Sustainability: Water treatment with nanotechnology

Can you imagine if only using the energy of the sun and air we could treat polluted water? Well, apparently we are just a short time away from this becoming a reality in everyday life.

Researchers from the IPN's Center for Research and Advanced Studies (CINVESTAV), led by Dr. Refugio Rodríguez Vázquez, have undertaken the task of cleaning the canals of Xochimilco in Mexico City, through the use of micro and nanobubbles. The nanobubbles generate benefits for aquatic and terrestrial species and local residents. In addition to favoring tourist activity, having a clean canal means that more and more people will want to visit it.

But what are nanobubbles? They are spherical air pockets with diameters between 10 and 100 nm, which improve oxygenation, generate reactive oxygen species and reduce anaerobic conditions, which in turn reduce the emission of greenhouse gases such as methane, carbon dioxide or hydrogen sulfide. As a result, the concentration of organic compounds such as pesticides used in the area and pathogenic microorganisms is reduced.

This technology is part of a water treatment train and is used as a first step to reduce treatment time, increase oxygen transfer and improve solids capture efficiency. The second step is a photocatalysis process, which uses titanium dioxide nanoparticles and ultraviolet light to degrade organic compounds that are difficult to remove with conventional treatments.

Using the nanobubble system is a method that has easy-to-use equipment: water pump and piping systems, which are driven by the energy generated by photovoltaic panels, making it a sustainable and user-friendly technology. The systems are anchored to the trajineras, which are characteristic boats of the area used as a tourist attraction and for transporting merchandise. The equipment is supervised by the oarsmen of each boat. The objective is that each trajinera has its own system and the nanobubbles are generated along all the canals of Xochimilco.

Currently, dozens of prototypes have already been installed in different vessels, and the first positive results have already been generated with the use of this technology. This allows us to take a step towards sustainable technologies that can decontaminate water, starting with the canal system in Xochimilco and someday, all Mexican bodies of water that can incorporate this technology.

From My Nano Academy, we believe that the use of nanotechnology can be the solution to the major water problems that Latin America is facing, and could worsen in the coming years.