洗涤剂LAS在土壤上吸附行为及机理研究

Adsorption behaviour and its mechanism of linear alkylbenzene sulphonate (LAS) on soils.

使用连续反应器研究了２５℃温度下ＬＡＳ在土壤上吸附的行为和机理．ＬＡＳ在自然土壤上的吸附等温线可分成线性和指数增长两个阶段．在低ＬＡＳ浓度（＜９０μｇｍｌ－１）下，吸附等温线为直线，Ｋｄ＝１．２－２．０．在高ＬＡＳ浓度（＞９０μｇｍｌ－１）时，ＬＡＳ产生协同吸附，吸附量呈指数增加．土壤吸附ＬＡＳ的机理主要是专性点位表面相互作用及氢键，吸附容量主要取决于土壤物理性粘粒的含量．

The adsorption behaviour and its mechanism of linear alkylbenzene sulphonate (LAS) onsoils are studied at 25℃ using a continuous adsorption apparatus. The adsorptionisotherms of LAS on natural soils could be divided into two stages of linear and exponentially increasing. At low LAS contents (<90 μg ml-1 ), the adsorption isotherms are linear (Kd= 1. 2-2. 0), and at high contents (>90 μg ml-1 ), the cooperative adsorption isobserved and the adsorption amount of LAS is increased exponentially. The adsorptionmechanisms are mainly specific site surface interactions and hydrogen bonding, while theadsorption capacity is significantly dependent on the physical clay content of soils.