Composting Cattle Dung Wastes by Using a Hyperthermophilic Pre-treatment Process

• Published in: Journal of bioscience and bioengineering Vol. 104; no. 5; p. 408
• Main Authors: Yamada, Takeshi, Miyauchi, Keisuke, Ueda, Hideyo, Ueda, Yasuichi, Sugawara, Hiroyuki, Nakai, Yukihiro, Endo, Ginro
• Format: Journal Article
• Language: English
• Published: Osaka Elsevier Limited 01.11.2007
• ISSN: 1389-1723; 1347-4421

To solve malodorous odor problems by ammonia emission in composting of cattle dung wastes, we developed an alternative composting method consisting of a hyperthrmophilic pre-treatment reactor (HTPRT) (first step) combined with a general windrow post-treatment system (WPOT) (second step). In this study, physicochemical and microbiological differences in compost materials during the HTPRT-WPOT process and a simple windrow composing process (SWC) were investigated. The HTPRT-WPOT process removed excess ammonia in the compost materials by physical ammonia stripping, and controlled the malodorous ammonia emission. The organic matter evolution index showed that the HTPRT-WPOT process also contributed to accelerate formation of humic acids in composting. Quantitative real-time PCR analyses using Bacterial-, Archaeal- and fungal-protozoan-specific primer sets showed that small subunit ribosomal RNA (SSU rRNA) gene copy numbers differed much between composting materials of these two processes. Particularly, the SSU rRNA gene copy of eukaryotic microbes (fungi-protozoa) in the HTPRT-WPOT process was much higher than in the SWC process. From these results, we conclude that the HTPRT-WPOT process has great advantages for the control of malodorous odor problems caused by ammonia emission, and for high rate of composting evaluated by the humification rate and microbial characterization of the composting materials.