UV/Fenton Photocatalytic Oxidation Process for Treatment of Liquid Crystal Display Cleaning Wastewater

Ultraviolet/Fenton(UV/Fenton) photocatalytic oxidation process was used to treat liquid crystal display(LCD) cleaning wastewater which contains high concentration surfactant and is of refractory industrial wastewater.Effect and main influencing factors,such as reaction time,agent concentration,UV intensity,pH,pollutant concentration etc.,were investigated.The results show that when initial pH is at 3.0-7.2,COD decreases from 1 468 mg/L to under 100 mg/L after 2 hours.The COD removal efficiency increases with the prolongation of reaction time and then tends to be steady,and proper reaction time is about 2 hours.With lower H_2O_2/Fe~(2+) ratio,initial COD removal is obviously higher.Under the condition of this research,appropriate and least FeSO_4·7H_2O concentration is 543.5 mg/L and appropriate H_2O_2 dosage is 2.5-3 mL/L in one process.Increasing UV-radiation intensity and adding TiO_2 into UV/Fenton system can significantly improve oxidation efficiency.