Catalysts based on pillared clays with Al-Fe have been synthesized from a commercial bentonite and tested for catalytic wet peroxide oxidation (CWPO) of 4-chlorophenol (4-CP). Different H2O2 doses have been tested in order to find the lowest amount of that reagent needed for an efficient oxidation treatment since this is a main component of the economy of the process. Using a hydrogen peroxide dose of 150 mg/L, less than one-half the stoichiometric amount, complete conversion of 4-CP and the most toxic species of the oxidation pathway (aromatics, as 4-chlorocatechol and hydroquinone), was achieved. Short-chain carboxylic acids were the remaining products found after 4 h of reaction together with a small amount of unconverted hydrogen peroxide. The resulting effluents were submitted to a biological treatment for further removal of the remaining oxidation byproducts. Aerobic respirometric studies showed that a dose of hydrogen peroxide below one-half the stoichiometric is sufficient for obtaining an easily biodegradable effluent from the CWPO step.