PROTOTYPE OF HEXAGONAL PHOTO-REACTOR FOR DEGRADATION HUMIC ACID USING CU-ZNO AS A CATALYST IN VISIBLE LIGHTS

Abstract

Humic acid is a heterogeneous organic compound that is carcinogenic in peat water and is very difficult to degrade biologically. Water is a source of life, therefore the need for clean water is increasing. This study aims to carry out the degradation of humic acid using the photocatalytic method. Photocatalysis is the degradation of humic acid using light in the presence of a photocatalyst in the reaction process. The photocatalyst used in this study was 7% Cu doped ZnO. The Cu doped ZnO used with a band gap of 2.57 eV and a particle size of 27 nm. In this study, the humic acid degradation process used a hexagonal photo reactor with various stirring speeds of 500, 1000, 1500 rpm and without stirring. The degradation process is carried out using outdoor light (direct sun). The light intensity can be measured using lightmeters on the front and rear of the reactor. The degradation process uses variations in irradiation time of 1, 2, 3, 4 and 5 hours. The degradation results were measured using a UV-Vis spectrophotometer to see the absorbance before and before degradation. The results of this study obtained the highest percentage degradation at the speed of each stirring of 500 rpm of 90.09% at 5 hours of irradiation, 1000 rpm of 97.37% at 5 hours of irradiation, 1500 rpm of 97.79% at 5 hours of irradiation. hours and without stirring of 71.71% at 5 hours of irradiation. The maximum degradation concentration in this study was obtained at a stirring speed of 1500 rpm and an irradiation time of 5 hours. The speed and irradiation time have an influence on the degradation results obtained.