Evaluation of Adsorption Isotherms and Industrial Wastewater Treatment for COD Reduction Using Acid Impregnated Peanut Shell Activated Carbon

Phosphoric acid impregnated activated carbon has been successfully prepared from readily available agro waste (peanut shell) and applied in the treatment of industrial wastewater for reduction of organic matter contributing to the chemical oxygen demand (COD). Functional groups identification and surface morphology characterization of the activated carbon have been performed by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). Effects of pH (2.1-10.2), initial concentration (50-320) mgL-1, contact time (10-70) min and adsorbent dose (0.1-0.7) g on the percentage reduction of the COD have been studied and evaluated. Four selected adsorption isotherm models have been tested and their linear regression correlation coefficient (R2) values were in the order of Langmuir>Freundlich>Temkin> Dubinin Radushkevich (0.9433>0.9383>0.8967>0.8415) respectively.