Rhizofiltration for treatment of oil and gas produced water

Abstract

Production of conventional oil, natural gas and coal bed methane is often accompanied by the release of large volumes of oil and gas produced wastewater (PW). Numerous incidents are documented annually in the United States where PW is released to local environments from well blowouts and via damaged pipelines. There is a need to formulate an effective means of treating PW following a release. The reported project involves the use of a hydroponics system to assess the ability of four plant species (sunflower, Helianthus annuus; Indian mustard, Brassicajuncea; cattail, Typha latifolia; and sedge, Carex blanda) for rhizofiltration treatment of synthetic PW. After reaction with PW for nine weeks, Brassica juncea was most effective in removal of sodium from the PW. All species accumulated more metals in roots compared to aboveground shoots. Helianthus annuus were the most effective at translocation of metals to the shoots, regardless of complete plant death by five weeks. Based on current findings, several green plants may serve as a low-cost, environmentally benign method for treatment of PW.