Abstract:

Carbon dioxide (CO2) and ammonia (NH3) are the two main gases emitted as a result of aerobic biological composting. CO2 is a green house gas and NH3 can produce odour problem. CO2 emission can reduce the carbon (C) content and NH3 emission can reduce the nitrogen (N) content in the final compost.  In this study, the influence of brewery sludge, amendments, C/N ratio, starting culture and aeration rate on the percentage losses of C and N in terms of CO2 and NH3 respectively are experimented using Taguchi’s L8 orthogonal array with two replications. An in-vessel reactor with forced aeration system using synthetic organic fraction of municipal solid waste (OFMSW) and brewery sludge (BS) with provision for trapping CO2 and NH3 was used. The analysis of the results show that the most significant factors influencing the reduction in the loss of C as CO2 were amendment (coconut pith) and C/N ratio and in reducing the loss of N as NH3 was the interaction between BS and coconut pith.

Keywords: carbon dioxide, ammonia, co-composting, OFMSW, BS