In the rectangular agitated in-vessel composting bioreactor
In the rectangular agitated in-vessel composting bioreactor, the waste is placed in the infeed conveyor. The extraction conveyor moves to mix the compost. To prevent heating up and aerate the compost material, oxygen is supplied by forced aeration through the plenum and blowers at the bottom of the bed. Tumbling or mixing occurs at regular intervals to agitate the material, break up clumps and maintain porosity before discharging it in the outfeed conveyor (FAO, 2003). After a retention time of 6-12 days in the bin, the material is windrowed for 1-2 months i.e. the curing period until stability is reached. The horizontal rectangular tank is well suited for sewage sludge, MSW and mixtures of MSW and sludge (Tchobanoglous et al., 2002).