Comparative Evaluation of Moringa oleifera Coagulants and Polyaluminum Chloride for Rural Water Treatment in Guerrero, Mexico
摘要
Agricultural pollution compromises the quality and availability of drinking water in rural areas due to cattle fecal deposition, pesticides, and fertilizers, posing significant health risks. This study evaluates the performance of Moringa oleifera (MO) based natural coagulants derived from seeds and peels for the clarification of untreated surface water in Atlixtac, Guerrero, Mexico, and compares their effectiveness with that of the conventional coagulant, polyaluminum chloride (PAC). Coagulation performance was assessed through jar-test experiments conducted under real water conditions, considering physicochemical parameters (turbidity, nitrate-nitrogen (NO₃⁻–N), phosphates, and pH) and microbiological indicators (Escherichia coli and total fecal coliforms). MO seed coagulants achieved the highest reductions in turbidity and nitrate-nitrogen, while peel-derived coagulants showed superior bacterial performance, achieving complete E. coli removal and up to 95% reduction of total fecal coliforms after 24 h of settling. These reductions are consistent with the presence of cationic proteins and bioactive compounds previously reported for MO, which have been associated with bacterial destabilization mechanisms. In contrast, PAC showed lower or more variable removal efficiencies for nutrients and turbidity and induced a more pronounced decrease in pH. Overall, the results demonstrate that MO seed and peel coagulants provide an effective and technically robust alternative to conventional chemical coagulation under real rural water conditions, with performance strongly influenced by influent water quality. These findings support the application of MO coagulation as a practical component of decentralized water treatment strategies in resource-limited rural communities.