Ind. Eng. Chem. Res. 2008, 47, 3813–3819
3813
Removal of 2-Chlorophenol from Aqueous Solution by Mg/Al Layered Double Hydroxide (LDH) and Modified LDH Ya Hui Chuang,† Yu Min Tzou,‡ Ming Kuang Wang,*,† Cheng Hua Liu,† and Po Neng Chiang† Department of Agricultural Chemistry, National Taiwan UniVersity, Taipei, Taiwan 106, Republic of China, and Department of Soil and EnVironmental Sciences, National Chung-Hsing UniVersity, Taichung, Taiwan 402, Republic of China
Sorption is a common treatment for removing pollutants from natural environments. Layered double hydroxides (LDHs), which consist of brucite-like positive layers and sodium dodecyl sulfate intercalated with LDH (SDS-LDH), are considered to be potential organic pollutant sorbents. The objectives of this study were (1) to evaluate the impact of removing 2-chlorophenol (2-CP) using Mg3-Al-(NO3) LDH and SDS-LDH and (2) to investigate the removal efficiencies of these two compounds. All fitted sorption data reveal that the second-order model and the Langmuir model best describe the sorption kinetics and isotherms, respectively. By visual MinteqA2 (2000) calculation, the dissociation pKa of 2-CP is 8.56. The experimental results indicate that a high concentration of 2-CP is sorbed by the hydrophilic-hydrophilic physical interaction of LDH when the pH is >8.56; however, the hydrophobic-hydrophobic partition interaction of SDS-LDH is more vital when the pH is
