IFM was approached by a transmission manufacturing facility with the intent to prove ultrafiltration as a primary treatment technology. Previously about 350,000 gallons of old spent coolant was stored on site in tanks waiting for disposal. Another company completed initial demonstration testing to determine that an ultrafiltration system could further dewater / concentrate the material. IFM then utilized a system from inventory that would concentrate the waste and minimize the hauling costs.
The membrane assembly that was used is known as the FEG™ tube manufactured by Koch Membrane Systems. It was designed to separate the emulsified feed into two separate streams: a high concentrated oily waste stream and a low concentrated waste stream.
After startup it was difficult for the process fluid to filter through the membranes and it was determined that they were fouled. The membranes were sent to MicroVision Laboratories for microscopic and spectroscopic examination. IFM used this information and determined that membrane cleaning must occur.
With oxidant cleaning followed by alkaline surfactant wash the membranes would remove the foulants and return the membranes to near acceptable level. With the concentration of the waste, cleaning of the membranes and separation of the two feeds, IFM successfully minimized the amount of waste stored on site to be disposed of by discharging the clean water.
Attached is the MicroVision Laboratories membrane report and the full case study.