Growing populations and industrialization have increased water demand, leaving 36% of the global population with inadequate water supplies.  Contaminated water is a major problem, especially in low- and middle-income countries. Advanced Oxidation Processes (AOPs), particularly photocatalysis using TiO2, offer a solution by oxidizing organic pollutants.  While TiO2's photocatalytic activity was discovered in 1972, its widespread use is hindered by limitations such as a large band gap energy and aggregation.  However, modifications like doping and surface modification improve TiO2's light absorption, charge separation, and pollutant adsorption.  TiO2-based AOPs are applicable to various industrial wastewaters, including textile, municipal, pharmaceutical, and petroleum waste.  Future research should focus on developing cost-effective and reusable TiO2 photocatalysts to enhance sustainability.