Flocculation with Lysozyme: A Non‐Enzymatic Application

Abstract

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.

Experimental methods in chemical engineering: Zeta potential

“…Researchers apply it for colloidal nanoparticle based solutions in medicine, pharmaceutical products, chemical manufacturing, mineral processing, soil and water purification. [8,[39][40][41][42][43] ZP influence intra-cellular trafficking and cellular stabilization in in vitro experiments. [33,[44][45][46][47][48][49] WoS assigned most articles to pharmacology and pharmacy (777), followed by physical chemistry (659), multidisciplinary materials science (583), chemical engineering (515), and multidisciplinary chemistry (493) is the last category in the top five.…”

Chemical and Enzymatic Protein Cross-Linking To Improve Flocculant Properties

“…Failure of chitosan flocculants in an erosion control study was partially attributed to relatively low MW of chitosan compared to synthetic polymeric flocculants. Proteins are being increasingly recognized for their potential as biobased flocculants. − Proteins derived from agricultural byproducts can be inexpensive, and some, such as hemoglobin from slaughterhouse blood, display good flocculant properties.…”

Surface interaction between phyllosilicate particles and sustainable polymers in flotation and flocculation

“…12,13 Application of various types of these "biopolymers" as kaolinite clay occulants has been comprehensively researched. [14][15][16][17][18][19] A few studies have reported the effectiveness of various biopolymers to improve otation and occulation processes in mineral processing. found that chitosan (the amine-based polysaccharide) could depress chalcopyrite (copper ore) selectively in the otation of copper-lead ores.…”

“…18 Y. C. Ho (2010) 12 considered the effect of pectin for occulation of kaolinite particles, and it was found that pH 3 was the optimum treatment condition for pectin occulating activity. 26 Bonilla (2015-2017) 14 studied the effectiveness of proteins (protamine and lysozyme) on the dewatering of pulp and paper mill biosludge and found that lysozyme showed higher occulating activity. 14,27,28 Previous studies only focused on kaolinite clay particles and the potential of biopolymers to mitigate other types of phyllosilicates in otation and dewatering has not been evaluated.…”

“…26 Bonilla (2015-2017) 14 studied the effectiveness of proteins (protamine and lysozyme) on the dewatering of pulp and paper mill biosludge and found that lysozyme showed higher occulating activity. 14,27,28 Previous studies only focused on kaolinite clay particles and the potential of biopolymers to mitigate other types of phyllosilicates in otation and dewatering has not been evaluated. More importantly, the main mechanism of interaction between biopolymers and clay surfaces is not yet well understood and has not been considered yet.…”