The use of Al mineral salts in wastewater treatment is a well known process and most common . For a long time we have been studying the feasibility of the aluminium anodizing waste as coagulant. In previous works, we have tested anodizing sludges in the treatment of municipal wastewaters and of paint industry wastewater in batch processes . In this study we have tested the use of the aluminium anodizing waste as coagulant for the treatment of municipal wastewaters in continuous processes. Different muds from nine different anodizing facilities were collected and prepared for use as coagulant. In addition, two mud mixtures were prepared to study the influence of the combination of different muds in the efficiency of the treatment. The tests were made, being controlled important parameters such as pH, turbidity and chemical oxygen demand (COD). We have verified that the coagulation process was effective for all the muds and mixtures tested. The formation of flocs that settle rapidly was visible and the Turbidity and COD reduction obtained has demonstrated the efficiency of the anodizing mud as coagulant. Aluminium anodizing plants generate a large quantity of wastes that are a burden to the industry. This works regards the reuse of anodizing sludges in wastewater treatment.