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Produce Safe Drinking Water | Ohio Sea Grant

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Produce Safe Drinking Water

Developing new treatment methods for contaminated drinking water to remove algal particles and toxins

One of the most direct impacts of algal blooms on humans is the safety — or lack thereof — of drinking water. The August 2014 harmful algal bloom in Toledo shut off water for more than two days, an impact felt by residents and businesses alike. In addition to monitoring bloom locations, researchers are developing new treatment methods for contaminated drinking water that remove both algal particles in general and the toxins produced by cyanobacteria in particular.

Projects

Treatment of Cyanotoxins by Advanced Oxidation Technologies

Principal Investigator

Dionysios Dionysiou, University of Cincinnati


Project Summary

New research from the University of Cincinnati is looking into finding new and cost-effective ways to remove and destroy cyanotoxins from drinking water.

Using various technologies to treat different stages of water from the Greater Cincinnati Water Works, the research team led by Dionysios Dionysiou from the University of Cincinnati will explore different doses and types of degradation processes to see which will destroy the algal toxin microcystin-LR the fastest. The processes being tested in the lab include combinations of chlorination and light degradation via ultraviolet (UV) rays. A related project at the University of Toledo is expanding the range of methods tested with ozonation and filtration.

The hope is that the project will find not only the most cost-effective technologies for the treatment of water contaminated with cyanotoxins, but also understand the mechanisms behind different processes. Another concern is what products the cyanotoxins may leave behind after they are degraded, so water treatment plants don’t replace one harmful compound with another by accident.

The Bottom Line

Using new removal processes, cities’ treatment plants will be able to eliminate cyanotoxins in drinking water at a lower cost and with higher water quality.

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Development of Microcystin-Detoxifying Water Biofilters

Principal Investigator

Jason Huntley, University of Toledo


Project Summary

Researchers at the University of Toledo are putting toxineating bacteria to work purifying water.

When lakes or reservoirs develop harmful algal blooms, communities have to think twice about what’s coming out of the tap. Normally, water treatment plants ensure safe drinking water by putting the incoming water through a series of standard cleansing steps. But with the increasing frequency of harmful algal blooms, water treatment experts are seeking effective and affordable techniques to remove algal toxins from water.

A team of researchers from the University of Toledo has developed a new low-cost treatment method that harnesses bacteria that naturally feed on the toxin microcystin. Led by Jason Huntley, an assistant professor of medical microbiology and immunology, the team is growing helpful bacteria on the filters that water must pass through during purification. They are currently testing the combination of filter material, bacteria type and water conditions that remove microcystin fastest from water. The next step will be to build a pilot processing system and test the technique on larger scales.

The Bottom Line

A new technique in the toolbox of water treatment plants that face harmful algal blooms in their source waters.

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Investigation of ELISA and interferences for the detection of cyanotoxins

Principal Investigator

Dragan Isailovic, University of Toledo


Project Summary

A research project at three Ohio universities aims to double-check the accuracy of the most widely used test for harmful algal toxins.

During the 2014 water quality crisis in western Lake Erie caused by harmful algal blooms, there was one test that all public health agencies turned to: ELISA. Standing for Enzyme-Linked ImmunoSorbent Assay, ELISA is the most widely used way to test water for harmful algal toxins. However, there may be some conditions — for instance, when certain other chemicals like calcium are present in water — under which ELISA may give inaccurate answers.

In order to know for sure, a research partnership among the University of Toledo, The Ohio State University and the University of Cincinnati are checking ELISA’s answers against results from a much more time-consuming but reliable method, liquid chromatography-mass spectrometry. The team will test ELISA’s performance detecting algal toxins in many possible mixtures that simulate lake and reservoir water as well as the stages that water goes through in a water treatment plant.

The Bottom Line

More certain results when public officials need to monitor and communicate water quality information about harmful algal blooms.

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Guidance for Powdered Activated Carbon Use to Remove Cyanotoxins

Principal Investigator

John Lenhart, The Ohio State University


Project Summary

Harmful algal blooms can produce a family of toxins called microcystins that have to be scrubbed from water before it is safe to drink. Most water plants use powdered activated carbon (also called activated charcoal) to absorb and remove the toxins, but knowing the specific dosage to use can be a complicated matter, as it depends on varying levels of toxin and environmental conditions.

The research team, led by John Lenhart, an environmental engineer at The Ohio State University, will develop guidelines for water treatment plant operators to help them know exactly which dosage of powdered activated carbon to use under which conditions. These guidelines will take into account the types and concentrations of toxins present and the composition of the water — for instance, the presence of decaying organic matter from plants and animals, which is known to affect how the carbon absorbs toxins.

The Bottom Line

Clean drinking water for communities and money savings for water plants that will be able to apply powdered activated carbon in a more targeted fashion.

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Prevention of Cyanobacterial Bloom Formation Using Cyanophage

Principal Investigator

Jiyoung Lee, The Ohio State University


Project Summary

Jiyoung Lee, an environmental health scientist for Ohio State, is searching for a more environmentally friendly way to reduce microcystins in both lake water and water treatment plants.

Ingesting water contaminated with microsystins can cause everything from stomach cramps to liver failure. In August 2014, microcystins shut down Toledo’s water supply for more than two days. Microcystins are a toxin produced by the cyanobacteria, also known as blue-green algae, that cause harmful algal blooms.

Lee believes there may be a solution in cyanophages, which are viruses prevalent in water that infect only their host, cyanobacteria. Cyanophages can add or delete genes from their host.

“Cyanophages have been studied in marine water, but not much in lake water,” Lee said. “We need to better understand what kind of cyanophages we have in Ohio lakes, and quantify them.”

The Bottom Line

The hope is that researchers will discover a way to use cyanophages to both limit cyanobacteria in lake water located near a water intake, and to use them in water treatment plants in place of chemicals such as chlorine, activated carbon and ozone.

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Identifying Bacterial Isolates for Bioremediation of Microcystin-Contaminated Waters

Principal Investigator

Xiaozhen Mou, Kent State University


Project Summary

Because of its unusual shape, the chemical microcystin does not break down easily in the conditions found in most water treatment plants. However, bacteria naturally present in lake water and sediments have evolved to use microcystin and related chemicals as a food source — a fact that water treatment plants would like to take advantage of.

Kent State University microbiologist Xiaozhen Mou and her team have been collecting water and sediment samples since 2013 to find bacteria that thrive when exposed to microcystin. Now, they are purifying cultures of the bacteria to see if they can be used as part of bioremediation systems in water treatment plants.

The Bottom Line

A better understanding of lake ecology and a hope for a new clean drinking water technology.

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Investigation of Water Treatment Alternatives in the Removal of Microcystin-LR

Principal Investigator

Youngwoo (Young) Seo, University of Toledo
Isabel Escobar, University of Kentucky


Project Summary

Research under development at the University of Toledo and The Ohio State University is designed to create alternative treatments for algal toxins often found in drinking water drawn from Lake Erie.

While activated carbon is an effective way to remove algal toxins such as microcystin from drinking water, high toxin levels can lead to extensive and potentially unsustainable use of activated carbon, which can add as much as $10,000 to water treatment costs per day. An effective alternative is needed to expand treatment plants’ options for water treatment during harmful algal blooms.

A research team led by Youngwoo Seo at the University of Toledo will screen three water treatment processes for their abilities to remove or destroy microcystin toxin in drinking water, and to determine the ideal environmental conditions in which each treatment method functions best. Information will be shared with the City of Toledo, who is a partner in the project, and at statewide meetings of community water managers.

The Bottom Line

Cities will be able to provide clean drinking water while maintaining cost-effectiveness of activated carbon treatments that reduce algal toxins.

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Transport and Fate of Cyanotoxins in Drinking Water Distribution Systems

Principal Investigator

Youngwoo (Young) Seo, University of Toledo


Project Summary

Research under development at the University of Toledo will examine whether toxins from harmful algal blooms “stick” to water infrastructure like pipes and storage tanks, and how that potential stickiness could impact toxin concentrations in drinking water.

While reducing harmful algal bloom toxins at water treatment plants is a well-studied process, how toxin travels through and potentially remains in other parts of the system between plant and consumer is not well understood. “Flushing pipes” after a toxin event can remove any dissolved toxins in the water itself, but particles could adhere to pipes and be released later, potentially raising toxin levels after checks are performed at the water treatment plant.

The research team, led by Youngwoo Seo at the University of Toledo along with scientists from the University of Cincinnati and The Ohio State University will determine how cyanotoxins interact with various pipe and storage tank materials in laboratory experiments. That data will then be used to update commercial software used in water treatment plants, which in turn will be evaluated by engineers familiar with the software packages.

The team is partnering with the City of Toledo, whose water supply was heavily affected by the August 2014 harmful algal bloom in western Lake Erie.

The Bottom Line

Safe drinking water for community residents and peace of mind for water managers who want to ensure the entire water delivery system is safe again after a toxin event.

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