Study On The Treatment Of Phenol-containing Wastewater By The Integrated Process Of Photocatalysis-biomembrane-filtration

With the rapid development of industrial production and the constant demand for chemical supplies,a large amount of phenolic wastewater is discharged into the water environment.In addition,the leakage of chemical substances further increases the emission of phenolic substances.However,the current traditional water treatment technology has many disadvantages,such as the photocatalyst in photocatalytic technology is easy to fall off,difficult to recover.The biological technology is difficult to degrade high concentration phenolic wastewater and other problems restrict the treatment of phenolic wastewater.So it is necessary to look for a new type treatment process of industrial wastewater with high efficiency.To solve these problems,this paper puts forward a new processing technology:A kind of photocatalytic-biofilm-filtration integration process.The prepared nanosheet titanium dioxide photocatalyst?TiO₂?and the nitrogen-doped nanosheet black titanium dioxide visible photocatalyst?N-B-TiO₂?are respectively supported by the pretreated glass fiber cloth?GFC?,and get the TiO₂/GFC carrier and the N-B-TiO₂/GFC carrier.After microbial inoculation,culture and domestication,the two carriers grow biofilms of a certain thickness on the surface,respectively.The synergistic effect of photocatalysis and microorganism and the filtration effect of glass fiber cloth are used to realize the integration of the three processes.This process have a good effect on degradation of phenolic wastewater and filtration of suspended matter in water,which makes up for the deficiency of traditional water treatment process.The performance and effect of the integrated process of photocatalysis-biofilm-filtration are tested and the experimental results are analyzed.The analysis of the experimental results can be divided into the following two aspects:?1?When TiO₂/GFC is used as the carrier,UV light is the best light source,the best amount of carrier is 35%,the best effective depth is 1cm,and the best pH is 7.In these conditions,when the concentration of phenol and 2,4-dichlorophenol is 100mg/L and 20 mg/L respectively,the reaction time is 5 h and 6 h respectively,the reaction temperature of 21?,the aeration rate is 4L·min^-1,the degradation of phenol and 2,4-dichlorophenol rate are 78.6%and 75.5%,respectively,the process of the removal rate of SS?suspended solids?up to 61.68%.The degradation mechanism and degradation kinetics of photocatalysis-biofilm-filtration process are proposed.?2?When N-B-TiO₂/GFC is used as the carrier,system in the treatment of phenol pollutants and suspended solids,visible light as the light source,the best amount of carrier is 35%,the best pH is 6,the SS concentration is 20 mg/L,the best effective depth is 1 cm,after 5 h of degradation,The removal rates of phenol at100mg/L and SS at 20mg/L in the system are as high as 94.81%and 61.68%,respectively,and the degradation rate of 2,4-dichlorophenol after 6h is 84%,which well demonstrates the synergistic effect of photocatalysis and biodegradation in the integrated system of photocatalysis-biofilm-filtration,resulting in a good removal performance of pollutants in the system.The following cycle experiments also prove that the photocatalysis-biofilm-filtration integrated system has good stability and long service life.The degradation mechanism and degradation kinetics of photocatalysis-biofilm-filtration process are proposed.