摘要
以十二烷基二甲基甜菜碱(BS-12)单一修饰和十二烷基二甲基甜菜碱+十二烷基磺酸钠(SDS)复配修饰塿土黏化层土壤,采用批处理法研究了Cd2+在供试土样上的吸附-解吸行为,并对其吸附-解吸机制进行了探讨.结果表明,在20℃、40℃下起始浓度较小时,复配修饰土样吸附量大于BS-12单一修饰土样,温度对吸附的影响不大.Langmuir模型最适合描述供试土样对Cd2+的吸附等温线.复配修饰土样20℃、40℃解吸量差异不大,原土和BS-12单一修饰土样随温度升高解吸量增加.土样净吸附量20℃时BS-12单一修饰土样最高,而复配修饰土样和原土差异不大,40℃时复配修饰和单一修饰土样差异不大,但均高于原土.复配土样的吸附是静电作用和有机修饰剂有机相的疏水阻力综合作用的结果.
Using batch experiments,the adsorption and desorption of Cd2＋ on clay layer of Lou soil modified with dodecyl-dimethyl-betaine（BS-12） and dodecyl-dimethyl-betaine ＋ sodium dodecyl-sulphonate（BS-12＋SDS） mixture were investigated,and the mechanisms of adsorption and desorption were illustrated. The results showed that when the initial concentration was low the amount of Cd2＋ adsorbed on soils modified with BS-12＋SDS mixtures was higher than that of soils modified with BS-12. The temperature （20℃ and 40℃） has little influence on Cd2＋ adsorption.The Langmuir model best describes the Cd2＋ adsorption isotherm. The difference of the amount of desorption for soils modified with BS-12＋SDS was small between 20℃ and 40℃ while that of CK and soils modified with BS-12 increased with temperature.The net amount adsorbed was the highest for soil modified with BS-12 while the difference between CK and soil modified with BS-12＋SDS was not obvious at 20℃. At 40℃,the soil modified with BS-12＋SDS and BS-12 performed similarly and the net amount adsorbed was higher than that of CK. Cadmium adsorption by soils modified with BS-12＋SDS mixture was the result of a combination of electrostatic interactions and hydrophobic interactions with the organic modifiers.
出处
《环境科学学报》
CAS
CSCD
北大核心
2010年第10期2011-2016,共6页
Acta Scientiae Circumstantiae
基金
国家自然科学基金(No.40301021)~~
关键词
复配修饰
塿土
重金属Cd2+
吸附解吸
mixture modification
lou soil
heavy metal Cd2＋
adsorption and desorption
