Coking wastewater treatment using a magnetic porous ceramsite carrier

•Preparation of porous ceramsite using urban sludge and industrial waste.•Magnetic modified porous ceramsite with simply achievable method.•Magnetic modified porous ceramsite applied for the treatment of coking wastewater.

In this study, porous ceramsite was modified using a magnetic material. The modified porous ceramsite was applied to the treatment of coking wastewater in a biofilm reactor. The results showed that the COD and NH3-N removal efficiencies in the modified porous ceramsite biofilm reactor were 25–30% higher than in an activated sludge reactor, and 15–20% higher than in a biofilm reactor without a magnetic carrier. Under conditions with an aeration flow of 1.5 mL/h, aeration duration of 10 h/d, and a temperature of 25–30 °C, the removal efficiencies for COD and NH3-N in the porous ceramsite biofilm reactor were ∼90%.