Development of cross-linked bio-based flocculants for the removal of colloidal suspensions

M. Essandoh, R.A. Garcia, C.M. Nieman
United States Department of Agriculture,
United States

Keywords: biodegradable flocculant, colloidal particles, bridging mechanism, protein cross-linking


Abstract/Summary Over the past several decades, there have been increasing demand for environmentally friendly substitutes for synthetic polymeric flocculants. Various industries that are the forefront in this pursuit include wastewater treatment, mining, petroleum, as they all challenged on daily basis to effectively remove fine suspended particles from their wastewater streams. Unfortunately, when one of the most commonly used synthetic organic flocculants (polyacrylamide) is employed, the carcinogenic and mutagenic nature of its monomer and derivatives have caused a lot of public disapproval. Our lab have found some bio-based materials (proteins) to naturally promote the flocculation of aqueous suspensions, but these materials are much smaller than modern polymeric flocculants, and they are often not as potent. In this study, we enhanced the clarification ability of the proteins and converted a non-flocculant (0% clarification) to a super-clarifying agent (~98% clarification) through crosslinking. This presentation will therefore give an overview of flocculants (clarifying agents), the development of crosslinked bio-based material through enzymatic and chemical means, detailed characterization of the cross-linked materials and it potential application as a clarifying agent.