This payer describes the non-catalytic oxidation and the solid-catalysed oxidation of a chlorinated organo-compound contained in softwood pulp mill effluents. The oxidation of 4-chloroguaiacol was catalysed efficiently using Pt/alumina, manganese/cerium and cobalt/bismuth composite oxide catalysts. Self-inhibition of the parent pollutant, recalcitrance of highly stable organic by-products, and catalyst deactivation were the main causes that prevented full mineralization of the waste-water organic load. A comprehensive homogeneous-heterogeneous deactivation reaction network model was used to account for the distribution of carbon in the liquid, in the gas and on the solid phases. The model combined a two-parallel reaction scheme for the non-catalytic oxidation and a Langmuir-Hinshelwood approach for the catalyst-mediated oxidation.