title: Treatment of oil sands process-affected water (OSPW) using ozonation combined with integrated fixed-film activated sludge (IFAS).
abstract: Two integrated fixed-film activated sludge (IFAS) reactors were operated continuously to treat raw (untreated) and ozonated (30 mg/L) oil sands process-affected water (OSPW). After 11 months, 12.1% of the acid extractable fraction (AEF) and 43.1% of the parent naphthenic acids (NAs) were removed in the raw OSPW IFAS, while 42.0% AEF and 80.2% of parent NAs were removed in the ozonated OSPW IFAS. UPLC/HRMS analysis showed that NA biodegradation significantly decreased as the NA cyclization number increased. Confocal laser scanning microscopy (CLSM) results showed that the biofilm in the ozonated OSPW IFAS was significantly thicker (94 ± 1.6 μm) than the biofilm in the raw OSPW IFAS (72 ± 2.8 μm) after 283 days of cultivation. The quantitative polymerase chain reaction (q-PCR) revealed that the abundance proportions of both nitrifier genes (AomA, NSR and Nitro) and denitrifier genes (narG, nirS, nirK and nosZ) within total bacteria were significantly higher in biofilms than in flocs in the raw OSPW IFAS system, but a different trend was observed in the ozonated OSPW IFAS system.
authors: Department of Civil and Environmental Engineering, University of Alberta, Edmonton, Alberta, Canada T6G 1H9.
authors: Chunkai
authors: C
authors: Huang
authors: Department of Civil and Environmental Engineering, University of Alberta, Edmonton, Alberta, Canada T6G 1H9.
authors: Yijing
authors: Y
authors: Shi
authors: Department of Civil and Environmental Engineering, University of Alberta, Edmonton, Alberta, Canada T6G 1H9. Electronic address: mgamalel-din@ualberta.ca.
authors: Mohamed
authors: M
authors: Gamal El-Din
authors: Department of Civil and Environmental Engineering, University of Alberta, Edmonton, Alberta, Canada T6G 1H9. Electronic address: yang.liu@ualberta.ca.
authors: Yang
authors: Y
authors: Liu
mesh_terms: D001419:Bacteria / Q000235:genetics / Q000378:metabolism; D001673:Biodegradation, Environmental; D018441:Biofilms / Q000187:drug effects*; D002264:Carboxylic Acids / Q000737:chemistry; D019652:Extraction and Processing Industry; D005798:Genes, Bacterial; D007220:Industrial Waste; D061329:Oil and Gas Fields; D010126:Ozone / Q000737:chemistry*; D012722:Sewage; D014865:Waste Disposal, Fluid / Q000379:methods*; D062065:Wastewater / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000737:chemistry
chemical_list: D002264:Carboxylic Acids; D007220:Industrial Waste; D010126:Ozone; D012722:Sewage; D062065:Wastewater; D014874:Water Pollutants, Chemical; C046170:naphthenic acid
keywords: Bioreactors; Integrated fixed-film activated sludge (IFAS); Oil sands process-affected water (OSPW); Ozonation