PREPARATION AND CHARACTERIZATION OF LAFEO3 USING DUAL-COMPLEXING AGENTS FOR PHOTODEGRADATION OF HUMIC ACID

Abstract

Humic Acid (HA) is considered as one of the major components that represents a major fraction of dissolved in natural water. Complex mixture of organic compounds on HA lead to the problematic issue for municipal wastewater treatment plants such as undesirable taste, colour to drinking water and fouling in pipe line. The reaction of HA with chlorine during disinfection processes would produce carcinogenic by-products like trihalomethanes. In this study, for the first time, LaFeO3 photocatalyst was successfully synthesized via gel-combustion method using combined glucose/citric acid as chelating agents and was further calcined at 400°C. The photocatalytic activity of samples was investigated by degradation of Humic Acid (HA) in water under visible light irradiation. Results proved that the photocatalytic degradation of HA is dependent on the catalyst dosage, initial concentration of HA, and oxygen availability in the aeration. The photocatalytic degradation also was enhanced by high surface area of synthesized LaFeO3 obtained by amorphous structure. Overall, the percentage removal of HA by varying the catalyst dosage are in the order of 88%, 90%, 98% and 97% for 0.6 g/L, 0.8 g/L, 1.0 g/L, and 1.2 g/L respectively for an irradiation period of 120 minutes. Next, the removal of HA by manipulating its initial concentration are 98%, 90%, 85% and 86% with respect to 10 g/L, 20 g/L, 30 g/L and 40 g/L taken for 120 minutes. Overall, the optimal operational parameters for the removal of HA of catalyst dosage is 1.0 g/L performing at 98%, for initial concentration of HA which was removed efficiently at 97% is 10 g/L and via aeration in this study was about 93%, after 120 min of irradiation times.