Study on Influencing Parameters of Total Phosphorus Degradation in Cattle Farm Wastewater by Electrocoagulation Using Magnesium, Aluminum, and Iron Electrodes

Abstract

Magnesium, aluminum, and iron electrode were common anodes in electrocoagulation (EC), but there were few studies comparing the influence of operating parameters on the reaction and the effects of these three different anodes in removing total phosphorus (TP) in cattle farm wastewater (CFW). This study used these three different electrodes as the anode of the electrocoagulation method. The operating parameters such as electrode distance (ED), initial pH, and voltage were examined by the Taguchi method and single-factor method. The result of Taguchi analysis shows that voltage has a significant impact on TP removal of magnesium (Mg) and aluminum anode (Al), and ED has a significant impact on TP removal of magnesium and iron anode (Fe). Among the three operating parameters, the first in the order of the impact on the reaction was ED because ED has the greatest influence on the dissolution of the anode. The result of single-factor analysis shows that the optimum conditions of Mg were ED = 3 cm, voltage = 5 V, pH = 7, Al were ED = 3 cm, voltage = 5 V, pH = 5, and Fe were ED = 3 cm, voltage = 5 V, and pH = 7. For Mg and Fe, the voltage and reaction results follow the second-order reaction kinetics, and Al is the first-order reaction kinetics. Through comparison of the three anodes, it was found that Al worked best in actual CFW. It was noted that the conditions obtained by the single-factor method were more economical in the treatment of actual CFW. This work could provide reference for determining the extent of the influence of operating parameters when other contaminants are removed, and provide reference for comparing the other anodes in EC.