biodegradation test, residual surfactants in the perfused fluid were analysed by total organic carban (TOC).It was observed that TOC decreased sharply immediately after the initiation of perfusion because of the adsorption onto soil,and biodegradation occured after lag time about 40 days.These results show that the adsorption of nonionic surfactants on the soil plays an inportant role in the disappearance phenomena in the soil environment.Then,the adsorption behavior of nonylphenol ethoxylate(NPE,n=10,15,18,20)on soil and soil clays in aqueous solution was examined.Adsorption isotherms of NPE on such clay minerals as Kaolin,Cericite and Ca-bentonite could be divided into two distinct stages below CMC (critical micelle concentration),at which adsorption amount attained nearly constant values. Isotherms showed a Langmuir-type in a lower concentration range,and then adsorption amount increased with an increase in concentration.The adsorption amounts decreased with increasing number of ethylene oxides,n, attached to nonylphenol.These results suggest that in a lower concentration range molecules of NPE arrange themselves on the clay surface in such a way that the hydrophilic constituents,ethylene oxides,are parrallel to the surface,while in a higher concentration range aggregates of two or three dimentional micelles are formed on the surface by the hydrophobic interaction.The adsorption behavior of NPE on soil clay was similer to that on clay minerals.On the other hand,adsorption isotherms on humic soil obeyed the Freundrich equation at concentration lower than CMC.This experiment is continued to clarify the adsorption properties of nonionic surfactants on humic substances.

【摘要】：为了明确烷基乙氧基化物、烷基酚乙氧基化物等非离子表面活性剂在土壤环境中的去向,进行了土壤灌注法生物降解试验。 结果表明，非离子表面活性剂在土壤上的吸附对土壤环境中的消失现象起到了重要作用。因此，壬基酚聚氧乙烯醚（NPE，n=10,15,18,20）在水溶液中对土壤和土壤粘土的吸附行为为： NPE在高岭土、绢云母、钙膨润土等粘土矿物上的吸附等温线在CMC（临界胶束浓度）以下可分为两个不同的阶段，此时吸附量几乎达到恒定值。等温线在较低浓度范围内呈Langmuir型，然后吸附量随着浓度的增加而增加。吸附量随着壬基酚上附着的环氧乙烷n的数量的增加而减少。这些结果表明，在较低浓度范围内，NPE分子在粘土表面上的排列方式使得亲水性成分环氧乙烷被分散。 与表面平行，而在较高浓度范围内，通过疏水相互作用在表面形成二维或三维胶束的聚集体。NPE在土壤粘土上的吸附行为与粘土矿物相似。另一方面，在浓度低于CMC时，腐殖土上的吸附等温线遵循Freundrich方程。本实验继续澄清吸附 非离子表面活性剂对腐殖质的作用。