Microbial desalination demonstration plant launched for brackish water

MIDES consortium has inaugurated its first project demonstration site at the Aqualia Racons Brackish Water Desalination Plant in Denia, Spain.

The MIDES project (for Microbial Desalination) features a natural process aimed to drastically lower energy use in desalination while also treating waste water.

“We opened the desalination plant with the lowest energy consumption anywhere in the world,” said Victor Monsalvo, Head of Eco-efficiency with Aqualia, MIDES coordinating organization. “This is the first time bio technology is being used for a sustainable desalination process at this scale.”

Mides says Microbial Desalination Cells (MDC) can generate around 1.8 kWh of bioelectricity while treating of 1 m3 of wastewater. This energy is used to remove salt content in seawater, which lowers the energy required to complete desalination. The goal of the first demonstration site is to produce 150 L/h of desalinated water with less than 0.5 kWh/m3 of energy used. 

The challenge

The MIDES (Horizon 2020) consortium of 10 organizations from 7 countries has been working since 2016 to scale up this MDC configuration from successful laboratory results with new materials to this demonstration phase. The Denia demo site will produce drinking water in challenging real environment conditions by treating brackish water through advances in ultrafiltration pre-treatment, MDC application, disinfection and remineralization. A ceramic microfiltration process will pretreat the raw water from the Racons River, a complex water source with dense organic matter and high membrane fouling capacity. “We started with only drops of water from a tiny MDC system at laboratory scale, and now we can even swim in our production quantities!” added Mr. Monsalvo.

The process

The MDC simultaneously desalinates saline water and treats wastewater. Electroactive bacteria in the anode side of the MDC feed on organic compounds in wastewater, and release electrons. These electrons travel to the cathode side to create an electrostatic force that breaks the salts into a positively charged-particle that goes to the cathode – and a negatively charged particle that goes to the anode. “In short, this MDC process generates electricity to reduce salt content in saline water, and also limits the environmental impact that carbon-rich compounds would have if they were discharged into natural water sources,” said Dr. Angeles Mendoza Sammet, Lecturer of Environmental Planning and Mgmt. with IHE Delft Institute for Water Education, from the demo site launch in Denia.

The consortium claims a low-energy drinking water production process like MIDES can benefit communities that have access to a salt/brackish water source, but lack the power infrastructure to support conventional desalination. MIDES is also planning two future demo sites for different water conditions. “This first plant in Denia will optimize the process and serve as a reference site in the progress of this breakthrough solution. We look forward to publishing demo site results in early 2020, and fully exploring our MDC capabilities,” concluded Mr. Monsalvo.

The MIDES consortium is made up of:

  • Aqualia (lead partner)
  • IHE Delft Institute for Water Education
  • IMDEA Water
  • Mikrolin
  • Oncontrol
  • SGL Carbon
  • SimTech Simulation Technology
  • University of Gabes

For more information:

Sergio Salinas, IHE Delft Institute for Water Education: [email protected]

Matt Luna, IHE Delft Institute for Water Education: [email protected]