Treatment of potato chips manufacturing wastewater by electrocoagulation

Treatment of wastewater from potato chips manufacturing by electrocoagulation (EC) was investigated. Experiments were conducted to determine the optimum operating conditions such as electrode type, pH, current density and retention time. Aluminium and iron electrodes were used, and aluminium electrodes were found to be more suitable since it had a higher removal rate of COD, turbidity and suspended solids than the iron electrode. The removal efficiencies of COD and turbidity were high, being 60% and 98%, respectively, with retention time < 40 min. 0.05-1.75 kg (per kg COD removed) of dried sludge was removed. COD removal kinetics during EC process was described by a macro-kinetics model. Results from the kinetic studies showed that the kinetic data fit the second-order kinetic model well. The operating costs investigated in the present study were the energy cost of EC and the material cost due to the consumption of aluminium electrode. Operating costs were varied in the range of 0.48 to 5.42 $/m(3) and 0.62 to 6.32 $/m(3) wastewater treated at 20-300 A/m(2) and 5-40 min, respectively. The energy consumption was 4 kWh/m(3) for wastewater treated less than 8 min under typical operating conditions.