| In order to achieve the purpose of nitrogen and phosphorus removal, the technology of biological sewage treatment usually sets up anaerobic, anoxia and aerobic pond and needs it to reflow in the mixture to supplement the carbon source. Which will increase the function cost of the sewage disposal.(AO)2 technology using partial influent and reflow sludge into the first stage of the hypoxic zone, and the remaining water enters into the second stage of the hypoxic zone. So that it forms a concentration gradient. In addition, due to the use of sub-water system, each area generated by a period of aerobic nitrification liguid directly into the next section of denitrification zone, no liquid inside in the reflowing of nitrification facilities, and can make use of wastewater of organic matter as a carbon source in the denitrification zone. Without additional carbon source, it achieves the purpose of higher efficiency for denitrification. At the same time,it is effective to the removal of phosphorous due to the constant efflux of sludge. The technology has both the quality of removal of phosphor and the needs to the carbon, so it improves the system's overall performance and abolishes the back flow of the nitration mixture.A lot of energy can be saved compared to the traditional A/O technology.Step Feed (AO)2Process analyzed the simulation of sewage effects of nitrogen and phosphorus removal. It discussed the temperature, DO, pH and other factors on the effect of removing. And it analyzed the distribution of MLSS in the internal reactor. The course of the experiment changes in SVI. We analyze the stability of the system, as well as the ability to remove pollutants by observing the biological phase of Sludge micro-organisms. We analyze the different water removal rate of pollutants at the stage of pilot study.We observe the law to remove pollutants by changing the water flow, changes in the way of sludge load. The result shows that water levels in substage. A/O technology has a good effect of nitrogen and phosphorus removal. When the Q1/Q2 for the 2:1-1:1,the ratio of sludge back is 50%,the TKN removal rate is more than 75%,ammnia nitrogen removal rate is more than 85%,the ratio of COD removal is more than 90%, and PO43- removal rate is up to 50% around. At the same time, the test determines the best operating conditions: temperature 10-25℃, pH=6.9-7.5, HRT for 8h, dissolved oxygen for aerobic zone is about 2.5mg//L and dissolved oxygen in hypoxic zones is below 0.5mg/L. System can achieve the water quality discharge standards at the national level (GB8978-1996) when the Q1/Q2=2:1. It is better than Q1/Q2 = 1:1 at the time of treatment.Through the comprehensive and detailed analysis for various working conditions of removing pollutants under each circumstance (including COD, NH3-N, TN, TP).It analysis the impact of the removal of pollutants for various control parameters (HRT, F / M, the concentration of activated sludge , SVI) , through the establishment of dynamic model of COD removal, it reaches vmax = 7.03 d-1, Ks = 63.46mgCOD / d, Degradation Kinetics ofmatrix equation as follows: v =(?); NH3-N to carry out dynamic analysis of n = 0.2, k= 1.27.( AO)2 technology has the following characteristics: high efficiency nitrogen, strong resistance to impact load, saving capital investment, lowering operating costs.The test makes useful explorations for the dealing of biological nutrient removal sewage for domestic sewage life, and provides a new way of thinking for improving the efficiency of biological nitrogen synchronous.
|
PDF Full Text Request