title: Microbial mats as a biological treatment approach for saline wastewaters: the case of produced water from hydraulic fracturing.
abstract: Treatment of produced water, i.e. wastewater from hydraulic fracturing, for reuse or final disposal is challenged by both high salinity and the presence of organic compounds. Organic compounds in produced water may foul physical-chemical treatment processes or support microbial corrosion, fouling, and sulfide release. Biological approaches have potential applications in produced water treatment, including reducing fouling of physical-chemical treatment processes and decreasing biological activity during produced water holding; however, conventional activated sludge treatments are intolerant of high salinity. In this study, a biofilm treatment approach using constructed microbial mats was evaluated for biodegradation performance, microbial community structure, and metabolic potential in both simulated and real produced water. Results demonstrated that engineered microbial mats are active at total dissolved solids (TDS) concentrations up to at least 100,000 mg/L, and experiments in real produced water showed a biodegradation capacity of 1.45 mg COD/gramwet-day at a TDS concentration of 91,351 mg/L. Additionally, microbial community and metagenomic analyses revealed an adaptive microbial community that shifted based upon the sample being treated and has the metabolic potential to degrade a wide array of contaminants, suggesting the potential of this approach to treat produced waters with varying composition.
authors: †Department of Civil and Environmental Engineering and ‡Department of Computational and Systems Biology, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, United States.
authors: Benay
authors: B
authors: Akyon
authors: †Department of Civil and Environmental Engineering and ‡Department of Computational and Systems Biology, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, United States.
authors: Elyse
authors: E
authors: Stachler
authors: †Department of Civil and Environmental Engineering and ‡Department of Computational and Systems Biology, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, United States.
authors: Na
authors: N
authors: Wei
authors: †Department of Civil and Environmental Engineering and ‡Department of Computational and Systems Biology, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, United States.
authors: Kyle
authors: K
authors: Bibby
mesh_terms: D001419:Bacteria / Q000235:genetics / Q000378:metabolism*; D001673:Biodegradation, Environmental; D002244:Carbon / Q000378:metabolism; D000067071:Hydraulic Fracking; D007700:Kinetics; D056186:Metagenomics; D054712:Salinity; D012722:Sewage / Q000737:chemistry; D062065:Wastewater / Q000382:microbiology*; D014867:Water; D018508:Water Purification / Q000379:methods*
chemical_list: D002244:Carbon; D012722:Sewage; D062065:Wastewater; D014867:Water