‘MIDES H2020 will guarantee supply of quality water for human consumption’
By Águeda García de Durango, iAgua
The MIDES H2020 project aims to revolutionize desalination by developing a sustainable low-energy process called the Microbial Desalination Cell (MDC). The main development center is the Desalination Innovation Center (CID) that Aqualia has opened in Denia, Spain. To learn more about this project, we spoke with Víctor Monsalvo, Head of the Aqualia Eco-Efficiency Area.
Question: What are the objectives of the MIDES H2020 project in terms of energy efficiency, and how are those objectives being achieved?
Answer: The main objective is to obtain water for human consumption from seawater with an energy consumption of 0.5 kWh / m3, which represents an 85% reduction in current energy consumption. Furthermore, the biological process from which the energy is obtained simultaneously, but in different compartments of the device, purifies residual water for its reincorporation into the medium or reuse in suitable conditions.
The European MIDES consortium has been working on the solution development for 4 years, especially on the Microbial Desalination System or MDC (Microbial Desalination Cell). The knowledge provided by the multidisciplinary team on microbiology, biotechnology, new materials, pre- and post-treatment systems, advanced engineering and simulation tools has built aspects so that today there is the demonstration desalination plant with lower energy consumption. The first plant is in operation at the Desalination Innovation Center at EDAS Racons (Denia), and the second will be launched in the coming weeks at EDAM Oeste (Tenerife).
Q.- MIDES intends to develop a desalination system without energy cost. Where will the project get energy from?
A.- The energy source used for desalination is the chemical energy contained in the waste water. The organic matter present in the wastewater is an excellent source of carbon and energy for the bioelectrogenic microorganisms housed in the MDC. As a result of its metabolism, electrons that are captured in the MDC are obtained thanks to the use of new biocompatible conductive materials. The electron current obtained generates an electrical potential difference that causes the migration of the salts present in the salt water (anions and cations) through the ion exchange membranes, thus reducing its salinity.
Q.- What materials have been developed for it?
A.- The current design of the MDC has been optimized thanks to the development of (1) innovative conductive materials that maximize the capture of electrons generated by micro-organisms, (2) selective ion exchange membranes, and (3) recycled plastic materials to house the elements that make up the system.
Q.- Until now, what results have been obtained?
A.- The process has been scaled in three steps: laboratory, pre-pilot and pilot. Four years ago we started from a laboratory-scale device that fit in one hand (100 cm2); this stage was key to being able to demonstrate the concept, optimize the design, the materials and the operating conditions that created a foundation for scaling. Subsequently, the operation of the 6000 cm2 system at the IMDEA Agua facilities allowed validating the scalability of the system and verified its effectiveness in achieving complete desalination of sea and brackish water. The net production of the system has increased 160 times in just 2 years, reaching desalination speeds of up to 12.5 L / m2 · h.
Currently, the MDC pilot plant at the Desalination Innovation Center at EDAS Racons (Denia) has a daily production capacity of 1 m3. All the processes required for pre-treatment and conditioning have been integrated into the Center to ensure that the product water presents the quality required for human consumption. Thanks to the electronic capture of the device mediated by bio-electrogenic microorganisms responsible for removing organic matter from the fed waste stream, the MDC pilot plant does not require external energy input to carry out the desalination process.
Q.- In which type of plants could the results obtained in MIDES be applied?
A.- The desalination capacity of the system has been verified in the project for waters with a wide range of salinity, from brackish water to sea water. On the other hand, the wastewater used as an energy source has been both urban and industrial. Furthermore, the excellent results obtained in the desalination of brackish water, provide an interesting opportunity in wastewater regeneration systems where the end use requires low conductivity.
Q.- What do the results of the project contribute to sustainability?
A.- The solution supposes a technological revolution in the balance of sustainability, the purification and desalination of currents. There are two paradigm shifts: (1) purification of wastewater with energy production that can redefine this current not as a problem but as an opportunity for its use as a new renewable energy source, constant and locally produced, and (2) desalination without energy consumption, which will expand the use of unconventional sources.
Q.- What role can projects like MIDES play in the conception of the cities of the future?
A.- The solution is of special relevance considering that the increase in the number of cities and population in coastal areas will require new approaches to managing the integral water cycle.
The developed process will guarantee the supply of quality water for human consumption using renewable energy obtained locally. A facility based on the process developed in the MIDES project will provide a synergistic and simultaneous solution to the purification of wastewater and the supply of drinking water using brackish and salty water sources.
Q.- In what other projects does Aqualia participate that promote eco-science and energy sustainability?
A.- Currently Aqualia is developing almost 20 local, regional, national and European projects in which quality, sustainability, eco-efficiency and intelligent management of the processes involved in the integral water cycle coexist. Inexorably, in all of them energy efficiency, the use of resources and the sustainable management of water, are common objectives around which we work in the Department of Innovation and Technology, in close and fruitful collaboration with the other departments of the company.
(original article in Spanish) https://www.iagua.es/noticias/aqualia/mides-h2020-permitira-garantizar-suministro-agua-calidad-consumo-humano