Reverse Osmosis Concentrate: Physicochemical Characteristics, Environmental Impact, and Technologies

Abstract

This study’s aim is to generate a complete profile of reverse osmosis concentrate (ROC), including physicochemical characteristics, environmental impact, and technologies for ROC treatment, alongside element recovery with potential valorization. A systematic literature review was used to compile and analyze scientific information about ROC, and systematic identification and evaluation of the data/evidence in the articles were conducted using the methodological principles of grounded data theory. The literature analysis revealed that two actions are imperative: (1) countries should impose strict regulations to avoid the contamination of receiving water bodies and (2) desalination plants should apply circular economies. Currently, synergizing conventional and emerging technologies is the most efficient method to mitigate the environmental impact of desalination processes. However, constructed wetlands are an emerging technology that promise to be a viable multi-benefit solution, as they can provide simultaneous treatment of nutrients, metals, and trace organic contaminants at a relatively low cost, and are socially accepted; therefore, they are a sustainable solution.

Environmental-, social-, and governance-related factors for business investment and sustainability: a scientometric review of global trends

“…The study phase began with the extraction of data, including identifying data closely related to the purpose of this study. Systematic article analysis and data evaluation were performed based on the grounded data theory (Valdés et al, 2021 ). Through a comparative analysis of articles, data were collected, coded, and investigated to produce ideas.…”

Submerged membrane/adsorption hybrid process in water reclamation and concentrate management—a mini review

“…ROC contains high concentrations of salinity, nutrients (phosphorus, nitrogen), NOM and OMPs. Adverse effect on the ecology and environment can result with indiscriminate disposal of partially or untreated ROC (Umar et al 2015 ; Joo and Tansel 2015 ; Valdés et al 2021 ; Arola et al 2019 ; Zhang and Liu 2021 ) as well as loss of a scarce water resource (20–30% of total wastewater volume (Umar et al 2015 ; Yang et al 2019 )). In many jurisdictions, sustainable treatment and management and safe disposal of ROC are mandated.…”

“…There are several methods of treating wastewater including coagulation/flocculation, activated carbon (AC) adsorption, oxidative and biological processes, membrane-based technologies, electro-dialysis and capacitive deionisation, either alone or in combination (Umar et al 2015 ; Arola et al 2019 ; Xiang et al 2019 ; Valdés et al 2021 ; Zhang and Liu 2021 ). Of these, a combination of methods has generally been found to be more efficient (Xiang et al 2019 ; Dewi et al 2021 ).…”

“…Membrane separation technologies, especially reverse osmosis (RO), is one of the most widely used technology in the world to produce clean water (Joo and Tansel 2015 ; Yang et al 2019 ; Algieri et al 2021 ; Valdés et al 2021 ; Wu et al 2021 ). However, RO generates a waste stream known as RO concentrate (ROC) that generally contains 20–30% of the feed stream (Umar et al 2015 ; Yang et al 2019 ).…”

Impacts of Desalination Brine Discharge on Benthic Ecosystems

“…5,6 Currently, seawater desalination is the leading technology used to bridge the widening gap between natural freshwater supply and the growing demand, with a daily global production rate of 99 million m 3 day −1 . 7−9 To date, ∼70% (and growing) of the desalination industry worldwide uses seawater reverse osmosis (SWRO), 7,10 which is the focus of this review. Reverse osmosis desalination is a membrane separation process in which highly saline feedwater is pressurized through specially structured membranes.…”