Simultaneous carbon and nutrients removal and PHA production in a novel single air lift bioreactor treating an industrial wastewater

In this article, the performance of a continuous feed and intermittent discharge air lift bioreactor (CFIDAB) to treat an industrial wastewater and also its potential for producing poly-hydroxyalkanoate (PHA) was examined. HRT and airflow rate in the range of 12-24 h and 1-3 l/min, respectively, were considered as two independent variables to determine the optimum operating condition. From the reported results, air flow rate had a positive effect on removing TCOD, TP, and TN, while HRT indicated reverse effects. TCOD, TN, and TP removal efficiency of 92%, 71%, and 69%, respectively, were obtained under a condition with 18.5 h of HRT and 2.5 l/min of air flow rate. In the next step, the obtained excess sludge at the optimum condition was examined in the accumulating bioreactor with three different carbon sources to determine the capability of sludge to produce PHA. Excess sludge showed up to 34.2, 4.8, and 11.3% of accumulating PHA (mg PHA/mg TSS x 100) using acetate, soft drink wastewater, and Faraman industrial wastewater as carbon sources, respectively. As a conclusion, this single bioreactor is capable of removing carbon and nutrients from wastewater which led to create a potential to be a selected system for PHA producing microorganisms. (C) 2020 Elsevier B.V. All rights reserved.