Treatment of Real Produced Water by an Indigenous Halophilic Consortium in a Membrane Bioreactor
Volume Title: 1
1Department of Chemical Engineering, Amirkabir University of Technology, Tehran, Iran
2University of Tehran
3Department of Ecology and Environmental Pollution Control, Research Institute of Petroleum Industry (RIPI), Tehran, Iran
In the present study, a soil-based halophilic consortium was used to treat the PW of the Ahvaz 2 oilfield desalination unit in a membrane bioreactor. The bioreactor was set up in eight phases for 165 days with an average SRT of 100 days. In the first two phases in which the nitrogen and phosphorus compounds were added to PW, with a reduction in HRT from 48 to 24 hours, COD removal efficiency increased from 14.8% to 23.4% and TOC removal efficiency increased from 74.5% to 79.4%. Results showed that addition of yeast extract at the concentration of 0.01% increased the COD removal efficiency to 33% and reduced TOC removal efficiency to 76.2%. By increasing the concentration of yeast extract to 0.03%, the COD and TOC removal decreased slightly despite a significant increase in the microbial population. In the fifth and sixth phases which membrane bioreactor output from phases 3 and 4 was used as the bioreactor feed, the results showed that doubling the HRT (while at the same time average OLR only decreased by 28%) COD and TOC removal were increased in the range of 4 to 10%. Addition of glycine betaine to the output of phase 2 (as feed of bioreactor) as a compatible solute at the concentration of 1 mM increased the COD and TOC removal efficiency by 9.3% and 10.1%, respectively. Increasing the glycine betaine concentration to 5 mM, significantly increased the microbial population, while the COD and TOC removal decreased compared to phase 7.