Hybrid SBR–FO system for wastewater treatment and reuse: Operation, fouling and cleaning

Rodrigo Valladares Linares, Zhenyu Li, Victor Yangali-Quintanilla, Qingyu Li, Johannes S. Vrouwenvelder, Gary L. Amy, NorEddine Ghaffour

Research output: Contribution to journalArticlepeer-review

35 Scopus citations

Abstract

Forward osmosis (FO) is a novel membrane separation process that potentially can be used as an energy-saving alternative to conventional membrane processes. A hybrid sequential batch reactor (SBR)–FO process was explored. In this system, a plate and frame FO cell including two flat-sheet FO membranes was submerged in a bioreactor treating synthetic domestic wastewater. The dissolved organic carbon (DOC) removal efficiency of the system was 98.55%. Total nitrogen removal was 62.4%, with nitrate, nitrite and ammonium removals of 58.4%, 96.2% and 88.4%, respectively. Phosphate removal was almost 100%. The 15-hour cycle average water flux of a virgin membrane with air scouring was 2.95 L/m2·h− 1. Air scouring can help to remove loose foulants from the membrane active layer, thus helping to recover up to 89.5% of the original flux. Chemical cleaning of the fouled active layer of the FO membrane was not as effective as air scouring. Natural organic matter (NOM) characterization methods (liquid chromatography–organic carbon detection (LC–OCD) and 3-D fluorescence excitation emission matrix (FEEM)) show that the FO membrane has a very good performance in rejecting biopolymers, humics and building blocks, but a limited ability in rejecting low molecular weight neutrals. Transparent exopolymer particles (TEP) and other biopolymers might be associated with fouling of the membrane on the support layer. A 1% sodium hypochlorite (NaOCl) cleaning solution was proved to be effective for removing the foulants from the support layer and recovering the original flux.
Original languageEnglish (US)
Pages (from-to)31-38
Number of pages8
JournalDesalination
Volume393
DOIs
StatePublished - Apr 5 2016

Bibliographical note

KAUST Repository Item: Exported on 2020-10-01
Acknowledgements: The research reported in this paper was supported by King Abdullah University of Science and Technology (KAUST), Saudi Arabia. The authors would like to thank Hydration Technology Innovations for providing the FO membranes. The authors extend their gratitude to the Water Desalination and Reuse Center (WDRC) staff for the support.

ASJC Scopus subject areas

  • Water Science and Technology
  • General Materials Science
  • General Chemical Engineering
  • General Chemistry
  • Mechanical Engineering

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