Effects of different flocculants and environment on the flocculation effect of potato starch-processing wastewater

ABSTRACT Potato starch-processing wastewater belongs to high-concentration organic wastewater, as direct discharge is more polluting to the environment. Flocculation treatment, as the initial process of wastewater purification, can remove large debris in wastewater, reduce energy consumption for subsequent treatment and reduce production costs. In this study, the effects of traditional flocculants and biological flocculants on the treatment of potato starch-processing wastewater under different pH, dosage, stirring rate and settling time were studied. It was found that traditional flocculants and biological flocculants have their own advantages in the purification ability of organic matter, and the removal rates of suspended solids (SS) and total phosphorus (TP) of traditional flocculants are better than biological flocculants for sweet potato starch-processing wastewater, but the flocculation time and settling time are long. Biological flocculants are environmentally friendly, safe and non-polluting, and do not produce secondary pollution when the flocculation treatment of wastewater is conducive to the secondary reuse of wastewater and flocculation sediment resource treatment. According to the flocculation effect and cost, chitosan is the best flocculant for treating sweet potato starch-processing wastewater.