Phenolic compounds removal by wet air oxidation based processes

Enhanced degradation of Bisphenol A from high saline polycarbonate plant wastewater using wet air oxidation

“…The reaction temperature plays a very important role in the WAO process for degradation of aqueous organic compounds. It is reported that in the WAO system, both the reaction rate and the overall reduction of COD and/or TOC are depending on reaction temperature (Erjavec et al, 2013;Zhou et al, 2018;Pintar et al, 2008). Additionally, due to generation of the different types of free radicals at higher temperature, the mechanism of degradation of organic substances in the WAO system is strongly related to the reaction temperature (Zhou et al, 2018;Pintar et al, 2008).…”

“…Due to the aromatic structure of phenolic compounds, their activation energy for WAO is reported to be high. Therefore, higher reaction temperature are needed to overcome such high activation energy barriers (Zhou et al, 2018). Based on our results and in order to reduce severe operating conditions, the optimum reaction temperature was considered to be 150 • C for decomposition of the BPA present in PCW by the WAO process and used for future experiments.…”

“…The total air pressure in the WAO process influences the reaction kinetics and the distribution of intermediates. On the other hand, higher partial oxygen pressures are needed to increase the concentration of oxygen in the reaction medium in high temperature (Zhou et al, 2018). In order to determine the influence of total air pressure on the degradation of BPA in PCW, experiments were performed under two total air pressures namely, 2 and 3 MPa.…”

“…In contrast, advanced oxidation processes (AOPs) have recently been proved to be highly efficient to degrade recalcitrant organic substances based on the capability to form of highly active reactive oxidizing free radicals such as hydroxyl (HO) and sulfate (SO 4 − ) radical species (Athalathil et al, 2015;Ahmadi et al, 2016;Garoma and Matsumoto, 2009;Moussavi et al, 2018;Reddy and Kim, 2015). Several types of AOPs have been applied for the decomposition of BPA, including Vacuum-Ultraviolet (VUV)/H 2 O 2 process (Moussavi et al, 2018), electrogenerated ferrous ion activated ozone, H 2 O 2 and persulfate system (Akbari et al, 2016), photochemical degradation process (Doong and Liao, 2017;Yuelai et al, 2017), Fenton and Fenton like process (Ahmadi et al, 2016;Yang et al, 2016;Park et al, 2017) and catalytic wet air oxidation process (Erjavec et al, 2013;Zhou et al, 2018). Among AOPs, wet air oxidation (WAO) is considered as one of the most important and promising techniques for the degradation of hazardous organic compounds.…”

“…On the other hands, there is no need to add chemicals, leading to cost reductions on the purchases of toxic chemicals. WAO involves liquid phase oxidation and its efficiency depends on temperature, oxygen partial pressure, reaction time and extent of the oxidizability of the intended contaminants (Athalathil et al, 2015;Arena et al, 2015;Zhou et al, 2018;Kim and Ihm, 2011;Tembhekar et al, 2015;Padoley et al, 2012a). Therefore, optimization of this process to degrade recalcitrant and toxic organic materials such as BPA is of utmost importance.…”