Don't you think the requirements of a sustainable moon base might have some spin offs in areas like water and air purification as two easy examples?
Probably not. Those are problems that have been extensively studied over the last century for a variety of reasons. I imagine existing solutions will be used.
Historically, the cross over from space exploration to other situations has been surprisingly small. Doing stuff that could be done in labs on Earth at the end of long and exceedingly costly supply chains is unlikely to be a cost effective way to approach most things.
Of course, some stuff can't be done on Earth, but I don't see a moon base -- or the ISS for that matter -- as being the best way to get that research done. I think Skylab -- an orbiting laboratory that is occupied for a while every now and then to do complex experiments that actually need to be done in space and can't easily be done using unmanned vehicles was probably a better approach.
Moonbase? Not a current need I think. Instead, spend a lot less, spend a couple of decades looking at the moon intensively with rovers and low altitude observation satellites. Then -- If there is stuff that actually needs human inspection, by all means, send some folks out to look at it.