Abstract
Considerable attention has been paid to the bio-treatment of lipid-rich wastewater discharged from the kitchens of many kinds of restaurants, but it is still technologically undeveloped in terms of lipid-degrading microorganisms' abilities, cost performance and wastewater treatment system, etc. In this study, for developing the practical system of bio-treatment of such a lipid-rich wastewater, we isolated bacteria capable of strongly assimilating lipids (salad oil, lard, beef tallow, and olive oil) from soil samples. The bacterium, strain AIK, with the highest lipid degradation ability was identified as Burkholdia cepacia and also confirmed to be a non-pathogenic and safe bacterium based on animal tests and so on. The CSL medium containing 3% CSL (corn steep liquor) and 1% glycerol was favorable and effective for the growth of the bacterium and its lipid-degrading activity. Fieldworks at drainage facilities of practical fast food restaurants were successfully done by using the strain AIK and our developed system with the water pump which is instantly applicable to existing facilities and is reasonable in terms of cost. As an example of it, we report here a representative example of a fast food restaurant showing that lipid concentration was rapidly decreased from 1100mg/L to 100mg/L.
