Removal of pharmaceuticals from WWTP secondary effluent with biofilters

Abstract

In this study the performances of a biological activated carbon filter (BAC) followed by an ultrafiltration step have been evaluated with specific regard to pharmaceutical active compounds removal (PhACs) from secondary effluent of wastewater treatment plant. The long-term operation of this technology resulted in overall removal (>75%) of the studied compounds. Aiming at understanding the mechanisms ruling the removal of the investigated PhACs, together with the BAC pilot plant, a lab-scale column set-up was operated. The column set-up was composed by two biotic columns and by an abiotic one. This scheme allowed to highlight the capability of biofilters to remove via biodegradation compounds which are classified as recalcitrant to biological process. On the same time, the column characterized by the combined effect of adsorption and biological activity, showed removal percentages which were not obtained neither in the standard biofilter (sand) nor in the standard granular activated carbon (abiotic) filter. In conclusion, both the results from the pilot and the lab-scale, suggested biofiltration as a viable option to improve secondary effluent quality and to efficiently remove PhACS.