WEF Discussion Forums
Operation and Maintenance
Polyethylene Glycol Treatability
We have an industry that wishes to discharge a waste containing Polyethylene Glycol (PEG) which is used in the process of cutting silicon wafers. It has a COD in the millions (!!) but a BOD of only around 50,000 mg/l, so it does not seem to be very amenable to aerobic treatment. Incidentally, WW plants have been receiving PEGs for quite a while as certain of them are used in the stuff you get to drink the night before a colonoscopy!!! Whatever, my question has to do with whether anyone has determined in PEG's are treatable by ANaerobic digestion. AND...how would you test anaerobic treatability??
PS: don't confuse PEGs with antifreezes. They are related to the propylene glycol in antifreeze but are much larger molecules with sizes from 400 to 1000 daltons.
I would suggest you contact your local university that has an civil/environmental engineering laboratory. Most should be able to perform a sludge degradability test that will indicate the toxicity of this chemical, which will tell you how slow to bleed it into the system.
As far as Anaerobic - this should be perfect for treating glycol. Anaerobic treatment is best at treating high concentrations of waste but may not completely remove all COD/BOD and the sidestreams will likely be more potent, so be sure the aerobic system can tolerate this.
The large influx of high strength, low solids waste will be greatly beneficial for gas production without impacting solids handling.