Patent ID: 7510656

Claim:
A method for generating fracturing water from produced water comprising: transferring produced water contaminated with slick water, methanol and boron into an anaerobic pond; holding the produced water in the anaerobic pond for at least a first mean residence time; transferring anaerobic pond effluent to an aeration pond; aerating the anaerobic pond effluent in the aeration pond for a second mean residence time; transferring aeration pond effluent from the aeration pond to a dissolved air flotation treatment system; floating the aeration pond effluent with the dissolved air flotation treatment system to generate a floated aqueous effluent and a separated solids effluent; biologically digesting the floated aqueous effluent in a bioreactor until a desired concentration of methanol is obtained; transferring bioreactor effluent from the bioreactor to a reverse osmosis system; separating contaminants from bioreactor effluent with the reverse osmosis system, the reverse osmosis system passing at least some boron in its permeate; and removing at least some of the boron from the reverse osmosis permeate via a boron-selective removal process to obtain a desired level of boron in the reverse osmosis permeate.