Heterogeneity of biochar amendment to improve the carbon and nitrogen sequestration through reduce the greenhouse gases emissions during sewage sludge composting
The research paper investigates the effects of biochar as an amendment in sewage sludge (SS) composting, focusing on its impact on greenhouse gas (GHG) emissions and the dynamics of composting. The study employs six different dosages of biochar (low dosage: 2%, 4%, 6%; high dosage: 8%, 12%, 18%) mixed with SS and wheat straw (WS) in a 4:1 ratio. The results indicate that high dosage biochar (HDB) significantly reduces emissions of methane (CH4), nitrous oxide (N2O), and ammonia (NH3) by 92.85–95.34%, 95.14–97.30%, and 58.03–65.17%, respectively, while not affecting carbon dioxide (CO2) emissions. HDB also enhances the humification process, increasing the levels of humic and fulvic acids compared to lower dosages and control treatments. The study highlights that HDB improves composting efficiency by shortening the thermophilic phase and promoting microbial activity, as indicated by increased dehydrogenase activity. The findings suggest that the optimal biochar dosage for effective SS composting is 12%, which balances GHG emissions reduction and nutrient conservation.
This research paper is significant in the field of environmental science and waste management, particularly in composting practices. It contributes to ongoing discussions about sustainable waste management strategies by demonstrating how biochar can mitigate GHG emissions during composting. The findings provide practical insights for improving composting processes, which is crucial for reducing the environmental impact of organic waste. The research underscores the importance of selecting appropriate amendments to enhance compost quality and reduce nutrient losses, offering valuable information for researchers, practitioners, and policymakers in the field.
