The gas agitation can promote the mixing between continuance phase and dispersed phase. At the same times , droplets of dispersed phase can be broken up to a small one.

Some topics such as digestion approach, reactor volume and dimension, agitation, heating and gas collection system are discussed in this paper concerning Process Design for Sludge Anaerobic Digestion.

Mechanical agitation, can be equipped with special air sparger, make mechanical agitation combined with gas litres of mixing, reduce power consumption.