title: Adsorption of phenthoate and acetochlor from water by clays and organoclays.
abstract: Adsorption of phenthoate and acetochlor onto kaolin, montmorillonite, bentonite clays and respective organoclays prepared by the exchange of quaternary ammonium as tetradecyltrimethyl ammonium bromide(TTAB), dodecyltrimethylammonium bromide (DTAB), and cetylpyridinium chloride (CPC) were studied. The adsorption equilibrium data points were fitted to Freundlich isotherm equations. The adsorption of phenthoate and acetochlor were significantly enhanced by surfactant treatment of the clays. The amount of both pesticides adsorbed per unit mass of organoclay followed the order of TTA-kaolin < TTA-montmorillonite < TTA-bentonite, which is inconsistent with the organic carbon content of the clays. The removal efficiency of organomontmorillonite to treat acetochlor is in the order of CP (C16)-montmorillonite > TTA (C14)-montmorillonite > DTA (C12)-montmorillonite. Phenthoate is adsorbed to greater extent than acetochlor by each adsorbent, which may be due to the higher hydrophobicity of phenthoate, indicating considerable hydrophobic interaction between adsorbent/adsorbate systems.
authors.affiliation: College of Environmental and Resource Sciences, Department of Resources Science, Zhejiang University, Hangzhou 310029, China. liaomin@zju.edu.cn
authors.forename: Min
authors.initials: M
authors.lastname: Liao
authors.forename: Xiao-Mei
authors.initials: XM
authors.lastname: Xie
mesh_terms: D000327:Adsorption; D000538:Aluminum Silicates / Q000737:chemistry*; D001965:Bromides / Q000737:chemistry; D002681:China; D002851:Chromatography, High Pressure Liquid; D009946:Organothiophosphorus Compounds / Q000737:chemistry; D010575:Pesticides / Q000737:chemistry*; D000644:Quaternary Ammonium Compounds / Q000737:chemistry; D013501:Surface-Active Agents / Q000737:chemistry; D014052:Toluidines / Q000737:chemistry; D014877:Water Pollution, Chemical / Q000517:prevention & control*
chemical_list: D000538:Aluminum Silicates; D001965:Bromides; D009946:Organothiophosphorus Compounds; D010575:Pesticides; D000644:Quaternary Ammonium Compounds; D013501:Surface-Active Agents; D014052:Toluidines; C043377:acetochlor; C008838:phenthoate