Impact of salinity on the population dynamics of microorganisms in a membrane bioreactor treating produced water

• Published in: The Science of the total environment Vol. 646; pp. 1080 - 1089
• Main Authors: Kose Mutlu, Borte, Ozgun, Hale, Ersahin, Mustafa Evren, Kaya, Recep, Eliduzgun, Selvihan, Altinbas, Mahmut, Kinaci, Cumali, Koyuncu, Ismail
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.01.2019
• Subjects: biomass; Bioreactors - microbiology; effluents; fouling; Membrane bioreactor; membrane bioreactors; Membranes, Artificial; microbial communities; Microbial community; microorganisms; Nanofiltration; oils; Osmosis; Population Dynamics; Produced water; Reverse osmosis; Salinity; Waste Disposal, Fluid - methods; Waste Water - microbiology; wastewater; Water Purification; wells; Membrane bioreactor; Nanofiltration; Reverse osmosis; Produced water; Microbial community; Salinity
• ISSN: 0048-9697; 1879-1026; 1879-1026
• DOI: 10.1016/j.scitotenv.2018.07.386

Biomass characteristics may change subject to a salinity increase when treating high strength wastewater. In this study, the impact of salinity in a membrane bioreactor (MBR) was investigated for the treatment of produced water (PW). MBR was operated as a pre-treatment prior to nanofiltration (NF) and reverse osmosis (RO). Mixed PW, that was originated from different oil, gas, and oil-gas wells, were subjected to pre-treatment for 146 days including three different operational phases: Low-salinity (~10 mS/cm), gradual increased salinity (10–40 mS/cm) and high salinity (~40 mS/cm). The results of this study showed that microorganisms could adapt using real wastewater and treat PW up to a certain level of the salinity. At high salinity levels of PW, the floc structure started to be disrupted and membrane fouling was accelerated. PCR-DGGE analysis confirmed the changes in microbial communities' composition in relation with high salinity. The results of the final treatment experiments presented that NF and RO treatment produced high-quality effluents that could be suitable for reuse. [Display omitted] •Produced water (PW) was subjected to biological pre-treatment for 146 days by MBR.•NF and RO treatment produced high-quality effluents for discharge and reuse.•Microorganisms could adapt and treat PW up to a certain level of the salinity.•At high salinity, the floc structure was disrupted and membrane was fouled.•PCR-DGGE analysis indicated changes in the microbial communities' composition.