滇池泥炭土对两种抗生素和双酚A的吸附

用不同浓度NaOH溶液处理采集自云南滇池的泥炭土，研究处理前后的泥炭土对两种抗生素磺胺甲恶唑（SMX）、卡马西平（CBZ）及双酚A（BPA）的吸附机理，并深入探讨3种污染物及泥炭土性质对吸附特性的影响.吸附等温线拟合结果表明，Freundlich模型对3种物质在泥炭土上的吸附等温线有较好的拟合优度.3种物质中，BPA的非线性指数n值最低，这可能是由于其不对称的结构特征导致.随着处理泥炭土的NaOH浓度增加，3种吸附质在泥炭土上的吸附顺序为BPA > CBZ > SMX，BPA的吸附最高可能是由于其含有两个酚羟基，与泥炭土有较强的极性作用导致，而CBZ的吸附比SMX的吸附高是由憎水性作用引起.NaOH处理后并没有增加泥炭土对这3种吸附质的吸附，说明对于离子型化合物，吸附过程和机理复杂，BPA蝴蝶状结构及苯环上含有两个羟基可能导致其在泥炭土上出现特异性吸附，这导致其吸附系数最高；NaOH处理后泥炭土的有机碳含量增加但比表面积可能降低，从而使3种污染物的吸附降低.因此，本研究3种离子型化合物在泥炭土上的吸附受到吸附质的官能团及溶解度、泥炭土的有机碳含量及官能团等多种因素的影响.

Adsorption of two antibiotics and bisphenol A on Dianchi peat

The Dianchi peat soil was collected from Dianchi Lake in Kunming, Yunnan, China. The peat soil was treated by different concentrations of NaOH solutions, and effect of alkali solution for the properties of peat soil and the sorption characteristics of contaminants was evaluated. Adsorption mechanisms of two antibiotics, sulfamethoxazole (SMX), carbamazepine (CBZ), and bisphenol A (BPA) on peat soils before/after NaOH treated were discussed. Effects of the properties for contaminants as well as the peat soils on their sorption characteristics were investigated. Adsorption isotherms for SMX, CBZ and BPA were well fitted by the Freundlich model, and the fitting results showed that the Freundlich nonlinearity factor n values of BPA were the lowest among these three contaminants, which may be due to its asymmetric structural characteristics. As the concentration of NaOH increased, adsorption of these three contaminants on peat soils was BPA > CBZ > SMX. BPA has two phenolic hydroxyl groups and thus it could interact with peat soils by polar interaction, this may result in the highest sorption of it on peat soils. Adsorption of CBZ was higher than that of SMX was due to the hydrophobic interactions between CBZ/SMX and peat soils. Adsorption of SMX, CBZ and BPA on peat soils treated by NaOH solutions was not increased, this suggested that the sorption processes and mechanisms of ionic compounds on peat soils were complex, many factors such as functional groups and solubility of contaminants, the contents of organic carbon and functional groups of peat soils affected the sorption. The butterfly structure and two hydroxyl groups of BPA may lead to its specific adsorption on peat soil, which resulted in the highest adsorption coefficient. The organic carbon content of peat soil increased but the specific surface area may decrease after NaOH treated, and thus reducing the adsorption of these three contaminants. Therefore, adsorption of these three ionic compounds on the peat soils was affected by various factors, including the functional groups and solubility of adsorbates, the organic carbon content and functional groups of peat soils in this study.