Environmental Research Center (ERC), Department of Applied Chemistry, Faculty of Chemistry, Razi University, Kermanshah, Iran.
Environmental research Center (ERC), Department of Applied Chemistry, Faculty of Chemistry, Razi University, Kermanshah, Iran
Department of Gas and Petroleum, Yasouj University, Gachsaran, Iran.
Department of Environmental science, Faculty of Natural resources and Marine Science, Tarbiat Modares University, Noor, Iran.
In this study, the potential of four different culture selection methods under short-term enrichment time (STE) to accumulate PHA-producing bacteria in mixed activated sludge was compared and the most efficient culture selection method was introduced. This means, PHA-producing microbial community was firstly enriched in a sequencing batch bioreactor (SBR) with four different selection methods including an anaerobic-aerobic process (SBR1), a fully aerobic batch process (SBR2), an uncoupled carbon and nitrogen feeding regime (SBR3) and aerobic/anoxic process (SBR4). In the next step, cellular PHA content was maximized in a fed-batch accumulator. From the obtained results, PHA could be accumulated up to 13.2, 10.8, 22.36, and 6 % (mg-PHA/mg-TSS) in SBR1, SBR2, SBR3, and SBR4, respectively. Uncoupled carbon and nitrogen feeding regime (SBR3) showed the best PHA accumulating ability when acetate was used as feed. Also, the SBR3 was fed by soft-drink industrial wastewater to evaluate the capability of the selected strategy for treating real wastewater, which 13.75% of mg-PHA/mg-TSS was achieved.