Comparative Study on Adsorption Kinetics of Heavy Metals in Produced Water Using Banana Peel and Luffa Cylindrica Derived Activated Carbon

Abstract

This paper investigates the potentials of activated carbon (AC) derived from Banana peel and Luffa cylindrica biowaste for the removal of heavy metals such as zinc, copper, nickel, and iron from produced water. Activated carbon was obtained by carbonizing adsorbents (Banana peel and Luffa cylindrica), using an impregnation ratio of 1:3 of H₃PO₄ for 24 hrs. The experimental runs were conducted using the batch adsorption method, where produced water was treated using a 2 g adsorbent dosage for 2, 4, and 6 hours of contact time. Adsorption kinetics were analysed using both the pseudo-first-order and pseudo-second-order model equations. The results show that Luffa cylindrica-derived AC achieved up to 85.7, 88.3, 54.7, and 52.2 % removal in Zn, Cu, Ni, and Fe, respectively, while banana peel AC led to 85.4, 70.7, and 35.2% removal in Zn, Cu, Ni, and Fe., respectively. Kinetic data indicated that pseudo-first-order best described Zn, Cu, and Fe adsorption (R² > 0.76) on both adsorbents, while only Fe adsorption on banana peel AC fitted well with pseudo-second-order (R² = 0.9998). These findings suggest the potential of these low-cost, sustainable biosorbents for effective treatment of produced water.