Technical and economic analysis of electrocoagulation for the treatment of poultry slaughterhouse wastewater

Electrocoagulation (EC) is assessed by a preliminary technical and economic analysis for the treatment of poultry slaughterhouse wastewater (PSW). Chemical oxygen demand (COD) and oil-grease removal efficiencies, and total operating cost have been used for analysis purpose. Various direct and indirect cost items including electrical, sacrificial electrodes, labor, sludge handling, maintenance and depreciation costs have been considered in the calculation of the total cost. Iron and aluminum have been tested as sacrificial electrode material. Initial pH, current density and operating time were investigated as process variables. The experiments demonstrated the effectiveness of EC for the treatment of PSW. Aluminum electrode performed better in reducing the COD, with a removal efficiency as 93% in 25 at low initial pH, such as 3, and current density of 150 A/m2. On the other hand, iron electrode was more successful in removing oil-grease with 98% efficiency, irrespective of the initial pH. From economic point of view, iron electrode is clearly preferable; the total operating cost is between 0.3 and 0.4 $/m3, which is nearly half that of aluminum electrode. The total operating costs may also been calculated on the basis of $/kg COD removed, which are 0.015 and 0.027 for iron and aluminum electrodes, respectively.