Fungal bioflocculants are potential and eco-friendly flocculating agents that have been identified as powerful flocculating agents in wastewater bio-treatment. This chapter gives an inclusive description of fungal bioflocculants such as their characterization, mechanisms, exploitation, and applications in wastewater bio-treatment. First, characterization includes identification of fungal strain as bioflocculant-producing fungi, methods of extraction, and their physicochemical properties, such as molecular weight, charge density, and structure. Many fungal strains, such as Aspergillus, Penicillium, and Rhizopus, as bioflocculant-producing strains, have already been identified, and polysaccharides are their major constituents. Mechanism of action includes several mechanisms, which involve bridging, charge neutralization, and hydrophobic interaction, causing suspended particles to come into contact. The effectiveness of these systems is determined by things like pH and temperature as well as the presence of ions. What makes fungal bioflocculants advantageous over chemical flocculants, apart from being biodegradable with few secondary pollutants, is that they can be made using cheaper materials. For example, agricultural waste or even the wastewater itself can serve as substrates for their production, thereby making it more sustainable. Fungal bioflocculants have great potential in removing suspended solids, organic matter, heavy metals, and pathogens during wastewater treatment. They have been employed in different types of coagulation-flocculation systems together with other treatment methods or alone alongside sedimentation and filtration units, among others. Therefore, fungal bioflocculant represents one way toward sustainable wastewater management through efficient contaminant elimination while minimizing environmental impacts associated thereof. Further research is warranted to optimize production methods, elucidate mechanisms, and upscale applications for broader implementation in wastewater treatment systems.
