Transformation of spent broiler litter from exogenous matter to compost in a sub-tropical context

Composting, an environmentally-sound treatment option for confined animal feeding operations (CAFO)-derived wastes, provides opportunities for stabilisation and hygienisation. A 110-day systematic composting study investigated Salmonella presence and survival of total coliforms, faecal coliforms, Escherichia coli and faecal enterococci in three experimental windrows consisting of SBL/bagasse mixture in a close-sided roofed facility. Salmonella was absent throughout the experiment. Log(10) reductions of -6.98, -8.03, -8.18 and -5.96 occurred in TC, FC, E. coli and FE concentrations respectively. As expected, FE exhibited resistance to high temperature compared to E. coli especially for the first 21 days. Temperature histories revealed hygienisation attainment. Differences in mean, representing benchmark stages of composting, were highly significant (P < 0.05) for all pathogen indicators. VSRed (%) proved effective in depicting system progress. Final respiration rate of 0.000206 mg CO2 g(-1) organic-C day(-1) with no phytotoxicity showed the stability achieved. Besides stabilisation, quantitative analysis of the sanitisation potential of composting is elemental for hygienic compliance. (C) 2006 Elsevier Ltd. All rights reserved.