Iron(III)oxide and Silver oxide -Chromolaena odorata leaf biochar nanocomposites as effective bio-inorganic material for the treatment of borehole water

This study investigates the synthesis, characterization and application of iron(III) oxide–Chromolaena odorata leaf biochar nanocomposite (Fe2O3-COLBN) and silver oxide–Chromolaena odorata leaf biochar nanocomposite (Ag2O-COLBN) as effective bio-inorganic materials for borehole water purification. The nanocomposites were prepared through one pot facile hydrothermal process after pyrolysis of the Chromolaena odorata leaves, leveraging the high surface area and porous structure of C. odorata biochar for enhanced contaminant adsorption. Comprehensive characterization was conducted using UV–Vis spectroscopy, Scanning Electron Microscopy coupled Energy Dispersive X-ray spectroscopy (SEM/EDX), X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), and Transmission Electron Microscopy (TEM) to elucidate the morphological, structural, and functional properties of the nanocomposites. The physicochemical parameters of the borehole water was determined using standard procedures and values compared to W.H.O standard. The microbial content including biochemical and morphological tests was done using standard procedures. The Ag2O-COLBN and Fe2O3-COLBN were multifunctional, microporous and crystalline with average crystallite size of 27–39 nm. Physicochemical analysis of borehole water before and after treatment revealed significant reductions in turbidity, total dissolved solids (TDS), anions and heavy metal concentrations, demonstrating the high adsorption capacity of the materials. Antimicrobial results indicated that both Ag2O-COLBN and Fe2O3-COLBN effectively inhibited the growth of pathogenic microorganisms, with Ag2O-COLBN showing superior bactericidal performance in most samples. This study highlights the potential of Ag2O-COLBN and Fe2O3-COLBN as sustainable, low-cost, and efficient materials for improving water quality, offering a promising solution for rural water treatment applications and in areas of water scarcity due to war and other natural disasters.