Effect of UVC Based Photocatalyst on the Degradation of Humic Acid with Variations of pH and Variations of Concentration

Abstract

Humic acid is an organic compound that has changeable properties and is globally yellow and black in color. Humic substances act as substrates for the needs of the development of microorganisms and will give out unwanted yellow or brown colors (Adnan et al., 2022). Simply put, photocatalyst is a combination reaction between photochemistry and also a catalyst whose process with the help of a light or photo is used to speed up a chemical reaction (Chandra, 2012). The type of photocatalyst used is TiO 2 (Titanium Dioxide) which is varied with Fe 3 O 4 to determine the pH of the humic acid solution. TiO 2 (Titanium Dioxide) is one type of inorganic oxide. Semiconductor materials such as TiO2 are widely used as photocatalysts of organic substances with the help of UV light. Based on research conducted by Pradipta et al. ( 2021), TiO 2 catalyst can be combined with Fe 3 O 4 , as evidenced by the high degradation by Fe 3 O 4 /TiO 2 nanocomposites. In the catalyst activity test using 3 variations of pH, namely 3, 7 and 10 with a concentration of 15 ppm, there are differences in each solution. Experiments were carried out at the same time but at different pH. The photocatalyst activity test was continued with variations in concentration using pH 3 (acidic), research on variations in concentrations of 15 ppm, 20 ppm and 25 ppm. The three solutions were tested using UVC light with 1 g of TiO 2 added as a catalyst so that organic compounds could be degraded. The research used, the optimum result is pH 3 (acidic) the reason is because the percentage decrease from pH 3 and other pH is different. The optimum concentration result was 15 ppm with a pH of 3 (acidic). The lower the concentration in the solution, the pollutants contained in the solution are easier to degrade. A low solution concentration of ions at an acidic pH will increase the activity of the catalyst. The percentage of degradation from pH 3 (acid) concentration of 15 ppm is 92.7954%, which means it is bigger than other pH variations.