Degradation of furfural in aqueous solution using activated persulfate and peroxymonosulfate by ultrasound irradiation

• Published in: Journal of environmental management 2020-07, Vol.266, p.110616-110616, Article 110616
• Main Authors: Kermani, Majid, Farzadkia, Mehdi, Morovati, Maryam, Taghavi, Mahmoud, Fallahizadeh, Saeid, Khaksefidi, Razieh, Norzaee, Samira
• Format: Article
• Language: English
• Subjects: Degradation; Furaldehyde; Furfural; Oxidation-Reduction; Peroxides; Peroxymonosulfate; Persulfate; Ultrasonic Waves; Ultrasound; Water Pollutants, Chemical
• ISSN: 0301-4797; 1095-8630
• DOI: 10.1016/j.jenvman.2020.110616

Furfural is a toxic compound that can cause many problems for human health and the environment. In this study, we addressed the degradation of furfural in aqueous solution using the activated persulfate (SPS) and peroxymonosulfate (PMS) through the ultrasonic (US) wave. Besides, the effect of various parameters (pH, oxidizing dose, initial furfural concentration, US frequency, Inorganic anions concentration, and scavenger) on SPS + US (SPS/US) and PMS + US (PMS/US) processes were examined. The results showed, in order to furfural removal, the US had excellent efficiency in activating SPS and PMS, as in SPS/US and PMS/US processes, 95.3% and 58.4% of furfural (at 25 mg/L concentration) was decomposed in 90 min, respectively. The furfural degradation rate increased with increasing oxidizing dose and US frequency in both SPS/US and PMS/US processes. Considering the synergistic effect, the best removal rate has occurred in the SPS/US process. In the SPS/US and PMS/US processes, furfural removal increased at natural pH (pH 7), and the presence of inorganic anions such as NO3− and Cl− had negative effects on furfural removal efficiency. Also CO32− and HCO3− acted as a radical scavenger in the SPS/US process but these anions in the PMS/US process produced more SO4−° radicals, and subsequently, they increased the furfural degradation rate. The results also showed that the predominant radical in the oxidation reactions is the sulfate radical. This study showed that the SPS/US and PMS/US processes are promising methods for degrading organic pollutants in the environment. •Ultrasonic waves were utilized for activation of persulfate (SPS) and peroxymonosulfate (PMS).•Efficiency removal of furfural were investigated using activated SPS and PMS processes.•Mineral anions (HCO3−, NO3−, CO32− and Cl−) had inhibitive effect on furfural degradation.•Scavenging test determined the sulfate as the dominant radical.•Activated SPS decomposed the furfural more efficient than the activated PMS.