Performance of co-composting sewage sludge and organic fraction of municipal solid waste at different proportions

• DOI: 10.1016/j.biortech.2017.08.136
• Publication Date: 2017-08-25T01:17:55Z
• Authors: Difang Zhang; Wenhai Luo; Yun Li; Guoying Wang; Guoxue Li
• Keywords: Sewage sludge; Fraction (chemistry); Thermal hydrolysis; Biodegradable waste; Urban waste

In this study, the co-composting performance of sewage sludge (SS) and organic fraction of municipal solid waste (OFMSW) at different proportions was investigated. Cornstalk was added at 15% (of total wet weight) to improve the co-composting process. Results show that higher SS proportion could rapidly initialize the co-composting process; while increasing OFMSW percentage enhanced organic content for biodegradation, thus prolonging the thermophilic period and increasing the humification degree during co-composting. However, excessive OFMSW required longer co-composting period to ensure a desirable compost maturity and quality. Over 15days of rapid co-composting, adding 55-85% OFMSW aggravated compost quality by increasing the compost salinity (3.5-4.6mScm-1) and plant toxicity (indicated by the low germination index of 54.1-77.3%). Moreover, different proportions of SS and OFMSW varied gaseous emissions during co-composting. Our results suggested that OFMSW should be less than 55% for rapid co-composting with SS and cornstalk.