Activated Sludge Incineration Ash Derived Fenton-like Catalyst: Preparation and Degradation Performance on Methylene Blue

Fe@zeolite materials are widely applied in the production of <middle dot>OH by catalyzing Fenton-like reactions for degradation of recalcitrant organic pollutants due to their comprehensive sources, simple preparation and low environmental impact. However, the high cost of Fe@zeolite synthesis and the lack of Fe2+ regeneration strategy are serious issues that limit the application of Fe@zeolite as a Fenton-like catalyst in industrial-scale systems. In this study, the ash generated from activated sludge incineration treatment was utilized as raw material to selective recover Si, Al and Fe, preparing Fe2+-sodalite (FSD) material. Consequently, it was used as a Fenton-like catalyst to activate peroxyacetic acid (PAA) for the degradation of methylene blue (MB) in wastewater. Results indicated that FSD was capable of effectively catalyzing PAA to generate various active oxygen species such as <middle dot>OH, O-1(2) and R-O<middle dot>in a wide pH range, thereby degrading MB through hydroxylation and sulfonation pathways. MB can be completely removed during 20 min under optimized conditions of 0.3 mmol/L PAA and 0.3 g/L FSD prepared with 0.5 mol/L Fe2+. In addition, the reductive S species in FSD can maintain its catalytical activity by enhancing Fe2+ regeneration, and the FSD/PAA system has been proven to be effective in the degradation of various organic pollutants under practical and complex environmental conditions.