Electrochemical treatment of dairy effluent using combined Al and Ti/Pt electrodes system

This work deals with investigation of electrochemical technique for the treatment of milk liquid fractions. The removal of COD, phosphate and turbidity was investigated by varying the operating conditions. The batch experimental results revealed that the removal efficiencies of the overall turbidity, COD and phosphate concentration, depend on the nature of the electrodes material. The results indicated that turbidity is eliminated only by coagulation process and depends principally on aluminum concentration, whereas, soluble COD and phosphate might be eliminated by indirect oxidation. The greatest removal efficiency was obtained with the use of both cathode and anode made of aluminum (Al–Al system). With this latest system, optimal values of current density, initial pH, NaCl concentration and electrolysis time were 0.5 mA/cm2, 6.6, 1.5 g/L and 2 min respectively. For these optimal parameter values, the removal efficiency of COD, phosphate and turbidity attained respectively 80%, 59% and 96%. Corresponding energy consumption was very low and equal 0.03 kWh/kg and 0.04 kWh/kg, for COD and phosphate removal respectively. Scanning electron microscopy (SEM), energy dispersion spectra (EDS) and fourier transform infrared spectroscopy (FT-IR), were used to characterize the resulting sludge.

► Effect of the main operating parameters on the process efficiency was investigated.
► COD and phosphates were removed by both coagulation and electro-oxidation processes.
► Turbidity removal was controlled solely by coagulation process.
► Sludge formed during the process treatment was characterized by SEM, EDS and FT-IR.