Study On Hair Dyeing Wastewater Treatment By Combination With Muti Unit Methods Of Physical And Chemical

The color in hair plays an important fashion trend now in the process of status,hair dye which is used along with professional production technology and innovation.The wastewater generated in the process,it is the most difficult to synchronize the removal of COD and color.The wastewater contains surfactan,shampoo,conditioner and another solvents,it will produce large amounts of foam in the aeration process;Heavy metals contained in the hair dye will inhibit microbial growth,deal with biochemical instability,therefore the use of physical and chemical methods in this paper.The coupled with AC and PAC as the pretreatment,combined O3 oxidation,KMnO4 oxidation to get the best combination of technology and effective removal of COD and color,the method provided for reference of hair dye wastewater treatment.In the process of coupled coagulation pretreatment,the adsorption of AC and the coagulation of PAC are selected in the experiment.The results showed that the coupled with AC and PAC coagulation is the best treatment of hair dyeing wastewater;pH=8.0,the concentration of AC is 1200mg/L,the adsorption time is 45min;the concentration of PAC is 70mg/L,100r/min rate of stirring 5min.The removal of COD and color reached 81.84%and 78.91%.To observe the change of AC during the reaction from the analysis in the microscopicl view,it was carried out by SEM(scanning electron microscope)to analysis the charaterization.For wastewater after coupling coagulation,O3 oxidation and KMnO4 oxidation respectively during the experiment.O3 oxidation process maintains the input air flow 0.4L/min,the rate of range is 3.82～4.76mg/min and the concentration of O3 is 9.54～11.90mg/L,afer the reaction time 30min,there is no significant changes of COD,but the removal of color up to 90%;Duing the experiment of KMnO4 oxidation,pH=3.0,the concentration of KMnO4 is 20mg/L,the reaction time is 45min,the color has not improved,but removal of COD up to 90%.The secondary coagulation of PAC in the wasterwater afer the oxidation of KMnO4,the results show that the removal of COD and color all reach up to 90%.During the process of oxidation,it is little significant to use O3 to remove COD,the worst is the consumption of required energy.There should be considered when a large amouts of bubble during the input of O3,and then control the amount of gas strictly,but the reaction time cosumes.Because of the lower efficience,it is too difficult to practice in the large scale.There are more larger latitude of the condition in KMnO4 oxidation,easier operation and more efficient to the removal of COD.In the unit and coupling experiments,investigated the different concentration of material,reaction time and pH on COD,color and another indicators.The experimental results show that the concentration of residual COD、Chroma、TP、Turbidity in the wastewater was 45.93mg/L,22.8 times,8.04mg/L,16.25NTU.