Ammonia Wastewater Treatment by Hydroxy Radical Oxidation at PbO2 Powder Porous Electrode

ammonia wastewater was treated by hydroxyl radical oxidation generated from electrolysis using homemade PbO2 powder porous electrode as anode and stainless steel as cathode. The effect of the percentage of mixed power added, current density, initial ammonia concentration on ammonia removal was investigated: The results showed that the optimum mass percentage of graphite and activated carbon powder added was 20%, in which the electrode could produce a higher hydroxyl radicals, and completely oxidized ammonia in a relatively short period of time; the time of ammonia completely oxidized decreased with the increasing current density, but the anode efficiency decreased significantly when the current density was more than 40mA/cm(2), though the concentration of hydroxyl radical generated was still higher; the ammonia oxidation rate could be a constant which was independent of the initial concentration of ammonia; besides, the concentration of hydroxyl radicals affected the product of ammonia oxidization, to improve the generation of hydroxyl radicals could reduce the generation of nitrogen compounds, and enhance the efficiency of ammonia being oxidized to N-2