According to various international estimates, more than 80% of the wastewater generated worldwide is discharged into the environment without being treated correctly, posing a risk to ecosystems and human health. In this context, new technological approaches aim to not only purify water but also integrate it into circular economy models that make use of each and every one of its components.
Some of these emerging solutions for more efficient and sustainable management use the physical principles of the speed of sound to purify water: a system capable of transforming complex fluids into reusable water and recoverable raw materials through sonic evaporation, with low energy consumption and no need for chemicals.
One example is ASEC (adiabatic sonic evaporation and crystallization) technology developed by the Spanish startup Water Challenge. The approach is based on a simple principle: harnessing physical phenomena such as evaporation and crystallization to separate water from contaminants in a disruptive, efficient, and continuous manner.
Sonic evaporation and crystallization in a single process
Conventional industrial wastewater treatment systems typically involve multiple stages, using various separate pieces of equipment and chemical processes. However, ASEC technology proposes a different approach by integrating evaporation and crystallization into a single, continuous process.
The system operates in a series of interconnected phases that optimize the use of available energy. The key step is the acceleration of the contaminated fluid to the speed of sound at Mach 1 (or 400 meters per second, if you prefer) at the evaporation chamber inlet. A phase change occurs and produces pure water and dry solids, and the heat from the steam is then reused, thereby reducing energy consumption.
This approach makes it possible to treat fluids with a wide range of properties, including high concentrations of salts, metals, or organic compounds, regardless of their pH, density, or conductivity.
Energy efficiency as a strategic pillar
One of the key features of this technology is its energy efficiency. Estimated consumption is less than 20 kWh per cubic meter treated, which is significantly lower than many conventional zero liquid discharge (ZLD) systems.
Furthermore, since it is a physical process, no chemical reagents or additional consumables are required, which reduces both operational costs and the risk of generating secondary waste.
The system can also be integrated into industrial environments by harnessing residual heat from other processes or using renewable energies as a power source, helping reduce the carbon footprint.
As regards the circular economy, this model makes it possible to recover 100% of the treated water for reuse in industrial processes, irrigation, or other applications. At the same time, the solids recovered — which may include salts, minerals, or metals — can be reintroduced into the value chain as raw materials, thereby promoting their reuse.
Open innovation to accelerate the transition
Water Challenge has been selected as one of the participants in Moeve light up, the startup accelerator program launched by Moeve to address the major challenges of the energy transition. The goal is to promote innovation and support disruptive projects in areas such as green molecules, industrial decarbonization, and sustainable mobility.
Water Challenge is one of the ten technologies promoted by the energy company after being selected in mid-2025 at the corporate startup accelerator Selection Day event. At the end of 2026, they will present the results of their pilot projects during Demo Day, where the company will select the technologies it will continue to accelerate with the goal of scaling them up and turning them into real projects.
These initiatives make it possible to validate emerging technologies in real-world industrial settings and explore their integration into complex energy ecosystems, where efficient water management is an increasingly strategic aspect.
As pressure on natural resources increases, solutions such as sonic evaporation demonstrate that engineering can find innovative answers in seemingly simple physical principles.