Degradation of glucocorticoids in water by dielectric barrier discharge and dielectric barrier discharge combined with calcium peroxide: performance comparison and synergistic effects

Abstract

BACKGROUND: Degradation of glucocorticoids (GCs), including fluocinolone acetonide (FA), triamcinolone acetonide (TA) and clobetasol propionate (CP), in water by dielectric barrier discharge (DBD) and DBD combined with calcium peroxide treatment (DBD/CaO 2 ) were investigated. Effects of discharge power, pH, plasma-working gas and CaO 2 dosage were examined during DBD and DBD/CaO 2 treatments. The synergistic output from the combination of CaO 2 with DBD on •OH concentration, pH, conductivity, CaO 2 adsorption and the overall influence on GC removal were assessed. Toxicity variations and feasibility to various water matrices by DBD and DBD/CaO 2 treatments also were analyzed and compared. RESULTS:The removal efficiencies of FA, TA and CP achieved were 74%, 70% and 75%, respectively, at 36.68 W over 120 min in air with unadjusted pH (energy yield of 7.47 mg kW −1 h −1 ). Significant synergistic effects were observed in combining CaO 2 with DBD with a CaO 2 -concentration-dependent mechanism. The removal efficiency of FA, TA and CP increased by 7%, 32% and 31%, respectively, by DBD/CaO 2 in comparison with DBD alone after 60 min treatments at CaO 2 dosage of 0.4 g L −1 . In addition, DBD/CaO 2 treatment was more effective in controlling toxicity and had better efficacy in various water matrices than DBD alone. CONCLUSION:This study provides a reference point for the application of DBD and DBD/CaO 2 treatments to effectively remove GCs from water.

Key-study on plasma-induced degradation of cephalosporins in water: Process optimization, assessment of degradation mechanisms and residual toxicity

“…Among these, multi-pin corona discharge system has been proposed as an appropriate reactor to improve the discharge energy density requiring a lower voltage for the discharge formation [35]. In addition, several novelties have been also introduced to maximize the energy efficiency of plasma processes including the use of innovative power sources, especially those based on nanosecond pulsed generators [36][37][38], or the supplementary use of catalysts/additives to boost the generation of the reactive species [38][39][40][41]. Nevertheless, the use of catalysts introduces extra costs and recovery steps.…”

Simultaneous degradation of glucocorticoids and sterilization using bubbling corona discharge plasma based systems: A promising terminal water treatment facility for hospital wastewater

“… Approach Substance E EO Operating cost a Ref. (kWh L −1 ) ($ L −1 ) DBD glucocorticoids 32.28 4.69 [5] DBD/CaO 2 glucocorticoids 18.28 2.65 [19] DBD 2, 4-dichlorophenol 4.83 0.70 [47] Microplasma organophosphorus 0.56 0.08 [67] Microplasma organochlorine 2.56 0.37 [67] Photo-Fenton terbutryn, chlorfenvinphos, pentachloro-phenol , and diclofenac 31.47 4.57 [68] Photo-Fenton micropollutant 0.17 0.02 [31] PBCD glucocorticoids 1.39 0.20 this study PBCD/ACF glucocorticoids 0.76 0.11 this study PBCD/Fe-ACF glucocorticoids 0.38 0.05 this study a The European Union currently maintains an average industrial electricity price of US $0.15/ kWh [69] . …”

“…Major types of NTP reactors include corona discharge (CD), dielectric barrier discharge (DBD), arc discharge (AC) and contact glow discharge electrolysis (CGDE) [18] . Our previous study reported that GCs could be efficiently degraded by DBD [19] . However, energy consumption and mass transfer efficiency at the gas-liquid interface are the main factors limiting its expansion [19] , [20] .…”

“…Our previous study reported that GCs could be efficiently degraded by DBD [19] . However, energy consumption and mass transfer efficiency at the gas-liquid interface are the main factors limiting its expansion [19] , [20] .…”