Catalytic Wet Peroxide Oxidation (CWPO) of 2-Hydroxybenzoic acid and contaminated industrial effluent using LnMO3(Ln= La or Pr and M= Fe or Fe-Co)

Abstract

The present study involves investigation of CWPO (Catalytic Wet Peroxide Oxidation) process for the removal of 2-Hydroxybenzoic acid (2-HBA or Salicylic acid), a moderate pollutant in industrial effluent. The best experimental conditions concerning selected varied parameters viz. pH, temperature were determined using hydrogen peroxide as oxidant in process. Different B-site substituted La and Pr based perovskite catalyst were synthesised via glycine combustion method. The structural analysis of the perovskite powders was monitored by X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) was performed to analyse the morphology of solids. The images of SEM show distinct pores with particle size ranging between 50-280 nm. The results demonstrated CWPO of 2-HBA was largely influenced by B- site bimetallic catalyst (M = Fe-Co) at pH = 3.5, Cat[Conc.] = 20% and T = 100 °C, degrading 85-90% of the contaminant in 120 min, meanwhile for the B-site monometallic catalyst (M = Fe), the degradation was 80-88% under same reaction conditions. The catalytic performance of LnMO3(Ln = La or Pr and M = Fe or Fe-Co) was also performed for an industrial effluent. Presence of aromatic carboxylic acid derivatives in industrial effluent were confirmed by GC-MS analysis and were successfully degraded in the range of 80-85%.