Chapter 5: Conclusions and recommendations

Most of the OFUSW components tried out had good biogas production potential. They promise high gas yields at residence time similar to that of aerobic composting.

Solid-state stratified bed reactor approach can be used to ferment components of USW with small corrections for their fermentation pattern.

Under SSB fermentation conditions, following pattern was observed:

•  OFUSW will undergo >50% VS conversion. A greater VS destruction is also possible if the proper start up procedures employed.

•  A significant part of the VS lost was not accounted as gas production. Appropriate steps to raise efficiency are needed.

•  The liquid recycling rate adopted was high and did not uniformly leach the biomass bed. Its design needs to be improved.

•  A part of the methanogenesis occurred in the digester liquid outside the digester as seen from profuse bubbling.

Liquid waste treatment carried out under DFFBR mode shows:

That the bagasse and leaf biomass could form a long functioning biofilm support. The flow pattern through the support needs to be improved to harness a high conversion potential.