Paracetamol Degradation by Catalyst Enhanced Non-Thermal Plasma Process for a Drastic Increase in the Mineralization Rate

Abstract

In order to remediate the very poor mineralization of paracetamol in water, even when well degraded by using a Non-Thermal Plasma (NTP) process at a very low dissipated power, a plasma-catalyst coupling process was tested and investigated. A homemade glass fiber supported Fe3+ catalyst was immersed in the liquid to be treated in a Dielectric Barrier Discharge plasma reactor. The plasma-catalysis process, at the same low dissipated power, achieved a mineralization rate of 54% with a full conversion rate of paracetamol at 25 mg L−1 in initial concentration after 60 min treatment, thanks to Fenton-like effects. The synergetic effects of the plasma-catalysis coupling process also improved the Energy Yield by a factor of two. The catalyst before and after use for treatment was characterized by Brunauer-Emmett-Teller and Thermogravimetric analysis. High-Performance Liquid Chromatography was used to measure the concentration of treated solution and to investigate the intermediates. Two of them, namely 1,4-hydroquinone and 1,4-benzoquinone, were formally identified. Some intermediates are presented in this paper as a function of treatment time and their UV absorbance spectra. NTP processes with and without catalyst coupling were compared in terms of acidity, conductivity, and nitrate concentrations in the treated solution.

Insight into plasma degradation of paracetamol in water using a reactive molecular dynamics approach

“…Ring opening is also frequently reported in advanced oxidation process studies at ambient temperature [6,7,58,59].…”

“…The present simulation methodology enables an "equivalent local temperature" to be reached that allows the decomposition of organic molecules in water activated by a fraction of oxidizing radicals (HO • here). In fact, if the local equivalent temperature is high, while the overall temperature remains at 300 K, as for plasma discharges (He jets, dielectric barrier discharges) above liquid [12,[6][7][8]49], the effects of the missing H2O molecules required to reach an experimental [HO • ]/[H2O] ratio of 10 -6 are captured by the thermostat controlling the temperature, both for ramp and constant temperature simulations. These simulations do not inform about the form of the equivalent temperature source but suggests that the observed degradation step requires a source that provides effects such as an "equivalent temperature".…”

“…Moreover, paracetamol is suspected to have endocrine disruptive effects on both males and females as it is a prostaglandin synthesis inhibitor [2][3][4]. Electric-discharge non-thermal plasmas have been proposed as an efficient advanced oxidation technique for the abatement of organic micropollutants, including pharmaceutical residues [5][6][7][8][9], as nonthermal plasmas in and in contact with liquids, are rich sources of reactive oxygen and nitrogen species (RONS) such as HO • , O2 •− , HOO • , O3, 1 O2, O, • NO, H2O2, ONOO − , NO2 − and UV radiation [10][11][12][13][14][15][16][17][18][19][20][21][22][23]. One of the major goals of studying plasma-liquid interactions and in particular, the interactions of RONS with organic molecules, is to understand the basic mechanisms and predict the products generated [12].…”

Electrical investigation of a pin-to-plane dielectric barrier discharge in contact with water

“…Adding a dielectric to the device in order to limit the current is a commonly used technique and the discharge then becomes a discharge called Dielectric Barrier Discharge (DBD) in which the current is selflimited [12,13]. Some authors used such a pin-to-water DBD configuration to degrade pharmaceutical molecules in water with a non-thermal plasma [14,15], while Marotta et al [16] used a wire-to-water DBD configuration to degrade aqueous phenol. In both cases, the electrodes are not in contact with the liquid, thus preventing the introduction of metal ions from electrolysis at the submerged electrode into the treated solution.…”

Catalysts: Special Issue on Plasma-Catalysis for Environmental and Energy-Related Applications

“…This special issue demonstrates the interest in plasma catalysis as solution to environmental problems caused by greenhouses gases CO 2 and CH 4 [1,2] that can be converted to value-added products and fuels, gas pollution with stable polycyclic aromatic hydrocarbons [3] and volatile organic compounds [4], as well as water pollution [5]. The special issue includes a review article and four articles devoted to particular applications.…”