title: Sorption of tylosin on clay minerals.
abstract: The equilibrium sorption of tylosin (TYL) on kaolinite and montmorillonite was measured at different solution pH using batch reactor systems. The results showed that all the sorption isotherms were nonlinear and that the nonlinearity decreased as the solution pH increased for a given clay. At a specific aqueous concentration, the single-point sorption distribution coefficient (KD) of TYL decreased rapidly as the solution pH increased. A speciation-dependent sorption model that accounted for the contributions of the cationic and neutral forms of TYL fit the data well, suggesting that the sorption may be dominated by both ion exchange and hydrophobic interactions. The isotherm data also fit well to a dual mode model that quantifies the contributions of a site-limiting Langmuir component (ion exchange) and a non-specific linear partitioning component (hydrophobic interactions). X-ray diffraction analyses revealed that the interlayers of montmorillonite were expanded due to the uptake of TYL. TYL molecules likely form a monolayer surface coverage.
authors.affiliation: College of Environment and Energy, South China University of Technology, Guangzhou 510006, China; The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, Guangzhou 510006, China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Zhang
authors.forename: Chen
authors.initials: C
authors.lastname: Yang
authors.forename: Weilin
authors.initials: W
authors.lastname: Huang
authors.forename: Zhi
authors.initials: Z
authors.lastname: Dang
authors.forename: Xiaohua
authors.initials: X
authors.lastname: Shu
mesh_terms: D000327:Adsorption; D000538:Aluminum Silicates / Q000737:chemistry*; D000900:Anti-Bacterial Agents / Q000032:analysis / Q000737:chemistry*; D000077215:Clay; D006863:Hydrogen-Ion Concentration; D008903:Minerals / Q000737:chemistry*; D008956:Models, Chemical; D012989:Soil Pollutants / Q000032:analysis / Q000737:chemistry*; D015645:Tylosin / Q000032:analysis / Q000737:chemistry*
chemical_list: D000538:Aluminum Silicates; D000900:Anti-Bacterial Agents; D008903:Minerals; D012989:Soil Pollutants; D000077215:Clay; D015645:Tylosin
keywords: Clay; Interlayer; Tylosin; X-ray diffraction; pH effect