Kiyohiko Nakasaki*, Hidekazu Kuratomi*, Hiroaki Wakizaka*, Reiko Hiyama* and Koichi Fujie**

* Department of Materials Science and Chemical Engineering, Shizuoka University
** Toyohashi University of Technology

+ Correspondence should be addressed to Kiyohiko Nakasaki:
(3-5-1 Johoku, Hamamatsu city 432-8561 Japan)

Abstract

The ammonia and odorous sulfur compounds generated in aerobic composting processes were measured by the titration method and by gas chromatography, respectively. The composting temperature was set at two different points, 50*C[Celsius degeree] and 60*C[Celsius degeree], and the concentrations and cumulative quantities of odorous compounds generated by these two composting processes were compared. Under both operational temperatures high concentrations of methyl melcaptan (MMC), dimethyl disulfide (DMDS), and NH3 were generated by the composting process after 50 hours had elapsed, when approximately 40% of the carbon in the raw material of compost had been converted to CO2. In contrast, dimethyl sulfide (DMS) was generated only in the 50*C[Celsius degeree] composting process. It was also confirmed that the generation pattern for the odorous compounds in the two composting processes differed with the cumulative quantities of MMC and NH3 generated at 60*C[Celsius degeree] composting, the patterns of the latter being larger than those generated at 50*C[Celsius degeree] composting process. However, the differences in the actual quantity of these compounds generated at the two composting temperatures were relatively small.

Key words: composting, micro-organisms, odor, odorous sulphur compounds, ammonia