title: Toxicity and biogas production potential of refinery waste sludge for anaerobic digestion.
abstract: Two waste streams from an oil refinery wastewater treatment system, float from a dissolved air flotation unit (DAF sludge) and waste activated sludge (WAS), were investigated to determine toxicity and biogas production potential for anaerobic digestion through batch testing methods. Ozonation as a pretreatment was investigated to observe the impacts of waste solubilization on both toxicity and biodegradability. Anaerobic toxicity assays resulted in no detectible inhibition from WAS, neither with nor without ozonation. Untreated DAF sludge exhibited inhibition that amplified with the increases in DAF sludge inclusion. Ozone treatment effectively reduces this inhibition. The biodegradability of WAS, measured by biochemical methane potential tests, doubled with low dose ozonation. DAF sludge biodegradability was negligible prior to treatment and was successfully enhanced through ozonation.
authors.affiliation: Department of Civil and Environmental Engineering, University of Nevada, MS-0258 Reno, NV 89557-0258, USA.
authors.forename: Laura
authors.initials: L
authors.lastname: Haak
authors.affiliation: Department of Civil and Environmental Engineering, University of Nevada, MS-0258 Reno, NV 89557-0258, USA.
authors.forename: Ratul
authors.initials: R
authors.lastname: Roy
authors.affiliation: Department of Civil and Environmental Engineering, University of Nevada, MS-0258 Reno, NV 89557-0258, USA. Electronic address: pagilla@unr.edu.
authors.forename: Krishna
authors.initials: K
authors.lastname: Pagilla
mesh_terms: D000693:Anaerobiosis; D001673:Biodegradation, Environmental; D056804:Biofuels / Q000032:analysis*; D008697:Methane / Q000032:analysis*; D000066388:Oil and Gas Industry; D010126:Ozone / Q000737:chemistry*; D012722:Sewage / Q000737:chemistry* / Q000382:microbiology; D062065:Wastewater / Q000737:chemistry / Q000382:microbiology / Q000633:toxicity*; D018508:Water Purification / Q000379:methods*
chemical_list: D056804:Biofuels; D008697:Methane; D010126:Ozone; D012722:Sewage; D062065:Wastewater
keywords: Anaerobic digestion; Anaerobic toxicity assay; Biochemical methane potential; Industrial wastes; Ozonation