Effect of reactor material and its reuse on photo-Fenton process efficiency at near-neutral pH: Alterations in E. coli inactivation and resorcinol degradation kinetics in water

Abstract

Abstract The effect of reactor material (borosilicate and polyethylene terephthalate-PET) and its reuse on the microbiological and chemical decontamination of water by the photo-Fenton reaction at near-neutral pH was assessed. Escherichia coli was used as an indicator of faecal contamination and resorcinol was employed as a model organic pollutant in water. Total E. coli removal was achieved using 0.3/20 mg L−1 (5.4 × 10−3/0.6 mM) of Fe2+/H2O2 after 120 and 180 min in commercial borosilicate (R1) and PET (R2) bottles, respectively. Likewise, under the same conditions, total degradation of resorcinol was reached at 120 min of treatment in both R1 and R2 reactors. Despite the UV transmittance level is higher in borosilicate reactors than in PET, no significant differences in removal kinetics were observed in the new reactors. However, the reuse of the R1 reactors showed a detrimental effect on optical properties of the material, leading to a reduction in the E. coli removal and resorcinol degradation by the photo-Fenton process. Conversely, when reused R2 was employed the removal of such contaminants was slightly faster than that observed in new reactors. This fact was attributed to the additional reactive oxygen species (ROS) produced from the oxidation of polymeric material during the photo-Fenton reaction.