I have a couple of quick questions about using glyoxal for sizing.

First, for those who dip the paper in a bath of glyoxal, can you reserve the solution and reuse it or does it need to be thrown out after each sizing session?
Second, if you have to throw it out, is it ok to send it down the drain or do I need to collect it and take it to a hazardous waste facility?

My apologies if these questions have been addressed elsewhere. I have searched, but haven't turned up any answers. Up to now I've been using formalin as a hardener, but am wanting to give glyoxal a try.

Thank you in advance,