Comparison of composting of chemically pretreated and fermented sugarcane bagasse for zero-waste biorefinery

Sugar industries produce vast quantity of sugarcane bagasse (SCB) waste which is used as raw material by biorefineries; however, the resulted pretreated waste or fermented residues remain unaddressed. Keeping sustainable utilization in view, recycling of pretreated SCB through composting was conducted for an eco-friendly waste management approach. This study was designed to recycle and evaluate biodegradation of different types of chemically pretreated and fermented SCB that were used as bulking agent under composting condition while untreated SCB set as control. After 112 days, composts were considered mature at 23–29 °C with pH 7.1–7.3 and 30–35% moisture content. Gravimetric analysis and FT-IR spectroscopy suggested that pretreated and untreated composted SCB showed significant cellulose reduction and delignification, respectively. Black gram seeds (Vigna mungo) were selected for phytotoxic test that showed germination index using compost extract > 80%, significantly higher than composted cattle manure and chemical fertilizer. Water holding capacity (WHC) of compost was highest in the case of fermented SCB suggesting the formation of better textured compost. Taken together, composting of chemically pretreated and fermented SCB resulted in improved biodegradation of lignocellulosic waste with better WHC and no phytotoxicity. The results may lead towards the establishment of a zero-waste sugarcane bagasse biorefinery.