9907333 Higgins The objective of this project is to develop a fundamental understanding of the interactions between cations and exocellular biopolymers produced by microorganisms during processing of wastewaters in suspended growth bioreactors. The project will address factors that affect aggregation of bacteria into flocs, their settling characteristics and dewaterability. Previous work has shown that lecitins, a class of proteins produced by many bacteria, can provide bridging opportunities for the formation of bioflocs. The initial focus of this work will be to determine the role that lecitins play in binding polysaccharides and cations as a step toward obtaining a better understanding than now exists of biofloc formation. Laboratory bioreactors will be used to study the effect of operational factors including the source of cations and their concentrations. Sources to be investigated will include calcium, magnesium, sodium and iron and operational conditions will include mean cell residence time. Floc samples will be analyzed for their stability, settling and dewateringl properties.
Results of this project are likely to improve the engineering design and operation of wastewater treatment processes that are based on use of suspended growth biofloc reactors. This research therefore has the potential of significantly improving the efficiency of biological treatment processes with the resulting decrease in capital and operation expense and/or improvement in the efficiency of processes based on use of suspended biologically active flocs.***
