Abstract: Two-sludge technology is a representative of denitrifying phosphorus removal technologies and has potential advantage in treating municipal wastewater with low carbon source. There have a large number of reports about the technology, but few concerned with the modeling of it. So this paper was aim to develop a mathematical model which can be used to simulate the processes of Two-sludge system. A series of kinetic models which were simplified to linear form basing on some assumption and referencing to ASM2D were adopted to represent the main biochemical processes including phosphorus release（organic storing under anaerobic condition）, nitrating, aerobic biodegradability of organic and denitrifying phosphorus uptake. Then the model of Two-sludge technology was developed on the base of material balance and the principal components of the model were a set of linear equations. The input variables of the model include water quality parameters,HRT of each reactor,MLSS of anaerobic tank, MLSS of nitrifying tank, reflux ratio and transfluence ratio.The kinetic parameters and stoichiometry parameter of the model can be estimated base on experiment data. In this paper, the values of the reaction rate constants of organic storing under anaerobic condition, aerobic biodegradability of organic in nitrifying tank, nitrating in nitrifying tank, aerobic biodegradability of organic in postpositional aeration tank and phosphorus uptake in postpositional aeration tank were estimated from the run datum of a Two-sludge system pilot and the values were respectively 0.29 L/(g.h), 0.26 L/(g.h), 0.64 L/(g.h), 0.31 L/(g.h), 0.20 L/(g.h), 2.326 L/(g.h).The stoichiometry parameters were also estimated from experiment. The stoichiometry relation between the organic consumption and denitrification is 10.03g(COD)/g(N), the stoichiometry relation between phosphorus release and organic storing is 0.2g(P)/g(COD) and that between denitrification and phosphorus uptake is 0.98g(N)/g(P).It is worthy of special mention that, the reaction rate denitrifying phosphorus uptake is expressed as the product of the duration of the phosphorus uptake and the average rate of denitrifying phosphorus uptake per MLSS（ KP-upt） reflect the effect of phosphorus release on denitrifying phosphorus uptake because it was shown by the former experiment that the value of KP-upt is related with the amount of phosphorus release per MLSS and duration of the phosphorus uptake. The value of KP-upt can be got from a table which reflect the KP-upt relation of , the amount of phosphorus release per MLSS and duration of the phosphorus uptake. The table can be drawn from denitrifying phosphorus uptake. But not as other parameters, the value of KP-upt can’t be ascertained before the model being solved ,for the amount of phosphorus release is unknown, so the solution of the model can’t be obtained by solving linear equations in on time. For that problem, trial balance method was adopted. The model was verified by experiment, and it was proved that the model can simulate the variation of the concentration of each kind of pollutant of every unit of Two-sludge system well, but the high accuracy was possibly benefit from the mutual offset of difference partially，So further study is still needed.

Key words: denitrification and phosphorus removal, denitrifying phosphorus removal;twosludge, mathematical model

摘要： 污泥是典型的反硝化除磷工艺，在处理低碳源生活水方面，极具应用前景。目前有关双污泥工艺的试验研究成果较多，而在双污泥工艺相关数学模型方面研究报道较少。本文的研究目的为建立一种可模拟双污泥反应过程的数学模型。参照ASM2D等模型，对主要生化反应过程的动力学模型进行线性简化，并列出了各单元污染物的物料平衡方程组，成为双污泥工艺数学模型的核心。模型的输入量包括水水质、各反应器停留时间、厌氧池污泥浓度、硝化池污泥浓度、回流比、越流比。模型的动力学参数与化学计量学参数由一实验室双泥系统的稳定运行数据估计得出（英文摘要给出了各参数的具体值）。针对目前反硝化聚磷数学模型无法体现厌氧释磷对反硝化聚磷过程影响的问题，采用平均比污泥聚磷速率与缺氧池反应时间乘积来描述缺氧聚磷过程的线性简化模型，平均比污泥聚磷速率与厌氧释磷量及反应时间有关，因此可反映厌氧释磷过程对缺氧聚磷速率的影响。 可查比污泥反硝化聚磷速率表得出，该表反映了比污泥反硝化聚磷速率与比污泥厌氧释磷量及反应历时之间的关系，可由反硝化聚磷实验获得。在模型求解之前，因比污泥厌氧释磷量未知，所以 无法确定，故无法通过一次求解模型中的线性方程组得出模型的解，针对此种情况，采用试算法求解模型。模型通过一连续流实验室双泥系统验证，结果表明，模型对各污染物浓度及沿程变化规律的预测具有较高准确性，但模型中可能存在不同误差相抵的情况，仍需进一步验证或改进。

关键词: 除磷脱氮, 反硝化除磷, 双污泥, 数学模型