title: The sorption behavior of DDT onto sediment in the presence of surfactant cetyltrimethylammonium bromide.
abstract: The sorption behavior of p,p'- and o,p'-dichlorodiphenyltrichloroethane (DDT) in the presence of a cationic surfactant cetyltrimethylammonium bromide (CTAB) on sediment was studied. Batch experiments were carried out to investigate the kinetics and thermodynamics of the process. The kinetic behavior of these three chemicals on sediment was described by pseudo-second-order kinetic equations, and the isotherms followed the Freundlich model well. The presence of CTAB was able to remarkably accelerate and enhance the sorption of DDT, whereas DDT showed no effect on the sorption of CTAB in our considered concentration ranges. The thermodynamic parameters, such as standard enthalpy change (ΔH0), standard entropy change (ΔS0) and standard Gibbs free energy change (ΔG0) showed that the sorption process of p,p'- and o,p'-DDT was physical, spontaneous and exothermic, and the randomness at the solid-liquid interface increased during the process. In the presence of CTAB, the sorption of DDT showed significantly negative ΔG0 and ΔH0 values.
authors.affiliation: Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao 266100, China.
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Cao
authors.forename: Huayu
authors.initials: H
authors.lastname: Han
authors.forename: Guipeng
authors.initials: G
authors.lastname: Yang
authors.forename: Xiaofei
authors.initials: X
authors.lastname: Gong
authors.forename: Jianning
authors.initials: J
authors.lastname: Jing
mesh_terms: D000327:Adsorption; D000077286:Cetrimonium; D002593:Cetrimonium Compounds / Q000737:chemistry*; D003634:DDT / Q000737:chemistry*; D019015:Geologic Sediments / Q000737:chemistry*; D007700:Kinetics; D008956:Models, Chemical; D013501:Surface-Active Agents / Q000737:chemistry*; D013816:Thermodynamics
chemical_list: D002593:Cetrimonium Compounds; D013501:Surface-Active Agents; D003634:DDT; D000077286:Cetrimonium