Removal of 2-Chlorophenol from Aqueous Solution by Mg/Al Layered Double Hydroxide (LDH) and Modified LDH

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• 作者：Ya Hui Chuang ; Yu Min Tzou ; Ming Kuang Wang ; Cheng Hua Liu ; Po Neng Chiang
• 刊名：Industrial & Engineering Chemistry Research
• 出版年：2008
• 出版时间：June 4, 2008
• 年：2008
• 卷：47
• 期：11
• 页码：3813 - 3819
• 全文大小：135K
• 年卷期：v.47,no.11(June 4, 2008)
• ISSN：1520-5045

文摘

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 pK_a 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 <8.56. LDH and SDS−LDH can be removed not only in the ionic form, but also in the molecular form of 2-CP. The efficiencies of LDH and SDS−LDH, in regard to enhancing 2-CP sorption, are strongly dependent on the pH, 2-CP speciation, ionic strength, and metal dissolution. These results are of practical interest, with respect to the selection of sorbents, to optimize aquatic environment remediation technologies.