Effects of brown sugar and calcium superphosphate on the secondary fermentation of green waste

► A two-stage composting (with primary and secondary fermentations) is described. ► Brown sugar and calcium superphosphate are evaluated as fermentation additives. ► Maturity time is shortened and maximum of fermentation temperature is attained twice. ► Physico-chemical characteristics explain the rapid decomposition of green waste. ► pH, C/N ratio, organic matter, GI value, void ratio, and particle size are optimized.