Sustainable Biotreatment Approaches for Improving the Quality of Harvested Rainwater in Rural Communities

Abstract

Water scarcity remains a significant global challenge, particularly in rural communities where access to safe drinking water is limited. Rainwater harvesting (RWH) has emerged as a viable alternative water source, yet concerns regarding its quality due to microbial contamination, heavy metal presence, and physicochemical imbalances necessitate effective treatment solutions. Conventional chemical treatments, such as aluminum sulfate (alum), present potential health risks and economic constraints, thereby necessitating the exploration of sustainable, eco friendly alternatives. This study evaluates the efficacy of plant-based biotreatment methods using banana peels, orange peels, almond leaves, and Moringa oleifera seeds in improving the quality of harvested rainwater stored in underground tanks in Ogbadibo Local Government Area, Benue State, Nigeria. A total of 234 water samples were collected from 27 underground tanks across three different seasons to assess physicochemical (pH, turbidity, total dissolved solids, heavy metals) and microbiological parameters (total viable count [TVC], total coliform count [TCC]). Experimental biotreatment was conducted using varying concentrations of the selected plant wastes, and the results were statistically analyzed using ANOVA and Duncan Multiple Range Test (DMRT). The findings revealed significant contamination in untreated rainwater, exceeding WHO permissible limits for microbial loads and physicochemical properties. Among the plant-based treatments, almond leaves demonstrated the highest microbial reduction (TVC: 108 CFU/ml, TCC: 58 CFU/100ml), followed by Moringa oleifera seeds. The treated water exhibited improved pH stability (6.5–8.5) and reduced total dissolved solids, enhancing its suitability for domestic use. Comparative analysis indicated that plant-based treatments were as effective as aluminum sulfate in microbial reduction but with the added benefits of being non-toxic, cost-effective, and environmentally sustainable. This study underscores the potential of plant-based biotreatment as an innovative, scalable solution for rural water purification.While the biotreatment methods significantly improved water quality, none fully met the WHO standard for microbial parameters, indicating the need for further optimization. The integration of these natural purification techniques into local water management policies can enhance water security, reduce dependence on chemical treatments, and promote public health sustainability. Future research should explore advanced combinations of plant materials and process modifications to achieve superior water quality standards.