Sustainable treatment for persistent pollutants

Scientists at the University of Nottingham are developing a reactor called the ‘fountain photo-catalytic reactor’ to treat water contaminated with pesticides and pharmaceutical by-products using titanium dioxide.

The idea is to pump contaminated water through a specially designed nozzle while adding titanium dioxide to it. The water emerges from the nozzle in an umbrella shaped fountain, which is then treated with sunlight or artificial light that falls on the canopy of the umbrella.

Researchers say the process allows the photo-catalyst to absorb the solar radiation efficiently resulting in an effective break down of pollutants.

This research is important to ecological preservation, says Dr Gianluca Li Puma, lead scientist of the research. “Certain pesticides, and other chemicals such as synthetic and human oestrogens, can persist in the environment,” Li Puma says. “If these compounds find their way into water courses they can end up in rivers and accumulate in fish, causing ecological damage. Some of these compounds are also cancer causing.”

Li Puma sees his technique as a sustainable technology that could be beneficial in warm countries such as those in South America and Asia. His group is also investigating whether the same treatment could be used to disinfect water.

The traditional method to break down persistent contaminants uses granular activated carbon, which burns off the pollutants whilst simultaneously releasing noxious gases into the atmosphere. Scientists at Nottingham say their method of using the inexpensive titanium dioxide is much gentler on the environment and can be installed into current water treatment plants by application of the nozzle in an open air, sunlight activated treatment plant.