Optimization and application of banana stem-derived coagulant for domestic wastewater treatment

Abstract Chemical coagulation of wastewater has several problems, including the management of sludge, expense, safety issues, and environmental contamination. To ascertain whether banana plant stem (Musa acuminate) coagulant can efficiently remove contaminants from wastewater, a study was carried out. In this study, a coagulant was extracted from the stem of banana plants using the conventional hydrothermal extraction (CHE) method, with NaCl as the solvent at concentrations of 0.1 M, 0.5 M, and 1 M. Again central composite design was used to study the effect of variation in levels of mixing time (min), the dose of coagulant (mg/l), and pH to remove COD (mg/l), TSS (mg/l), and alkalinity (mg/l) of wastewater. The maximum COD (mg/l), TSS (mg/l), and alkalinity (mg/l) removal obtained by banana stem coagulant during wastewater treatment were 65.3%, 76.5%, and 59.4%, respectively. The independent variables’ main and interaction effects were discussed for coagulant preparation and wastewater treatment. Finally, an optimal condition of 14.61 min mixing time, 62.92 mg l −1 doses of coagulant, and 5.93 pH was obtained with a desirability of 0.76.