scholarly journals Modular treatment of arsenic-laden brackish groundwater using solar-powered subsurface arsenic removal (SAR) and membrane capacitive deionization (MCDI) in Vietnam

2020 ◽  
Vol 10 (4) ◽  
pp. 513-526
Author(s):  
U. Hellriegel ◽  
E. E. Cañas Kurz ◽  
T. V. Luong ◽  
J. Bundschuh ◽  
J. Hoinkis
Keyword(s):  
Brackish Water ◽  
Energy Demand ◽  
Arsenic Removal ◽  
Specific Energy Consumption ◽  
Mekong Delta ◽  
Water Desalination ◽  
Photovoltaic System ◽  
Capacitive Deionization ◽  
Modular Treatment ◽  
Solar Powered

Abstract To evaluate energy efficient concepts for the modular treatment of brackish water, pilot trials for groundwater desalination and arsenic (As) removal were carried out in the Mekong Delta, Vietnam. Groundwater here is affected by naturally occurring high iron (Fe2+) and As concentrations, while, in coastal regions, groundwater is additionally contaminated by high salinity mostly due to seawater intrusion. Desalination was conducted by membrane capacitive deionization (MCDI), which shows low specific energy consumption (SEC). Anoxic groundwater with As(III) and Fe2+ was treated using a pre-oxidation step called subsurface arsenic removal (SAR) with the main advantage that no As-laden waste is produced. The pilot plant was operated using a photovoltaic system (3 kWp) and a small wind turbine (2 kWp). The SEC of drinking water produced was 3.97 kWh/m3. Total dissolved solids (TDS) of 1,560 mg/L were lowered to 188 mg/L, while Fe2+ was reduced from 1.8 mg/L to the below detection limit and As from 2.3 to 0.18 μg/L. The results show that SAR is a feasible remediation technique for Fe2+ and As removal in remote areas, and demonstrate the potential of MCDI for brackish water desalination coupled with renewable energies. However, improvements in energy demand of the MCDI module can still be achieved.

Optimization and economic analysis for a small scale nanofiltration and reverse osmosis water desalination system

2015 ◽  
Vol 15 (5) ◽  
pp. 1027-1033 ◽  
Author(s):  
Manoj Chandra Garg ◽  
Himanshu Joshi
Keyword(s):  
Predictive Model ◽  
Reverse Osmosis ◽  
Brackish Water ◽  
Energy Demand ◽  
Specific Energy Consumption ◽  
Water Desalination ◽  
Small Scale ◽  
Water Recovery ◽  
Salt Rejection ◽  
Validation Experiment

This paper presents the results of a techno-economic investigation of a nanofiltration (NF) and reverse osmosis (RO) process for treating brackish water. Optimization experiments of six commercially available small scale RO and NF membranes were carried out using formulated artificial groundwater. A predictive model was developed by using response surface methodology (RSM) for optimization of input process parameters of brackish water membrane processes to simultaneously maximize water recovery and salt rejection while minimizing energy demand. A predictive model using multiple response optimization revealed that CSM RO and NF250 membranes showed the optimal efficiency with 20.24% and 18.98% water recovery, 90.22% and 70.64% salt rejection and 17.87 kWh/m3 and 9.35 kWh/m3 of specific energy consumption (SEC), respectively. Furthermore, confirmation of RSM predictions was carried out by an artificial neural network (ANN) model trained by RSM experimental data. Predicted values by both RSM and ANN modeling methodologies were compared and found within the acceptable range. Finally, a membrane validation experiment was carried out successfully at proposed optimal conditions, which proved the accuracy of the employed RSM and ANN models. Detailed analyses of the economic assessment showed that the recovery rate can play a major role in reducing the cost of a membrane system.

scholarly journals Integrated Capacitive Deionization and Humidification-Dehumidification System for Brackish Water Desalination

Energies ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 7641
Author(s):  
Sadam-Hussain Soomro ◽  
Yusufu Abeid Chande Jande ◽  
Salman Memon ◽  
Woo-Seung Kim ◽  
Young-Deuk Kim
Keyword(s):  
Renewable Energy ◽  
Salt Concentration ◽  
Brackish Water ◽  
Waste Heat ◽  
Renewable Energy Sources ◽  
Water Desalination ◽  
Energy Sources ◽  
Capacitive Deionization ◽  
Combined System ◽  
Flow Rates

A hybrid capacitive deionization and humidification-dehumidification (CDI–HDH) desalination system is theoretically investigated for the desalination of brackish water. The CDI system works with two basic operations: adsorption and regeneration. During adsorption, water is desalted, and during the regeneration process the ions from electrodes are detached and flow out as wastewater, which is higher in salt concentration. This wastewater still contains water but cannot be treated again via the CDI unit because CDI cannot treat higher-salinity waters. The discarding of wastewater from CDI is not a good option, since every drop of water is precious. Therefore, CDI wastewater is treated using waste heat in a process that is less sensitive to high salt concentrations, such as humidification-dehumidification (HDH) desalination. Therefore, in this study, CDI wastewater was treated using the HDH system. Using the combined system (CDI–HDH), this study theoretically investigated brackish water of various salt concentrations and flow rates at the CDI inlet. A maximum distillate of 1079 L/day was achieved from the combined system and the highest recovery rate achieved was 24.90% from the HDH unit. Additionally, two renewable energy sources with novel ideas are recommended to power the CDI–HDH system.

Nanoarchitectured metal–organic framework/polypyrrole hybrids for brackish water desalination using capacitive deionization

2019 ◽  
Vol 6 (7) ◽  
pp. 1433-1437 ◽  
Author(s):  
Ziming Wang ◽  
Xingtao Xu ◽  
Jeonghun Kim ◽  
Victor Malgras ◽  
Ran Mo ◽  
...  
Keyword(s):  
Brackish Water ◽  
Metal Organic Framework ◽  
Water Desalination ◽  
Capacitive Deionization ◽  
Metal Organic ◽  
First Time ◽  
Organic Framework

Metal–organic framework/polypyrrole hybrids are synthesized and directly used in capacitive deionization for the first time.

scholarly journals Towards Electrochemical Water Desalination Techniques: A Review on Capacitive Deionization, Membrane Capacitive Deionization and Flow Capacitive Deionization

Membranes ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 96 ◽  
Author(s):  
Gbenro Folaranmi ◽  
Mikhael Bechelany ◽  
Philippe Sistat ◽  
Marc Cretin ◽  
Francois Zaviska
Keyword(s):  
Brackish Water ◽  
Research Area ◽  
Water Desalination ◽  
Ion Adsorption ◽  
Capacitive Deionization ◽  
Major Research ◽  
Modus Operandi ◽  
Solvated Ions ◽  
The 1960S ◽  
Simple Potential

Electrochemical water desalination has been a major research area since the 1960s with the development of capacitive deionization technique. For the latter, its modus operandi lies in temporary salt ion adsorption when a simple potential difference (1.0–1.4 V) of about 1.2 V is supplied to the system to temporarily create an electric field that drives the ions to their different polarized poles and subsequently desorb these solvated ions when potential is switched off. Capacitive deionization targets/extracts the solutes instead of the solvent and thus consumes less energy and is highly effective for brackish water. This paper reviews Capacitive Deionization (mechanism of operation, sustainability, optimization processes, and shortcomings) with extension to its counterparts (Membrane Capacitive Deionization and Flow Capacitive Deionization).

scholarly journals Flow-electrode capacitive deionization enables continuous and energy-efficient brine concentration

2020 ◽  
Author(s):  
Matthias Wessling
Keyword(s):  
Energy Demand ◽  
Saline Water ◽  
Ionic Species ◽  
Economic Feasibility ◽  
Water Desalination ◽  
Capacitive Deionization ◽  
High Concentration ◽  
Agricultural Applications ◽  
High Concentrations ◽  
Desalination Technology

Many industrial and agricultural applications require the treatment of water streams containing high concentrations of ionic species for closing material cycles. High concentration factors are often desired, but hard to achieve with established thermal or membrane-based water treatment technologies at low energy consumptions. Capacitive deionization processes are normally assumed as relevant for the treatment of low salinity solutions only. Flowelectrode capacitive deionization (FCDI), on the other hand, is an upcoming electrically driven water desalination technology, which allows the continuous desalination and concentration of saline water streams even at elevated salinities. Ions are adsorbed electrostatically in pumpable carbon flow electrodes, which enable a range of new process designs.In this article, it is shown that continuously operated FCDI systems can be applied for the treatment of salt brines. Concentrations of up to 291.5 g/L NaCl were reached in the concentrate product stream. Based on this, FCDI is a promising technology for brine treatment and salt recovery. Additionally, a reduction of the energy demand by more than 70% is demonstrated by introducing multiple cell pairs into a continuous FCDI system. While the economic feasibility is not investigated here, the results show that FCDI systems may compete with established technologies regarding their energydemand.

Sign in / Sign up

Export Citation Format

Share Document