Removal of fluoride and aluminium using plant-based coagulants wrapped with fibrous thin film

Abstract

Abstract The coagulation activity of Moringa oleifera seed and Hibiscus esculentus (okra) mucilage were assessed for their ability to remove both anionic and cationic contaminants in aluminium sulphate and hydrofluoric acid synthetic wastewater. The effect of encasing these coagulants in a fibrous thin film along with their effect on pH and concentration were also assessed. Assessment using the jar test showed a 79.9% aluminium reduction and 91.7% fluoride reduction using okra mucilage and Moringa oleifera, respectively. Besides that, there was no effect on both the pH and coagulation activity in the application of fibrous thin film. The plant-based coagulation activity is comparable with conventional coagulant as fluoride removal treated by polyaluminium chloride formulation was 85.3 ± 0.8% with the optimum dosage of 3 g/L. The significance of these findings in the application of fibrous thin film with plant-based coagulants could be an advantage for industries to commercialise mechanically prepared coagulants, which has a much longer shelf life as compared to chemically prepared coagulants, as it has the potential to reduce the turbidity associated with mechanically prepared coagulants. Also, these results indicate the possibility of having a cost-effective yet environmentally friendly water treatment solution that combines the application of both plant-based and conventional coagulants.