Photocatalytic Coupled Filtration And Integrated Process For The Treatment Of Phenol-containing Wastewater

With the antrorse development of modern industries,water pollution has become more serious,which has been greatly affected human living environment.The traditional water treatment technology can not meet the needs of today's society.Therefore,the new photocatalytic technology,as a research hotspot,has been widely investigated and applied.However,it is difficult to improve the photocatalytic performance,and the defects,such as the difficulty of photocatalyst recycling,limit the practical application of photocatalytic technology.For the deficiencies of various processes,this paper proposes a unique treatment process,named as the integrated process of photocatalysis coupling filtration.Two kinds of photocatalysts,3D microscopic spherical TiO₂ and Ag/B-TiO₂ visible light photocatalysts have been prepared.And then it is loaded on the surface of different pretreated glass fiber cloths,which can also be used as a filter medium to intercept suspended solid and degrade phenolic pollutants in the waste water.X-ray diffraction?XRD?,scanning electron microscopy?SEM?,and Raman techniques are used to research the morphology and surface elemental of the prepared samples.This coupling process is used to degrade the phenolic pollutants and filter the suspended solids,and the influence of different reaction conditions on the performance of the coupling system is focused investigated.The main research contents are divided into the following aspects:?1?3D spherical TiO₂ photocatalyst is successfully prepared using TBOT as a raw material by simple one-step hydrothermal method,and then the photocatalyst is loaded on the surface of a high-temperature treated glass fiber cloth by a dipping-lifting method.The best operating conditions can be obtained through several tests,the water flow rate should be controlled at 20 mL/min,the filter cloth keeps 1 cm from the water surface.Meanwhile,the pH value maintains at 4 and the TiO₂ photocatalyst content?mass ratio to glass fiber cloth?is 28%,which loads on the surface of glass fiber cloth for 4 times.It is found that the removal rates of phenol?100 mg/L?and suspended solids?50 mg/L?achieve 83.2%and 85.1%after the coupling process treatment for 6 h under simulated solar light irradiation,respectively.?2?The 3D sphere Ag/B-TiO₂ photocatalyst is successfully prepared by noble metal deposition and in-situ reduction.Then the photocatalyst is loaded onto the acid-base leached glass fiber cloth by dip-draw method.Through several tests,the proper operating conditions can be obtained.The initial concentration of phenol and the suspension concentration are 100 mg/L and 50 mg/L,the water flow rate controls at 40 mL/min and the filter cloth keeps 1 cm from the water surface.Besides,the pH value is adjusted to 6 and 28%content of Ag/B-TiO₂ is loaded on the glass fiber cloth for 4 times.In this condition,the removal rates of phenol and suspended solids come up to 93.7%and 90.9%with the treatment of coupling process for 3 h.?3?Based on the study of the characterization and properties of loaded TiO₂ and Ag/B-TiO₂,the degradation mechanism and degradation kinetics are proposed.The improvement of photocatalytic performance is mainly attributed to the addition of Ti³⁺or the synergy between Ag and Ti³⁺,which can effectively enhance the photo response in the visible light region and improve the separation speed of the electron-holes pairs.Meanwhile,the glass fiber cloth,as a carrier,can be used to fixed the photocatalysts powder,and the utilization of visible light is enhanced if it is placed at an appropriate depth.