Effect of Nickel Concentration on Ozone Production using Nickel-Antimony Doped Tin Oxide for Wastewater Treatment

Nickel-antimony doped tin oxide (NATO) catalyst has greatly considered its capability to treat high organic matter and eliminate colour in wastewater as palm oil mill wastewater with electrochemical ozone generation. This study presents the optimal Ni content of NATO and its properties to enhance ozone generation. The NATO anodes were fabricated by dip-coating, varying the Ni content between 0.5% and 5%. The key findings show that all anodes showed a single phase of rutile structure with the cracked mud on the surface. The binding energies of the Sb3d3/2 peak at 540.48 eV and 541.58 eV agree with Sb3+ and Sb5+, respectively. The optimal ozone current efficiency of 37% at the current density of ca. 0.22 A cm-2 in   0.5 M H2SO4 at 2.7V was obtained on the NATO anode with 2% Ni content calcined at 700 oC. The palm oil mill wastewater treatment result showed that decolourisation TOC and COD removal efficiency increased with increasing electrolysis time. The colour removal efficiency achieved was more than 85% for a reaction time of 15 min. The efficiency of TOC and COD removal was reached ca. 80% in 20 min. The overall results appeared that NATO with electrochemical ozone generation could be employed to treat palm oil mill wastewater with high efficiency due to •OH and O3.