FLOCCULATION WITH LYSOZYME: A NON-ENZYMATIC APPLICATION

Bioflocculants have been previously recognized as an alternative to synthetic polymers due to their renewable sources and biodegradability. In this study, the flocculating activity of lysozyme on kaolin suspensions was investigated and compared to a known flocculant, a cationic polyacrylamide. Lysozyme was found to significantly aid in the flocculation of kaolin particles. The flocculating activity of lysozyme on kaolin was affected by the pH of the suspensions, while the addition of Mg2+ and Ca2+ ions did not have a significant effect. Potential industrial applications such as the flocculation of powdered activated carbon and algae suspensions were investigated and the addition of lysozyme resulted in significant flocculation. Furthermore, the flocculating properties of lysozyme are independent of its enzymatic activity. Our results indicate that lysozyme acts as a low molecular mass cationic polymer, where the main mechanism for flocculation on negatively-charged particles is charge neutralization. Other cationic proteins could potentially be used as bioflocculants to enhance solid-liquid separation.