Study On Oxidative Degradation Of Bisphenol A By Potassium Ferrate In Water

It has been reported that BPA has estrogenic activity and acute toxicity to aquatic organisms and human cells. Because BPA was widely used in industries,BPA pollutes surface water and groundwater through lots of ways. Further human beings are directly or indirectly exposed under BPA through water and foods. As reported, even after chlorination and ozonization, BPA can still be detected in the water outlet. Therefore BPA treatment technology in water confront the new challenge. Traditional water treatment agents can not satisfy the requirement, because water quality standards are more and more stringent. Potassium ferrate(VI), as a new, efficient, non-toxic and multipurpose water treatment agent that has the effects of oxidation, disinfection, adsorption and coagulation, overcome shortages of the traditional water treatment agents.In this study, the oxidative degradation of bisphenol A in water by potassium ferrate was investigated. We analyzed the characters and purity of potassium ferrate, and then studied the efficiency and the influencing factors of bisphenol A degradation, analyzed the transformations of intermediate productss.The results showed that the purity of the potassium ferrate used in this experiment was evaluated to be 78.3%. The influences of different potassium ferrate dosages, different pH,different bisphenol A initial concentrations and different reaction time on the bisphenol A degradation were investigated. Potassium ferrate has strong oxidation capacity to degrade bisphenol A. The optimal pH was in weak acidic condition, and the suitable oxidation time was 30min. With a low initial BPA concentration in water, the BPA degradation rate decreased. With low K2FeO4 dosages bisphenol A could not be degraded completely. UV wavelength scanning and TOC testing testified that the by-products can be absorbed at UV254, and the absorbance of was evident in the UV band of 190～215nm and 230～300nm. DOC in water proved that only 50% of BPA was mineralized. The background constituents in natural water could also affect the BPA degradation, Humic acid, silicate and tert-butanol, a typical free radical inhibitor, inhibited the BPA degradation, while the HCO3-, another free radical inhibitor enhanced the BPA degradation.