De or het vochttoediening?

The correct Dutch article is:

de vochttoediening

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

How to use vochttoediening

the vochttoedieningde vochttoediening
this vochttoedieningdeze vochttoediening
that vochttoedieningdie vochttoediening
our vochttoedieningonze vochttoediening
your vochttoedieningjouw vochttoediening
every vochttoedieningelke vochttoediening
which vochttoediening?welke vochttoediening?
a big vochttoediening / the big vochttoedieningeen grote vochttoediening, de grote vochttoediening