Adsorption process. Stock solutions of individual compounds
were prepared in both ultrapure water and wastewater
treatment plant effluent (WTPE). The WTPE used was
an effluent from the wastewater treatment plant (Madrid
Community, Spain). This wastewater was analyzed according
to the Standard Methods for the Examination ofWater
andWastewater,[17] and the following average values for the
main parameters were obtained: pH 7.8 ± 0.2; the organic
matter content measured as TOC = 13.4 ± 0.1 mg.L−1 and