The Coupling Technology Of The Dynamic Membrane Formed On Ceramic Support-fenton Oxidation To Treatment Of Dyeing Wastewater

With the development of society and economy,the printing and dyeing industry is developing rapidly.A large number of printing and dyeing wastewater discharged below the standard has led to a large area of water environment in China being damaged to varying degrees.Printing and dyeing wastewater has the characteristics of large amount of water,unstable water quality,high concentration of organic pollutants and high chroma.Traditional physical,chemical and biological treatment methods can not achieve the desired treatment effect because of their respective shortcomings.In order to treat printing and dyeing wastewater efficiently and environmentally,a new process of coupling ceramic-based dynamic membrane technology with Fenton oxidation technology was used to treat printing and dyeing wastewater.In this experiment,distilled water was used as filter material to study the permeability of ceramic membrane carrier.The relationship between permeation flux of ceramic membrane and operation time,operation temperature,transmembrane pressure difference and cross-flow velocity was investigated.The ceramic-based dynamic membrane was prepared by using ceramic membrane as carrier and siderite as particle of dynamic membrane coating.The main influencing parameters of ceramic-based dynamic membrane preparation,such as transmembrane pressure difference,cross-flow velocity and concentration of coating suspension,were studied.The effects of various factors on the separation of printing and dyeing wastewater by ceramic-based dynamic membrane filtration were investigated by orthogonal experiments.The optimum preparation conditions of ceramic-based dynamic membranes were obtained by synthesizing various factors.In addition,a stable ceramic-based dynamic membrane was prepared under the optimum preparation conditions and used to separate and filter printing and dyeing wastewater,focusing on the effects of operating pressure,material-liquid flow rate and material-liquid temperature on the separation performance of ceramic-based dynamic membrane.Taking printing and dyeing wastewater as the treatment object,Fenton oxidation method was used to treat it,and Fenton oxidation was studied by orthogonal experiment and single factor experiment.The effects of the amount of hydrogen peroxide,siderite,p H value and reaction time on COD_cr removal rate of printing and dyeing wastewater in the system were studied.Finally,the ceramic-based dynamic membrane was prepared under the optimum preparation conditions,and the p H value of printing and dyeing wastewater was adjusted at room temperature to study the effect of the new technology of ceramic-based dynamic membrane-Fenton oxidation coupling on the treatment of printing and dyeing wastewater.The results show that:(1)With distilled water as the filter medium,the permeation flux of ceramic membrane keeps stable with the increase of filtration time and flow rate,and increases linearly with the increase of temperature and pressure difference across the membrane,and the linear fitting coefficient can reach 0.999.(2)When the critical pressure is0.19 MPa,the cross-flow velocity is 0.9 m·s^-1,and the concentration of suspension is 0.5 g·L^-1,the dynamic membrane coating has the best effect.The order of preparation conditions affecting the filtration and separation efficiency of dyeing wastewater is the cross-membrane pressure difference>the concentration of suspension>the cross-flow velocity through orthogonal experiment analysis.When the COD_cr removal rate of printing and dyeing wastewater was taken as the objective,the order of preparation conditions affecting the filtration effect was the concentration of film suspension>cross-flow velocity>transmembrane pressure difference.The optimum preparation conditions of ceramic-based dynamic films were obtained by comprehensive analysis:transmembrane pressure difference of 0.21 MPa,suspension concentration of 0.7 g·L^-1 and cross-flow velocity of 0.8 m·s^-1.(3)Orthogonal experiments were carried out to analyze the influencing factors of COD_cr removal rate of printing and dyeing wastewater treated by Fenton oxidation process.The order of influencing factors was p H>Siderite dosage>30%H₂O₂ dosage>Fenton reaction time.When the p H value of 200 ml printing and dyeing wastewater was 4,Siderite dosage was 0.9 g,30%H₂O₂ dosage was 1.2 ml and Fenton reaction time was 60 min,the COD_cr removal rate of printing and dyeing wastewater was the best.(4)The COD_cr removal rate of printing and dyeing wastewater treated by ceramic-based dynamic membrane-Fenton oxidation coupling technology is more than 84%,which is much higher than that of single dynamic membrane technology or Fenton oxidation technology.