Active removal of ibuprofen by Money plant enhanced by ferrous ions

Abstract

In this study, the removal of ibuprofen (IBP), a pharmaceutical compound, from aqueous media by Money plant (Epipremnum aureum) was investigated. The effect of ferrous iron (Fe2+) on enhancing the IBP removal rate was also analyzed. The first-order removal rate constants showed higher values for lower IBP initial concentrations in the range of 0.20–0.28 d−1 for an initial concentration of 125 μg L−1 to 0.03–0.13 d−1 for an initial concentration of 1000 μg L−1. Introducing ferrous iron to the aqueous media enhanced the first-order removal rate constant up to 6.5 times in a 3 d time period. Along with the removal of IBP from the media, the endogenous concentration of H2O2 also decreased presumably by the production of hydroxyl radical (OH). Reduction in the endogenous H2O2 concentration was recorded to be 38% and 98% in the absence and presence of Fe2+ respectively in the first day and the H2O2 level remained considerably low until day 7 which then gradually increased slightly. Simultaneous reduction of IBP and endogenous H2O2 concentration could be due to the reaction of IBP with OH and presumably OH production itself accelerated via Fenton reaction. In addition, presence of sodium bicarbonate (NaHCO3) as OH scavenger in the system showed reduction of first-order removal rate constant from 1.30 d−1 to 0.07 d−1 which could be a possible evidence of biological advanced oxidation process which is believed to play an important role in phytoremediation.