Investigation On Dispose Of Bisphenol A By Gas-surface Discharge Combined With ACF Adsorption

Bisphenol A(BPA) is an important chemical raw material, which is widespread in the aquatic environment as a typical endocrine disruptors, the ozone oxidation technology for water treatment exist some drawbakes, such as low ozone utilization rate, slow the reaction rate, low mineralization characteristics. Activated carbon fiber(ACF) has special physical adsorption characteristics and surface chemical structure, which is not only as adsorbents, also as an inducer and catalyst in ozone oxidation system.The surface-gas discharge plasma technology can produce O3,·OH and other advanced oxidation substances, the removal of BPA in water by gas-surface discharge combined with ACF adsorptionwas explored. The results are as follows:(1) The use of gas-surface discharge plasma technology for BPA wastewater degradation was studied firstly. The optimal electrode structure (spring diameter/pitch= 1/5) and ai flow rate (3 L/min), BPA degradation rate increased with the discharge voltage increasing, decreased with the solution initial concentration increasing, and the alkaline condition was more beneficial to the degradation of BPA.(2) The removal of BPA in water by gas-surface discharge combined with ACF adsorption(referred to as "combined treatment")was explored, In the voltage of 7 kV, combined treatment increased the removal efficiency of BPA by 23.6% compared with single discharge after 30 min, which improved the ozone utilization. Increaing amount of activated carbon fibers can improve the adsorption capacity of BPA, thereby enhancing the combined removal; there was not a positive correlation between discharge voltage and combined removal; the decrease of BPA removal rate for combined treatment is less than single gas-surface discharge after adding free radical scavenger, due to ozone oxidation was induced by carbon fiber.(3) The microscopic structure of ACF before and after combined treatment was analyzed by SEM and FT-IR, there were a large number of channels on the ACF surface after the combined treatment; and the restore functional group on ACF surface reduced, which may react with ozone producing strong oxidizing free radicals; Besides, BPA removal pathway was speculated by LC-MS.(4) After nitric acid modified, although the adsorption capacity of ACF was decreased, but combined treatment improved the removal efficiency of BPA by 35.2% compared with single discharge after 30 min. The removal rate of BPA was affected by dipping concentration of nitric acid; Afeter analyzed by SEM and FT-IR, ACF surface appeared greater pore channels and the NH functional group after the combined treatment.(5) After sodium hydroxide modified, the adsorption capacity of ACF increases, the combined treatment improved the removal efficiency of BPA by 43.6% compared with single discharge after 30 min. The removal rate of BPA was affected by dipping concentration of sodium hydroxide; Afeter analyzed by SEM and FT-IR, ACF surface only appeared a certain number of small holes, in addition to CO groups, OH, C= C groups are basically unchanged after the combined treatment.