Environmental scientists' new ozonation method treats water from antibiotic residues

November 17, 2020

Clean drinking water is considered to be one of the earth's most precious and threatened resources. Recent studies show that increasing concentrations of pharmaceuticals can be found in surface waters, which can end up in drinking water. TalTech environmental scientists are looking for ways to treat drinking water from hazardous pharmaceutical residues.

TalTech research group of the Laboratory of Environmental Technology led by Senior Researcher Niina Dulova published an article in the journal Environmental Research titled "Individual and simultaneous degradation of sulfamethoxazole and trimethoprim by ozone, ozone/hydrogen peroxide and ozone/persulfate processes: A comparative study".

Niina Dulova says, "Removal of hazardous micropollutants of different origins from water is still one of the unresolved problems in today's environmental technology. Our study investigated application of new efficient water treatment methods for elimination of two micropollutants: sulfamethoxazole and trimethoprim. These antibiotics are widely used to treat lung and kidney diseases both in veterinary and human medicine."

The application of advanced oxidation processes that take advantage of the high oxidizing capacity of radicals is considered to be the most effective tool for removal of micropollutants from water. These technologies are applied to remove poorly biodegradable substances from water almost completely through mineralization. Advanced oxidation processes can be classified in different ways, but they are mostly divided into categories according to the source of free radicals. Conventionally the oxidants used to form free radicals include hydrogen peroxide (H2O2) and ozone (O3), but in recent years other alternative oxidants, such as persulfate (PS), have been used increasingly.

"In our study we focused on the O3, combined O3/H2O2 and O3/PS processes. The latter, O3/PS technology, is an evolving promising solution in the field of radical-based oxidation processes. The efficiency of the O3/PS process in the decomposition of antibiotic residues (sulfamethoxazole, trimethoprim and a combination of sulfamethoxazole and trimethoprim) in water has not been studied previously and our findings are promising," Niina Dulova says.

The current EU Water Framework Directive does not address the issues of these antibiotic residues in water. Therefore, our wastewater treatment plants do not consider it necessary to tackle the problem. However, the situation will change over the next five years as the European Union is on the way towards establishing stricter water framework directives. This would also change the requirements for our water treatment plants. The best solution in this case would be the introduction of a new water treatment technology, i.e. a free radical based process," Dulova says.

Currently ozone is mainly used in water treatment plants for water disinfection, which, however, is not sufficient to remove hazardous pharmaceutical residues. Only using ozone also for oxidation would remove antibiotic residues from water.

Niina Dulova says, "If you ask why water containing antibiotic residues is hazardous to people, the answer is be very concrete: when exposed to water contaminated with such antibiotic residues, bacteria develop resistance to these antibiotics. This, in turn, makes it increasingly difficult to treat people exposed to these bacteria with antibiotics in the future."
Source: Environmental Research, "Individual and simultaneous degradation of sulfamethoxazole and trimethoprim by ozone, ozone/hydrogen peroxide and ozone/persulfate processes: A comparative study" 10.2020 https://doi.org/10.1016/j.envres.2020.109889

Additional information: Senior Researcher at TalTech Laboratory of Environmental Technology Niina Dulova, niina.dulova@taltech.ee

Kersti Vähi, TalTech Research Communications Officer

Estonian Research Council

Related Ozone Articles from Brightsurf:

Investigating the causes of the ozone levels in the Valderejo Nature Reserve
The UPV/EHU's Atmospheric Research Group (GIA) has presented a database comprising over 60 volatile organic compounds (VOC) measured continuously over the last ten years in the Valderejo Nature Reserve (Álava, Basque Country).

FSU Research: Despite less ozone pollution, not all plants benefit
Policies and new technologies have reduced emissions of precursor gases that lead to ozone air pollution, but despite those improvements, the amount of ozone that plants are taking in has not followed the same trend, according to Florida State University researchers.

Iodine may slow ozone layer recovery
Air pollution and iodine from the ocean contribute to damage of Earth's ozone layer.

Ozone threat from climate change
We know the recent extreme heat is something that we can expect more of as a result of increasing temperatures due to climate change.

Super volcanic eruptions interrupt ozone recovery
Strong volcanic eruptions, especially when a super volcano erupts, will have a strong impact on ozone, and might interrupt the ozone recovery processes.

How severe drought influences ozone pollution
From 2011 to 2015, California experienced its worst drought on record, with a parching combination of high temperatures and low precipitation.

New threat to ozone recovery
A new MIT study, published in Nature Geoscience, identifies another threat to the ozone layer's recovery: chloroform -- a colorless, sweet-smelling compound that is primarily used in the manufacturing of products such as Teflon and various refrigerants.

Ozone hole modest despite optimum conditions for ozone depletion
The ozone hole that forms in the upper atmosphere over Antarctica each September was slightly above average size in 2018, NOAA and NASA scientists reported today.

Increased UV from ozone depletion sterilizes trees
UC Berkeley paleobotanists put dwarf, bonsai pine trees in growth chambers and subjected them to up to 13 times the UV-B radiation Earth experiences today, simulating conditions that likely existed 252 million years ago during the planet's worst mass extinction.

Ozone at lower latitudes is not recovering, despite Antarctic ozone hole healing
The ozone layer -- which protects us from harmful ultraviolet radiation -- is recovering at the poles, but unexpected decreases in part of the atmosphere may be preventing recovery at lower latitudes.

Read More: Ozone News and Ozone 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.