Sludge treatment and resource recovery towards carbon neutrality in China: current status and future perspective

Global warming – mainly caused by carbon emissions – is a major global challenge for human sustainable development. Carbon emission reduction and resource recovery from sludge treatment are critical to the carbon neutralisation of future wastewater treatment plants. This paper analyses the key elements of carbon emissions during sludge treatment and disposal, namely energy source carbon emissions, fugitive carbon emissions and carbon compensation. Of the four mainstream process routes analysed in this work, anaerobic digestion + dry incineration is identified as the route with the highest potential for reducing carbon emissions in the future. Finally, based on a review of current international research hotspots, the future development directions for sludge treatment and resource recovery are discussed. This paper thus provides a comprehensive understanding of the current sludge treatment processing routes and serves as a reference for process route selection and future research on carbon neutralisation.