Is it permissible to pray and recite Qur’an in a room beneath which runs a sewage drain, given that there is a copy of the Noble Qur’an and a religious library within it?

It is permissible to use what is on the surface of a drum (duff) or similar, if the drum is below and the surface is above it. What is forbidden is to pray on dung heaps. The correct view is the permissibility of praying and reciting the Quran on their surfaces.