Generation and Collection of Biogas:
For the generation and collection of total gas produced, the digesters were fed with the slurry, prepared above and then sealed before the end of the PVC tube from the digester was connected to the inlet of a Buckner flask containing some quantity of silica gel, which served as a drying agent. The digesters were then jacketed in polyurethane form to minimise the temperature changes in the digester. Another PVC tube was connected to the outlet of the Buckner flask and the other end of the tube was connected to separate inverted 1000 cm3 capacity measuring cylinders which was filled with water. The downward displacement of water in each measuring cylinder was taken as a measure of the volume of biogas produced for each digester, and the volume of daily biogas production for each digester was recorded separately.