The effect of different mixing ratio on co-composting of yard trimmings and food waste

This paper presents the potentials and performance of combined treatment of yard trimmings (YT) and food waste (FW) in indoor environment through co-composting. The objectives were to investigate the appropriate yard trimmings/food waste mixing ratio. The mixing ratios of yard trimmings to food waste were 0:1, 1:4, 1:2, 1:1 and 2:1 respectively by dry weight/dry weight. The duration of the whole composting process took 42 days. Leachate samples were analyzed for total organic carbon (TOC), chemical oxygen demand (COD), electrical conductivity (EC), pH, redox and organic acids. C/N ratio and germination index were chosen as compost maturity indicators. Results showed that 1:1 mixing ratio was best comparing to others, which the C/N ratio was 14.15 and germination index was 180%, 200% and 185% in seeds of Sorghum saccharatum, Lepidium sativum and Sinapis alba wew.