Purelab flex water purifier

The NA mixture, magnetite particles, potassium persulfate, sodium chloride, ferrous chloride tetrahydrate, potassium persulfate, and ethanol, were obtained from Sigma-Aldrich. Acrylic acid, ammonium persulfate, and N,N’-methylene bisacrylamide (NNMA) were purchased from Acros Organics. Commercial membranes PVDF400HE, NF8 were supplied by Nanostone Water Co., Oceanside, California, and DOW FLIMTECH NF270 membrane was obtained from the DOW Chemical Company. Produced water samples were provided by Chevron (Refer SI, Table S2 for water composition). Deionized (DI) water used at all stages of the experiments was obtained (final resistivity <18.2 MΩ, TOC <1 ppb) using a Purelab flex water purifier from ELGA Lab water. All chemicals were of reagent grade and were used with as received.

Aqueous dispersion of Graphene Oxide (4 mg/ml) was purchased from Graphenea, Inc. PS35 (ultrafiltration membrane) and Dow NF270 (nanofiltration membrane) was supplied by Nanostone water Co. and Dow Flimtech, respectively. Reagent grade isopropanol, magnesium sulfate, ferricyanide ([Fe(CN)₆]³⁻), rodamine B labeled polyethylene glycol with molecular weight of 5000 g/mol, FITC labeled polyethylene glycol with molecular weight 2000 g/mol, Tris(4-carbazoyl-9-ylphenyl) amine and humic acid were purchased from Sigma-Aldrich. All reagents were used as received. Water used at all stages of the experiments was purified (final resistivity <18.2 MΩ, TOC<1 ppb) using a Purelab flex water purifier obtained from ELGA Lab water.