Chapter 24 - Activated rice husk for copper removal from aqueous solution: A sustainable approach

Abstract

In this study, a low-cost and eco-friendly acid-base-treated adsorbent (Rice Husk) has been used for the removal of Copper (II) from wastewater through column as well as batch study. The comparative adsorption efficiency for copper ions at various medium of adsorbent (neutral, acid, and base-treated rice husk) was also studied at same bed depth and found that neutral (NRH) and base-treated rice husk (BRH) gives satisfactory results such as 95.53% and 96.75% removal efficiency, respectively. However, the adsorption percentage was also affected by bed depth due to large passage and contact time of adsorbate and adsorbent. The batch adsorption data of copper by ARH were used for kinetics and isothermal study and found to be good coefficient of determination ( R 2 ) 0.998, 0.998, 0.998, and 0.998 at 20, 50, 100, and 200 mg/L, respectively, for second-order kinetics. The Langmuir isotherm best fitted reveals good R 2 to be 0.998 at 298 K, 0.998 at 303 K, and 0.999 at 308 K, which indicates the monolayer coverage and uniformity on the adsorbent surface.