Adsolubilization of 2,4,6-trichlorophenol from aqueous solution by surfactant intercalated ZnAl layered double hydroxides

Adsolubilization is an efficient adsorptive way to remove organic pollutants from natural environment. By intercalation of anionic organics, a three-dimensional hydrophobic interlayer region can be obtained in the gallery of layered double hydroxides (LDHs), which can be further used as outstanding adsolubilization materials. In this work, dodecylbenzenesulfonate (DBS) and dodecylsulfate (DS) intercalated ZnAl layered double hydroxides (DBS-LDH and DS-LDH) were prepared as adsorbents toward removing 2,4,6-trichlorophenol (2,4,6-TCP) from aqueous solutions. Batch adsolubilization experiments were conducted to study several influence factors on 2,4,6-TCP removal. DBS-LDH and DS-LDH have the adsorption capacities of 166.8 mg/g and 96.7 mg/g at 298 K under pH = 3, respectively. DBS-LDH presented better adsolubilization property than that of DS-LDH. The adsorption kinetics was found to follow the pseudo-second order model and the spontaneous adsorption process was verified by the negative value of Delta G degrees. The equilibrium isotherms for organic contaminants uptake were fitted well with the linear model. The LDH-based adsorbents still have good adsorption performance after 10 adsorption cycles. Therefore, the two surfactant intercalated LDHs can be considered as potential adsorbents in environmental applications for the removal of 2,4,6-TCP pollutant from aqueous solutions. (C) 2015 Elsevier B.V. All rights reserved.