Role of biochar amendment in mitigation of nitrogen loss and greenhouse gas emission during sewage sludge composting

The objective of the present study was to mitigate the greenhouse gas (GHG) emissions during composting of dewatered fresh sewage sludge (DFSS) employing biochar combined with zeolite (B + Z) and low dosage of lime (B + L). The 12% biochar was mixed at a 10%, 15% and 30% of zeolite and 1% lime, while without any additives was used as control. The results indicated that the combine use of B + Z was significantly increased the enzymatic activities and reduced the ammonia loss 58.03-65.17% as compare to B + L amended treatment, while CH4 92.85-95.34% and N2O 95.14-97.28% decreased than control. The B + L1% amendment significantly increased the organic matter degradation but the reduction was lower than B + Z and that could reduce the CH4 and N2O emission by 55.17-63.08% and 62.24-65.53% as compare to control, respectively. Overall our results demonstrated that 12% B + Z10% addition into DFSS can be potentially used to improve the DFSS composting by mitigation of GHG emission and nitrogen loss. (C) 2016 Elsevier Ltd. All rights reserved.