Waste Reduction in Aluminuim Anodizing Industries

Subject Areas : environmental management

Mostafa Khezri ¹ , Farideh Atabi ² , Mehdi Borghei ³ , Fatemeh Akbari ⁴

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Received: 2007-12-11 Accepted : 2008-04-11 Published : 2012-04-02

Keywords: waste minimization, aluminium, anodizing, Wastewater treatment,

Abstract :

The Aluminium Industries are one of the greatest consumers of water in anodizing unit and also discharge large volumes of wastewater to the environment. Due to the different pH of the materials used in the industry the wastewater produced includes a wide range of pH. The purpose of control and minimization of wastes is to reduce pollution loads and wastewater during the process by using different techniques. In order to decrease, more or less, the difficulties of industrial wastewater treatment plants. Basically, waste minimizing programs are complicated and included management responsibility, definition of main targets and economic and technical assessment, accomplishment of programs and permanent assessment. In this study, the aluminium industry’s anodizing section was studied and by recognizing the production line of mentioned unit saloon, general processes were drawn. Main processes include several units such as: grease removal, etching, neutralizing, anodize unit, presealing and sealing operations, color units, and washing. These were drawn after each process. For this reason, wastewater produced by each process had special features. After gathering the necessary information, different ways were suggested to decrease consuming materials and to minimize wastes. Using two-way crane instead of one-way ones, and transferring profiles vertically. Installing electronic taps and sensors in bathtubs instead of manual ones, to prevent discharge. Changing the starting hours of work and using much more of daylight in order to decrease the consumption of electricity. According to the test results on using different coagulants, using 80 mg/lit of Alum as coagulant materials in wastewater treatment plant is suggested, which decrease the produced sludges by about 30% compared to the present amount.