内分泌干扰物双酚A在黏土防渗层中的吸附作用研究

Adsorption characteristics of endocrine disrupting chemicals biphenol-A on clay impermeable layer

双酚A(BPA)是典型的内分泌干扰物,其在水体中广泛存在,可通过多种途径使人类遭受直接或潜在的暴露风险。研究了黏土对垃圾渗滤液中BPA的吸附机制规律及其吸附模型,讨论了溶液pH、土水比等影响因素对吸附效果的作用机制。结果表明,黏土对BPA的吸附过程遵循准二级动力学方程,黏土对BPA的最大吸附量可达到0.571mg/g,吸附等温线符合Langmuir模型。在吸附开始阶段,不同水土比的黏土吸附速率均较大,约90min达到吸附平衡,平衡吸附量为0.133mg/g;当pH≥8.39时,吸附量随着BPA的电离而减小。通过与其他各类物质进行比较时发现,黏土对氨氮的吸附性能较强,对BPA等内分泌干扰物的平衡吸附量很小,因此有必要对黏土层进行改性,以保障地下水的安全。

Bisphenol-A （BPA） as a typical endocrine disruptor is widely exist in the water body,it could make people suffer from direct or potential risk of exposure through variety of ways. The adsorption rule and adsorption models of BPA on clay have been explored and the influences of the factors such as pH and clay dosage on the adsorw tion have been studied. The results showed that the adsorption process of BPA on clay is in compliance with the sec- ond-order kinetics, the maximum adsorption capacity is 0. 571 rag/g, and the adsorption isotherms fit well to Langmuir equation. The reaction occurred quickly at the beginning of the adsorption for different qualities of clay,it takes almost 90 min to reach the equilibrium,and the equilibrium adsorption capacity is 0. 133 mg/g. The adsorption capacity of BPA reduced at higher pH（phi8.39） due to the ionization of BPA. Compared with other substances,the adsorption capacity of ammonia nitrogen on the clay is highest,while the equilibrium adsorption capacity of BPA and other endocrine disruptors is small,so it is necessary to modify the clay impermeable layer to ensure the safety of the groundwater.