Degradation of High Concentrations of Glycols , Antifreeze , and Deicing Fluids

A microbial consortium (EG-c) capable of degrading high concentrations of glycol-based waste was isolated from soil enrichments. The isolate primarily responsible for glycol degradation was a gram-negative rod (EG-y) that produced a water-soluble pigment. Initial laboratory experiments measured the degradation of ethylene glycol (EG) and propylene glycol (PG) at 25OC. Cell biomass optical densities increased (660nm) from 0.01 to 0.5 within 48 h and reached a miximum of 0.73 at 72 h. Respirometry experiments showed oxygen consumption rates of ca. 1, OOO mgwday with glycol degraded at a rate of ca. 2,000 mg/L/day, (confirmed with gas chromatography). Laboratory tests were expanded to evaluate the degradation of a commercial antifreeze (primarily EG based) and two deicing fluids (one PG and one EG based) at both 25 and 4°C (a more realistic winter temperature).