Evaluation of Plant-Based Natural Extracts as Coagulants for Surface Water Treatment.

This study investigated the use of natural extracts as bio-coagulants for water treatment and purification. The utilization of natural materials represents important progress in sustainable environmental initiatives, and their application is directly associated with improved quality of life due to their low toxicity, cost-effectiveness, and naturally renewable properties. Therefore, three plant species were identified, and their effectiveness was evaluated in the laboratory on surface water samples: Moringa oleifera (MO), Cicer arietinum (CA), and Pinus roxburghii (PR). Water samples were collected from the River Kunhar, Garhi Habibullah (Mansehra) for laboratory analysis. A combined treatment (coagulation and filtration) was found to be more efficient compared to direct filtration or coagulation alone. The highest turbidity removal of 99.17 percent, solids reduction of 93.21 percent, hardness reduction of 67.35 percent, and total coliform removal of 86.13 percent were achieved for the filtered water samples treated with MO. CA provided the maximum chloride reduction of 54.85 percent compared to the other two. These extracts slightly affected the acidity, alkalinity, pH, and conductivity of water samples. However, a slight increase in biological and chemical oxygen demand was found in treated water. Among the three natural coagulants, MO caused a significant increase in organic matter. This problem can be avoided by using the purified form of active coagulating agents rather than crude extract. This research shows the effectiveness of MO for surface water treatment and also illustrates the great potential of CA and PR as promising bio-coagulants for the treatment of polluted surface water samples. [ABSTRACT FROM AUTHOR]