Ammonium removal from landfill leachate by Clinoptilolite adsorption followed by bioregeneration

This paper reports on the application of a new process for ammonium nitrogen removal from landfill leachate using a reactor filled with zeolite. The process consisted of ammonium nitrogen adsorption from raw leachate followed by zeolite regeneration via nitrification. Zeolite initial adsorptive capacity was first evaluated. Afterwards, biological regeneration was carried out using zeolite containing adsorbed ammonium in the presence of nitrifying bacteria suspension and sodium bicarbonate. The adsorptive capacity (q) was reduced by only 4.55% after regeneration from q = 10.80 ± 2.14 mg NH4+-N/g zeo to 10.32 ± 0.74 mg NH4+-N/g zeo. Regeneration by nitrification occurred in 72 h and the main product was nitrite.