Porous polymers embedded with iron carbon enhanced densified activated sludge formation and wastewater treatment

[Display omitted] •The filler of iron carbon inserted porous polymers was innovatively constructed.•Combining mesh granulation and iron carbon expedited the formation of DAS.•The DAS with small particle size and good sedimentation was cultivated.•Nitrogen and phosphorus removal were significantly enhanced. Municipal wastewater treatment plants in China face significant challenges in effectively removing pollutants from low-strength wastewater with a low carbon-to-nitrogen (COD/N) ratio. This study proposes a novel approach incorporating porous polymers embedded with iron-carbon (PP-IC) into an activated sludge system to enhance treatment. The PP-IC accelerated the formation of densified activated sludge (DAS), characterized by small particle sizes (