Study On Dyeing Wastewater By Combination Of Coal Char And Ozone Process

In this experiment, acid red B was chosen as simulated dyeing wastewater. The degradation processes of acid red B in ozonation and coal char/ozone were investigated. The catalytic capability of shenfu, xiayukou, sangshuping and xiangshan coal char was compared. The parameters such as the pH value of solution, the flow rate of ozone, the reaction time and the temperature were investigated. The change of organic contents and species was detected by GC-MS, and the mechanism of ozonation and coal char/ozone was proposed.The results of the degradation efficiency of acid red B in ozonation indicated that it could be benefit from the increasing of the flow rate of ozone and the temperature. The pH had greatest effect on the efficiency of acid red B removal. The degradation efficiency of COD and chroma reached 58.1% and 12.0% respectively after 3 hours, when the concentration of acid red B was 600mg/L, the pH value of the solution was 11.02, the flow rate of ozone was 500mL/min, and the temperature was 28 centigrade. The main intermediates were detected by GC-MS, such as benquenze, maliec acid.The removal efficiency of acid red B in coal char/ozone was investigated, while the degradation efficiency of acid red B in ozonation was limited. The results indicated that the degradation efficiency by shenfu char was much better than others. The degradation efficiency of COD and chroma reached 90.2% and 2.0% respectively after 3 hours, when the concentration of acid red B was 600mg/L, the pH value of the solution was 11.02, the flow rate of ozone was 500mL/min, the temperature was 28 centigrade, and the quantity of coal char was 1.0g.The removal efficiency of acid red B in coal char/ozone was much better than ozonation. It had obvious catalytic effect of ozone by coal char. The proportion of small residual molecule organic compounds in water increased after coal char/ozone. It could be more easily assimilated by bacteria. The results of UV spectrum in ozonation and coal char/ozone indicated that the structure of benzene loop and naphthalene loop were broken to some small residual compounds. The absorbency of acid red B in coal char/ozone was lower than ozonation. It indicated that the efficiency of coal char/ozone was much better than ozone alone.The results of GC-MS indicated that the residual organic compounds in coal char/ozone were small molecular materials such as carboxyl acid, while the residual organic compounds in ozone alone were bigger molecular materials. It indicated that the organic contents decreased evidently and the efficiency of coal char/ozone was much better than ozonation.