Coupling of chemical and biological processes in 17alfa-ethinylestradiol removal from aqueous solutions: A critical evaluation of adsorption and catalysis contribution

The removal of 17alfa-ethinylestradiol (EE2) from synthetic aqueous solutions under adsorption process and enzyme catalysis mediated by immobilized laccase from Trametes versicolor was studied. Both processes were carried out in fluidized bed reactors filled with not activated or enzyme activated polyacrylonitrile (PAN) beads. Six EE2 concentrations (from 20 to 240 µM) were investigated and the enzyme contribution for each concentration was calculated by combining the time dependence of the two processes in the same experimental conditions. The results obtained after 90 min with laccase-activated PAN beads were compared with the ones due to adsorption alone. Results indicate that at concentrations lower than 145 μM the enzyme contribution is smaller than the one of adsorption, while at concentrations higher than 145 μM the enzyme contribution is greater.