Location: Dairy and Functional Foods ResearchTitle: Influence of methylation and polymerization on flocculant properties of bovine blood
Submitted to: ACS Omega
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/31/2021
Publication Date: 1/12/2022
Citation: Lee, C., Garcia, R.A., Bumanlag, L.P., Liang, C. 2022. Influence of methylation and polymerization on flocculant properties of bovine blood. ACS Omega. https://doi.org/10.1021/acsomega.1c06126.
Interpretive Summary: Modern wastewater treatment relies on synthetic polymers for removing solid contaminants. While these polymers are very effective, they are made from non-renewable resources, they persist in the environment, and they may have negative human health impacts. Past research has shown that slaughterhouse blood can serve as a bio-based substitute for these polymers, but also that it has limitations. In the present research it is shown that certain simple chemical treatments can overcome blood’s limitations and make it a better substitute for the conventional polymers. Such modified blood may provide a biodegradable, renewable, and safe alternative to the substances currently used in wastewater treatment.
Technical Abstract: Flocculants are used in the primary step of wastewater treatment to precipitate solids. Bovine blood is a slaughterhouse by-product, and there is limited evidence in the literature demonstrating that it can be used as a flocculant. In this study, native bovine blood (NBB) and three types of chemically modified blood (methylated bovine blood (MeBB), polymerized bovine blood (PolyBB), and polymerized & methylated bovine blood (PMBB)) were tested against suspensions of negatively charged kaolin or positively charged hematite. The methylation reaction had the expected effect of increasing the apparent isoelectric point of MeBB and PMBB relative to that of the NBB starting material, and the polymerization reaction had the intended effect of increasing average molar mass. NBB and PolyBB performed well with kaolin suspensions at pH =5.5, and MeBB showed high and consistent performance, across the pH range from 4.5 to 8.5. Relative to NBB, MeBB had improved potency and pH-independence, but also the disadvantage of being more sensitive to overdosing; PolyBB’s performance was very similar to that of NBB. PMBB had performance enhancements similar to those of MeBB, with modest improvement in its overdose sensitivity. The performances of MeBB and PMBB with hematite suspensions were poor at all tested doses (2-100 mg/g hematite), whereas a 30 mg/g dose of PolyBB showed 81% precipitation in an hour. The results show that simple chemical treatments can improve the utility of blood as a flocculant for negatively charged solids.