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

Abstract

ABSTRACTAn 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.