Degradation of phenol by ball-milled activated carbon (ACBM) activated dual oxidant (persulfate/calcium peroxide) system: Effect of preadsorption and sequential injection. (January 2023)

• Record Type: Journal Article
• Authors: Masud, Md Abdullah Al; Shin, Won Sik; Kim, Do Gun
• Is Part Of: Chemosphere. Volume 312:Part 1(2023)
• Publication Date: 2023-01
• Subjects: Ball-milled activated carbon -- Calcium peroxide -- Dual oxidant -- Persulfate -- Pre-adsorption -- Sequential injection; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2022.137120
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: This study explored pre-adsorption and sequential injection of dual oxidant (DuOx) of persulfate (PS) and calcium peroxide (CP) for phenol degradation in an aqueous solution. Ball-milled activated carbon (ACBM ) was used as the catalyst in the following systems: pre-adsorption and sequential injection of PS and CP (ACBM + PS + CP), pre-adsorption and simultaneous injection of PS and CP (ACBM + PS/CP), simultaneous injection of ACBM, PS, and CP (ACBM /PS/CP), simultaneous injection of ACBM and PS (ACBM /PS), and simultaneous injection of ACBM and CP (ACBM /CP). The ACBM had a larger specific surface area, more graphitic structures, and more defects. Moreover, it showed better phenol removal when introduced simultaneously with PS and CP. The phenol removal was most the efficient in ACBM + PS + CP (98.8%) with a near-neutral final pH, followed by ACBM + PS/CP, ACBM /PS, ACBM /PS/CP, and ACBM /CP. This indicates that pre-adsorption and separate injection of PS and CP were the key strategy for improved performance and maintained favorable pH for the activation of PS and CP. The dual oxidant system (PS/CP) is superior to single oxidant systems (PS or CP). Scavenger experiments and the electron spin resonance spectra (ESR) demonstrated that non-radical species ( 1 O2 ) were dominantly involved in ACBM + PS + CP, but radical species (HO, SO4 − ) also contributed. HCO3 − and HPO4 2− inhibited phenol degradation in ACBM + PS + CP, whereas Cl − and HA had negligible effects. The ACBM + PS + CP showed high total organic carbon removal and ACBM was recyclable with a slight decrease in activity. This work is important as it provides a detailed insight into the strategy of pre-adsorption and sequential injection of dual oxidants for a practical and cost-effective method of groundwater remediation. Graphical abstract: Image 1 Highlights: ACBM was better than AC in activating PS and CP. Pre-adsorption by ACBM and sequential injection (ACBM + PS + CP) phenol degradation. 1 O2 was predominantly responsible for phenol removal in the ACBM + PS + CP system. Phenol removal in ACBM + PS + CP not markedly affected by pH, Cl −, HA, consecutive uses.