Related Experiment Video
Updated: May 26, 2025

Ion-Exchange Membranes for the Fabrication of Reverse Electrodialysis Device
Published on: July 20, 2021
Application of Membrane Capacitive Deionization as Pretreatment Strategy for Enhancing Salinity Gradient Power
Seoyeon Lee1, Juyoung Lee1, Jaehyun Ju2
1School of Civil and Environmental Engineering, Kookimin University, 77 Jeongneung-ro, Seongbuk-gu, Seoul 02707, Republic of Korea.
Abstract:
Salinity gradient power (SGP) technologies, including pressure-retarded osmosis (PRO) and reverse electrodialysis (RED), have the potential to be utilized for the purpose of harvesting energy from the difference in salinity between two water streams. One challenge associated with SGP is a reduction in power density due to membrane fouling when impaired water is utilized as a low-salinity water stream. Accordingly, this study sought to explore the feasibility of membrane capacitive deionization (MCDI), a low-energy water treatment technique, as a novel pretreatment method for SGP. Laboratory-scale experiments were conducted to evaluate the impact of MCDI pretreatment on the performance of PRO and RED. The low-salinity water was obtained from a brackish water reverse osmosis (BWRO) plant, while the high-salinity water was a synthetic seawater desalination brine. The removal efficiency of organic and inorganic substances in brackish water reverse osmosis (BWRO) brine by MCDI was estimated, as well as theoretical energy consumption. The results demonstrated that MCDI attained removal efficiencies of up to 88.8% for organic substances and 78.8% for inorganic substances. This resulted in a notable enhancement in the lower density for both PRO and RED. The power density of PRO exhibited a notable enhancement, reaching 3.57 W/m2 in comparison to 1.14 W/m2 recorded for the BWRO brine. Conversely, the power density of RED increased from 1.47 W/m2 to 2.05 W/m2. Given that the energy consumption by MCDI is relatively low, it can be surmised that the MCDI pretreatment enhances the overall efficiency of both PRO and RED. However, to fully capitalize on the benefits of MCDI pretreatment, it is recommended that further process optimization be conducted.
More Related Videos
08:06Merging Ion Concentration Polarization between Juxtaposed Ion Exchange Membranes to Block the Propagation of the Polarization Zone
Published on: February 23, 2017
09:39Proof-of-Concept for Gas-Entrapping Membranes Derived from Water-Loving SiO2/Si/SiO2 Wafers for Green Desalination
Published on: March 1, 2020
Related Concept Videos
Potentiometry: Membrane Electrodes
MOS Capacitor
The metal gate is typically made from highly conductive materials such as aluminum or polysilicon. Beneath the metal gate lies a thin layer of...
Dialysis
Dielectric Polarization in a Capacitor
Capacitors
When a voltage source is connected to a capacitor, positive and negative charges accumulate on the opposite plates. This accumulation generates a potential difference that equals the product of the...
What is an Electrochemical Gradient?
The chemical gradient relies on differences in the abundance of a substance on the outside versus the inside of a cell and flows from areas of high to low ion concentration. In contrast, the electrical gradient revolves around an...