BS-12+CTMAB复配修饰黄棕壤对菲的吸附

为了探究两性阳离子复配修饰黄棕壤对菲的吸附效应及影响机制,基于两性修饰剂十二烷基二甲基甜菜碱(BS-12)和阳离子型表面修饰剂十六烷基三甲基溴化铵(CTMAB)复配修饰膨润土吸附苯酚的最佳修饰比例,分别以蒙脱石含量为43%和6%的2种黄棕壤制备了2个系列的BS-12+CTMAB复配修饰土样。通过批处理法研究了两性复配修饰黄棕壤对菲的吸附特征,分析了温度、pH值和离子强度对复配修饰黄棕壤吸附菲的影响,并探讨了复配修饰黄棕壤对菲的吸附机理。结果表明,随着总修饰比例的增大,2种复配修饰黄棕壤对菲的吸附能力均逐渐增强,Henry模型适合描述2种复配修饰黄棕壤对菲的吸附;2种修饰黄棕壤对菲吸附量均随温度、pH值的升高而降低,在低浓度范围内,随离子强度的增大而升高;2种复配修饰黄棕壤对菲的吸附均以分配吸附为主,总体上修饰黄棕壤对菲和苯酚的吸附具有相似的机制。土样阳离子交换量(CEC)和修饰比例是两性复配修饰黄棕壤吸附菲的决定因素。

Adsorption of phenanthrene on amphoteric-cationic modified yellow-brown soil

Two series of amphoteric-cationic modified yellow-brown soils, containing 43% and 6% montmorillonite, were used to explore the adsorption effect and mechanism of phenanthrene on co-modified yellow-brown soils. The experiment was based on the best modification ratio of adsorption of phenol on montmorillonite modified by an amphoteric modifier of dodecyl dimethyl betaine(BS-12) and a cationic modifier of hexadecyltrimethyl ammonium bromide(CTMAB). The adsorption properties of phenanthrene at different temperature, pH, and ionic strength were analyzed. The related adsorption mechanism was also explored. Results showed that adsorption of phenanthrene on co-modified yellow-brown soils increased as the total modification ratios increased. The Henry model successfully described the adsorption of phenanthrene. Adsorption of phenanthrene on modified yellow-brown soils decreased as temperature and pH increased, but increased as ionic strength increased at low concentration ranges. Distribution played a leading role in the adsorption of phenanthrene on co-modified yellow-brown soils. In general, the mechanism of phenanthrene adsorption on modified yellow-brown soils was similar to that of phenol. Overall, cation exchange capacity(CEC) and modification ratios were the most important factors influencing the adsorption of phenanthrene on co-modified yellow-brown soils.