Removal of iron, manganese, and arsenic from groundwater by using banana and pineapple peel charcoal: evidence from sophisticated techniques

Abstract

This study presents a novel and sustainable approach for removing iron (Fe), manganese (Mn), and arsenic (As) from groundwater using biochar adsorbents derived from banana (Musa ornata) peel (BP) and pineapple (Ananas comosus) peel (PP). Unlike conventional chemical or synthetic adsorbents, these agro-waste-derived materials provide a cost-effective and environmentally friendly alternative. The structural characterization of the developed biochars revealed porous surfaces with irregular cavities and well-developed microstructures as observed through Scanning Electron Microscopy (SEM), while Fourier Transform Infrared Spectroscopy (FTIR) confirmed the presence of key functional groups (–OH, –COOH, and C=C) involved in metal binding. Groundwater analysis from Jaghati village, Jashore, Bangladesh, revealed elevated concentrations of Fe (4.14 mg L ¹), Mn (2.26 mg L⁻¹), and As (0.014 mg L⁻¹). Adsorption experiments demonstrated that BP charcoal achieved 96.31 % at 180 minutes with a 350 mg L^-1 dose in pH 7.0, while PP charcoal achieved a maximum Fe removal efficiency of 98.97 % at 60 minutes with a 350 mg L^-1 dose in pH 7.0. For Mn, BP charcoal showed a maximum removal of 83.12 % at pH 7.0 with a 250 mg L⁻¹ dose after 180 minutes. However, both adsorbents showed limited capacity for As removal, with maximum efficiencies of 11.67 % (BP charcoal) and 12.94 % (PP charcoal). The study highlights the promising potential of BP and PP charcoals for effectively removing Fe and Mn from groundwater, contributing to the development of low-cost, biodegradable treatment options for rural and resource-limited settings.