title: Study on sulfadimethoxine removal from aqueous solutions by hydrous ferric oxides.
abstract: Significant concerns have been raised over the presence of antibiotics including sulfadimethoxine (SDMO) in aquatic environments. This study investigated the removal capability and mechanism involved in the removal of SDMO by hydrous ferric oxides (HFO). Results showed that SDMO removal was highly pH and ionic strength dependent. The pseudo-first-order model fitted well the kinetic results, and the value of the calculated activation energy for SDMO adsorption onto HFO was 8.6 kJ mol(-1). Adsorption isotherms at varied temperatures were well described by the Langmuir model. Thermodynamic parameters (change in enthalpy > 0, change in entropy > 0, and change in Gibbs free energy < 0) calculated from the temperature-dependent sorption data revealed spontaneous and endothermic process. The exchange of the surface hydroxyl groups of HFO and the negative anions of SDMO(-) and the electrostatic interaction between the positively charged surface of HFO and the deprotonated imino (-N(-)-) accounted for the uptake of SDMO by HFO.
authors.affiliation: College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China E-mail: hongjiewang@bjfu.edu.cn.
authors.forename: Weixiao
authors.initials: W
authors.lastname: Zhu
authors.affiliation: Beijing Urban Construction Design & Development Group Co., Ltd, Beijing 100037, China.
authors.forename: Jianduo
authors.initials: J
authors.lastname: Wang
authors.affiliation: College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China E-mail: hongjiewang@bjfu.edu.cn.
authors.forename: Yili
authors.initials: Y
authors.lastname: Wang
authors.affiliation: College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China E-mail: hongjiewang@bjfu.edu.cn.
authors.forename: Hongjie
authors.initials: H
authors.lastname: Wang
mesh_terms: D000327:Adsorption; D005290:Ferric Compounds / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D009994:Osmolar Concentration; D013412:Sulfadimethoxine / Q000737:chemistry*; D013696:Temperature; D013816:Thermodynamics; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D018508:Water Purification / Q000379:methods
chemical_list: D005290:Ferric Compounds; D014874:Water Pollutants, Chemical; C000499:ferric oxide; D013412:Sulfadimethoxine