Microbial Populations and Enzymatic Activities as Parameters for Characterization of the Composting Process

A. I. Khalil, A. I.; Bin Ali, A. R.; Yaqub, M. M.

doi:10.21608/asejaiqjsae.2012.3169

Microbial Populations and Enzymatic Activities as Parameters for Characterization of the Composting Process

Document Type : Original Article

Authors

¹ Department of Environmental Studies, Institute of Graduate Studies and Research, University of Alexandria, Alexandria, Egypt.

² Department of Environmental Sciences, Faculty of Natural Resources and Environmental Sciences, University of Omar Al-Mukhtar, Al-Bayda, Libya.

10.21608/asejaiqjsae.2012.3169

Abstract

Changes in microbial populations and enzymatic activities during composting process of municipal solid wastes were investigated. Changes in some physical and chemical parameters were also determind. The results showed that the temperature reached the maximum (57.5 ^oC) after 15 days and then decreased. Marked changes in pH value were found. The organic matter (OM) decreased from 61.52% to 48.92% and the the loss in OM reached to 40.1%. The carbon/nitrogen C/N ratio decreased from 25.70 to 11.82. The populations of mesophilic bacteria, actinomycetes, and fungi were greatly decreased with time. The thermophilic bacteria reached the maximum after 30 days and then decreased. The thermophilic actinomycetes reached the maximum after 10 days and then decreased with time until 60 days and disappeared after that. The population of thermophilic fungi reached the maximum after 10 days and disappeared after that. The activity of á-amylase, carboxymethylcellulase (CMCase) and xylanase enzymes was increased and reached the maximum after 10, 20 and 30 days respectively then was decreased.

Main Subjects