Research On Synergistic Degradation Of Bisphenol A Using A Combination Of Ultrasound And Photocatalysis

Endocrine Disrupting Chemicals(EDCs), which is also called EnvironmentalHormone, is a kind of exogenous chemicals that can destroy normal metabolism，functionsof exudation and procreation of organism and human being through disrupting thesynthesis, exudation, and metabolism of nature hormone. As an important material oforganic industry, Bisphenol A(BPA) exists widely in the environment, which is veryharmful to organism and human being.Advanced Oxidation Process(AOPs) are being used in BPA treatment field. Theprinciple of AOPs is utilize the powerful oxide such as hydroxyl radical which produced insitu, not only to turn macromolecule pollutant into harmfulless micromolecule substance,but also mineralize it into harmless water and carbon dioxide. Although a single AOPsplays a role in wastewater treatment, but because of technical and economic reasons, thesingle AOPs technology have a low degradation efficiency, and it can not mineralize thepollutant utterly. This study put forth a combination of ultrasound and photocatalysis BPAtreatment system, the purpose of this study was to explore synergistic effect and theoptimum combination ways of ultrasound and photocatalysis. This research designedcirculating and non-circulating ultrasound (US) directly intensified photocatalytic reactor,the reactor performance and synergistic effect were investigated, under the optimalconditions, the degradation effect of BPA and the mineralization process in the twocombination ways was studied. The results are as follows:1. Using dye methyl orange (MeO) as pollutant model, the performance ofcirculating reactor was studied, the result suggest that the synergy value is as high as2.26under the optimal conditions, indicated that the ultrasound (US) directly intensifiedphotocatalytic reactor have a good synergistic effect, and because of the ultrasoundreaction unit is independent with the photocatalysis unit, this reactor becomeindustrialization easily, have a good application prospect.2. The law of synergistic effect is: photocatalysis plays a great role in the degradationof BPA, ultrasound plays a synergistic intensified role, help to enhance the degradation rateof BPA, but not to change the degradation trend with photocatalysis treatment.3. In the combination of ultrasound and photocatalysis reaction system, under theoptimal conditions, the150min degradation rate of BPA in cirlulating reactor andnon-circulating reator is respectively90.47%、99.60%, the synergy value is demark1.18、 1.41.4. This study put forth two new concept—Energy efficiency (Ee) and Intensificationefficiency(Ie), Ee and IE can be used for degradation assessment in different reactor but thesame reaction system. The Ee value and Ie value of circulating reactor and non-circulatingreactor is respecttively5.82×10-6mg/J、4.08×10-6mg/J and2.21×10-7mg/J、8.90×10-8mg/J,shows that the circulating ultrasound intensified photocatalysis reaction system is the betterBPA degradation reaction system.