Introducing ultra-high-pressure low-salt-rejection reverse osmosis for energy-efficient concentration of industrial brines

Brine is an inevitable product of desalination plants and various industrial sectors. The appropriate disposal of brines and their highly concentrated salts and other diverse contaminants is a critical environmental challenge to most plants. Recently, the FO process is gaining attention as a viable alternative to conventional brine concentration methods, primarily due to its reduced energy consumption. This study aimed to fabricate a high-performance nonwoven FO membrane from cellulose acetate (CA) blended with polysulfone (PS) via the phase inversion technique. The prepared membrane was investigated in both saline water desalination and brine concentration. The FO membrane performance was tested for saline water desalination at different NaCl concentrations and applied in brine concentration using two kinds of draw solutions: ammonium bicarbonate (NH4HCO3) and a mixture of ammonium hydroxide/ammonium bicarbonate (NH4 OH)/(NH4HCO3) at different concentrations. It was observed that a high flux of 150 LMH was attained by using 2 M NaCl as a draw solution against distillate water as a feed solution. For brine concentration, by application of (NH4 OH)/(NH4HCO3) draw solution mixture at a 1:1 ratio, the modified cellulosic FO membrane exhibited the highest water flux of 113 LMH.

Selectrodialysis with bipolar membrane for the reclamation of concentrated brine from RO plant

As global desalination capacity continues its rapid growth, the impetus for reducing the adverse environmental impacts of brine discharge grows concurrently. Although modern brine outfall designs have significantly limited such impacts, they are costly. Recovering valuable components and chemical derivatives from brine has potential to resolve both environmental and economic concerns. In this article, methods for producing sodium hydroxide (“caustic”) from seawater reverse osmosis (SWRO) brine for internal reuse, which typically involve brine purification, brine concentration, and sodium chloride electrolysis, are reviewed. Because process energy consumption drives process cost and caustic purity determines product usability in drinking water systems, reviewed technologies are benchmarked against thermodynamic minimum energy consumption and maximum (stoichiometric) NaOH production rates. After individual reviews of brine purification, concentration, and electrolysis technologies, five existing facilities ...

Green utilization of the concentrated brine from two-stage membranes in coal chemical industry using selectrodialysis with bipolar membrane

The use of reverse osmosis as a 35,600m 3/day concentrator in the waste water management scheme at 4640 MW Bayswater/Liddell Power Station complex - Australia

Disposal of concentrates from brackish water desalting plants by means of evaporation technology

Concentration of brines from RO desalination plants by natural evaporation

Disposal of rejected brine is a fundamental part of reverse osmosis desalination technology, it presents negative influences on the marine ecosystem due to the high salt content and the presence of other harmful chemicals in the concentrate. Solar distillation is a promising technology for brine management. The main goal of this study was to treat high salinity solution of reverse osmosis desalination brine and to recover valuable resources while producing freshwater. The implementation of the study is through two phases: the first phase includes desalination by a reverse osmosis process to produce fresh water and the concentrated brine, while the second phase consists of recovering solid salts using the solar distillation. Thus, different experiments of desalination by reverse osmosis pilot and solar distillation were carried out under optimal experimental conditions. The obtained results showed that chlorides are the most dominant constituents in the composition of brines, while the daily water productivity contributed to around 80% of the total productivity of the solar system (volume of the water produced/m2/day) and the amount of salt crystallized by solar distillation represents 35 grams per liter of brine, this salt is greatly demanded in several sectors such as agriculture, industry, and others.

Emerging water regulations and fresh water scarcity are driving the natural gas processing industries in Qatar towards implementing Zero Liquid Discharge (ZLD) systems. ZLD implies that all wastewater produced in the plant is contained within the plant fence and treated industrial and process water (TIPW) is not discharged into the environment. This paper presents an evaluation of technologies, their potential effectiveness and challenges in achieving ZLD. Pre-treatment facilities for TIPW re-use generally consist of neutralisation and filtration packages, Hydrogen Sulfide (H2S) strippers and Dissolved Air Floatation (DAF) and Membrane Bioreactor (MBR) units. A combination of technologies such as Brine Concentrators, Ultrafiltration (UF), Reverse Osmosis (RO), evaporation-crystallisation unit, and other emerging technologies, are considered as viable solutions for ZLD. However, space limitations, capital expenditure, and concentrate management (brine disposal minimisation) are being recognised as significant obstacles for the existing plants. Deep well injections, evaporation ponds (and landfill disposal options) and discharge to the marine environment (with proper mixing) are the only feasible options for disposal of concentrated brine. With restrictive environmental permits and requirements for these disposal methods, industrial facilities find it difficult to economically justify a ZLD system. A combination of re-concentration techniques and a comprehensive utilisation of concentrated brine, with supportive governmental policies, would be one of the most effective ways to fulfill ZLD.

We present a zinc|ferricyanide hybrid flow battery that achieves extensive first-pass desalination while simultaneously supplying electrical energy (10 Wh/L). We demonstrate 85% salt removal from simulated seawater (35 g/L NaCl) and 86% from hypersaline brine (100 g/L NaCl), together with reversible battery operation over 100 h with high round-trip efficiency (84.8%). The system has a high operating voltage (E0 = +1.25 V), low specific energy consumption (2.11 Wh/L for 85% salt removal), and a desalination flux (4.7 mol/m2·h) on par with that of reverse osmosis membranes. Salt removal was similarly effective at higher feed salinities, for which reverse osmosis becomes physically impossible because of the pressure required. The results have positive implications for regions that rely on desalination for their freshwater needs, especially where sea salinity is high. Alternatively, the battery may also be useful in minimal liquid discharge wastewater treatment if operated as a brine concentrator.

Crystallization of calcium sulfate on reverse osmosis membranes

Optimization of forward osmosis system for the utilization of reverse osmosis brine

Evaluation of technologies for a desalination operation and disposal in the Tularosa Basin, New Mexico

Demonstration of a piston type integrated high pressure pump-energy recovery device for reverse osmosis desalination system

Concentrating saline water is essential for zero liquid discharge (ZLD) of wastewater. However, prevailing membrane-based technologies, such as reverse osmosis (RO) and electrodialysis (ED), can hardly handle high concentration differences (ΔC) in a single stage, where multi-stage operation is needed, which increases the operational difficulties and energy input. However, membrane capacitive deionization (MCDI) is theoretically applicable to high ΔC. This study explored the feasibility of employing an MCDI in brine concentrating and proposed several regulating measures on the electrode's porosity, electrical quantity for charging-discharging, and desorption conditions. Based on the determination of salt and water fluxes, these measures were confirmed to mitigate water transfer across the membrane, thereby facilitating salt transportation for brine concentrating. To address the mass imbalance between adsorbed and desorbed, a novel pre-charge strategy was designed, which enabled successful MCDI continuous operation over 50 cycles. A concentration difference of 161 g/L NaCl was achieved per single stage, which is the highest reported result among RO, ED, and MCDI studies. The concentrating rate was as high as 38.4 g/(m2·h) with a comparative energy consumption at RO and ED. This study demonstrated that MCDI is an optional technology for the future application of brine concentrating in ZLD facilities.