ARSENIC REMOVAL IN GROUNDWATER BY UV BASED PHOTOCATALYSIS WITH IMMOBILIZED ZINC OXIDE NANOPARTICLES ON CERAMIC PLATE

• Main Author: Adnan, Arfan
• Format: Theses
• Language: Indonesia
• Subjects: Teknik saniter dan perkotaan; teknik perlindungan lingkungan
• Online Access: https://digilib.itb.ac.id/gdl/view/37018
• Institution: Institut Teknologi Bandung

Arsenic (As) is naturally present in the lithosphere (earth crusts, soil, rocks, and sediment) and hydrosphere (surface water, aquifers, deep wells, and oceans). It can exist in the groundwater from the weathering process of rocks which causes a high concentration of As in groundwater and increases risk of health when the contaminated water is consumed. To reduce this risk, As standard in drinking water is set by WHO and Indonesia's drinking water standard at 0,01 mg/L. In this study, treatment of arsenic contaminated water is carried out using advanced oxidation process combined with UV/ZnO photocatalytic. The immobilized ZnO nanoparticle catalyst is coated onto a ceramic plate by dip coating method. Kinetic study was performed in a batch reactor with artificial ground water using sodium arsenite (NaAsO2) at pH 4, 7, and 10 with initial concentration of arsenic varied by 1 mg/l, 2 mg/l, 3 mg/l, 4 mg/l, and 5 mg/l, and catalyst dose varied by 1,86 g/l, 2,73 g/l, and 3,64 g/l. ZnO was irradiated by UV-C light (? = 254,7 nm) for photocatalysis of arsenite As(III) oxidation into arsenate As(V) for 2 hours. Data analysis in the study used the AAS to measure total arsenic concentration and the colorimetric spectrophotometer method to measure As(III) concentration and to determine the adsorption of ceramic plate coated by ZnO to As. The characteristics of immobilized ceramic plate ZnO nanoparticles was analyzed by SEM-EDS and FTIR. Removal efficiency using UV/ZnO photocatalysis for arsenic total was 99,99%, 99,95%, 83,25%, 73,40%, and 51,82% and for As(III) was about 100% in neutral pH condition. ZnO nanoparticles coated onto ceramic plate surfaces was 80,65% (5,5 mg/cm2) with Zn-O bonds at frequency of 470 cm-1, 1050 cm-1, and 3450 cm-1, and As-O bonds after treatment at 1500-2200 cm-1. In this study, isoterm adsorption for total arsenic was suitable with Langmuir approach and for arsenite with Langmuir and Freundlich approach. Reaction rate kinetics for arsenic removal in all variations of this study followed pseudo second order kinetics.