Abstract Wastewater treatment plants face the challenge of controlling disinfection by-products, such as carcinogenic trihalomethanes, which are formed when disinfectants react with organic compounds and humic substances in water sources. To ensure the prevention of water pollution, effective control measures must be implemented to mitigate the release of these harmful by-products into water bodies. This study focused on the application of an electrooxidation-adsorption hybrid process for the treatment of chlorate, a prevalent disinfection by-product found in sewage plant effluent. The investigation aimed to evaluate the impact of various parameters including current density, empty bed contact time (EBCT), granular activated carbon (GAC) injection amount, electrode installation spacing, and pH on the treatment efficiency. Optimal operating conditions were determined, including a current density of 75 A/m2 , an EBCT of 5 minutes, a GAC injection amount of 2.0 w/v (%), an electrode installation spacing of 2 cm, and a pH of 2. These conditions demonstrated effective removal of disinfection by-products, even in the presence of coexisting pollutants. The findings highlight the viability of the electrooxidation-adsorption process as a promising approach for the treatment of disinfection by-products in sewage treatment plant effluent. This research contributes to the development of efficient strategies for mitigating the environmental impact of wastewater treatment processes and ensuring the protection of public water resources.