Influence of composting techniques on microbial succession, temperature and pH in a composting municipal solid waste

Abstract

Composting of urban wastes was carried out using both passive aeration technique (PACT) and conventional pit method. Feacal coliforms, Pseudomonas, Streptococcus, Proteus , Seratia and Bacillus species as well as fungi were isolated at mesophilic stage of degradation. A number of these microorganisms did not grow at the thermophilic stage but grew at cooling down stage. The trends in microbial succession in the composting wastes in pot and pit were somewhat similar. There was, however, repeated re-heat after turning the wastes in the pit until about 5 months later. Each time the waste was turned in the pit, there was an increase in temperature until the 21st week. Temperature however, stabilized at the 7th week in the pot. pH also stabilized as the composting process progressed in the pit. Good quality compost was obtained in 5 weeks when PACT was used. Conventional pit method lasted over several weeks.


Key Words: Municipal wastes; passive aeration; pit composting; temperature; microbial succession.


African Journal of Biotechnology Vol. 3 (4), 2004: 239-243