Salinity build-up in osmotic membrane bioreactors: Causes, impacts, and potential cures

Xiaoye Song; Ming Xie; Yun Li; Guoxue Li; Wenhai Luo

doi:10.1016/j.biortech.2018.02.101

Salinity build-up in osmotic membrane bioreactors: Causes, impacts, and potential cures

Bioresour Technol. 2018 Jun:257:301-310. doi: 10.1016/j.biortech.2018.02.101. Epub 2018 Feb 23.

Authors

Xiaoye Song¹, Ming Xie², Yun Li³, Guoxue Li³, Wenhai Luo⁴

Affiliations

¹ Beijing Key Laboratory of Farmland Soil Pollution Prevention and Remediation, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China; Strategic Water Infrastructure Laboratory, School of Civil, Mining and Environmental Engineering, University of Wollongong, Wollongong, NSW 2522, Australia.
² Institute for Sustainability and Innovation, College of Engineering and Science, Victoria University, PO Box 14428, Melbourne, Victoria 8001, Australia.
³ Beijing Key Laboratory of Farmland Soil Pollution Prevention and Remediation, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China.
⁴ Beijing Key Laboratory of Farmland Soil Pollution Prevention and Remediation, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China. Electronic address: luowenhai@cau.edu.cn.

PMID: 29500063
DOI: 10.1016/j.biortech.2018.02.101

Abstract

Osmotic membrane bioreactor (OMBR), which integrates forward osmosis (FO) with biological treatment, has been developed to advance wastewater treatment and reuse. OMBR is superior to conventional MBR, particularly in terms of higher effluent quality, lower membrane fouling propensity, and higher membrane fouling reversibility. Nevertheless, advancement and future deployment of OMBR are hindered by salinity build-up in the bioreactor (e.g., up to 50 mS/cm indicated by the mixed liquor conductivity), due to high salt rejection of the FO membrane and reverse diffusion of the draw solution. This review comprehensively elucidates the relative significance of these two mechanisms towards salinity build-up and its associated effects in OMBR operation. Recently proposed strategies to mitigate salinity build-up in OMBR are evaluated and compared to highlight their potential in practical applications. In addition, the complementarity of system optimization and modification to effectively manage salinity build-up are recommended for sustainable OMBR development.

Keywords: Biological treatment; Draw solution; Forward osmosis (FO); Osmotic membrane bioreactor (OMBR); Salinity build-up.

Publication types

Review

MeSH terms

Bioreactors*
Membranes, Artificial
Osmosis*
Salinity
Wastewater
Water Purification*

Substances

Membranes, Artificial
Waste Water