Study On Standard Treatment Of Printing And Dyeing Wastewater Using Anaerobic/Aerobic And Fenton Combined Process

The new Discharge Standards of Water Pollutants for Dyeing and Finishing of Textile Industry (GB4287-2012) has announced new requirements for dealing with wastewater from textile dyeing industries. According to the research of corporate processes and the quality of treatment wastewater from printing and dyeing industry in Shaoxing, especially six typical plants, printing and dyeing water discharged was hard to meet the new discharge standards. In order to meet the new discharge standards, a pilot plant utilized hydrolytic acidification reactor (HAR), anaerobic fluidized bed (AFB), moving bed biofilm reactor (MBBR), and contact oxidation reactor (COR) with Fenton oxidation, which was engaged in completely dealing with printing and dyeing wastewater. Based on the result of the procedure, this process was stable and efficient, and the effluent met the new discharge standards as well.1) According to the research of printing and dyeing wastewater in Shaoxing, printing and dyeing wastewater discharged was hard to meet the new discharge standards. In this paper, six typical dyehouses were investigated, anaerobic and aerobic process was used in treatment of mixed wastewater from printing and dyeing industry. The qualities of the effluent water might usually not reach the new Discharge Standards Water Pollutants for Dyeing and Finishing of Textile Industry (GB4287-2012), especially including the aniline compound.2) In this experiment, HAR-AFB-Aerobic MBBR-COR-Fenton Process was used to treat the actual printing and dyeing wastewater. The experimental results showed that the effluent water quality could meet the new Discharge Standards. The time of microorganism culture and acclimatization of HAR, AFR, Aerobic MBBR and COR was 50days,84days,61 days,50days, respectively. According to the result of optimizing operation parameters, the optimal operation condition was following: the HRT was 18h and pH was about 9.0-10 in the hydrolytic acidification reactor; the HRT was 3days and pH was approximately 6.5-7.5 in the anaerobic fluidized bed; the HRT was 24h, DO was between 4.0-5.0 mg/L and pH was around 6.5-7.5 in the moving bed biofilm reactor; the pH value was 4.0, the dosage amount of FeSO4·7H2O and H2O2 were 1.0g/L and 8ml/L respectively, the reaction time was 120min. Results of the 100 days stable operation showed that, the system had better treatment result for printing and dyeing wastewater. The effluent COD was between 91-122mg/L, the effluent BOD5 was between 24-38mg/L, the effluent chroma was 30-60, the effluent NH4+-N was between 2.77-5.93mg/L, the effluent TP was between 0.25-0.85mg/L, the effluent aniline was between 0.25-0.98mg/L, the effluent AOX was between 0.9-1.1mg/L. Thus, the effluent water quality could meet the new Discharge Standards.5) Gas chromatography-mass spectrometry (GC-MS) was applied to determine the degradation process of organic pollutants in treatment progress. The results showed that main pollutants including aniline compounds, quinoline, indole, anthraquinone and its derivatives in wastewater had been degraded completely.