General information about SMP

Soluble microbial products are the major component of the residual organic fraction in biological wastewater treatment effluent.  Their presence, therefore, has significant implications for the performance of wastewater treatment processes, the quality of the receiving waters and membrane fouling. Much attention, therefore, has recently been paid to the formation of SMP in biological systems, with the question of how to reduce the SMP concentration in secondary wastewater treatment effluent of particular interest.

It is essential to distinguish UAP and BAP as they are chemically distinct with UAP resulting from the processing of low MW compounds under substrate utilizing conditions and BAP from the conversion of high MW molecules in the endogenous process. 

系统运行工艺条件对于SMP形成的影响

SMP的形成受多项工艺条件的影响，如进水基质浓度，溶解氧水平和温度。 

活性污泥中不同的微生物组分对于不同的因素的响应速率也是不同的。俞汉青教授团队的文章做了功以操作条件对于SMP的影响。

实验中除了常规的三氮指标，COD,MLSS, MLVSS的检测外，还用离子树脂交换的方法提取了EPS。另外检测了OUR.

1. EPS的监测方法来源于：Enzymatic activity in the activated-sludge floc matrix

2. OUR的监测方法是：

 (1) 250 ml mixed liquor sample was taken from the reactors during aeration time; 

(2) a DO electrode was used to monitor the changes in levels of DO; 

and (3) the OUR values were calculated based on the DO depletion rate. 

3. SMP的监测方法来源于：Soluble microbial products formation in anaerobic chemostats in the presence of toxic compounds

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SMP[as COD]=[Soluble COD(SCOD) ]-1.07*[Acetate]

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文章的主要结论是基质的变化对于SMP的产量的影响最大，溶解氧对于SMP的影响不明显。温度对于SMP也有较为明显的影响，温度低的时候SMP产量会减少，但UAP会增加。

When DO concentration decreased and with the reactor under oxygen-limitation conditions, less SMP were produced by autotrophs. However, SMP production from autotrophs was a small fraction of the total SMP production and therefore had no effect on total SMP production.

这篇文章还讲了可以通过实验得到异养菌及自养菌分别对于SMP产生的贡献。

The SMP concentration of heterotrophs, AOB andNOB in the first batch test

SMP的数学模拟过程

Activated sludge model在对于污水处理过程模拟中并没有设计SMP这一部分，因此基于ASM的模型或者软件并没有考虑SMP。在查阅UAP,BAP模拟参数的时候，查看了Biowin的Manual，并没有找到相关的信息。因此在后期的资料查阅过程中一定要对ASM以及美国人做的模型进行仔细比对。

MacCarty教授在BT中基于Mass balcance做了建立了如下的关系式：

Rittman_ChB5_P8

要利用上面的关系式进行数值模拟的时候就要对相关的参数进行必要的拟合，这是能否使用模型进行预测的关键。 

俞汉青教授课题组的一篇EST文章中建立了下表所描述的数学方程

这个模型可以推测四种不同的固体成分（包括活性的异养菌，EPS，储存物质以及残留的惰性固体物质）和三种溶解性成分（包括进水基质，两种SMP和电子受体）。具体方程如下图：

 Non-Steady-State Mass-Balance Equations for All Components in the Expanded Unified Model Stoichiometric and Kinetic Coefficients (20 °C) for the Expanded Unified Model

Rittmann 教授的一篇文章也对于这个过程建立了相关的数学模型，但这个是概念模型，没有列举具体的参数。

A unified theory for extracellular polymeric substances, soluble microbial products, and active and inert biomass