Study on a fixed zeolite bioreactor for anaerobic digestion of ammonium-rich swine wastes

► A fixed zeolite bioreactor was constructed. ► The ammonium was adsorbed via the fixed zeolite. ► Many microorganisms fixed on the surface zeolite. ► The bioreactor reduced the inhibition of high ammonium concentration. ► Start-up time decreased and methane production increased.