Fluoranthene removal in aqueous phase by Fe(II) activated sodium percarbonate: mechanisms and degradation pathways

In this study, the removal performance and degradation mechanisms of fluoranthene (FLT) in sodium percarbonate (SPC) activated by Fe(II) system were investigated, in which 97.5% removal of FLT could be achieved within 15 min when the concentrations of SPC and Fe(II) were 0.03 and 0.2 mM, respectively. The presence of HO center dot, O-2(-)center dot and O-1(2) was demonstrated by probe tests and electron paramagnetic resonance (EPR) detections, and scavenging experiments further proved that the leading reactive oxygen species (ROSS) contributed to FLT removal in SPC/Fe(II) system was HO center dot. The p-hydroxybenzoic acid analytical result (the reaction product between benzoic acid and HO center dot) found that 66.5% of HO center dot in the system was produced in the first 5 min of the reaction. Several intermediates of FLT were detected by GC-MS and three probable FLT degradation pathways were proposed. The effect of SPC dosage, Fe(II) concentration, initial solution pH and inorganic anions (Cl- and HCO3-) on FLT degradation were assessed. 90.3% FLT was removed in actual groundwater when the dosages of SPC and Fe(II) were 0.15 and 1.0 mM, respectively. This result indicated that FLT removal could be improved by elevating the dosages of SPC and Fe(II) and adjusting the initial solution pH to 5.0, confirming the effective removal of FLT in actual groundwater in SPC/Fe(II) system. Overall, this study demonstrated that SPC/Fe(II) system has broad prospective in the remediation of FLT-contaminated groundwater. [GRAPHICS] .

Automated summary

The study investigated the removal performance and degradation mechanisms of fluoranthene in a sodium percarbonate (SPC) activated by Fe(II) system. Results showed that increasing the dosages of SPC and Fe(II) and adjusting the initial solution pH to 5.0 could improve the removal efficiency of FLT in actual groundwater. This study demonstrates the potential of SPC/Fe(II) system in remediating FLT-contaminated groundwater.