Use of gel-type weak acid resin for the adsorption of La(III) from aqueous solution

Abstract

The adsorption properties of a gel-type weak acid resin (110-H) for La(<span style="color:black;mso-bidi-font-weight: bold">III) have been studied with chemical methods. The e<span style="font-family: " palatino="" linotype";mso-ascii-font-family:"times="" new="" roman""="" lang="EN-GB">ffects of process variables, such as initial <i style="mso-bidi-font-style: normal">p</i>H of solution, initial concentration of La(<span style="color: black;mso-bidi-font-weight:bold">III), contact time and temperature, on the adsorption of La(<span style="color:black;mso-bidi-font-weight:bold">III)) have been studied using batch technique. The results show that the optimal adsorption condition of GTWAR for La(<span style="color:black;mso-bidi-font-weight: bold">III) is achieved at <i style="mso-bidi-font-style:normal">p</i>H 5.0 in HAc-NaAc medium. The maximum uptake capacity of La(<span style="color:black; mso-bidi-font-weight:bold">III) is found to be 263 mg/g resin at 298 K. The adsorption of La(<span style="color:black;mso-bidi-font-weight: bold">III) follows the Langmuir isotherm better than Freundlich isotherm, and the correlation coefficients have been evaluated. Even kinetics on the adsorption of La(<span style="color:black;mso-bidi-font-weight:bold">III) has been studied. The thermodynamic parameters Δ<i style="mso-bidi-font-style: normal">S</i> 121 J/(mol·K) and Δ<i style="mso-bidi-font-style:normal">H</i> 16.4kJ/mol indicate the endothermic nature of the adsorption process. A decrease in Gibb’s free energy with increasing temperature indicates the spontaneous nature of the adsorption process. Finally, La(<span style="color:black;mso-bidi-font-weight:bold">III) can be eluted by using 0.5mol/L HCl solution and the gel-type weak acid resin can be regenerated and reused. The sample is evaluated by IR spectroscopy and thermogravimetric analysis.

</span></span></span></span></span></span></span></span></span>