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Tiny catalysts could wipe billions off the cost of cleaning wastewater

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Experts in aquatic toxicity at Brunel University London today hailed a significant development in ridding drinking water and waterways of oestrogenic hormones and pharmaceuticals that pass through conventional wastewater treatment plants.

The team tested the efficacy and safety of TAML activators, tiny man-made catalysts that activate nature’s own oxidants hydrogen peroxide and oxygen. They found that, once mixed, they effectively removed ethynylestradiol (EE2), a contraceptive pill hormone, from treated wastewater samples.

Earlier work at Brunel University London found that male fish in water sources containing the pollutant underwent a process of feminisation, causing male fish to display female sexual characteristics, including female reproductive anatomy.

However, on treating the water with the catalysts, the feminisation of male fish in the water was significantly reversed with no discernable adverse effects.

The government estimates that 1,360 UK sewage plants would fail European Union proposed standards for EE2, yet it would cost tens of billions of Euros to upgrade them with ozone or carbon-activated treatment technology, which also have large carbon footprints. The researchers believe TAML activators could be the solution – just a kilogram of catalyst could treat tens of thousands of tons of wastewater.

Brunel University’s Professor in Ecotoxicology and Director of the Institute of Environment, Health and Societies, Susan Jobling, said: “We’ve found TAML activators to be safe and effective, which opens the door to large-scale improvements in wastewater treatment which could be achieved by retro-fitting TAML treatment rather than building expensive high-energy plants. This could revolutionise how we clean our water.”

“Preliminary research suggests they would be equally effective against pollution caused by antimicrobials in personal care products and antibiotic pharmaceuticals. This is particularly relevant for halting the rise of antibiotic resistant bacteria.”

Reflecting on the potential of this development, Dr Ian Walker, Technical Director at WRc plc, an Independent Centre of Excellence for Innovation and Growth, said “This research addresses a key problem for the wastewater treatment sector. Current solutions are expensive to operate and costly to implement; the application of these novel catalysts offers real hope for a long term resolution of problem micro-pollutants. I will be looking at how this technology develops from the laboratory scale and recommend that the wastewater companies take a very close interest too.”

TAML activators were created by Professor Terence Collins, the Teresa Heinz Professor of Green Chemistry at Carnegie Mellon University’s Institute for Green Science in Pittsburgh, USA.

Describing the purpose of TAMLs, Professor Collins said: “Pharmaceuticals can be bioactive at low environmentally-relevant concentrations and are typically tough to break down. We need to get these micropollutants out of our water systems. Fish are indicators of what can happen when hormone control systems get hijacked by synthetic chemicals. We humans are also animals with endocrine systems, after all.”

The Brunel University London and Carnegie Mellon University research teams now plan to compare TAMLs against ozone and activated carbon treatment systems in pilot treatment plants to reveal the exact cost and explore carbon footprint savings.

The paper ‘Removal of ecotoxicity of 17α-ethinylestradiol using TAML/peroxide water treatment’ by Matthew R. Mills, Karla Arias-Salazar, Alice Baynes, Longzhu Q. Shen, John Churchley, Nicola Beresford, Chakicherla Gayathri, Roberto G. Gil, Rakesh Kanda, Susan Jobling, & Terrence J. Collins is published in Nature’s Special Reports: http://www.nature.com/srep/2015/150612/srep10511/full/srep10511.html.