In the domain of wastewater treatment, flocculation and coagulation are widely utilized. In search of an ecologically-friendly approach, the flocculation and coagulation properties of starch-based flocculants are analyzed herein. The investigation was conducted using flocculants derived from potato starch. The goal was to evaluate the removal of particles and nutrients, such as phosphorus. The trials were undertaken using two different cationic and three different anionic flocculants. Pig manure was treated by means of separation with a fine filter and flocculation. Separation and flocculation using the cationic flocculants resulted in a separation of 79% phosphorus, as well as a reduction in dry matter by 69%. Trials were carried out that included separation and flocculation with cationic and anionic flocculants, which achieved a separation of 86% phosphorus, as well as a dry matter diminution of 75%.