[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 (kPHA,OUR) and proton consumption proportion (kPHA,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