广西红树林沉积物对诺氟沙星的吸附特征研究

The characteristics of norfloxacin adsorption on mangrove sediment of Guangxi provinece

采用批量平衡吸附实验研究了广西红树林沉积物对诺氟沙星的吸附特性,以及p H、盐度和表面活性剂等对吸附的影响。结果表明,诺氟沙星在沉积物上的吸附过程包括快速吸附和慢速吸附两个阶段;在实验浓度范围内吸附等温线呈非线性,可用Freundlich模型和Langmuir模型进行良好的拟合。在p H为3~10时,诺氟沙星的平衡吸附量随p H的增大,先增后减;而平衡吸附量随盐度的上升呈下降的趋势。在表面活性剂浓度为5.00 mg/L时,3种类型表面活性剂对诺氟沙星在红树林沉积物上吸附均有促进作用,

Batch equilibrium experiments were conducted to study the adsorption characteristics of norfloxacin on man- grove sediment collected from Guangxi. The effects of experimental parameters such as pH, salinity and surfactants on the sorption of norfloxacin were inveatigated. The results showed that the sorption of norfloxacin to the mangrove sedi- ment is a two-step process that includes a rapid sorption step and then a slow sorption one. Equilibrium modeling for the sorption data is nonlinear,and both the Freundlich isotherm and Langmuir isotherm fit well to the sorption data. With the increasing of pH values, the equilibrium uptake capacity of norfloxacin increased at first and then decreased. The adsorption capacities of norfloxacin on sediment decreased as salinity of solutions were increasing. At the same concentration （5 mg· L-1 ）, the promotion effect of three surfactants on the adsorption ability of norfloxacin on the mangrove sediment followed the sequence of Tween20 〈 SDBS 〈 CTAB.