Microbial and Physicochemical Properties of a Regulated Compost

Abstract

Composting is one of the universally accepted methods of waste disposal which has become a waste management option in the developing countries. In this study, which was conducted to assess the microbial population dynamics in regulated compost. Organic wastes (Cassava peel, poultry droppings and grass clippings) was decomposed by selected inoculants (Pseudomonas sp., Bacillus sp., Aspergillus sp., Pleoretus ostreatus and Chlorella vulgaris-green algae). Fourteen perforated plastic pots were used as composting reactors with varying compositions of inoculants in the reactors. Seven set up containing organic waste was autoclaved while the other seven were not autoclaved and sawdust was used as bulking agent. The microbiological and physicochemical parameters of the compost were monitored as the composting proceeded. The microbial population ranged from 1.05 X102 and 4.15 x1011 CFU/g of bacterial count and between 1.05X101 SFU/g and 2.10x107 SFU/g of fungal counts for the un-sterilized samples while the microbial population in the pre-sterilized samples ranged between 1.07X101 and 7.62x1011CFU/g of bacterial count and 1.05 X101SFU/g and 6.32x105 SFU/g of fungal count. The bacterial population showed increase with decreasing total organic carbon, total organic nitrogen, Phosphorus and potassium, with a corresponding increase in conductivity, nitrate and pH. Bacterial population declined as the substrates stabilized and microbial consortium in set six and thirteen were most effective in breaking down the waste with a maximum temperature of 28°C. This study have shown that the consortium of Aspergillus spp. Chlorella vulgaris, Pleoretus ostreatus, Pseudomonas spp. and Bacillus spp. could be effectively employed in waste management; as it is able to degrade waste and it is worthy of note that organisms utilize waste as carbon source for the generation of energy required to carry out their decomposition, therefore cleaning up our environments. This decomposed waste could be amended /fortified with nitrogen fixing bacteria to produce a good bio-fertilizer for landscaping and agricultural purposes.