A. Hernández-Martínez, M. Valdés-Callado, K. González-Labrada, M. Rapado-Paneque, A. Chávez-Ardanza, M. Arias, P. Serp, R.R. Bacsa, U.J. Jáuregui-Haza
University of Artemisa,
Keywords: adsorption, degradation, advanced oxidation processes, carbon nanomaterials
Summary:The processes integration does the treatment of wastewater polluted with pharmaceuticals a more efficient process. The adsorption of pollutants on different material, like carbon based or silica is one of the technologies more studied for water decontamination. On the other hand, the advanced oxidation processes (AOP) are among the emergent technologies for pharmaceuticals degradation. A novel approach to treat polluted waters can be the integration of the adsorption and AOP. This work shows the results of the paracetamol adsorption in multiwalled carbon nanotubes (MWCNT) and graphene (G), and the ulterior degradation and desorption of the paracetamol with ultrasound at high (USh) and low (USl) frequency and gamma radiation. The analytical processes were carried out by High Performance Liquid Chromatography. The adsorption of paracetamol on MWNTC and G was experimentally determined, being the adsorption on MWNTC higher than in G (Fig 1). Also fit to theoretical models were developed to a better understand of the processes. Satured nanostructures were whashed with ethanol and dried under 60 ºC .Then satured nanostrustures were treated with USh at a frequency of 862 kHz and a power of 30.6 W, desorption and degradation of the paracetamol was observed at the same time. With USl at 42 kHz, only a partial desorption of the studied pharmaceutical was observed and degradation was not reached (Fig 2). For gamma radiation, the intensification of the process was also studied with hydrogen peroxide and it was observed that, starting from 40 kGy, the corresponding signal of the pharmaceutical in the chromatogram disappears. The mineralization was determined with a Total Organic Carbon analyzer, obtaining the best results for the gamma radiation with hydrogen peroxide, with values between 92.8 and 94.1%. This result shows the perspective of process integration of adsorption on carbon nanomateriales and the degradation with ultrasound and gamma radiation for the treatment of pharmaceuticals polluted waters.