impollute
/ɪmpɒˈluːt, ɪmˈpɒluːt/Definitions
1. verb
to prevent or make it impossible for something to be polluted
“The new law aims to impollute the nearby river and protect the local wildlife.”
2. verb
to free from pollution
“The company worked hard to impollute the contaminated site and restore it to its former state.”