Aluminum electrocoagulation followed by forward osmosis for treating hydraulic fracturing produced waters

摘要

Forward osmosis is an emerging membrane based separation technology that could find niche applications in the treatment of oil and gas produced water. Here, the feasibility of treating hydraulic fracturing produced waters using a combined electrocoagulation (EC) and forward osmosis (FO) process has been investigated. EC is shown to be effective in removing suspended solids and organic compounds which foul the membrane during FO. The amount of suspended solids and organic compounds that are removed depends on the EC reaction time. By accounting for internal and external concentration polarization as well as fouling due to deposition on the feed side barrier surface of the FO membrane, the expected flux may be determined. The effectiveness of removal of suspended solids and organic compounds may be modeled as changes in the permeability of the foulant layer that develops on the feed side of the membrane. The results obtained for real produced waters from Southwestern Energy operations in the Fayetteville Shale indicate that combined EC and FO could be an effective method for water recovery from hydraulic fracturing produced waters.