title: [Surface organic modification of acid vermiculite and its adsorption of hydrophobic micro pollutants in aqueous solutions].
abstract: To solve the problems of intercalated organoclay such as low surface area and inhomogeneous organic loading, natural vermiculite was activated by acid leaching and then modified by trimethylchlorosilane (CTMS) and triethylchlorosilane (CTES). The modified materials were characterized by FTIR, BET, SEM and TG. Experimental results indicated that the surface area of the modified acid vermiculite (361.0 m2 x g(-1)) was much larger than that of the intercalated organovermiculite (6.0 m2 x g(-1)), moreover, the organic groups were grafted onto the surface covalently. Diethyl phthalate (DEP), a typical hydrophobic micro-organic pollutant, was used to test the adsorption capacity of different adsorbents. The adsorption amounts of DEP were 63.7, 51.2 and 15.7 mg x g(-1) for CTES, CTMS and intercalated organovermiculite in this study, respectively. The high organic affinity of modified acid vermiculite was due to both the bigger surface area and the homogeneous organic loading. The adsorption kinetics was found to follow the pseudosecond-order model. The isotherms exhibited linear characteristics and could be described by Henry and Freundlich equations, indicating that the partition process is the main control mechanism of the removal of DEP.
authors.affiliation: College of Environment and Energy, South China University of Technology, Guangzhou 510006, China. 394444054@qq.com
authors.forename: Zheng-Ming
authors.initials: ZM
authors.lastname: Jiang
authors.forename: Xu-Biao
authors.initials: XB
authors.lastname: Yu
authors.forename: Yun
authors.initials: Y
authors.lastname: Hu
authors.forename: Yuan
authors.initials: Y
authors.lastname: Ren
authors.forename: Xue-Hui
authors.initials: XH
authors.lastname: Li
authors.forename: Chao-Hai
authors.initials: CH
authors.lastname: Wei
mesh_terms: D000143:Acids / Q000737:chemistry; D000327:Adsorption; D000538:Aluminum Silicates / Q000737:chemistry*; D057927:Hydrophobic and Hydrophilic Interactions; D009930:Organic Chemicals / Q000737:chemistry / Q000302:isolation & purification*; D010795:Phthalic Acids / Q000737:chemistry / Q000302:isolation & purification*; D014297:Trimethylsilyl Compounds / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000737:chemistry / Q000302:isolation & purification*
chemical_list: D000143:Acids; D000538:Aluminum Silicates; D009930:Organic Chemicals; D010795:Phthalic Acids; D014297:Trimethylsilyl Compounds; D014874:Water Pollutants, Chemical; C003760:vermiculite; C039293:trimethylchlorosilane; C007379:diethyl phthalate