Removal of <i>n</i> -hexane extractable material from synthetic oil produced water using Desmopan®5377A thermoplastic polyurethane packed bed reactor

Background: Water extracted during oil and gas exploration and production is known as produced water (PW). It contains dissolved and dispersed hydrocarbons and harmful chemical additives used in drilling or fracturing, rendering it highly polluted. This research investigates the efficiency of Desmopan® 5377A thermoplastic polyurethane beads in a packed bed sorption column to remove n-hexane extractable material (HEM) from synthetic PW. To our knowledge, the use of Desmopan® 5377A for removing HEM from produced water has not been documented. Methods: Experiments were designed using the D-optimal method within the response surface methodology (RSM) framework. Analysis of variance (ANOVA) was used to evaluate the effects of salinity, surfactant, and initial pH. Results: Under optimal conditions, a maximum HEM removal efficiency of 70.25% was achieved at high salinity, a surfactant (Tween 80) concentration of 482 mg/L, and an initial pH of 9. Salting-out was identified as the primary mechanism enhancing HEM removal. The lowest removal efficiency was observed at pH 7. The interaction between surfactant concentration and pH showed that increasing Tween 80 concentration improved removal efficiency at pH 4, 6, and 9 up to an optimal point, beyond which efficiency declined. Conclusion: A polymeric sorbent is recommended as a pre-treatment method to reduce HEM content in PW for treating complex contaminated media.