A research team from the University of Bath is leading the way in creating a new, more efficient way for the water industry to safely remove micropollutants from water without increasing their carbon footprint.

Professor Davide Mattia from the University of Bath’s Department of Chemical Engineering

Professor of Chemical Engineering Davide Mattia in Bath’s Centre for Advanced Separations Engineering (CASE) and Water Innovation & Research Centre is developing novel photocatalytic nanoporous anodic metal foams – a sponge-like substance - which will use sunlight to safely remove micropollutants from water.

Professor Mattia has been awarded a five-year Established Career Fellowship in Water Engineering by the Engineering and Physical Sciences Research Council (EPSRC).

One of biggest public health and environmental challenges

Micropollutants – found in toxic chemicals such as drugs, hormones and pesticides - represent one of the biggest public health and environmental challenges in the UK as well as other countries. Present in wastewater at very low concentrations, micropollutants slowly accumulate in the soil and in ground water, upsetting the ecological balance and eventually finding their way into the human food supply chain, with the potential to cause severe adverse long-term health effects.

A large number of compounds, including common anti-inflammatories, antibiotics, hormones, pesticides and and herbicides, are being added to the priority substances watch list for future regulation. Major capital investment will be needed by the water industry to meet legislation in the offing which will require their removal.

Existing technology in majority of water treatment plants not capable of removing micropollutants

There is an urgent need for novel technologies capable of degrading micropollutants safely and without generating significant increases in carbon emissions of the water industry, which already accounts for about 5% of UK emissions.

Existing technology in the majority of water treatment plants in the UK and abroad is not capable of removing micropollutants. Alternative technologies currently being tested in the UK and abroad all have limitations, in terms of high energy costs or high capital costs or production of toxic by-products, which require further removal.

The most promising technology to address the problem is photocatalysis, where light is used to speed up a reaction which breaks down organic pollutants to non-harmful constituents.

Given the very large volumes of water that need to be treated and the low concentration of micropollutants, very large amounts of nano-sized photocatalyst particles are required, creating a risk of the nanoparticles leaking from the water treatment plant and accumulating in the environment.

Photocatalytic foams to replace nanoparticles

Professor Mattia’s team is developing technology that entirely foregoes the use of nanoparticles replacing them with a highly porous photocatalytic foam, creating an efficient method of capturing all the micropollutants whilst preventing nanoparticulate material leaching into the environment.

Professor Mattia said:

“I will be working with academic and industrial partners to retrofit existing water treatment plants to accommodate this new technology. We hope this will result in a more effective way of removing micropollutants in water without increasing carbon emissions or producing toxic by-products.

“I believe our anodic metal foams represent an innovative and practical solution that water companies will be able to integrate in their existing infrastructure without radical changes, thereby lowering the barriers to their adoption.”

Director of the Water Innovation & Research Centre (WIRC @ Bath) at the University of Bath, Professor Jan Hofman, added:

“It is fantastic that Professor Mattia gets this opportunity for this exciting research for developing fundamentally new technology for organic micropollutant removal.

“Removal of these compounds from drinking water and wastewater is extremely important for public health and aquatic life. The water sector has great need for innovations in this field, which Professor Mattia’s research can provide.”

The European Water Industry Platform has concluded that the chance of removing micropollutants without significant increases in energy consumption with current technology is 'very low', and that this can be achieved only by 'leapfrogging traditional, polluting and resource-intensive technologies.'