Abstract: A method of treating a contaminated oil comprising preparing a brine solution, adding ozone to the brine solution to produce ozonated brine solution, adding a volume of ozonated brine solution to a volume of the contaminated oil, mixing the volumes of contaminated oil and ozonated brine solution with coagulant and surfactant at a shear rate sufficiently high so as to cause formation of an emulsion of the contaminated oil and the brine solution, stopping the mixing, thereby causing the emulsion to separate into an aqueous brine liquid phase and an oil liquid phase, separating the brine liquid phase from the oil liquid phase, and separating at least one contaminant from the oil liquid phase to produce a volume of purified oil.

Abstract: A method for treating wastewater is disclosed. The method is useful in particular for treating wastewater that is generated from the process of drilling, hydraulic fracturing and/or cleaning a bore of an oil or natural gas well bore. The method may include performing cold lime softening of the wastewater to form waste salt flocs, filtration of waste salt flocs, ozonation of the filtrate from the filtration, and reverse osmosis of the filtrate to produce a purified permeate.