isopropyl alcohol filter

[sphelps]

I'm looking for some ideas from you guys. I'm in the process of building a kind of automated parts washer which uses isopropyl alcohol as it's only solvent. The system works on a volume principal, very similar to a dishwasher, and has a sump system, very similar to an aquarium. The sump will have a mechanical filter to remove larger particular but because it's not pressurized the fluid relies on gravity alone to be forced through the media so it is limited. The alcohol will eventually become contaminated with small particles and oil. The volume of the system will be between 5 and 10 gallons, I'm aiming for as little as possible.

What I'm currently working on is a way to extend the life of the alcohol to reduce cost and of course environmental impact. So besides distillation anyone got any ideas on a filtration system? The system will be separate and filter the alcohol when the parts washer is not in use, as required. I would like to still use the same pump which is a Panworld 250PS-F, max head 45ft, max flow 1900gph.