查看文章

Dewatering of waste activated sludge (WAS) is of major interest in its volume reduction, transportation and ultimate disposal. Persulfate-based oxidation process is a newly developed option for enhancing WAS dewaterability through the generation of powerful sulfate radicals (SO₄⁻·). However, the enhancement in WAS dewaterability by persulfate differs with the species of iron catalysts used. In this study, two types of iron catalysts (i.e. Fe²⁺ vs. Fe⁰) were employed to initiate the persulfate (S₂O₈²⁻), and the catalyzing behaviors and the underlying principles in enhancing WAS dewaterability were investigated and compared. The Fe²⁺ exhibited the high effectiveness in catalyzing the decomposition of persulfate to sulfate radicals (SO₄⁻·), inducing the greater improvement in WAS dewatering. The WAS dewaterability (indicated by dry solids content after filtration) increased with the added S₂O₈²⁻/Fe²⁺ dosages …