'Loop' here is 'loophole', something that allows things that shouldn't happen to happen. This technotoilet has shut out the possibility of such things happening.
For example, most toilet devices work well so long as only faeces and urine are deposited in them. As soon as other matter is deposited, things go wrong (the 'loophole' if the manufacturers claim that their system can deal with all organic wastes - many toilets can't cope with potato peelings). Presumably the technotoilet can cope with potato peelings, pineapple tops and grass cuttings.
Mind you, the last sentence seems to suggest that this system also provides drinking water. hmmm ... no thanks.
Student or Learner