基于OUR-HPR测量在线估计活性污泥合成PHA量

活性污泥工艺是一种具有重要应用前景的工业化生产聚羟基烷酸酯(PHA)的方法.当前PHA测量主要采用离线分析方法,时间滞后、分析操作复杂,不适于PHA生产过程控制.本研究基于活性污泥同时储存生长-溶解性微生物产物模型(SSAG-SMP),认为在饱食(外部有机碳基质充足)期间,聚羟基烷酸酯(PHA)的合成速率与氧利用速率(OUR)及氢离子产生速率(HPR)呈线性关系,建立了一种基于OUR-HPR在线测量数据估计活性污泥合成PHA量的方法.本研究对乙酸作基质的不同浓度情况进行模拟,结果表明OUR及HPR的PHA合成的氧气消耗分数(kPHA,OUR)和质子消耗分数(kPHA,HPR)为常数,分别是0.67和0.57.利用建立的线性关系来预测饱食期PHA含量,结果显示预测值与实测值较为吻合,说明提出的基于OURHPR测量在线估计PHA合成量的方法可行.

On-line Estimation for the Amount of Stored PHA in Activated Sludge Based on OUR-HPR Measurements

Activated sludge process is an important approach for industrial Polyhydroxyalkanoate (PHA) production. Off-line measurement with a time lag and complex analysis, is a common method for PHA, but is not suitable for the process control of PHA production. Based on a model for simultaneous storage and growth-soluble microbial products (SSAG-SMP), it is assumed that there is the linear relationship between the PHA synthesized and OUR or HPR, respectively. Further, a novel method to estimate PHA content based on in-situ monitoring data of oxygen uptake rate (OUR) and hydrogen-ion production rate (HPR) is established in this paper. The results of modeling OUR and HPR under different substrate concentrations showed that oxygen consumption proportion (k_{PHA, OUR}) and proton consumption proportion (k_{PHA, HPR}) of PHA synthesis were 0.67 and 0.57, respectively. The predicted results based on the linear relationship were essentially consistent with measured ones, and indicated that the method is feasible.