Removal of pharmaceutical compounds from wastewater by adsorption on commercial materials and molecularly imprinted polymers

The main goal of this research was to develop a continuous flow adsorption/desorption process of pharmaceutical compounds from municipal wastewater, comparing the performances obtained with activated carbon, a polymeric neutral resin and several molecularly imprinted polymers (MIPs). The target micropollutants were carbamazepine, diclofenac and ibuprofen. After an initial screening of several sorbents based on isotherm tests, an activated carbon (Norit 1240 W), a polymeric resin (XAD16N) and a MIP were tested in continuous flow tests of carbamazepine adsorption. XAD16N resulted the best material, with 18360 bed volumes treated at the 20% breakpoint and a 12.4 mgCBZ/gdry resin sorption capacity, at a 3-min EBCT. In continuous flow desorption tests conducted with carbamazepine, diclofenac and ibuprofen, the best material resulted again XAD16N, with the attainment of a 90% desorption after 10 to 17 bed volumes of solvent, depending on the target micropollutant. Among the tested solvents, ethanol performed better than methanol and 2-propanol. These results indicate that XAD16N is a very promising material for the removal of pharmaceuticals, and that an in-situ desorption of pharmaceuticals can be effectively performed with a very limited amount of ethanol.