title: Adsorption and removal of clofibric acid and diclofenac from water with MIEX resin.
abstract: This study demonstrates the use of MIEX resin as an efficient adsorbent for the removal of clofibric acid (CA) and diclofenac (DCF). The adsorption performance of CA and DCF are investigated by a batch mode in single-component or bi-component adsorption system. Various factors influencing the adsorption of CA and DCF, including initial concentration, contact time, adsorbent dosage, initial solution pH, agitation speed, natural organic matter and coexistent anions are studied. The Langmuir model can well describe CA adsorption in single-component system, while the Freundlich model gives better fitting in bi-component system. The DCF adsorption can be well fitted by the Freundlich model in both systems. Thermodynamic analyses show that the adsorption of CA and DCF is an endothermic (ΔH(o) > 0), entropy driven (ΔS(o) > 0) process and more randomness exists in the DCF adsorption process. The values of Gibbs free energy (ΔG(o) < 0) indicate the adsorption of DCF is spontaneous but nonspontaneous (ΔG(o) > 0) for CA adsorption. The kinetic data suggest the adsorption of CA and DCF follow the pseudo-first-order model in both systems and the intra-particle is not the unique rate-limiting step. The adsorption process is controlled simultaneously by external mass transfer and surface diffusion according to the surface diffusion modified Biot number (Bis) ranging from 1.06 to 26.15. Moreover, the possible removal mechanism for CA and DCF is respectively proposed based on the ion exchange stoichiometry.
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, China.
authors.forename: Xian
authors.initials: X
authors.lastname: Lu
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, China; China Academy of Urban Planning & Design, Beijing, China. Electronic address: lucaspp@163.com.
authors.forename: Yisheng
authors.initials: Y
authors.lastname: Shao
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, China.
authors.forename: Naiyun
authors.initials: N
authors.lastname: Gao
authors.affiliation: College of Architecture and Civil Engineering, Xinjiang University, Urumqi, China.
authors.forename: Juxiang
authors.initials: J
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, China.
authors.forename: Yansen
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, China.
authors.forename: Qiongfang
authors.initials: Q
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, China.
authors.forename: Yuqi
authors.initials: Y
authors.lastname: Lu
mesh_terms: D000327:Adsorption; D002995:Clofibric Acid / Q000737:chemistry*; D004008:Diclofenac / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007474:Ion Exchange; D007475:Ion Exchange Resins / Q000737:chemistry*; D007700:Kinetics; D013696:Temperature; D013816:Thermodynamics; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D018508:Water Purification / Q000379:methods
chemical_list: D007475:Ion Exchange Resins; D014874:Water Pollutants, Chemical; D004008:Diclofenac; D002995:Clofibric Acid
keywords: Adsorption; Bi-component system; Clofibric acid; Diclofenac; MIEX resin; Single-component system