Electrocatalytic Degradation Of Ibuprofen In Aqueous Solution By Cobalt Doped Modified Lead Dioxide Electrode

As a typical non-steroidal anti-inflammatory drug(NSAID) Ibuprofen(IBU) is utilized for the cure of fever, muscle aches, inflammation, which is one of the most highly used NSAIDs worldwide and one of the most frequently detected drugs in the environment. It is necessary to research the degradation of IBU because it is persistent, nonvolatile, hard to biologically and chemically oxidize and potentially harmful to ecological security. Electrocatalytic process can degrade IBU efficiently; however, the anodes for IBU degradation were extremely expensive. In this paper, cheap and high efficient Co doped modified PbO2electrode was prepared to electrocatalytic oxidize IBU in aqueous solution, and preparation conditions of modified electrode were optimized, then influencing factors of IBU degradation reaction was investigate, The results showed that:Firstly, Ti/Sn-Sb/PbO2electrode was determined as anode after comparing degradation efficiency of IBU on Ti/Sn-Sb, Ti/Sn-Sb/PbO2and Ti/Sn-Sb/MnO2electrodes. Secondly, Co doped modified PbO2electrode was confirmed by comparing the degradation efficiency of IBU on different modified PbO2electrodes, including Co, grapheme, ionic liquid [Bmim]BF4and [Bmim]NO3,. Preparation conditions of modified electrode were optimized finally, and the optimal electrode was conducted at65C,40mA/cm2and5mM Co. Degradation efficiency of IBU on the optimal Co doped modified PbO2electrode achieved98.7%after60min, COD removal efficiency was53%after180min, average current efficiency(ACE) reached up to65.4%, energy consumption(Ec) was only0.10Wh/L. By contrast, Co doped modified PbO2electrode was more efficient and lower energy consumption, which was more suitable for degradation of IBU in effluent.Degradation experiments were conducted by optimal electrode, influence factors was investigated, such as initial IBU concentration, pH, degradation current density, natural organic matter HA and FA, organic acid oxalic acid and citric acid, electrolyte. The results demonstated that degradation efficiency of IBU and COD removal efficiency increased with initial IBU concentration, the maximum values were obtained at80mg/L IBU, then the values declined, and the minimum value of energy consumption was got at80mg/L IBU. Degradation capacity of IBU enhanced with acidity of reaction system increased, and it was suitable for electrocatalytic degradation of ibuprofen at pH=4, the augment of current density can improve degradation efficiency of IBU, whereas Ec increase sharply, Ec at30mA/cm2was25times as big as at3mA/cm2; low concentration of HA and FA could promote degradation of IBU, while high concentration of HA and FA inhibited degradation of IBU, and the inhibition enhanced with the adding concentration of HA and FA; addition of oxalic acid and citric acid could inhibit degradation of IBU, and the inhibition weakened with the increasing amount of oxalic acid and citric acid; CVs of IBU in different electrolyte hinted that Na2SO4was an efficient and environmentally friendly electrolyte comparing with NaCl and NaNO3.