Water processing: Light helps degrade hormones

Water... It is no less than the single most important resource for life as we know it.

We have used the abundance of water in our world as an excuse to dump all manner of waste, apparently thinking it will be diluted into harmlessness.

Of course, that thinking is far from correct.

Water processing: Light helps degrade hormones

Wherever people are living, hormones used in e.g. contraceptives or agriculture enter the wastewater. Steroid hormones, such as sex hormones and corticosteroids, may accumulate in the environment and adversely affect humans and animals, as they impair behavioral development and fertility. Sex hormones, for instance, may cause male fish to develop female sexual characteristics. It is therefore important to remove hormones, together with other micropollutants, from the wastewater before they enter the natural water cycle again, from which drinking water is extracted. "Supplying people with clean drinking water presently is one of the most important challenges worldwide," says Professor Andrea Iris Schäfer, Head of KIT's Institute for Advanced Membrane Technology (IAMT). "Micropollutants represent a big threat for our future, as they impair our fertility and brain function."

I should point out that fertility is a bigger issue than the source paper conveys. We are, after all, suffering a global decline in fertility; and this 'hormonal' pollution can't be helping the equation.

Inspired by solar cell technology, the field of work of Professor Bryce S. Richards from KIT, Schäfer had the idea to coat polymer membranes with titanium dioxide and to design photocatalytic membranes. Photocatalytically active titanium dioxide nanoparticles are applied to microfiltration membranes, whose pores are somewhat larger than in nanofiltration. Irradiation with light then triggers a chemical reaction, as a result of which steroid hormones are degraded on the membranes...

"We have developed a catalyst for water," Schäfer summarizes her work. Using the photocatalytic polymer membranes, steroid hormones were removed in the continuous flow mode down to the analytical detection limit of 4 ng/l. In fact, the concentrations measured were very close to 1 ng/l, the limit given in the new Drinking Water Guideline of the WHO. The researchers are now optimizing their technology by reducing the time needed and energy consumed. Moreover, their focus lies on using natural light. In particular, their research is aimed at degrading other pollutants by photocatalysis, such as industrial chemicals like perfluoro-alkylated and polyfluorinated substances (PFAS) or pesticides, such as glyphosate.

I can only hope this technology can be eventually developed and used to undo some of the damage we, in our persistent ignorance, have caused.

a reply to: Maxmars

If it worked like they say, would not sunlight clean water naturally?

Could we design artificial receptors where the steroids and all the unwanted stuff latches to and stays?

originally posted by: beyondknowledge
a reply to: Maxmars

If it worked like they say, would not sunlight clean water naturally?

Light (even sunlight) does affect certain chemical structures, including hormones. The application of other chemicals acting as a catalyst can accelerate the breakdown (or depositing) of those chemicals. In this case a chemical like a titanium compound could make the process a viable option to treat water. It will take research to determine if it is going to work. But there is a promising possibility for removing these otherwise harmful biological agents from the equation.