Study On Advanced Treatment Of Printing And Dyeing Wastewater By Catalytic Ozone - Biological Activated Carbon Technology

Printing and dyeing industry is a large water using industry in our country. Dyeing wastewater with large changes in water quality and quantity, and high organic content and high complexity of composition, it is difficult to completely degrade wastewater dyes and^_other refractory organics in conventional biological treatment. More and more attention is paid on the printing and dyeing waste water in its emission and reuse because of the strict environmental laws. Paper studies the depth of the dyeing wastewater treatment effect and the main factors for catalytic ozone and catalytic O3-BAC. The main contents and results are as follows:(1) Paper study effect of ozone oxidation time, pH and dosage of ozone on dyeing wastewater treatment in ozone technology. The results show Extension of ozonation time, increase or decrease in pH and Increased dosage chroma resulting in improved removal, COD and UV254removal rates were98.43%,17.2%and54.1%under the optimum process parameters (initial pH of9, ozone production is4.5g/h and oxidation time is30min);(2) Paper study effect and influencing factors iron catalytic ozone dye wastewater treatment. The result found that catalytic effect of Fe (Ⅱ) is superior to Fe (Ⅲ) by the same conditions, Iron dosage increases, and the better pollutant removal. Other parameters consistent with optimal parameters of ozone alone, the dosage of Fe(Ⅱ) is100mg/L, chroma, COD and UV254removal rates were98.7%,43.2%and70.2%.(3) Experimental study of adding tert-Butanol found that in a separate catalytic ozone and ozone treatment of dyeing wastewater, the removal of chroma is the direct oxidation of ozone molecules, the removal of COD follows the radical oxidation mechanism, the removal of UV254is given priority to ozone,hydroxyl radicals is complementary. Meanwhile, the experiment proved that under acidic conditions, the oxidation process is mainly ozone molecule oxidation. Under alkaline conditions, the oxidation process is mainly indirect oxidation by hydroxyl radicals, which produced by the decomposition of ozone molecule.(4) Kinetic analysis of catalytic ozone and ozone treatment of dyeing wastewater indicate that two techniques for removing organic compounds are of two stages,each stage are first-order reaction, and the reaction kinetics equation are obtained: (5) Paper study dye wastewater depth treatment of BAC After the catalytic ozone pretreatment. The results show, With the extension of the empty bed residence time, the better the removal of pollutants.When the empty bed residence time of BAC is45min, it gets better treatment effect, COD, TP, UV254, NH3-N and color removal was83.2%,85.3%,94.9%,72.7%and99.1%.(6) Finally, based on the small study, the technology and operation parameters intended for advanced treatment of wastewater from a printing and dyeing in Yancheng City were proposed, after the Experimental device is run, quality of treated water is stable, the chroma、COD、TP、UV254and NH3-N in the effluent from the advanced treatment process are less than15times%20mg/L、0.9mg/L、0.11cm-1and0.28mg/L,The treated wastewater quality have good economy and can reach the" surface water quality standards "(GB3838-2002) in Class IV water standards.