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Environmental News Network -- Know Your Environment
Road salt, used in copious helpings each winter to protect them from ice and preserve safe driving conditions, is slowly degrading the concrete they’re made of. Engineers have known for some time that calcium chloride salt, commonly used as deicer, reacts with the calcium hydroxide in concrete to form a chemical byproduct that causes roadways to crumble.
Unseen in the air around us are tiny molecules that drive the chemical cocktail of our atmosphere. As plants, animals, volcanoes, wildfires and human activities spew particles into the atmosphere, some of these molecules act as cleanup crews that remove that pollution.
The main molecules responsible for breaking down all these emissions are called oxidants. The oxygen-containing molecules, mainly ozone and hydrogen-based detergents, react with pollutants and reactive greenhouse gases, such as methane.
About half of atmospheric carbon dioxide is fixed by ocean's phytoplankton, mainly picocyanobacteria, through a process called photosynthesis. Picocyanobacteria are tiny, unicellular microorganisms that are abundant and widely distributed in freshwater and marine environments. A large portion of biologically fixed carbon is formed by picocyanobacteria at the sea surface and then transported to the deep ocean. But what remains a mystery is how colored dissolved organic matter which originates from plant detritus (either on land or at sea) makes it into the deep ocean. A team of scientists from the University of Maryland Center for Environmental Science and around the world potentially found a viable marine source of this colored material.
Removal of polluted sediment from lake and river bottoms can be costly and time consuming. Ohio Sea Grant researchers are developing a new method using ultrasound and chemical agents that bind to contaminants and render them inactive on the river bottom. The new approach means larger quantities of sediment can be scrubbed more thoroughly with each round of treatment, potentially making pollutant clean up faster and less costly. The overall goal is to treat contaminated sediments right where they are instead of having to dredge them up for treatment or disposal.
Planting trees is a popular strategy to help make cities “greener,” both literally and figuratively. But scientists have found a counterintuitive effect of urban vegetation: During heat waves, it can increase air pollution levels and the formation of ozone. Their study appears in ACS’ journalEnvironmental Science & Technology.
Previous research has shown that planting trees in cities can have multiple benefits, including storing carbon, controlling storm water and cooling areas off by providing shade. This has spurred efforts in cities across the U.S. and Europe to encourage the practice. However, it’s also known that trees and other plants release volatile organic compounds, or VOCs, that can interact with other substances and contribute to air pollution. And when it’s hot, plants release higher levels of VOCs. Galina Churkina and colleagues wanted to investigate what effects heat waves and urban vegetation might have on air pollution.
A University of Windsor professor is among an international team of scientists examining what challenges and opportunities the future may hold for invasive species research.
Professor Hugh MacIsaac travelled to the University of Cambridge last fall along with 16 other ecologists to reach a consensus on what they believed to be the emerging trends, issues, opportunities and threats for invasive science.
