(403d) Atomic Layer Deposition-Modified Membranes for Produced Water Treatment

Ghader Mahmodi^a, Anil Ronte^a, Payam Zarrintaj^a, Phadindra Wagle^b, David N. Mcllroy ^b, Joshua D. Ramsey^a, and Seok-Jhin Kim ^a*

^a School of Chemical Engineering, Oklahoma State University, 420 Engineering North, Stillwater, OK, 74078, United States

^b Department of Physics, Oklahoma State University, 145 Physical Sciences Bldg., Stillwater, OK, 74078, United States

Abstract

Produced water (PW) comes out of a well with crude oil during production and comprises of oil components, dissolved minerals, production chemicals, and produced solids, which there is a need for efficient and economical technologies for PW purification. ZnO atomic layer deposition (ALD) modified membranes were developed for treating PW. ZnO ALD membranes increased hydrophilicity with an oil contact angle increasing from 165.1° for the pristine membrane to 170.5° for ZnO ALD membrane (120 cycles). ZnO ALD membranes induced a dramatic rise in the pure water flux from 148 to 192 L m^-2 h^-1. ZnO ALD on the membranes increased Total Organic Carbon (TOC) rejection from 96% to 99% and decreased Total Dissolved Solids (TDS) content from 311388 ppm to 10 ppm. Roughness is high for the pristine membrane but decreases with increasing ZnO ALD cycles. The average roughness (S_a) was 509 nm for the pristine membrane and was reduced to 332 nm for the ZnO ALD membrane (120 cycles). Additionally, the anti-fouling property of membranes with flux recovery ratio (FRR) increased from 93% to 99%. ZnO ALD was able to efficiently enhance the permeability, selectivity, and anti-fouling property of the membranes.