Using electricity to break down pollutants left over after wastewater treatment

July 09, 2020

Pesticides, pharmaceutical products, and endocrine disruptors are some of the emerging contaminants often found in treated domestic wastewater, even after secondary treatment. Professor Patrick Drogui of the Institut national de la recherche scientifique (INRS) and his team have tested the effectiveness of a tertiary treatment process using electricity in partnership with the European Membrane Institute in Montpellier (IEM) and Université Paris-Est.

The advanced electro-oxidation process (EOA) uses two electrodes to break down non-biodegradable pollutants that remain after biological treatment. Electric current is passed through the electrodes, generating hydroxide radicals (* OH), which attack the refractory molecules. The primary advantage of this method is that it does not require any chemicals to be added to the water.

"EOA processes are revolutionary in the field of wastewater treatment. It's pioneering technology for treating wastewater contaminated by refractory pollutants such as pharmaceutical wastes," said Professor Patrick Drogui, co-author of the study published on June 18 in the prestigious journal Science of the Total Environment.

The researchers tested new catalytic electrodes. "We have shown that these electrodes are effective and produce large quantities of hydroxide radicals. They are also cheaper than the other electrodes currently on the market, which reduces the cost of the treatment," said Yassine Ouarda, Ph.D. student and first author on the study.

Versatile Tertiary Treatment

Researchers tested the technology on three types of water coming from different treatment processes: conventional, membrane bioreactor, and a treatment process that separates wastewater, including feces, at the source. They focused on paracetamol, otherwise known as acetaminophen. "We tested the process on this particular molecule because it's one of the world's most widely used drugs. We have already tested it at INRS for some 15 different pollutants, as the process can be used for other pharmaceutical molecules," said Mr. Ouarda.

During partial breakdown of pollutants such as pharmaceuticals, the by-products can be more toxic than the parent compounds. "We observed that the toxicity of the solution increased and subsequently decreased during treatment. This indicates that the toxic molecules are themselves broken down if the reaction continues," said Mr. Ouarda.

"This work once again confirms that advanced electro-oxidation processes are good candidates for breaking down drug wastes left behind after biological treatment," said Professor Drogui.
-end-
About the study

The paper "Electro-oxidation of secondary effluents from various wastewater plants for the removal of acetaminophen and dissolved organic matter", by Yassine Ouarda, Clément Trellu, Geoffroy Lesage, Matthieu Rivallin, Patrick Drogui and Marc Cretin, was published on June 18 in the journal Science of the Total Environment.

They received financial support from Mitacs through the Mitacs Globalink program. DOI: https://doi.org/10.1016/j.scitotenv.2020.140352

About the INRS

The Institut national de la recherche scientifique (INRS) is the only institution in Québec dedicated exclusively to graduate level university research and training. The impacts of its faculty and students are felt around the world. INRS proudly contributes to societal progress in partnership with industry and community stakeholders, both through its discoveries and by training new researchers and technicians to deliver scientific, social, and technological breakthroughs in the future.

Contact :

Audrey-Maude Vézina
Service des communications et des relations gouvernementales de l'INRS
418-254-2156 (cell)
audrey-maude.vezina@inrs.ca

Institut national de la recherche scientifique - INRS

Related Electricity Articles from Brightsurf:

Mirror-like photovoltaics get more electricity out of heat
New heat-harnessing 'solar' cells that reflect 99% of the energy they can't convert to electricity could help bring down the price of storing renewable energy as heat, as well as harvesting waste heat from exhaust pipes and chimneys.

Engineers use electricity to clean up toxic water
Powerful electrochemical process destroys water contaminants, such as pesticides. Wastewater is a significant environment issue.

Considering health when switching to cleaner electricity
Power plants that burn coal and other fossil fuels emit not only planet-warming carbon dioxide, but also pollutants linked to breathing problems and premature death.

Windows will soon generate electricity, following solar cell breakthrough
Semi-transparent solar cells that can be incorporated into window glass are a 'game-changer' that could transform architecture, urban planning and electricity generation, Australian scientists say in a paper in Nano Energy.

Static electricity as strong as lightening can be saved in a battery
Prof. Dong Sung Kim and his joint research team presented a new technology that can increase the amount of power generated by a triboelectric nanogenerator.

To make amino acids, just add electricity
By finding the right combination of abundantly available starting materials and catalyst, Kyushu University researchers were able to synthesize amino acids with high efficiency through a reaction driven by electricity.

Using renewable electricity for industrial hydrogenation reactions
The University of Pittsburgh's James McKone's research on using renewable electricity for industrial hydrogenation reactions is featured in the Journal of Materials Chemistry A's Emerging Investigators special issue.

Water + air + electricity = hydrogen peroxide
A reactor developed by Rice University engineers produces pure hydrogen peroxide solutions from water, air and energy.

Producing electricity at estuaries using light and osmosis
Researchers at EPFL are working on a technology to exploit osmotic energy -- a source of power that's naturally available at estuaries, where fresh water comes into contact with seawater.

Experimental device generates electricity from the coldness of the universe
A drawback of solar panels is that they require sunlight to generate electricity.

Read More: Electricity News and Electricity Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.