title: Removal of bentazone from micro-polluted water using MIEX resin: kinetics, equilibrium, and mechanism.
abstract: The contamination of surface and ground water by bentazone has attracted increasing global concern in recent years. We conducted a detailed investigation using MIEX resin to eliminate bentazone from waters. Batch experiments were carried out to evaluate the effect of process parameters, such as retention time, resin amount, and initial pesticide concentration, on removal efficiency of bentazone. Results showed the sorption process was fast and bentazone could be efficiently removed in 30 minutes. The kinetic process of bentazone sorption on MIEX resin was well described by pseudo second-order model and intraparticle diffusion was the rate controlling step. The MIEX resin possessed the highest sorption capacity of 0.2656 mmol/mL for bentazone according to Langmuir fitting. Bentazone is a hydrophobic ionizable organic compound, and both ionic charge and hydrophobic aromatic structure governed the sorption characteristics on MIEX resin. The different removal efficiencies of ionic and non-ionic pesticides, combined with the charge balance equations of bentazone, SO4(2-), NO3- and Cl-, indicated that removal of bentazone using MIEX resin occurred primarily via ion exchange.
authors.affiliation: State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085.
authors.forename: Zequn
authors.initials: Z
authors.lastname: Liu
authors.forename: Xiaomin
authors.initials: X
authors.lastname: Yan
authors.forename: Mary
authors.initials: M
authors.lastname: Drikas
authors.forename: Danong
authors.initials: D
authors.lastname: Zhou
authors.forename: Dongsheng
authors.initials: D
authors.lastname: Wang
authors.forename: Min
authors.initials: M
authors.lastname: Yang
authors.forename: Jiuhui
authors.initials: J
authors.lastname: Qu
mesh_terms: D000327:Adsorption; D001581:Benzothiadiazines / Q000737:chemistry*; D006540:Herbicides / Q000737:chemistry*; D006801:Humans; D007475:Ion Exchange Resins / Q000737:chemistry*; D015394:Molecular Structure; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D018508:Water Purification / Q000379:methods*; D014881:Water Supply / Q000032:analysis*
chemical_list: D001581:Benzothiadiazines; D006540:Herbicides; D007475:Ion Exchange Resins; D014874:Water Pollutants, Chemical; C002003:bentazone