Study On Acrylic Fiber Wastewater Medium-sized Treatment Using Anaerobic And Aerobic Biofilm Process

The acrylic fiber wastewater contained Dimethylacetamide(DMAC), toxic CN-and oligomer(AN and PAN). Because of the characteristic of the nitrilon wastewater, the effluent of treating processes is diffcult to achieve discharge standard. Then, the acrylic fiber wastewater made severe environment pollution. For resolving this problem, biofilm method of anaerobic and aerobic was used to treat acrylic fiber wastewater, the effect of process factor and operation parameters were studied.In the study, acrylic fiber wastewater was treated by biofilm method of anaerobic and aerobic. The removal effect of acrylic fiber wastewater was studied under different conditions. The results showed that when the anaerobic hydraulic retention time (HRT) remained at30h, the removal rates of COD and BOD5were respectively23.22%and37.57%. At the same time, the BOD5/COD decreased by17.96%. When the aerobic HRT and the volume ratio of water and gas were respectively controlled at24h and40:1, the removal rate of COD was56.7%. The removal rate of COD was high than60%, BOD was above95%, and those characteristic pollutantion DMAC and AN were almost to100%, when the total HRT of the process remained54h. This suggests that the system is stable and reliable when the anaerobic and aerobic HRT were respectively controlled at30h and24h, the ratio of gas and water was controlled at40:1.Microbial species in each reactor were observed and analyzed by SEM and microscope.The observation results show that anaerobic bank included coccus and bacillus microbe, filamentous fungus existed in the aerobic tank. In the aerobic tank, the species of microbe was more, and the biological chain was long。When system operation used A/O mode, reflux ratio on TN removal effect was not obvious. When the reflux ratio increased to300%, the removal of system on TN from15%to18%.Removal effect of acrylic fiber wastewater differention between medium-sized treatment and practical engineering was compared. The comparison showed that the quality indicators of medium-sized treatment effluent only NH4+-N and TN higher than practical engineering. Medium-sized treatment was significantly better than actual project for organic matter and characteristic pollutants.The results of paper research are very important on application of biofilm method of anaerobic and aerobic to guide practice. The processes are valuable to rebuild acrylic fiber wastewater treating system of Jilin Qifeng Chemical Fiber Co. Ltd..