Kiyohiko Nakasaki, Minoru Kataoka and Hidekazu Kuratomi

* Department of Materials Science & Chemical Engineering, Faculty of Engineering, Shizuoka University

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

Abstract

Quantitative analysis on the effects of rising temperature speed in the early stage of composting on the degradation rate of organic materials was made for three kinds of seeds added to the materials. Temperature raise was conducted in two ways. One was a slow raise which took 20hours from room temperature to 60*C[Celsius degeree] and the other was a quick raise which took only 5hours. The effects of raising the speed were found to be dependent on the kind of seeds used for composting. Based on effects on composting, those seeds were assigned to the following 3types:The first one showed a stimulatory effect on composting since it led to satisfactory degradation of organic materials independent of the temperature raise. The second was that giving rise to no significant effects since the degradation of the organic materials was discontinued at any rising speed of temperature. And the third one indicated that the effects of seeding are varied depending on the rising speed of temperature. The microflora in the seeds as well as the changes in microflora in the progress of com-

posting were significantly different among the seeds. Stimulatory effects of seeding were also observed. Thermophilic bacteria quickly proliferated at an early stage of composting and existed at a high concentration around 109cfu/g-ds throughout composting. The concentration of thermophilic actinomycetes reached approximately 107cfu/g-ds in the later stage of composting.

Key words: waste treatment, composting, organic matter degradation, seeding effect, microorganisms