Zinc removal mechanisms with recycled lignocellulose: from fruit residual to biosorbent then soil conditioner

Abstract

This study aims to remove zinc by using banana peel from an aqueous medium. The peel was a lignocellulosic adsorbent and characterized by FTIR spectra, SEM-EDS images, and elemental analysis. The effect of contact time, pH, and adsorbent dosage on the sequestration of zinc was observed. The sorption process of zinc was well described with the pseudo-second-order kinetic and Langmuir isotherm model. The rate-limiting step to the adsorption process was determined by applying the intra-particle diffusion model. The removal mechanism is that ion exchange, electrostatic interaction, complex formation, physical adsorption, and precipitation carried out in cooperation with the banana peel functional groups and zinc ion in many ways. FTIR analysis demonstrates that the surface carboxylic/hydroxyl functional groups of banana peel play a key role in the adsorption of zinc ions. The results showed that banana peel, a locally available fruit residual, is an efficient and eco-friendly adsorbent to reduce Zn2+. The usage of banana peel as an adsorbent for the sequestering of zinc from water ensures both the technical advantage and cost-effectiveness of the sustainable environmental management concept and zero waste strategy. Furthermore, the value-added products containing organic compounds and zinc can be used efficiently as a soil conditioner.