The dairy processing is considered a major source of food industry-based wastewater generation. Due to the higher organic load, fatty oil content, lower pH, and stenchful odor, it poses critical challenges for effluent treatment plants. The flocculation process plays a crucial role in stabilizing the extreme colloidal load of dairy effluent. During this flocculation process, a group of chemical species called flocculants interacts with colloidal particles and forms stable aggregates, facilitating their removal from wastewater. The biological flocculants derived from plants, fungi, and bacterial sources are thought to be eco-friendly alternatives for conventional polyelectrolytes used for flocculation. Potato starch offers abundant opportunities for developing bioflocculants suitable for dairy effluent treatment due to its abundant availability, high molecular weight, and ease of chemical modification. On the other hand, the wastewater treatment efficacy of fungi and bacterial flocculants is also well established. Fungal mycelia, fungi-derived polysaccharides, and their spores have been proven as potential candidates for effluent treatments. Similarly, bacterial extracellular polymeric substances (EPS) hold strong records for their excellent flocculation abilities. Most of the bacteria and fungi-based flocculants are produced by fermentation and are ready to use with minimal downstream processes. Since the potato starch does not have a spontaneous flocculation property, it needs chemical modifications such as grafting or ionization. These modifications increase the solubility and ionization potential of starch. The biological flocculants have exhibited removal of turbidity, color, COD, BOD, metals, pathogens, and sludge dewatering efficiencies in several industrial wastewaters. However, further improvements are required to bring their application to an industrial scale.
