Hao Zheng XiongZhong Tan Yong Tan WenJun Zhang School of Life Sciences, Sun Yat-sen University, Guangzhou, China Zhongmeng Environmental Construction Co., Ltd., Guangzhou, China Proceedings of the International Academy of Ecology and Environmental Sciences ISSN 2220-8860 http://www.iaees.org/publications/journals/piaees/online-version.asp 2026 16 4 123 144 International Academy of Ecology and Environmental Sciences Hong Kong 1 April 2026 30 April 2026 1 December 2026 tannery wastewater photocatalytic oxidation WO3/TiO2 composite sulfide removal ammonia nitrogen removal Odorous substances such as sulfides and ammonia nitrogen in tannery wastewater pose serious threats to the environment and public health, yet effective treatment methods remain limited. This study investigates the removal of these inorganic pollutants using photocatalytic oxidation with TiO2 and WO3 as catalysts. Simulated and real tannery wastewaters were treated under UV light (253.7 nm) in a batch reactor. The photocatalytic activity of single catalysts (TiO2, WO3) and their composites with different mass ratios was evaluated. Results showed that WO3 exhibited superior degradation of inorganic pollutants compared to TiO2, achieving over 91% sulfide removal under UV. The composite catalyst WO3/TiO2 significantly enhanced performance, with the optimal mass ratio determined as approximately 3.6:1 via mathematical modeling. Under this ratio, sulfide removal exceeded 90%, and ammonia nitrogen removal was also improved. X-ray diffraction analysis revealed that the enhanced activity is attributed to the heterostructure formation, which facilitates charge carrier separation and extends light absorption range. Notably, this work focuses on photocatalytic degradation of inorganic odorous compounds (sulfides and ammonia nitrogen) in the liquid phase, a rarely reported area rather than conventional organic pollutants. The composite catalyst shows promising potential for industrial application in tannery wastewater odor control. http://www.iaees.org/publications/journals/piaees/articles/2026-16(4)/removal-of-ammonia-nitrogen-and-sulfides.pdf