Composting of Biodegradable Organic Waste from Thai Household in a Semi-Continuous Composter

ABSTRACT

An 80-L prototype of a home composter was designed to be possibly applied in households with 4–6 members. Biodegradable waste generation was assumed to be 1–2 kg d⁻¹. The composter consisted of a waste chamber, a pair of 12-cm diameter aeration fans, and an agitator. Five experiments with various feeding rates, mixing frequencies, and composting periods were conducted using a semi-continuous compost process under partially aerobic conditions. Tested were a feeding rate of 1 or 2 kg d⁻¹ and a stirring frequency of 12 or 24 times d⁻¹, the organic content of the compost was 58%–78%, and total nitrogen, phosphorus, and potassium were 1.3%–1.9%, 0.1%–0.2%, and 0.5%–1.0%, respectively. The compost was dark brown and odorless. The compost all passed a 12.5-mm mesh, while over 85% passed a 2-mm mesh. It is suggested that with a feeding rate of 1–2 kg d⁻¹ the composting period should be 30 d. If the composting period has to be as short as 15 d, the feeding rate should be only 1 kg d⁻¹.

ACKNOWLEDGMENTS

Technical support provided by Kasetsart University and Thammasat University are gratefully appreciated. The authors are indebted to Dr. Wouter van Doorn for correcting the English.

FUNDING

The authors would like to thank the National Research Council of Thailand for financially supporting this study.