Abstract:
The removal of pharmaceutical compounds (PhCs) from water has numerous challenges mainly associated with their low concentration and varied nature and physicalo-chemical properties. Activated carbon adsorption and ozonation are considered consolidated technologies, with confirmed cost-efficient elimination of organic microcontaminants and toxicity in several full-scale wastewater treatment plants (WWTPs), namely in Switzerland and in Germany. Several biomass precursors, activation agents, and routes were explored at lab-scale (including cork processing by-products and carob processing acid residues pinpointing pine nut shell (PNS) as the most promising raw material: PAC steam activated sample PNS77/Steam performed similarly to the commercial golden standards (from Cabot-Norit and Chemviron). PNS-derived PAC production was scaled-up using CO2 activation and results prove that, for similar burn-off degrees, steam and CO2 activation attain similar and excellent textural properties. PACs were tested in WWTP mixed liquor and secondary effluent. Data modelling (HSDM – Freundlich isotherm) allowed estimating the PAC dose to the CAS bioreactor required for a given overall removal of the target-PhCs. Currently, EMPOWER+ project builds on the promising PNS-derived PACs, is focused on testing their performance for drinking water treatment (DWT) in both conventional and advanced treatment (adsorption/low-pressure membrane) technologies. Preliminary data prove that these lab-made materials also attain a high performance in this high- value application.