Oil-Water Emulsion Flocculation through Chitosan Desolubilization Driven by pH Variation

Water pollution isa major concern in our modern age. The contaminationof water, as a valuable and often limited resource, affects both theenvironment and human health. Industrial processes such as food, cosmetics,and pharmaceutical production also contribute to this problem. Vegetableoil production, for example, generates a stable oil/water emulsioncontaining 0.5-5% oil, which presents a difficult waste disposalissue. Conventional treatment methods based on aluminum salts generatehazardous waste, highlighting the need for green and biodegradablecoagulant agents. In this study, the efficacy of commercial chitosan,a natural polysaccharide derived from chitin deacetylation, has beenevaluated as a coagulation agent for vegetable oil emulsions. Theeffect of commercial chitosan was assessed in relation to differentsurfactants (anionic, cationic, and nonpolar) and pH levels. The resultsdemonstrate that chitosan is effective at concentrations as low as300 ppm and can be reused, providing a cost-effective and sustainablesolution for oil removal. The flocculation mechanism relies on thedesolubilization of the polymer, which acts as a net to entrap theemulsion, rather than solely relying on electrostatic interactionswith the particles. This study highlights the potential of chitosanas a natural and ecofriendly alternative to conventional coagulantsfor the remediation of oil-contaminated water.