Evaluation of Avocado Charcoal, Corn Cobs, and Eucalyptus for Purifying River Water in Cameroon

Abstract

ABSTRACT Access to safe drinking water remains a major challenge in Sub‐Saharan Africa, where surface water is frequently contaminated. This study evaluates the effectiveness of local charcoal from avocado trees ( Persea americana ), corn cobs, and eucalyptus ( Eucalyptus spp.) in improving the potability of river water, with a view to proposing simple and accessible solutions for rural communities. The charcoals were obtained by pyrolysis of local biomass, then crushed, sieved, washed, dried, and sterilized. The physicochemical composition of the coals was evaluated using standard methods: thermogravimetric analysis, x‐ray fluorescence, and pH measurement. Low‐flow filtration devices, such as gravity‐fed packed columns, were set up in the laboratory, with each material being tested in triplicate. Physicochemical and bacteriological parameters were analyzed before and after filtration using standard APHA methods. The data were processed using the Kruskal–Wallis test ( α = 0.05). Filtration led to an overall decrease in microbial load. Avocado charcoal showed the best bacteriological performance, with total elimination of fecal coliforms and more than 98% elimination of total coliforms and Escherichia coli . Eucalyptus charcoal particularly reduced fecal streptococci (96.78%). All charcoals significantly reduced turbidity (82%–90%), with values compliant with World Health Organization (WHO) standards. However, an increase in conductivity, total dissolved solids, and potassium was observed. Avocado charcoal is the most suitable material, thanks to its overall superior effectiveness in removing bacteriological contaminants and reducing turbidity. It is a simple and promising local solution for improving water potability.