enhanced photocatalytic degradation of 4-chlorophenol using lanthanum oxide nano-particles under uvc/vis irradiation

Photocatalytic oxidation using novel photo-catalysts has been considered as an effective method for destruction of recalcitrant organics. in this study, photocatalytic degradation of 4-chlorophenol (4-cp) using lanthanum oxide nanoparticles (lonps) was investigated under uvc/vis irradiation. effect of operational parameters including ph (2 – 11), catalyst content (250-3000 mg l-1), contact time (20 - 180 min) 4-cp concentration (25- 400 mgl-1) were investigated according to one factor at the time experimental procedure. highest removal efficiency of 4-cp was observed at ph =7. result was indicated that the removal of 4-cp was increased from 76% to 92%, with increasing catalyst dosage from 0.25 to 1 g l^-1. then, a decrease was observed in 4-cp removal with an enhancement in catalyst dosage from 1 to 3 g l^-1. highest 4-cp removal (98%) was observed at the initial concentration of 25 mg l^-1. at the contact time from 20 to 60 min, removal efficiency of 4-cp was increased from 24% to 64%, respectively. the contact time was increased to 120 min, removal efficiency of 4-cp was increased to 100%. therefore, the optimal reaction time was 100 min. the aos indices was showed an increasing trend of mineralization. in other words, the process of degradation of 4-cp was improved with photocatalytic degradation by uvc-la2o3. among the kinetic models, the pseudo-first order model due to the highest correlation coefficient of r2 = 0.991 for the la2o3-uvc process.