Study On Adsorption And Decolorization Of Printing And Dyeing Wastewater By Modified Zeolite

Printing and dyeing wastewater has the characteristics of high chroma,high content of organic matter,complex composition and poor biodegradability,which has gradually become one of the most difficult problems in water treatment.Natural zeolite is a composed of Si(AL)oxygen skeleton of a three-dimensional lattice frame crystal,internal cavities and channels of different sizes,large specific surface area,with certain adsorption and ion exchange.But natural zeolite directly for pollutants removal effect is not ideal.To this end,this paper mainly studies the natural zeolite on several types of water soluble dye adsorption effect and natural zeolite modified,modified zeolite on several types of water soluble dye adsorption effect and mechanism analysis,zeolite of printing and dyeing wastewater treatment effects,in order to modified zeolite in practical application and provide a theoretical basis.Main research results are as follows:(1)The adsorption effect of natural zeolite on neutral red,methylene blue and Congo red was studied.The results showed that the pH value of the dye solution was in the range of pH value;In a certain range,the higher the initial concentration of dye solution,higher temperature to adsorption;Presence of salt ions in the solution affect the adsorption effect,the natural zeolite adsorption of neutral red and methylene blue process is inhibited,the natural zeolite adsorption of Congo red is role in promoting.Natural zeolite of neutral red,methylene blue and Congo red adsorption process more in line with the Langmuir adsorption isothermal equation,linear correlation coefficient respectively reached 0.9991,0.9989 and 0.9813;The adsorption behavior of the three dyes on natural zeolite can be described by a quasi two stage kinetic equation,and the correlation coefficient is 0.9998,0.9997 and 0.9977.(2)By comparing the acid modification,alkali modification,salt modification,high-temperature calcination,acid modified and surface active agent instead of coupling change method change effect of natural zeolite,found the adsorption capacity of zeolite modified by CTAB for Congo red and acid orange II are natural zeolite’s 5 and 21 times,BS-12 modified zeolite on the amount of methylene blue adsorption equilibrium is 7 times that of natural zeolite;Modified zeolite prepared by the process of modifier concentration,the modification effect of natural zeolite of time and pH value,for Congo red,and the best conditions for modification is: the concentration of CTAB is 0.02mol/L,modified agent of natural zeolite for 1 h,modified pH 7.0;for methylene blue,the best conditions for modification is: BS-12 volume ratio of 1:10 and modification of natural zeolite for 12 h,modified pH 7.0;acid orange II and the best conditions for modification of: CTAB concentration is 0.02mol/L,modification agent of natural zeolite for 10 h,change of pH value of 7.0.(3)By modified zeolite of Congo red and methylene blue and acid orange II adsorption experiments showed elevated temperature is conducive to the adsorption process,the increasing of the initial concentration of dye,the equilibrium adsorption amount is large,the presence of salt ions on modified zeolite adsorption of methylene blue and acid orange II inhibitory effect and of modified zeolite adsorption of Congo red played a positive role in promoting;Langmuir adsorption isotherm equation could better describe the modified zeolite to Congo red and methylene blue and acid orange II adsorption phenomenon,the linear correlation coefficient respectively reached 0.9968,0.9899 and 0.9979;alignment of second order kinetic equation of linear correlation coefficient were 0.9998,0.9997 and 0.9995 and saturated adsorption amount of theoretical value and measured value of the relative error of 0.8%,2.1% and 0.8%.(4)Modified zeolite adsorption actual printing and dyeing wastewater dynamic experimental results show that the modified zeolite types of printing and dyeing wastewater treatment effect,water flow rate of the modified zeolite for the treatment of printing and dyeing wastewater has little effect,but velocity is increased,the breakthrough time decreased with the modified zeolite dosage increase increased the adsorption column,breakthrough time prolongs,better treatment effect;made by zeolite adsorption column,recycled four times after adsorption the efficiency can still be reached more than 87% when using for the first time.It still maintains a good adsorption performance and can be reused.