Study On The Treatment Efficiency Of Dye Wastewater By Electrolysis And Biological Contact Oxidation Process

Azo dye wastewater has deep color,large quantity,wide distribution,unstable water quality,high content of organic toxicant,which is a kind of industry wastewater that is really hard to dispose and biodegradable.Most of the current biological treatment methods have some problems like low efficiency,large amount of surplus sludge,using too much water treatment disinfectant and high operation fee.Thus,it is of great significance to study high efficient and economic dye wastewater biological treatment method.This project studies the B2RL(includes 3 Azo bonds)dye wastewater,developing an experimental research about the efficiency of electrolysis and biological contact oxidation method on removing the dye in wastewater.Through the parallel comparison method,it studies the removal efficiency of the B2RL and X-3B which are in the mimic wastewater and is treated by electrolysis and biological contact oxidation method,and it is compared with the removal efficiency of B2RL which is treated by the electrolysis and biological contact oxidation method.Besides,the study of how current density and hydraulic retention time affect the removal efficiency of Azo dye wastewater by using the electrolysis and biological contact oxidation method.Electrolysis reactor takes the iron as the positive pole and graphite as the negative pole.The biofilm carrier(hydroformylation of vigny fiber silk combination,the specific surface area is 1400-2500m2/m3)is put in the biological hydrolysis reactor and contact oxidation reactor.The standard refers to the dye concentration,tone,COD and the removal efficiency of ammonia nitrogen.Aerobic contact oxidation reaction hydraulic retention time is 7.95hr,flow rate is 2L/h.Experimental results show that,at the conditions of flow rate 2L/h and HRT 12h of electrolysis reactor,HRT 7.95h of biological contact oxidation reactor,current densityhas a significant impact on electrolysis-biological contact oxidation process of dye wastewater.When the current density is 0.096mA cm-2,the average removal of concentration,color,CODc,,and ammonia nitrogen of dye wastewater can be achieved separately by 97.40%,97.33%,87.76%and 56.07%.At the same condition,the results of iological hydrolysis-biological contact oxidation method can be 41.97%,56.67%.79.23%and 52.09%.Electrolysis-biological contact oxidation system has a good effect on monoazo dyes reactive brilliant red X-3B and three azo dyes based direct light blue B2RL.At a flow rate of 2L/h,HRT 12h,and the current density 0.096mA cm-2,the average removal of the syetem is about 98%,99%,86%and 52%.Electrolytic-biological contact oxidation process for reactive brilliant red X-3B and direct fast blue B2RL dye wastewater treatment effect is basically the same,processing power is stronger,the method is illustrated electrolysis to color key to open the dye molecules and the subsequent aerobic biological effective electrolytic product to degradation of dye molecules,and this ability is affected by the molecular structure of small.Experimental results show that,at the conditions of flow rate 2L/h and HRT 12h,current densityhas a significant impact on electrolysis-biological contact oxidation process of dye wastewater.The treatment effect of dye wastewater of lectrolysis-biological contact oxidation system increases with the increase of current density within the range of 0.024,0.048,0.072,0.084,0.096(in mA cm-2).When the current density is 0.096mA·cm-2,the experiment can get the best treatment effect,if continue to increase the current intensity,the removal rate increases is not obvious.When the current is low,the improvement of current density has a significant impact on the dye wastewater treatment of Electrolysis-biological contact oxidation process.Under the condition that the current density is 0.096 mA·cm-2,12h,11h,9.2h,8h.The change of the HRT of electrolysis-biological contact oxidation system processing chroma removal effect is most affected,the dye concentration is obvious as well,but has no effect on change of removal of CODcr and ammonia.When the HRT is 11h,the average removal rates of electrolysis-biological contact oxidation system of dye concentration,color,CODcr and ammonia are 96.89%,96.67%,84.95%and 64.61%.Electrolytic-biological contact oxidation system of dye concentration,chromaticity,CODcr,ammonia nitrogen removal rate is reduced with the decrease of the hydraulic retention time.When the HRT is 8h,the average removal rates are 86.83%,76.67%,77.67%and 60.11%.The mechanism of strengthen degradation analysis of electrolysis-biological contact oxidation shows that,the removal of lectrolysis_biological contact oxidation on dye concentration,color,CODcr and ammonia is better than biological hydrolysis-biological contact oxidation and the removal of dye concentration and color effect is particularly significant aspect.redox electrode effect,electric flocculation,flotation effect,electrophoretic effect induced by electrolysis on the degradation of dyes play a major role in promoting.In the biological contact oxidation reactor,the removal of contaminants mainly depends on the microorganisms outer packing and suspended in water.Sufficient contacted between the biofilm attached to the surface of packing and wastewater is in favor of removing contaminants.Electrolysis-biological contact oxidation method using electrolysis on the basis of the biological contact oxidation is an effective approach of azo dye wastewate.The method can not only ensure water effect,but also adapt to the changing of circumstances and conditions.