Analysis On Development And Mechanism Of A_mO_n Integrative Process To Treat Domestic Wastewater

In 2005, there was 52.45 billion tons of sewage discharged in our country. The amount of municipal sewage was 28.14 million tons, accounted for 53.7% of the total Wastewater. A large amount of municipal sewage in township is seldom treated, which pollute the water environment of township seriously, and it also become the main source of the region environmental pollution. As domestic Wastewater is the main component of township sewage, the Wastewater in Dong Qu Wastewater treatment plant was selected as the target which is mainly composed by domestic Wastewater. Use integrative A_mO_n process treats the Wastewater. After bench-scale and pilot-scale researching, with the help of molecular biology, mechanics was analyzed in this paper. At the end of this paper, mathematic model was also analyzed. The main parts of this paper are introduced as following:The content of bench scale test of the integrated A_mO_n process includes: (1) Optimal operation parameters of the A_mO_n process are determined as 8.5 hours. While when the HRT exceed 8.5h, HRT prolongation can't improve the effect of pollutant removal. (2) Study in optimization of sludge age. The results show that, for pollutant removal, when the environmental temperature is eligible, we can adopt the lower sludge age in A_mO_n process. Under the condition of water temperature surpass 20℃ and sludge age is 10d, the removal rate of COD, NH₃-N, TN and TP is individually 66.4%, 83.8%, 54.7%, 4 8.1%. (3)Study in the effect of the dissolve oxygen concentration in aerobic zone on the reactor. The results show that, the DO value in the aerobic zone is the key parameter of the process operation and control, which not only influences kinds of microbe activities, but also the valid volume of anaerobic/anoxic zone. The test shows that maintaining the DO value in the aerobic zone in the range 3.0～5.0mg/l is the suitable choice. (4) Research of suspended carrier integrated A_mO_n in bench-scale test. The test investigates the removal effect of different carrier filling rate with different DO concentration. The results show that, in the same DO concentration the removal ability of the reactor will decrease companied with the carrier filling rate decreasing. In the same carrier filling rate and the different DO concentration, the pollutant removal effect in the higher DO value is better. However, with the carrier filling rate decreasing, the difference of the treatment effect resulting from the DO concentration will be reduced. (5) Study in the suspended carrier and activated sludge integrated A_mO_n process. Because the suspended carrier can strengthen the aerobic nitrifying effect, activated sludge can be at a lower sludge age, which is good for the N removal effect of the whole system. When the carrier filling rate is at 30% and the activated sludge age is 9d, reactor removal rate is individually COD:75.2%, NH₃-N:76.5%, TN:65.5%, TP :55.2% .The mechanism research of the integrated A_mO_n process includes: (1) Study and analysis of community structure and characteristic of resources diversity of ammonia-oxidizing bacteria and nitrite-oxidizing bacteria in the integrated Wastewater treatment by the PCR-DGGE methodology. Results show that characteristic of...