Coagulation Performance of

The tofu processing industry generates significant amounts of wastewater, causing serious environmental challenges in Manokwari, West Papua. Protein extracted from Terminalia catappa seeds has potential as a natural coagulant for reducing the Total Suspended Solids (TSS) and turbidity in tofu wastewater. In this study, protein Terminalia catappa seeds (PTcS) were characterized using Fourier transform infrared spectroscopy (FTIR), and the effects of coagulant dosage and coagulation time on pH, TSS removal, and turbidity reduction were investigated. The results demonstrated that the coagulation efficiency of protein from Terminalia catappa seeds strongly depended on the wastewater pH. The optimum coagulant dosage was 1.2 g/L, achieving TSS and turbidity removal efficiencies of 90.74% and 57.55%, respectively, with an optimum coagulation time of 5 min. FTIR spectra revealed the presence of hydroxyl, aromatic, and carbonyl groups, indicating that phenolic compounds and proteins were the main active components contributing to coagulation. These findings highlight the potential application of Terminalia catappa seed as an eco-friendly and effective coagulant for tofu wastewater treatment.