Featured Stories | March 27, 2014
Oceans@MIT highlights from MIT Water Night 2014
Oceans at MIT attended MIT Water Night 2014 to report on some of the (salty water!) highlights, including nano-technological desalination of seawater, innovative wetland conservation, and ocean carbon cycle research.
Just in time for United Nations’ World Water Day, the MIT Water Club held Water Night 2014 on March 20th in the Walker Memorial Hall. The flagship research showcase represented the wide scope of the latest water-related research at MIT, as a few footsteps brought people from topics in desalination and waste water treatment to ocean biochemistry and water policy. A steadily growing crowd milled around the 40 posters at the event, plying the representatives of the research with questions and enjoying local beer and hor-d’oeuvres.
Opening remarks came from desalination researcher John H. Lienhard, the Collins Professor of Mechanical Engineering at MIT, Director of the Center for Clean Water and Clean Energy at MIT, and faculty adviser of the MIT Water Club. “As you can see just by looking around at these posters,” he said, “there is considerable interest in water here at MIT.” He called attention to MIT’s aggressive effort to develop new technologies to provide clean and sustainable water to the world’s 7 billion people and the vast amount of basic and applied research in hydrology, the water cycle, and coastal ecosystems.
Oceans at MIT highlights from Water Night 2014
Desalination of seawater, an increasingly important source of potable water globally, had a major presence at Water Night. For example, the Karnik group in MIT Microfluidics & Nanofluidics Research Laboratory presented their efforts to design more efficient seawater desalination membranes, largely to avoid the enormous energy demands of conventional reverse osmosis methods. Graduate students in the Karnik group, Sean O’Hern and Tarun Jain, described new desalination methods with graphene, a one-atom-thick layer of carbon that exhibits greater water permeability than the standard polymer membranes. And graduate student Jongho Lee, who won ‘best poster’ by audience vote later that evening, shared his group’s analytical model of a novel razor-thin membrane containing nanoscale pores (very, very small holes). This technology relies on the ability of water vapor to flow through the membrane and condense on the other side as purified water. Read more about this newly published desalination work with graphene and nanopore membranes on MIT News.
Phytoplankton in the ocean convert atmospheric carbon dioxide into carbon, which sinks in particles down to the deep ocean, yet the activities of marine bacteria re-release some of that carbon back into the environment. Only a small fraction of carbon makes it to depths where it can’t be exchanged with the atmosphere. Bethanie Edwards, a graduate student in the MIT/WHOI Joint Program and member of Ben Van Mooy‘s lab, is interested in the “chemical conversions” between marine microbes that ultimately impact carbon export in blooms. Using samples harvested on the June 2013 DYEatom Cruise, she found that phytoplankton increase production of chemical agents called ‘oxylipins’ when they are stressed out by low nutrient levels. In turn, the oxylipins triggered marine bacteria to make more nutrients available in the plankton bloom. At Water Night, she presented her lab’s new hypothesis that phytoplankton have chemical control over their bloom’s “happiness:” When nutrients are scarce, phytoplankton ramp up oxylipin production as a way to access more nutrition and prolong a healthy bloom, illuminating one more factor influencing carbon export in the ocean. Read her poster here (PDF).
Rivers are a key geochemical link between land and oceans, pouring freshwater, sediment, nutrients, and salts collected from the land into our oceans. Britta Voss, a graduate student in the MIT/WHOI Joint Program advised by Bernhard Peucker-Ehrenbrink, hopes that by learning something about the geochemical processes on land from the material carried by the river, her group will be able to detect changes from climate change or erosion. Her recent research took place in the pristine Fraser River in southwestern Canada, which supports the world’s largest sockeye salmon run on any single river. She collected a high-resolution time series record of strontium isotopes carried by the river water and showed how the chemical weathering contributions from the source of the Fraser River is greatest during the spring freshet, or the thaw that floods the river each year. This approach may help researchers to anticipate the future conditions of the Fraser’s salmon habitat, which is changing as the spring freshet arrives earlier each year due to global warming. Read about Voss’ research in her entries in the Global Rivers Observatory blog and in her newly published article in WHOI’s Oceanus Magazine: Of The River and Time.
Wetlands offer many socio-economical services, as these salt, brackish or freshwater bodies can prevent flooding, filter and purify water, replenish and store groundwater, reduce erosion, protect shorelines, and sustain biodiversity, to name a few. Unfortunately, “cities can’t protect all wetlands from development,” says Roxane Lavoie, postdoc in the MIT Department of Urban Studies and Planning, as she presented her work at Water Night. “So, it’s important to know which wetlands are most intact and valuable to the ecosystem.” She helped develop a decision-aid method based on the MACBETH approach, which allows people to quickly assess the value of the 1,347 wetlands in Quebec. The method builds an index that compares options that are hard to compare. Using the criteria ‘fragmentation,’ ‘production,’ ‘habitat diversity,’ ‘area’, ‘natural proportion of surrounding environment’ and ‘rarity,’ the method generates a map that ranks wetlands according to ecological value. In the context of competing conservation and development interests, the method takes the inherent subjectivity out of the value judgement because it makes the reasons for the map’s results explicit to everyone involved. “One advantage is that the method encourages more social cohesion,” she said. Learn about Roxane Lavoie’s past work in groundwater management.
There were so many other interesting projects aimed at the social and human welfare dimensions of water research, such as many new ideas to improve access to clean water in developing countries. Here is a description of the projects that were showcased at MIT Water Night 2014 (PDF). Categories include: Desalination, Nanotechnology, Wastewater Treatment, Earth and Oceans, Water and Human Development, Water Policy and Management, and Metering.