Landfill leachate contains ammonium and micropollutants. Ammonium can be biologically removed but bio-recalcitrant micropollutants removal requires post-treatment like ozonation. This study developed an expanded clay aggregates packed biofilm column (EBC) and demonstrated its feasibility of coupling biodegradation and ozonation (CBAO) to simultaneously remove nitrogen and bio-recalcitrant micropollutants. The first 60 days only had biodegradation process to start the bioreactor. 51 % nitrogen was biologically removed but the removal of micropollutant carbamazepine (CBZ) was only 30 %. From 61 d to 150 d, both biodegradation and ozonation were performed in the EBC. After 48 h-biodegradation, ozone gas was introduced and bubbling through EBC for 30 min to further remove residual micropollutants. At 0.4 gO3/gCOD, CBZ were completely removed. The average nitrogen removal efficiency (85 %) was increased by 34 % because the increased abundance of nitrifying and denitrifying bacteria in EBC. This study confirmed the promising potential of the CBAO process for treating landfill leachte.
Keywords: Ammonium; Bio-recalcitrant micropollutants; Expanded clay aggregates; Ozone; Packed biofilm reactor.
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