同步硝化反硝化（simultaneous nitrification and denitrification，简称SND）是氧化沟工艺实现优良脱氮效果的主要原因，为了较好实现SND，采用ORP作为氧化沟工艺SND的控制参数．采用缺氧-厌氧-氧化沟模型对市政污水进行了生物脱氮研...同步硝化反硝化（simultaneous nitrification and denitrification，简称SND）是氧化沟工艺实现优良脱氮效果的主要原因，为了较好实现SND，采用ORP作为氧化沟工艺SND的控制参数．采用缺氧-厌氧-氧化沟模型对市政污水进行了生物脱氮研究．UORP在-30～30mV，NH4^＋和NO3^-的含量均比较低，发生了较好的SND；UORP在30mV以上，出水的总无机氮（TIN）中95％以上为NO3^-，该状况下硝化效果良好，UORP在-30mV以下，硝化不充分，出水的TIN中78％以上为NH4^＋；UORP在-30～30mV，TN的去除率在88％以上，SND作用去除的NO3^-占总的NO3^-去除的99％以上；氧化沟中的NH4^＋和NO3^-之比的对数与UORP有着很好的相关性，相关系数R=-0．97．展开更多
Two full-scale systems operated in parallel, a conventional A2/O system consisting of anaerobic, anoxic and oxic compartments in succession and an inverted system consisting of anoxic, anaerobic and oxic compartments ...Two full-scale systems operated in parallel, a conventional A2/O system consisting of anaerobic, anoxic and oxic compartments in succession and an inverted system consisting of anoxic, anaerobic and oxic compartments without internal recycle, were compared in terms of their phosphorus removal performance, with an emphasis on phosphate （P） release behaviors, using both operational data and simulation results. The inverted system exhibited better long-term phosphorus removal performance （0.2 ± 0.3 vs. 0.7 ±0.7 mg/L）, which should be attributed to the higher P release rate （0.79 vs. 0.60 kg P/（kg MLSS.day）） in the non-aerated compartments. The P release occurred in both the anoxic and anaerobic compartments of the inverted system, resulting in more efficient P release. Although the abundances of the ＇Candidatus Accumulibacter phosphatis＇ population in the two systems were quite similar （（19.1 ＋ 3.27）% and （18.4 ＋ 4.15）% of the total microbe （DAPI stained particles） population in the inverted and conventional systems, respectively, by fluorescence in situ hybridization （FISH））, the high-concentration DAPI staining results show that the abundances of the whole polyphosphate accumulating organisms （PAOs） in the aerobic ends were quite different （the average ratios of the poly-P granules to total microbes （DAPI stained particles） were （45 ±4.18）% and （35 ± 5.39）%, respectively）. Both the operational data and simulation results showed that the inverted system retained more abundant PAO populations due to its special configuration, which permitted efficient P release in the non-aerated compartment and better P removal,展开更多
In this study, the performance of nitrogen and phosphorus removal in a full-scale closed-loop bioreactor （oxidation ditch） system was simulated using the ASM2d model. Routine data describing the process for two year...In this study, the performance of nitrogen and phosphorus removal in a full-scale closed-loop bioreactor （oxidation ditch） system was simulated using the ASM2d model. Routine data describing the process for two years were compiled for calibration and validation. To overcome the identifiability problem, the classic Bayesian inference approach was utilized for parameter estimation. The calibrated model could describe the long-term trend of nutrient removal and short-term variations of the process performance, showing that the Bayesian method was a reliable and useful tool for the parameter estimation of the activated sludge models. The anoxic phosphate uptake by polyphosphate accumulating organisms （PAO） contributed 71.2% of the total Poly-P storage, which reveals the dominance of denitrifying phosphorus removal process under the oxygen limiting conditions. It was found that 58.7% of the anoxic Poly-P storage and denitrification by PAO in the reactor was achieved in the aerated compartment, implying that the PAO＇s anoxic activity was significantly stimulated by the low dissolved oxygen （DO） level in this compartment due to the oxygen gradient caused by brush aerator.展开更多
文摘同步硝化反硝化（simultaneous nitrification and denitrification，简称SND）是氧化沟工艺实现优良脱氮效果的主要原因，为了较好实现SND，采用ORP作为氧化沟工艺SND的控制参数．采用缺氧-厌氧-氧化沟模型对市政污水进行了生物脱氮研究．UORP在-30～30mV，NH4^＋和NO3^-的含量均比较低，发生了较好的SND；UORP在30mV以上，出水的总无机氮（TIN）中95％以上为NO3^-，该状况下硝化效果良好，UORP在-30mV以下，硝化不充分，出水的TIN中78％以上为NH4^＋；UORP在-30～30mV，TN的去除率在88％以上，SND作用去除的NO3^-占总的NO3^-去除的99％以上；氧化沟中的NH4^＋和NO3^-之比的对数与UORP有着很好的相关性，相关系数R=-0．97．
基金supported by the National Natural Science Foundation of China (No. 20921140094)the Knowledge Innovation Project of Chinese Academy of Sciences(No. KSCX2-YW-G-054)
文摘Two full-scale systems operated in parallel, a conventional A2/O system consisting of anaerobic, anoxic and oxic compartments in succession and an inverted system consisting of anoxic, anaerobic and oxic compartments without internal recycle, were compared in terms of their phosphorus removal performance, with an emphasis on phosphate （P） release behaviors, using both operational data and simulation results. The inverted system exhibited better long-term phosphorus removal performance （0.2 ± 0.3 vs. 0.7 ±0.7 mg/L）, which should be attributed to the higher P release rate （0.79 vs. 0.60 kg P/（kg MLSS.day）） in the non-aerated compartments. The P release occurred in both the anoxic and anaerobic compartments of the inverted system, resulting in more efficient P release. Although the abundances of the ＇Candidatus Accumulibacter phosphatis＇ population in the two systems were quite similar （（19.1 ＋ 3.27）% and （18.4 ＋ 4.15）% of the total microbe （DAPI stained particles） population in the inverted and conventional systems, respectively, by fluorescence in situ hybridization （FISH））, the high-concentration DAPI staining results show that the abundances of the whole polyphosphate accumulating organisms （PAOs） in the aerobic ends were quite different （the average ratios of the poly-P granules to total microbes （DAPI stained particles） were （45 ±4.18）% and （35 ± 5.39）%, respectively）. Both the operational data and simulation results showed that the inverted system retained more abundant PAO populations due to its special configuration, which permitted efficient P release in the non-aerated compartment and better P removal,
基金The authors gratefully acknowledge the financial support from the National Natural Science Foundation of China （Grant No. 20921140094）, Chinesc Academy of Sciences （KS CX2-YW-G-054） and the Crucial Special Project- National Water Pollution Control and Management Science （2008ZX07314-003）.
文摘In this study, the performance of nitrogen and phosphorus removal in a full-scale closed-loop bioreactor （oxidation ditch） system was simulated using the ASM2d model. Routine data describing the process for two years were compiled for calibration and validation. To overcome the identifiability problem, the classic Bayesian inference approach was utilized for parameter estimation. The calibrated model could describe the long-term trend of nutrient removal and short-term variations of the process performance, showing that the Bayesian method was a reliable and useful tool for the parameter estimation of the activated sludge models. The anoxic phosphate uptake by polyphosphate accumulating organisms （PAO） contributed 71.2% of the total Poly-P storage, which reveals the dominance of denitrifying phosphorus removal process under the oxygen limiting conditions. It was found that 58.7% of the anoxic Poly-P storage and denitrification by PAO in the reactor was achieved in the aerated compartment, implying that the PAO＇s anoxic activity was significantly stimulated by the low dissolved oxygen （DO） level in this compartment due to the oxygen gradient caused by brush aerator.
