Efficient decontamination of ciprofloxacin at neutral pH via visible light assisted Fenton–like process mediated by Fe(III)–GLDA complexation. (February 2022) - He, Fangru
Abstract: This work demonstrated a novel N, N -bis(carboxymethyl)glutamic acid (GLDA) modified visible (vis) light assisted Fenton–like system which could effectively removal ciprofloxacin (CIP) at neutral pH. The removal rate of CIP in the GLDA/Fe(III)/H2 O2 /vis system was 97.9% within 120 min and was approximately twice as high as that in the Fe(III)/H2 O2 /vis system. GLDA could significantly accelerate the Fe(III)/Fe(II) cycle under visible light irradiation. Radical scavenging experiments demonstrated that 74.2% of the Fe(II) in the GLDA/Fe(III)/H2 O2 /vis system originated from the ligand–to–metal charge transfer reaction between Fe(III) and GLDA. The hydroxyl radical was the dominant species for CIP degradation. H2 O2 utilization kinetic modeling exhibited that 90.1% of H2 O2 was used for CIP mineralization. The effects of experimental parameters and coexisting substances on the removal of CIP in the Fe(III)/GLDA/H2 O2 /vis system were investigated in detail. The intermediate products of CIP were explored via the high–performance liquid chromatography-mass spectrometry. Graphical abstract: Image 1 Highlights: GLDA/Fe(III)/H2 O2 /vis process could effectively removal CIP at neutral pH. GLDA–Fe(III) complex facilitated the cycle of Fe(III)/Fe(II) under visible light. ·OH was the dominant reactive species for CIP degradation. The H2 O2 utilization efficiency in the GLDA/Fe(III)/H2 O2 /CIP/vis process was 90.1%.