that's a pretty big volume, but we've had success with using waterproofed, reinforced and welded up shipping containers with blowers in them. You can set the whole thing up for probably the amount of money you'd need to rent one and then just leave it in place as a tertiary treatment for later or strip it clean and re-sell the container after you're done with it.
You might end up with the problem that the temporary solution might end up working better than what it's replacing tho. Trickling filters are old-timers by now and you might be able to replace it completely for equal or less than the cost of rehabilitation once you've rented what is probably an expensive piece of equipment.
