Economical Evaluation of Aluminum Anodizing Plants Sludge Reusing

Aluminum anodizing plants produce a significant volume of sludge in the final step of wastewater treatment. If this sludge is not disposed by the common methods, it produces several environmental problems, which is taken into account as an imposed cost. The object of this study is economical evaluation of aluminum anodizing plants sludge reusing, to prevent releasing it in the environment and reducing water and soil pollutions. Therefore it causes environmental conservation in one hand and a suitable economical saving can be achieved for these plants in the other hand. For this purpose, data gathering about aluminum anodizing process, the related wastewater treatment units, and various uses of the sludge was performed. It is found that if anodizing sludge uses as raw material in fire- brick preparation, annually 780 million Rials benefit can be achieved by this plant. Furthermore, if anodizing sludge uses as coagulant in municipal wastewater treatment, annually 820 million Rials saving can be obtained by municipal wastewater treatment plants.