De or het volumevermindering?

The correct Dutch article is:

de volumevermindering

Rule Words ending in -ing: almost always de. See the rule

How to use volumevermindering

the volumeverminderingde volumevermindering
this volumeverminderingdeze volumevermindering
that volumeverminderingdie volumevermindering
our volumeverminderingonze volumevermindering
your volumeverminderingjouw volumevermindering
every volumeverminderingelke volumevermindering
which volumevermindering?welke volumevermindering?
a big volumevermindering / the big volumeverminderingeen grote volumevermindering, de grote volumevermindering