Influence of zeolite and lime as additives on greenhouse gas emissions and maturity evolution during sewage sludge composting
The study investigates the effects of adding zeolite and lime on greenhouse gas (GHG) emissions and the maturity of compost produced from dewatered fresh sewage sludge (DFSS). The research was conducted using various composting mixtures that included DFSS, wheat straw, and different concentrations of zeolite (10%, 15%, and 30%) combined with a fixed amount of lime (1%). The emissions of carbon dioxide (CO2), methane (CH4), ammonia (NH3), and nitrous oxide (N2O) were monitored throughout the composting process, which lasted for 56 days.
Key findings indicate that the addition of zeolite significantly reduced GHG emissions, particularly NH3 loss, with the combination of 30% zeolite and 1% lime yielding the best results. This treatment not only minimized GHG emissions but also enhanced the maturity of the compost, achieving higher stability compared to control and lime-only treatments. The study highlights that zeolite acts as a bulking agent, improving aeration and microbial activity, while lime helps to buffer pH levels, promoting optimal conditions for composting.
The research underscores the importance of managing sewage sludge effectively, given the increasing production of sewage sludge in China and the associated environmental challenges. The findings suggest that using zeolite and lime can be a sustainable approach to composting, reducing harmful emissions while improving the quality of the compost produced.
This research paper is significant in the field of waste management and environmental science, particularly in the context of composting sewage sludge. It contributes to ongoing discussions about sustainable waste management practices by providing empirical evidence on the effectiveness of mineral additives in reducing GHG emissions during composting. The study addresses critical environmental concerns, such as climate change and nutrient loss, by proposing a practical solution that can be implemented in wastewater treatment facilities. The findings are beneficial for researchers, policymakers, and practitioners in the field, offering insights into improving composting processes and enhancing the quality of organic fertilizers.
