Clarification of high-turbidity waters: a comparison of Moringa oleifera and virgin and recovered aluminum sulfate-based coagulants

Quality potable water it is of utmost importance for public health. Coagulation plays an important role in the chemical and physical characteristics and aesthetics of water, to separate suspended solids from water. The present work evaluates four coagulants clarification efficiency in high-turbidity waters, by comparing alternative coagulants such as Moringa Oleifera oily seed extract and recovered aluminum sulfate with commercially available aluminum sulfate. In most cases, apparent color and turbidity removal efficiencies were higher than 90%. Recovered aluminum sulfate showed a better result compared to virgin coagulant for high pHs. Moringa oleifera coagulants are advantageous for their non-impact in final pH, although the difficulty in obtaining large harvest areas precludes their application on a larger scale. Results supported discussions about advantages, disadvantages and limitations of each coagulant and demonstrated the technical feasibility of applying these to high-turbidity waters. This application promoted a superior sustainability index related to water treatment, reducing the costs in comparison with commercial coagulant acquisition, besides decreasing health risks caused by its excessive use.