A comparative study of biocoagulant powers in preparing drinking water: case of Moringa oleifera and Adansonia digitata

Abstract

Rivers in the Democratic Republic of Congo are a major source of pollution, with conventional methods of producing drinking water employing expensive and unclean chemicals. The addition of aluminum salts for coagulation often leads to high concentrations of dissolved aluminum, which is suspected to cause Alzheimer’s disease. Integrating biological processes for treating drinking water could be a sustainable alternative due to their availability and non-toxicity. This study evaluated the effectiveness of biocoagulants (Moringa oleifera Lam. and Adansonia digitata seeds) in preparing drinking water from surface water. Adansonia digitata seeds were unable to clarify raw river water, whereas Moringa oleifera seeds were. Oil extraction improved biocoagulant power, with hot extracts performing better than cold extracts. The optimal doses for hot extracts were 150, 150, 250, and 600 mg/l for turbidities of 39.6, 108, 380, and 960 NTU, respectively. Cold extracts were retained in the same raw water samples. Settlingtimes of 60 to 90 minutes were found to be sufficient to eliminate most suspended matter and colloids. The chlorine level required for effectivedisinfection was 12 to 13 mg/l. The extracts significantly increased the level of organic matter (OM) in the treated water. Moringa oleifera exhibited superior biocoagulant, bio-adsorbent, and bio-disinfectant propertiesover Adansonia digitata. Hot extracts from Moringa oleifera were more effective than cold extracts.