Optimization of low-cost cow dung based activated carbon for the removal of carbofuran from aqueous solution

Abstract

Water pollution has become a serious issue of this century due to increased industrialization. Several methods have been adopted to tackle this issue, including adsorption by activated carbon (AC). Conventional sources of AC preparation are costly and non-renewable as well. Several fruit and agricultural wastes have characteristics to become sustainable feedstock for AC preparation. This study aims to prepare cost effective AC from sustainable raw material, cow dung. The preparation has been analyzed and optimized by utilizing central composite design (CCD). The effect of activation temperature, time, and impregnation ratio (IR) on responses of percent yield ( R1) and percent pesticide removal (R2) has been analyzed. Quadratic models have been suggested with R2, adjusted R2, and predicted R2 values of 0.98, 0.96, 0.89 for R1, and 0.97, 0.94, 0.87 for R2, respectively. Activation temperature and KOH/Feedstock ratio significantly influence the yield and pesticide removal. Optimized conditions of activation temperature, KOH/Feedstock ratio, and activation time are 708.07 °C, 1.22 and 0.66 h, respectively. These conditions produced 14.78% yield and 89.18% pesticide removal. SEM and BET analysis of optimized AC also confirmed porosity development and large surface area availability due to activation process. Findings of this study suggest that cow dung can be used to prepare low-cost AC for pesticide removal from aqueous solution.

Keywords

• adsorbent
• activated carbon
• biowaste
• cow dung
• pesticides
• waste water treatment