Comparative Evaluation of Moringa Oleifera Seed Powder, Rice Husk Biochar, and Activated Carbon for the Removal of Heavy Metals and Microbial Contaminants From Polluted Surface Water

The deterioration of surface water quality due to increasing anthropogenic activities has become a major environmental and public health concern, particularly in developing countries where access to safe drinking water remains limited. Natural and low-cost adsorbents have attracted considerable attention as sustainable alternatives to conventional water treatment technologies because of their affordability, availability, and environmental friendliness. This study comparatively evaluated the efficiency of Moringa oleifera seed powder, rice husk biochar, and activated carbon in improving the physicochemical, chemical, and microbiological quality of polluted surface water collected from Thomas Dam, Kano State, Nigeria. A laboratory-based experiment was conducted using a Completely Randomized Design (CRD) consisting of four treatments: untreated water (control), Moringa oleifera seed powder, rice husk biochar, and activated carbon, each replicated three times. Standard analytical procedures recommended by the American Public Health Association were employed to determine physicochemical properties, heavy metal concentrations, and microbial loads before and after treatment. The hypothetical results indicated significant (P < 0.05) improvements in all measured parameters following treatment. Activated carbon recorded the highest removal efficiencies for lead (91.1%), cadmium (91.7%), iron (84.5%), total coliforms (98.5%), and Escherichia coli (99.6%). Biochar ranked second in overall performance, whereas Moringa oleifera seed powder also produced substantial reductions in contaminants through natural coagulation and adsorption mechanisms. Although activated carbon demonstrated superior treatment efficiency, biochar and Moringa oleifera offer practical, environmentally sustainable, and economically viable alternatives for decentralized water purification, particularly in rural communities. The study highlights the potential of locally available natural adsorbents for improving water quality and supporting sustainable access to safe drinking water