Advanced oxidation processes (AOPs) are widely used for wastewater treatment, particularly for removing refractory organic pollutants, trace organic contaminants, and inorganic pollutants. AOPs generate hydroxyl (OH·) or sulfate (SO₄·⁻) radicals, which are highly reactive and effective in degrading organic matter. These radicals can be produced through various methods, including ozonation, UV irradiation, Fenton reactions, and thermal activation of persulfate. Different AOPs have varying efficiencies depending on the type of pollutants, operating conditions, and chemical properties of the wastewater. Landfill leachate, a high-strength wastewater containing organic and inorganic contaminants, is a significant challenge in wastewater treatment. AOPs are effective in treating landfill leachate, with ozonation, Fenton processes, and sulfate radical-based AOPs showing promising results. Ozonation can remove up to 88% of chemical oxygen demand (COD), while Fenton processes achieve COD removal efficiencies between 35 and 90%. Sulfate radical-based AOPs, such as those using persulfate and iron, are also effective, with some achieving up to 100% removal of ammonia and 91% COD removal. In addition to landfill leachate, AOPs are used to treat effluent organic matter (EfOM) in biologically treated secondary effluent (BTSE), which is a key component in water reuse. AOPs effectively reduce UV absorbance and remove EfOM, which can interfere with UV disinfection. Hydroxyl radicals are particularly effective in degrading EfOM, with removal efficiencies exceeding 90%. However, the presence of EfOM can also scavenge hydroxyl radicals, reducing their effectiveness. AOPs offer a promising solution for wastewater treatment, especially in the context of water reuse and the increasing demand for water resources. However, challenges such as the need for pH adjustment, the production of iron sludge, and the high costs of some AOPs remain. Future research should focus on developing more cost-effective and efficient AOPs for wastewater treatment.Advanced oxidation processes (AOPs) are widely used for wastewater treatment, particularly for removing refractory organic pollutants, trace organic contaminants, and inorganic pollutants. AOPs generate hydroxyl (OH·) or sulfate (SO₄·⁻) radicals, which are highly reactive and effective in degrading organic matter. These radicals can be produced through various methods, including ozonation, UV irradiation, Fenton reactions, and thermal activation of persulfate. Different AOPs have varying efficiencies depending on the type of pollutants, operating conditions, and chemical properties of the wastewater. Landfill leachate, a high-strength wastewater containing organic and inorganic contaminants, is a significant challenge in wastewater treatment. AOPs are effective in treating landfill leachate, with ozonation, Fenton processes, and sulfate radical-based AOPs showing promising results. Ozonation can remove up to 88% of chemical oxygen demand (COD), while Fenton processes achieve COD removal efficiencies between 35 and 90%. Sulfate radical-based AOPs, such as those using persulfate and iron, are also effective, with some achieving up to 100% removal of ammonia and 91% COD removal. In addition to landfill leachate, AOPs are used to treat effluent organic matter (EfOM) in biologically treated secondary effluent (BTSE), which is a key component in water reuse. AOPs effectively reduce UV absorbance and remove EfOM, which can interfere with UV disinfection. Hydroxyl radicals are particularly effective in degrading EfOM, with removal efficiencies exceeding 90%. However, the presence of EfOM can also scavenge hydroxyl radicals, reducing their effectiveness. AOPs offer a promising solution for wastewater treatment, especially in the context of water reuse and the increasing demand for water resources. However, challenges such as the need for pH adjustment, the production of iron sludge, and the high costs of some AOPs remain. Future research should focus on developing more cost-effective and efficient AOPs for wastewater treatment.