| The spiral up flow reactor (SUFR) system(patent code:ZL03117335.7) was developed by our research team. The flow model of the spiral up flow reactor was analyzed in this paper. And the research on the effects of parameter of the guiding vane in the SUFR system was carried out. In the reactor, multistage agitation made the flow pattern so complex that it was difficult to be measured directly. So we combined RTD tests with CFD software-Phoenics to investigate the flow model of the reactor. In addition, the anaerobic,anoxic and aerobic zone were considered as the research objects respectively in order that the effects of the parameters of the guiding vane on phosphorus and nitrogen removal could be studied easily. Detailed work and major conclusion are as follows:①RTD tests showed that the flow pattern of the reactor has the characteristics of both plug flow pattern and complete-mix pattern. Combined with analysis of mass balance, Phoenics software was used to simulate the flow field and develop the flow model. The liquid's spiraling up in the reactor was observed from simulation. And the simulation showed that eight reactor units make up of the flow model, in which a plug flow reactor is followed by a complete-mix reactor. The volume ratio of plug flow reactor units in the flow model was estimated to account for about 63%, indicating that the major flow pattern of the reactor is plug flow pattern.②The grey relation entropy method was utilized to analyze the effects of the parameters of the guiding vane on phosphorus and nitrogen removal in the SUFR system. The results showed that the rotational speed,the pitch angle of the guiding vane,d/D and the layers of multistage impeller play important roles in the system because the grey relation entropy values are almost upward of 0.98. And the rotational speed is more important than other parameters in the experiments.③The anaerobic,anoxic and aerobic zone were considered as the research objects respectively. And the effects of the parameters of the guiding vane on phosphorus and nitrogen removal were investigated. Results are showed as follows:1) In the anaerobic zone, when the rotational speed is 20rpm, d/D=0.8,α=150°and n=2, the nitrogen and phosphorus removal efficiency of the SUFR system is better than other conditions in this research. The efficiency of the phosphorus release and the predominance of the PAOs decrease under such conditions: the increase of the rotational speed; the change of the layers of multistage vane from 2 to 4; the variety of the pitch angle of the guiding vane from 150°to 180°; the decrease of the d/D value from 0.8 to 0.3.2) In the anoxic zone ,the total nitrogen removal efficiency and the ratio of the denitrification bacteria increase while the phosphorus removal efficiency and the ratio of the DNPAOs decrease under such conditions: the increase of the rotational speed; the change of the layers of multistage vane (n)from 2 to 4; the variety of the pitch angle(α) of the guiding vane from 150°to 180°; the decrease of the d/D value from 0.8 to 0.3; when the rotational speed is 90rpm, d/D=0.3,α=180°and n=4, the nitrogen and phosphorus removal efficiency of the SUFR system is better than other conditions in this zone.3) In the aerobic zone ,the ammonia and phosphorus removal efficiency decreases under such conditions: increase of the rotational speed; the change of the layers of multistage vane (n) from 2 to 4; the variety of the pitch angle(α) of the guiding vane from 150°to 180°; the decrease of the d/D value from 0.8 to 0.3. And when the rotational speed was 20rpm, d/D=0.8,α=150°and n=2, the ammonia and phosphorus removal efficiency are better than other conditions in this research.④The effects of the parameters of the guiding vane were carried out. And the results showed as follows:1) In the anaerobic zone,the effects of the parameters of the guiding vane on q max,KA were observed clearly. The q maxvaried from 1.6 to 2.7 mgCOD/gVSS·min with the change of the parameters of the guiding vane in the research. And the range of the KA was from 0.85 to 13 mg/L2) In the anoxic zone , the effects of the parameters of the guiding vane on q max,KS were observed clearly. The q dmeanxit rificationdenvaried from 0.23 to0.75 mg NO3 ?-N /gVSS·min with the change of the parameters of the guiding vane in the research. And the range of the KS was from 3.55 to 87 mg/L.3) In the aerobic zone , the q nmitarxif icationvaried from 0.031 to0.11 NH 4+ ?N/gVSS·min with the change of the parameters of the guiding vane in the research. And the range of the K NH4 was from 14to 18.7 mg/L. The q mphaoxsphorusvaried from 0.17 to0.22 mg PO 43?-P /gVSS·min with the change of the parameters of the guiding vane. And the range of the K p was from 0.4to 27 mg/L.⑤The flow model and G value changed with the parameters of the guiding vane. And the change of the flow model was the key factor in the variety of the nutrient removal and sludge volume index. However, the proper G value may be beneficial to the SUFR system. The plug flow pattern was impaired under such conditions: the increase of the rotational speed from 30rpm to 90rpm; the change of the layers of multistage vane (n)from 2 to 4; the variety of the pitch angle(α) of the guiding vane from 150°to 180°; the decrease of the d/D value from 0.8 to 0.3. And the choice of the parameter of the guiding vane should be consistent with the influent wastewater and the requirement of the effluent disposal. |
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