The Electrochemical Behavior Of Environmental Estrogen Bisphenol A

The pollution of the Environmental Estrogen has become the great problem in the world, and it is much interested in most of country to research. Electrochemical method is a green technique that has been widely used to analysis and remove to pollution materials. In this dissertation, the properties of BPA is systematically analyzed and then a series of methods, such as Linear Sweep Voltammetry(LSV),Cyclic Voltammetry (CV), Square Wave Voltammetry(SWV), Chronocoulometry(CC), Chronopotentio metry (CP), Differential Pulse Voltammetry(DPV), AC Impedance (IMP) are proposed to evaluate the reactivity in the electrode. Some of the results are tested by instrument such as UV-Vis,FT-IR and HPLC. At first, we use CV to investigate adsorption of BPA in the electrode, which is the activity in the Pt much more than that of PtO. Both of them are Frumkin adsorption pattern which are tested by CC, and the ΔG_Pt is -27.762 kJ / mol, but ΔG_PtO is -27.143 kJ/ mol, which suggested that the electrode has spontaneity adsorption. The surface of the platinum electrode adsorption Γis 4.0×10^-7mol/cm². Secondly the result by CV suggested that the anode-oxidation BPA is process of irreversible, which indicate that the platinum electrode process for BPA are controlled by adsorption at acid medium and by diffusion or multi-controlled at alkaline medium. The result is tested by IMP, which is appeared two circle loops, implied that the electrode surface come into being a adsorption intermediate while processing chemical desorption reaction. The electrochemical reaction of BPA electron number is 1,which is consistent with CV. Thirdly it is satisfied that BPA is analyzed by DPV, and a linear relationship between peak currents and BPA concentrations was obtained in the range of 10^-3 to10^-6 mol/L,Detection limit of the method was found to be 10^-7 mol/L,and RSD was found to be the range 0.6% to 7.6%。it was concluded that there were no significant differences between the results obtained by the DPV and those obtained by the HPLC method. The formation of the electropolymerized film of BPA was evaluated by monitoring the change in the platinum and the carbon electrode response of the Fe(CN)6 4-/3 as a redox marker, which was used to observe slight change in the electrode surface during the formation of the electropolymerized film by CV. When the electropolymerized film is formed on the electrode surface, the trend is found that the potential of electropoloymerized BPA film is higher than that of the peak. When pH is 2.3, 7.0, 12.8, and the Ep of BPA is 0.822V, 0.750V, 0.384V at the platinum electrode, but the potential of electropoloymerized BPA film is 0.9-1.0V, 0.6-0.7V, 0.8V. When pH is 2.3, 7.0, 12.8 at the carbon electrode, the Ep of BPA is 0.927V, 0.885V, 0.327V, but the potential of electropoloymerized BPA film is 1.0-1.1V, 0.9-1.0V, 0.4-0.5V; Then result is constant with the IMP. The formation of the electropolymerized film of BPA is researched by IMP at different conditions, such as time,temperature,supersonic wave and the additive about Ag+ and so on. The relationship between the charge-transfer resistance and the double-layer capacitance with the time of electropolymerization at a potential was obtained through analyzing the impedance data, which the former is ascend and the later is descend. When the temperature rise, the behavior of dynamics control is gradually to minish and it is controlled by diffusion ultimately. The formation of the electropolymerized film of BPA is reduced at condition of supersonic wave. The charge-transfer resistance and the process of diffusion is changed with additive such as Ag+ and H2O2. The BPA is removed by the platinum-carbon felt electrode,which it is observed that the degradation solution of 0.1μmol/L BPA with application of a potential at 0.5V is much more than 80%, then discussed the removal of 0.1mmol/L BPA at different condition such as time,temperature,supersonic wave and the additive about Ag+ and so on. This work describes comparative electrochemical behavior of the BPA with the estradiol, and observed electrochemical mechanism of BPA is much similar with ES, which is firstly observed by electrochemical method in the domestic.