Research and Improvement of Biological Aerated Filter (BAF) for municipal wastewater treatment pilot
|School||Nanjing University of Technology and Engineering|
|Keywords||domestic wastewater treatment biological aerated filter BAF combined biological aerated filter CBAF improve backwash mathematical modelling|
The comparison and selection of homemade biological aerated filter’s media and the experimentation of the domestic sewerage treatment by single upflow and downflow biological aerated filter(BAF) were studied. On the basis of these, the combined biological aerated filter(CBAF) was exploit. The result of the domestic sewerage treatment by CBAF showed that the effect was wonderful. The average removal percent for SS, CODCr, NH4+ ~ N and TN was 96.4%, 82.5%, 98.2% and 63.4%, respectively. The average effluent concentration for SS, CODCr, NH4+ - N and TN was 4.9mg/L, 46.4mg/L, 0.5mg/L, 14.5mg/L, respectively. These effluent concentrations all can meet the requirement of first Class A of the national discharge standards(GB18918 - 2002), moreover, the capacity for absorbing hydraulic and organic shock loading was excellent. If the lower section of the first filter which the loading was higher was backwashed singly, the requirement of backwashing water and gas should be saved 6.7% and 16.7%, respectively, and the stability of whole procee should be enhanced. Some mechanisms were discussed and three mathematical modellings were designed by experimentations. The process connecting CEPS with CBAF should be rational. With the comparing of economy of technology, many advantages of CBAF process were summed up: low investment and running cost, small footprint size, good effluent quality, automated operation etc. . This process were very adapt to the situation of our country and could be an ideal alternative for upgading existing domestic wastewater treatment processes.