ESR12 Marcel Schneider – University of Copenhagen

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ESR12 Marcel Schneider

Project: Water treatment operations to remove natural toxins from surface water

Principal supervisor: Prof. Luděk Bláha, Ph.D.

Intro to project: 

Cyanobacteria, also known as blue-green algae, are phototrophic prokaryotes inhabiting the earth for billions of years being one of the oldest known groups of microorganisms. They utilize photosynthesis in order to produce energy and metabolize inorganic and organic matter. As secondary metabolites, some cyanobacteria produce toxic substances assumingly providing protective functions against other organisms. Besides odor and taste substances, species such as Anabaena, Aphanizomenon, Cylindrospermopsis, Microcystis, Nodularia and Oscillatoria generate a range of intra- and extracellular hepato-, neuro-, derma- and endotoxins harmful to animals, birds and humans. Intoxication with so called cyanotoxins is evidently known for almost 150 years, raising interest and concern of farmers, scientists and water treatment plant operators since then. Until now, numerous incidences of pet, livestock and/or wildlife or human poisoning, and in some cases subsequent deaths, have been associated with cyanotoxins – and are still happening. These toxic compounds can mainly be found in the aquatic environment, posing a major risk towards surface waters intended for drinking and recreational purposes; especially as the (anthropogenic) eutrophication of our waterbodies seems to increase, providing a very fruitful habitat for cyanobacteria and thus promoting more and more frequent blooms.

Most people know cyanobacteria only from newspaper articles or signs at beaches advising them not to ingest or come into contact with algal mats, but are not aware of the struggles environmental authorities and water treatment plant operators are facing in order to provide cyanobacteria-free and harmless drinking water. Since the research of cyanobacteria, cyanotoxins and removal techniques is still in progress and lacks crucial knowledge, most countries and the WHO have not yet enforced strict regulations but rather provisional guidelines for only few cyanotoxins in terms of maximum tolerable levels in drinking water. One of the main problems is the diversity of these toxins sometimes resulting in insufficient removal efficiencies when normal water treatment processes are applied.

As part of the NaToxAq network, this project focuses on water treatment operations targeting selected cyanotoxins by assessing various techniques for their removal or degradation efficiencies and also testing emerging methods such as advanced oxidation processes and non-thermal plasma-based approaches. As degradation not always has to lead to complete mineralization, we want to identify potential transformational by-products generated during the treatment and assess their toxicological properties.