Static adsoprtion of pemetrexed in aqueous phase by activated carbon for wastewater treatment

SSCI-VIDE+ATARI:CARE+BFU:CFE:LFI:AGF:JMCNational audienceConventional wastewater treatment plants are not able to remove efficiently most of organic micropollutants. As a consequence, a lot of these compounds are directly discharged into natural waters contributing to a new environmental issue. To solve this problem, adsorption of micropollutants on activated carbons can be used in tertiary treatment processes. Pemetrexed (PEME) is a new generation of anti-folate pharmaceutical used for the treatment of a variety of tumours in recent years [1]. However, PEME may cause potential risks, including genotoxic, mutagenic, cytotoxic effects to aquatic organisms when it is released into the water environment since not fully metabolized and removed from conventional wastewater treatment plants [2].In this study, three different commercial activated carbons originated from wood and activated by steam (OPW3) and H3PO4 (NORIT CA1, OPWH3PO4) were selected as target adsorbents to assess their removal efficiency of PEME from water. The activated carbons were characterized by ICP, Raman spectroscopy, nitrogen adsorption-desorption isotherm and their zeta potentials were determined. Correlation between the physicochemical properties and the adsorption capacity was proposed. The effects of adsorbent dose, contact time, temperature, initial concentration and solution pH on the adsorption of PEME by activated carbons were investigated. An optimal adsorbent dose of 0.0375 g/L, was chosen for all experiments and it was found that the adsorption of PEME onto activated carbons reached equilibrium after 36 hours. The kinetic data were better fitted by a pseudo-second-kinetic model. The adsorption capacity of activated carbons was shown in the order of OPWH3PO4 > NORIT CA1 > OPW3. As the pH of the PEME solution decreases, the adsorption capacity of activated carbons increases. Thermodynamic parameters indicated that the adsorption process was spontaneous and endothermic. The π-π electron-donor–acceptor, hydrogen bond, complexation, electrostatic interactions and chemisorption may be the main adsorption mechanism between PEME and activated carbons. These studies revealed that activated carbons could be applied to effectively removal Pemetrexed from water.Keywords: Pemetrexed; Activated carbons; Characterization; Adsorption[1] K Soni, A Mujtaba, K Kohli. International journal of biological macromolecules, 2017, 103: 139-151.[2] P H Secrétan, M Karoui, Y Levi, et al. Science of the total environment, 2018, 624: 1082-1094