As the world population increased the consumption of water and water treatment becomes critical. So, this research investigates the use of banana peel waste as a natural coagulant, eco-friendly modification of coagulation, synthetic water turbidity reduction, and river water purification. In this case, the typical particle size of the banana peel powder were 978 & PLUSMN; 37 nm, and modified powder were 571 & PLUSMN; 41 nm. The effectiveness of the coagulation was examined at various pH values, dosages, sedimentation periods, and NaCl concentrations. Up to 90% turbidity removal with 0.4 g/L of modified banana peel was found. While the coagulation performance was somewhat improved at concentrations of less than 0.4 g/L of NaCl, the activity was reduced, even in the modified powder, at higher concentrations. Banana peel powder significantly reduced watercolor, total dissolved and suspended solids, and chemical and biochemical oxygen demand in river water but only reduced turbidity by 75% and 83%, respectively, for non-modified and modified powders. The coagulation process was investigated and confirmed using SEM and FT-IR spectroscopy. Banana peel powder modified in this environmentally friendly way has a lot of potential as a cheap and accessible bio-coagulant and can likely help to decrease wastages.