Search results for " electrodialysis"
showing 10 items of 114 documents
CFD prediction of scalar transport in thin channels for reverse electrodialysis
2014
Reverse ElectroDialysis (RED) is a very promising technology allowing the electrochemical potential difference of a salinity gradient to be directly converted into electric energy. The fluid dynamics optimization of the thin channels used in RED is still an open problem. The present preliminary work focuses on the Computational Fluid Dynamics (CFD) simulation of the flow and concentration fields in these channels. In particular three different configurations were investigated: a channel unprovided with a spacer (empty channel) and two channels filled with spacers, one made of overlapped filaments the other of woven filaments. The transport of two passive scalars, representative of the ions …
Reverse Electrodialysis: Applications to Different Case Studies
2018
Salinity gradient is a non-conventional renewable energy form which is widely available worldwide. Reverse Electrodialysis is a promising and innovative technology able to convert directly this chemical renewable energy into electricity. This paper presents a number of different scenarios where salinity gradients are naturally available or they result from industrial/urban activities. A sophisticated model accounting for all the main phenomena (including all the detrimental ones) occurring within a Reverse Electrodialysis unit has been purposely developed. The model is used to calculate how much electric energy can be harvested from the above-mentioned salinity gradients.
Experimental analysis of a continuously operated reverse electrodialysis unit fed with wastewaters
2017
Reverse Electrodialysis (RED) is one of the most promising technologies to convert salinity gradient chemical energy into electricity. RED units are traditionally operated with natural streams as river water and seawater thereby limiting the spread of the technology in sites far from coastal areas. Aim of the present work is that of exploring and expanding feed possibilities for RED systems by employing waste streams. Thus, an experimental study was performed by testing, for the first time, a Reverse Electrodialysis (RED) unit fed with a high salinity wastewater originated in a fish canning factory, and a low salinity wastewater from a sewage treatment plant. Uninterrupted, long duration ex…
Utilization of Reverse Electrodialysis Processes for the Abatement of Pollutants in Water
2014
The simultaneous generation of electric energy and th e treatment of waters contaminated by Cr(VI) was carried out by reverse electrodialysis processes using salinity gradients. The effect on the process of the nature of the cathode was investigated.
Electrochemical Processes and Apparatuses for the Abatement of Acid Orange 7 in Water
2014
We have studied the electrochemical treatment of aqu eous solutions contaminated by Acid Orange 7 (AO7) by electro-Fenton process (EF). The main object ive was to evaluate how the electrochemical route affects the performances of the d egradation process. EF process was carried out in a number of very different reactors: conventional bench scale electrochem ical cell, microfluidic electrochemical reactor, microbial fuel cell and stack for reverse electrodialysis processes. The utilisation of micro devices allowed to work without the addition of a supporting elec trolyte and improved the performances of EF. Microbial fuel cell did not need the supply of electric energy bu t our device requir…
ELECTRICAL ENERGY STORAGE DEVICES BASED ON pH AND SALINITY GRADIENTS: MODELLING, EXPERIMENTS AND PILOTING
2021
Electrochemical Processe s and Apparatuses for the Abatement of Acid Orange 7 in Water
2014
We have studied the electrochemical treatment of aqu eous solutions contaminated by Acid Orange 7 (AO7) by electro-Fenton process (EF). The main object ive was to evaluate how the electrochemical route affects the performances of the d egradation process. EF process was carried out in a number of very different reactors: conventional bench scale electrochem ical cell, microfluidic electrochemical reactor, microbial fuel cell and stack for reverse electrodialysis processes. The utilisation of micro devices allowed to work without the addition of a supporting elec trolyte and improved the performances of EF. Microbial fuel cell did not need the supply of electric energy bu t our device requir…
Reverse electrodialysis: advanced modelling and scale-up
Electrodialysis Applications in Wastewater Treatment for Environmental Protection and Resources Recovery: A Systematic Review on Progress and Perspec…
2020
This paper presents a comprehensive review of studies on electrodialysis (ED) applications in wastewater treatment, outlining the current status and the future prospect. ED is a membrane process of separation under the action of an electric field, where ions are selectively transported across ion-exchange membranes. ED of both conventional or unconventional fashion has been tested to treat several waste or spent aqueous solutions, including effluents from various industrial processes, municipal wastewater or salt water treatment plants, and animal farms. Properties such as selectivity, high separation efficiency, and chemical-free treatment make ED methods adequate for desalination and othe…
Experimental assessment of reverse electrodialysis in closed loop configuration fed by NH4HCO3-water solutions
2018
Closed loop reverse electrodialysis is a novel technology for converting low-temperature waste heat into electric energy. This innovative heat engine consists of two units: (i) a reverse electrodialysis unit where power is produced exploiting the concentration difference between a diluted and a concentrated salt solution and (ii) a thermally driven regeneration unit where low-grade waste heat is used to re-establish the original salinity gradient between the two salt solutions. Among all the possible salt solutions suitable as working fluid in such application, Thermolytic salts solutions, in particular Ammonium bicarbonate solutions, may be promising thanks to their characteristic thermall…