Treatment of cattle slaughter house wastewater by electrocoagulation method using aluminium electrodes

Abstract

Electrocoagulation technique was used for the treatment of cattle slaughter house wastewater with the purpose of lowering the chemical oxygen demand concentration (3500 mg L-1) and turbidity (290 nephelometric turbidity units) to levels below the permitted directdischarge limits. All the experiments were carried out in batch mode by using sacrificial anodes (Al-electrodes) corrode to release active coagulant flocs usually aluminium cations into the solution. During electrolytic reactions hydrogen gas evolved at the cathode. The effect of different parameters such as pH, electrolyte concentration and current density was studied. The evaluation of treatment efficiency (%) was determined by measuring both the reduction of chemical oxygen demand and residual turbidity. Under optimum conditions, the removal efficiency was 93 and 96% for chemical oxygen demand and turbidity respectively at 7.8 pH, 0.001 mol L-1, electrocoagulant dose and 2.16 A/m2current density. It is concluded that the electro-coagulation process has potential to be utilized for the cost-effective treatment of wastewater specially using aluminium electrodes in terms of high removal efficiencies and operating cost.