Pilot-scale Study On Advanced Treatment Of Printing And Dying Wastewater

The textile industry that make a great contribution to the national economy is animportant livelihood industry. With the rapid development of textile industry, its waterand wastewater pollution problems have become increasingly prominent, so researchand application of the textile printing and dyeing wastewater advanced treatment andreuse is of great significance to promote China’s energy conservation work .In this paper, through the research of the intensive establishment of a combinedprocess "coagulation flotation" and "microwave electrodeless ultraviolet ray catalyzedoxidation" and " biological activated carbon filter", We identified best compositecoagulant dosage, and BACF biofilm formation and start, and the optimumparameters of microwave electrodeless UV lamp and catalytic oxidization. In addition,we studied the treatment effect of continuous operation and reuse effect analysis. Theresults show that:（1）The best composite coagulant dosage: 100mg/LPAC+0.25mg/LPAM +0.15ml/L cationic decolorizing agent of quaternary ammonium salt. The decolor-ization rate and the removal rates of COD reached 72.7% and 46.6%. Theformula used to the flotation device, the decolorization rate and the removalrates of COD is lower than the removal rate of the beaker experiment, wereabout 40% and 30%.（2） Biofilm will be success in a comparatively short time when we takethe cycle method between BACF and clear water tank, adding a certain percen-tage of engineering bacteria.（3）The best dosage of oxidant is determined through the condition optimiz--ation experiments: O₃ 30mg/L and H₂O₂ 3L/h. When open four microwaveultraviolet lamp, the wastewater which had treated in preprocessing phase tobecatalytic oxidation in photochemical tank, and then the processing ofbiological activated carbon filter. The total decolorization rate and removal rateof COD reached 96% and 85%. The removal efficiency of pollutants is superiorto sperate methods when used simultaneously, because the two have a synergistic effect.（4） Using an enhanced combination of processing of“coagulation flotation-microwave electrodeless ultraviolet ray catalyzed oxidation-biological activatedcarbon filter（BACF）" to treat printing and dyeing wastewater secondary effluent. The system operated for nearly 2 months in 240 tons of handling capacityand the results indicated that the chroma was stable at 16 times lower; theCOD was reduced to 100mg/L below; pH value was stable at around 7～8.The system is running well, the effluent water was stable, and we can achievethe main target of the requirements of the enterprise reuse. We can greatlysave the production cost if we use the process to treating and recycling. Thecosts will be recovered by one set of equipment in 3 year and will gain about330thousand yuan per year; there are significant economic benefits. At thesame time, we can also reduce the discharge of wastewater and pressure onthe environment...