OP, does the pump have any sort of "connector" or attachment inlet? Based on the pictures, it just looks like it would and not be exposed as is. Usually all pumps would have this where additional connectors would fit. You then can even add threaded connectors for future removal if needed. Although, none of this works if the size doesn't fit, I realize.
I assume the pump is basic "ABS". If so, I would think any transition PVC/ABC glue would work. Again, assuming the parts fit. But just something for you to know if case you ever do glue PVC/ABS. I use that to glue PVC to my bulkheads. Weld-on and other brands have this, FYI.