Effect of operating conditions on the production of polyhydroxyalkanoate (PHA) in sludge generated from a distillery wastewater treatment system using microfiltration membrane bioreactor
Abstract:
Studies effect of operating conditions on the production of polyhydroxyalkanoate (PHA) in sludge generated from a distillery wastewater treatment system using microfiltration membrane bioreactor. In this study, the system operated in the pilot scale. The wastewater for this system is distillery slop came from distillers and was diluted by water. The research on PHA production by MBR was divided into 3 experiments. The first experiment studied the effect of sludge age between 50 and 100 days. The second experiment studied the effect of intermittent aeration period between 60 and 90 minutes period. And the third experiment studied the effect of COD loading in wastewater between 1,000 and 1,500 mg/l From the first experiment, it was found that sludge from the system with sludge age of 50 and 100 days produced 0.28, and 0.41% (w/w) of PHA, respectively. The removal percentages for phosphorus were 90.77, and 97.00%, respectively; for VFAs were 89.40, and 95.42%, respectively; and for COD were 89.76, and 94.34%, respectively. The second experiment, it was found that sludge from the system with 60 and 90 minutes aeration period produced 0.48, and 0.44% (w/w) of PHA, respectively. The removal percentages for phosphorus were 97.01, and 96.68%, respectively; for VFAs were 93.19, and 92.54%, respectively; and for COD were 94.77, and 94.89%, respectively. The third experiment, it was found that sludge from the system with 1,000 and 1,500 mg/l COD produced 0.49, and 1.11% (w/w) of PHA, respectively. The removal percentages for phosphorus were 97.34, and 96.72%, respectively; for VFAs were 93.57, and 87.57%, respectively; and for COD were 94.85, and 94.44%, respectively. From overall experiments, the in MBR operation for highest PHA production in this research is the 60 minutes intermittent aeration period under 100 days sludge age and 1,500 mg/l COD. Therefore, MBR is a challenge system for PHA production from sludge.