The formation of active chlorine species on dimensionally stable anodes (DSA) has been used for the treatment of recalcitrant organic compounds contained in wastewater, whereby the present study develops a heteroge-neous model thoroughly describing the surface electro-chemistry of this mechanism arising in a FM01-LC reactor on Sb2O3-doped Ti/RuO2-ZrO2 anodes. The model accounts for fluid mechanics, mass transport, and kinetics of electrogenerated active chlorine according to the predom-inance (i.e., HClO species), being able to describe variations in current density and inlet flow rates. These results are compared against a classical homogeneous model to stand out the impacts of adsorbed chloride species and particularly remark deviations in concentration, current efficiency, and pH From experimental data. Experimental HClO concentration, current efficiency, and pH are substantially better simulated by the heterogeneous mechanism, denoting the role of absorbed chlorine species during chloride oxidation on DSA.