离子强度及pH对不同类型土壤中胶体释放的影响  

Effects of Ionic Strength and pH on Colloid Release from Different Soils

作　　者：吕雪艳[1] 姚遥[1] 孙媛媛[1] 吴吉春[1] 郭红岩[2] 

机构地区：[1]南京大学地球科学与工程学院水科学系表生地球化学教育部重点实验室,南京210023 [2]南京大学环境学院污染控制与资源化研究国家重点实验室,南京210023

出　　处：《农业环境科学学报》2014年第7期1358-1365,共8页Journal of Agro-Environment Science

基　　金：国家自然科学基金(41030746,41372234);教育部博士点基金(20110091110039)

摘　　要：采用实验室土柱纵向淋溶法,研究了离子强度及pH变化对常熟乌栅土原状、扰动土柱以及东北黑土、江西红壤扰动土柱土壤胶体释放的影响。结果表明离子强度变化对我国不同类型土壤胶体释放影响不同:淋洗液电解质为NaCl时,对于常熟乌栅土以及东北黑土,离子强度减小促进胶体的释放,反之抑制胶体的释放;对于江西红壤,离子强度变化对土壤胶体释放则不产生影响。淋洗液电解质为CaCl2条件下,土壤胶体的释放量低于淋洗液为NaCl,且离子强度变化对三种土壤胶体的释放均不产生明显影响。相同条件下,常熟乌栅土及东北黑土胶体释放量远远大于江西红壤,pH变化则对上述类型土壤胶体释放的影响不明显。研究结果有助于进一步阐明水化学条件的变化对我国不同类型土壤胶体释放的影响规律。Colloid mobilization would facilitate pollutant transport in the environment. In laboratory, leaching experiments were performed to investigate the effects of ionic strength and pH on colloid release from undisturbed and disturbed Wushan soil columns from Changshu, dis- turbed black soil column from northeast China（Dongbei） and disturbed red soil column from Jiangxi. The effects of ionic strength on colloid release were significantly different in various soils. In the electrolyte NaC1 system, increasing ionic strength obviously reduced the release capacity of soil colloids for Changshu Wushan soil and Dongbei black soil, while ionic strength had little effects on collois release in Jiangxi red soil. In electrolyte CaCI2 system, however, ionic strength had no significant impacts on soil collois release. Moreover, colloid release was much smaller in CaC12 than in NaCI. Under the same conditions of solution chemistry, the amount of colloid released was far greater in Changshu Wushan soil and Dongbei black soil than in Jiangxi red soil. pH showed little influence on colloid release. The research findings would be useful for further understanding the impacts of water chemical conditions on colloid release of different soils.

关 键 词：土壤胶体 释放 离子强度 PH 扰动土柱 原状土柱 

分 类 号：S153[农业科学—土壤学]