The addition of an aluminium and iron doping agent, bauxite red mud, has been tested with a commercial peat for the treatment of a secondary municipal wastewater. Based on a column study, phosphorus (P) removal was raised from about 17% to 21% on peat alone to over 95% with red mud treatment of peat. By this mean, the use of red muds allowed a reduction of P-t concentration effluent to below 0.15 mg/L. The boosting effect of red mud seemed to decrease with time and especially with the hydraulic loading. For a hydraulic loading of 30 cm/j, P removal met govermental guidelines (P, effluent < 1 mg/L) for a period of 50 days. Other classic efficiency parameters such as BOD5, COD and coliforms were not altered by the use of the doping agent.