Abstract
Membrane distillation (MD) was evaluated as a treatment option of wastewater reverse osmosis concentrate (WWROC) discharged from wastewater reclamation plants (WRPs). A direct contact MD (DCMD), at obtaining 85% water recovery of WWROC showed only 13–15% flux decline and produced good quality permeate (10–15 µS/cm, 99% ion rejection) at moderate feed temperature of 55 °C. Prevalent calcium carbonate (CaCO3) deposition on the MD membrane occurred in treating WWROC at elevated concentrations. The combination of low salinity and loose CaCO3 adhesion on the membrane did not significantly contribute to DCMD flux decline. Meanwhile, high organic content in WWROC (58–60 mg/L) resulted in a significant membrane hydrophobicity reduction (70% lower water contact angle than virgin membrane) attributed to low molecular weight organic adhesion onto the MD membrane. Granular activated carbon (GAC) pretreatment helped in reducing organic contents of WWROC by 46–50%, and adsorbed a range of hydrophobic and hydrophilic micropollutants. This ensured high quality water production by MD (micropollutants-free) and enhanced its reuse potential. The MD concentrated WWROC was suitable for selective ion precipitation, promising a near zero liquid discharge in WRPs.
Original language | English (US) |
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Pages (from-to) | 565-575 |
Number of pages | 11 |
Journal | Journal of Membrane Science |
Volume | 524 |
DOIs | |
State | Published - Nov 29 2016 |
Bibliographical note
KAUST Repository Item: Exported on 2020-10-01Acknowledgements: This study was funded by the Cooperative Research Centre for Contamination Assessment and Remediation of the Environment (CRC CARE) (Sustainable process for treatment of WWROC to achieve near zero liquid discharge). We acknowledge Sydney Olympic Park Authority (Dr. Andrzej Listowski) (WWROC sampling) and the team at University of New South Wales (Dr. James McDonald) (provision of HPLC analytical support).