Permian basin produced water treatment using combined membrane treatment

Permian Basin produced water presents various treatment challenges due to its high salinity and complex matrix, which drives high osmotic pressures and fouling and scaling in membrane systems. This study investigates and compares four processes designed to maximize water recovery from produced water while minimizing energy use and fouling. The treatment processes are (i) direct air gap membrane treatment (AGMD) (P1), (ii) pretreatment with FeCl 3 as a coagulant before AGMD (P2), (iii) direct forward osmosis (FO) with NaCl or MgCl 2 as draw solutes, followed by AGMD, and (iv) an integrated, sequential process combining pretreatment, FO, and AGMD in a single train (P4). FeCl 3 dosing was optimized at 100 mg L −1 to balance turbidity reduction. Across configurations, the integrated P4 delivered the best overall performance, achieving higher permeate flux, improved fouling resistance, and greater total water recovery compared to other processes. The results for all water matrices yielded permeates with TS less than 500 mg L −1 . The results highlight the critical role of pretreatment in protecting membranes, the importance of optimizing draw solute type and concentration to sustain FO performance under high internal concentration polarization conditions, and the beneficial synergy between FO, pretreatment, and AGMD for producing high-purity desalinated permeate from Permian Basin produced water. These findings inform scalable design considerations for the reuse of produced water, including safe discharge, such as optimizing coagulants, selecting membranes, and implementing effective fouling management strategies.