Synergistic Utilization of Inherent Halides and Alcohols in Hydraulic Fractuing Wastewater for Radical-Based Treatment: A Case Study of Di-(2-ethylhexyl) Phthalate Removal
Journal of Hazardous Materials
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The degradation of di-(2-ethylhexyl) phthalate (DEHP) was examined as an example to capitalize on the potential interactions of peroxydisulfate (PS) and ferrous iron (Fe2+) in the model Day-1/Day-90 and on-site hydraulic fracturing wastewater (FWW). The primary oxidative radicals in the Fe2+/PS system (i.e., SO4− and OH) were less effective for the degradation of DEHP (6.45%) in ultrapure water. Both chloride (Cl−) and bromide (Br−) at equivalent molar ratio with PS enhanced DEHP degradation (15.6% and 45.5%, respectively) via the generation of Cl and Br radicals, whereas the degradation rate was inhibited by the excessive amount of Cl− or Br− in the Day-1/Day-90 FWW. However, the co-presence of ethylene glycol (C2H4(OH)2, 0.043% v/v in the FWW) and halide ions (Cl− or Br−, 0.05 mM) resulted in the highest removal efficiency of 82.6 − 88.5% within 10 min by Fe2+/PS. Further investigation revealed that the formation of reductive alcohol radicals (C2H3(OH)2) slowed down or replenished the Fe2+ exhaustion. This study demonstrated that the Fe2+/PS-based advanced oxidation may show a synergistic interplay with Cl−/Br− and C2H4(OH)2 in the FWW, which depends on their relative concentrations. Thus, the inherent constituents in the fracturing wastewater can be utilized for the catalytic degradation of co-existing organic contaminants.
Fracturing wastewater treatment; Shale gas development; Persulfate radicals; Alcohol radicals; Sustainable remediatio; Salinity-rich wastewater
Hydrology | Oil, Gas, and Energy | Water Resource Management
Tsang, D. C.,
Synergistic Utilization of Inherent Halides and Alcohols in Hydraulic Fractuing Wastewater for Radical-Based Treatment: A Case Study of Di-(2-ethylhexyl) Phthalate Removal.
Journal of Hazardous Materials, 384