Seeking breakthroughs in advanced oxidation processes for waste activated sludge dewatering: A critical review of developments, bibliometrics and sustainable solutions

As a key step in waste activated sludge (WAS) treatment and disposal, WAS dewatering can minimize the amount of WAS and decrease the costs of transportation, storage management, treatment, and disposal. Advanced oxidation processes (AOPs) have been widely explored in WAS dewatering due to the excellent oxidizing properties and efficient decomposition capacity since the 21^st century. This review outlined the mechanisms of AOPs to improve WAS dewatering and pointed out the shortcomings of the existing mechanisms. Then, the applications of AOPs-based WAS dewatering processes for enhanced WAS dewatering were reviewed, and the intrinsic limitations of AOPs-based WAS dewatering processes in engineering applications were proposed. In addition, an overall review of AOPs-based WAS dewatering researches was also conducted through bibliometric analysis, and future research hotspots in the field of AOPs-based WAS dewatering were proposed. Finally, the positive effects of the AOPs-based WAS dewatering processes on pollutant removal and resource recovery were investigated, and an integrated plan for the harmless disposal of WAS was constructed to achieve a positive reform of the traditional WAS management plan. This review provided theoretical basis and technical reference for the development of efficient, economical, and environmental AOPs for enhanced WAS dewatering to facilitate the application of AOPs in actual WAS dewatering engineering.