Methods for using ozone to enhance anaerobic digestion

摘要

The invention discloses systems and methods for producing a gas stream containing ozone and a “carrier” or sweep gas that has an oxygen concentration that is below a predetermined percentage for treatment of organic waste feed stocks in an anaerobic digester. In one embodiment, ozone and unreacted oxygen from an ozone generator are delivered to a pressure swing adsorption cycle, wherein the ozone is adsorbed onto a sieve and the excess oxygen is removed from the cycle. The sweep gas, which has a limited oxygen concentration, is then used to desorb the ozone from the pressure swing adsorption cycle and deliver the ozone to an anaerobic digester, where the ozone is used to treat the feed stock.

主权项

1. A method comprising:
(a) generating a first gas stream comprising at least 4% ozone by weight and at least 50% oxygen by weight; (b) separating at least a portion of the ozone from the first gas stream; (c) forming a second gas stream comprising at least a portion of the ozone that was separated from the first gas stream in step (b), the second gas stream having no more than 18% oxygen by weight; (d) treating wastewater using an anaerobic digestion process; and (e) contacting the second gas stream with at least a portion of the wastewater either before the wastewater is treated using the anaerobic digestion process or while the wastewater is treated using the anaerobic digestion process.