<p>The interaction of chlorinated oxidants with linear alkylbenzene sulfonate, an anionic surfactant used in household detergents, in anaerobic effluents, is not well understood, necessitating further investigation. This study evaluated the oxidizing effect of hypochlorites on linear alkylbenzene sulfonate in domestic effluent from an anaerobic reactor. Experiments were conducted using a jar test system for 20&#xa0;min at 100&#xa0;rpm with a dosage of 2&#xa0;mg OCl⁻¹ L⁻¹. Three types of hypochlorites were tested: sodium and calcium hypochlorite, both commercially obtained, and a mixed-oxidant solution generated on-site through electrolysis. The mixed solution contained hydrogen peroxide, ozone, dichlorine, chlorine dioxide, and sodium hypochlorite. Concentrations of linear alkylbenzene sulfonate and its C₁₀, C₁₁, C₁₂, and C₁₃ homologues were quantified before and after oxidation. Results indicated that calcium hypochlorite, mixed-oxidant solution, and sodium hypochlorite reduced linear alkylbenzene sulfonate concentrations by 24%, 14.5%, and 8%, respectively. Calcium hypochlorite achieved the greatest reduction, likely due to its stable interaction with surfactant groups, leading to precipitate formation. Only calcium hypochlorite exhibited a preferential removal pattern, with the order being C₁₀ &lt; C₁₁ &lt; C₁₂ &lt; C₁₃. This behavior was not observed by other oxidants. While hypochlorite technologies are effective, complementary methods are needed to enhance linear alkylbenzene sulfonate removal. Although the mixed-oxidant solution showed different oxidation routes, it did not emerge as the most effective treatment for reducing linear alkylbenzene sulfonate concentration compared to the others. Nevertheless, its performance was better than that of the sodium hypochlorite solution, possibly due to the combined action of multiple oxidants.</p> Graphical abstract <p></p>