Abstract
The management of large volumes of flowback and produced water (FPW) generated in shale gas extraction is of great concern due to the high concentrations of total dissolved solids (TDS), scale forming constituents, and organics. The objective of this study was to evaluate the performance of a combined ultrafiltration (UF) and reverse osmosis (RO) process for treating FPW from the Weiyuan shale gas play, China. Under a constant pressure of 4.5 MPa, the RO process decreased the concentrations of TDS, chemical oxygen demand (COD) and Cl- to 192, 7.5 and 97 mg L-1 from 18900, 530 and 11000 mg L-1 in the feed, respectively. The effluent of the combined process met the requirements for surface water discharge and agriculture irrigation in China. The total fouling index of the UF membrane over a range of permeate fluxes suggests a critical flux of around 19 L m-2 h-1; operation at a low flux was effective for UF fouling control. The operating pressure and recovery of the RO system significantly affected the permeate flux and quality, with both the flux and rejection increasing with increasing operating pressure but decreasing with increasing recovery. Moreover, CaCO3 and BaCO3 crystals were identified on the RO membrane surface at high recovery. The rejection data for TDS and COD by the RO membrane were consistent with the Spiegler-Kedem membrane transport model.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 942-955 |
| Number of pages | 14 |
| Journal | Environmental Science: Water Research and Technology |
| Volume | 4 |
| Issue number | 7 |
| DOIs | |
| State | Published - Jul 2018 |
| Externally published | Yes |
Bibliographical note
Funding Information:Initial feed concentration (mol L−1 or mg L−1) Final feed concentration (mol L−1 or mg L−1) Permeate concentration (mol L−1 or mg L−1) Membrane permeate flux (L m−2 h−1 or m s−1) Critical flux (L m−2 h−1) Normalized specific flux Hydraulic permeability (L m−2 h−1 bar−1) Pressure difference (bar) Water recovery Universal gas constant (0.083145 L bar mol−1 K−1) Observed solute rejection Cake resistance (m−1) Intrinsic membrane resistance (m−1) Total hydraulic resistance (m−1) Residual sum of squares Residual variance Filtration time (s) Absolute temperature (K) Total fouling index (m−1) Transmembrane pressure of the new membrane (kPa) Transmembrane pressure after a period of filtration (kPa) Filtration volume (m3) The volume of filtered water per unit membrane area (Lm−2) the Applied Basic Research Program of Sichuan Province (2017JY0238), the China Postdoctoral Science Foundation funded project (2017M612965), and the Full-time Postdoctoral Foundation of Sichuan University (2017SCU12019).
Funding Information:
This work was supported by the National Natural Science Foundation of China (51678377 and 51708371), the Sichuan University Outstanding Youth Foundation (2015SCU04A35),
Funding Information:
This work was supported by the National Natural Science Foundation of China (51678377 and 51708371), the Sichuan University Outstanding Youth Foundation (2015SCU04A35), the Applied Basic Research Program of Sichuan Province (2017JY0238), the China Postdoctoral Science Foundation funded project (2017M612965), and the Full-time Postdoctoral Foundation of Sichuan University (2017SCU12019).
Publisher Copyright:
© 2018 The Royal Society of Chemistry.
