Use of Moringa oleifera seeds powder as bio-coagulants for the surface water treatment

The research aims to evaluate the effectiveness of surface water treatment by using Moringa oleifera seeds by-products as bio-coagulant to remove turbidity and natural organic matter. This approach brings more benefits as compared to others, particularly, no chemical use, low cost, easy to implement but equivalent efficiency and also safe for the health. The surface water samples were collected from three sites in the Dong Nai River, Vietnam, with the average concentrations of pH, turbidity, chemical oxygen demand (COD) and total Kjeldahl nitrogen (TKN) ranging from 6.2 ± 0.3 to 6.7 ± 0.2, 25.2 ± 2.5 to 41.7 ± 7.9 NTU, 22.4 ± 6.4 to 41.1 ± 5.9 mg L−1 and 0.70 ± 0.20 to 1.08 ± 0.15 mg L−1, respectively. The study has found that the optimum bio-coagulant dosage was 0.15 ml L−1 for the water samples in both rainy and dry seasons. In the rainy season, the turbidity removal efficiencies in Tan Luong Ferry, Nguyen Van Tri Park and Hoi Son Ferry ranged from 87.8 ± 2.9 to 93.3 ± 1.0%, while the tendency for dry season was obtained from 85.7 ± 2.5 to 94.3 ± 1.1%, respectively. The treated turbidity concentration met the Vietnam’s National Technical Regulation on domestic water quality. Furthermore, the paired t tests used to compare the pre-treatment and post-treatment dataset for COD and turbidity removal efficiencies were significant (p < 0.05) in three studied sites. Results indicated that Moringa oleifera extract is a promising material which is environmental-friendly and low cost to treat the surface water.