Shocking new way to get the salt out

Read the full story from MIT.

As the availability of clean, potable water becomes an increasingly urgent issue in many parts of the world, researchers are searching for new ways to treat salty, brackish or contaminated water to make it usable. Now a team at MIT has come up with an innovative approach that, unlike most traditional desalination systems, does not separate ions or water molecules with filters, which can become clogged, or boiling, which consumes great amounts of energy.

Instead, the system uses an electrically driven shockwave within a stream of flowing water, which pushes salty water to one side of the flow and fresh water to the other, allowing easy separation of the two streams. The new approach is described in the journal Environmental Science and Technology Letters, in a paper by professor of chemical engineering and mathematics Martin Bazant, graduate student Sven Schlumpberger, undergraduate Nancy Lu, and former postdoc Matthew Suss.

On Thin Ice: Big Northern Lakes Are Being Rapidly Transformed

Read the full story at Yale Environment 360.

As temperatures rise, the world’s iconic northern lakes are undergoing major changes that include swiftly warming waters, diminished ice cover, and outbreaks of harmful algae. Now, a global consortium of scientists is trying to assess the toll.

The energy and emissions footprint of water supply for Southern California

A J Fang, Joshua P Newell, and Joshua J Cousins (2015). “The energy and emissions footprint of water supply for Southern California.” Environmental Research Letters 10(11), 11 p. Online at Open access.

Abstract: Due to climate change and ongoing drought, California and much of the American West face critical water supply challenges. California’s water supply infrastructure sprawls for thousands of miles, from the Colorado River to the Sacramento Delta. Bringing water to growing urban centers in Southern California is especially energy intensive, pushing local utilities to balance water security with factors such as the cost and carbon footprint of the various supply sources. To enhance water security, cities are expanding efforts to increase local water supply. But do these local sources have a smaller carbon footprint than imported sources? To answer this question and others related to the urban water–energy nexus, this study uses spatially explicit life cycle assessment to estimate the energy and emissions intensity of water supply for two utilities in Southern California: Los Angeles Department of Water and Power, which serves Los Angeles, and the Inland Empire Utility Agency, which serves the San Bernardino region. This study differs from previous research in two significant ways: (1) emissions factors are based not on regional averages but on the specific electric utility and generation sources supplying energy throughout transport, treatment, and distribution phases of the water supply chain; (2) upstream (non-combustion) emissions associated with the energy sources are included. This approach reveals that in case of water supply to Los Angeles, local recycled water has a higher carbon footprint than water imported from the Colorado River. In addition, by excluding upstream emissions, the carbon footprint of water supply is potentially underestimated by up to 30%. These results have wide-ranging implications for how carbon footprints are traditionally calculated at local and regional levels. Reducing the emissions intensity of local water supply hinges on transitioning the energy used to treat and distribute water away from fossil fuel, sources such as coal.

Climate change is driving water cycle speed-up

Read the full story at EnvironmentalResearchWeb.

The global water cycle is getting faster. Over the last few decades rainfall has become heavier whilst evapotranspiration from terrestrial ecosystems has sped up. Now research reveals that climatic changes are the predominant driver of this accelerating hydrological cycle, and that rising carbon dioxide also plays an important role.

New Study Finds Limited and Uneven Water Reserves Near Earth’s Surface

Via Yale e360 Digest.

Roughly 5.5 million cubic miles of groundwater are stored in the earth’s crust, according to new research published in the journal Nature Geoscience, but the resource is distributed unevenly across the globe, as shown in this map. Combining data with models on the permeability and porosity of rocks and soils, and on water table gradients, researchers illustrated the depth of groundwater around the world. If earth’s groundwater were to cover the planet’s surface evenly, the scientists predicted that the pool would be approximately 600 feet deep. However, only six percent of this groundwater is usable for most purposes. This water, which is closer to the surface, is also more sensitive to climate change and human contamination. The research highlights how unevenly this resource is distributed across the globe, scientists say, as well as the need to manage water reserves in a sustainable way.

Innovating our way out of water shortages

Read the full story in GreenBiz.

The current trend with water utilities is that water conservation is critical and water prices need to increase. Utilities have to cover their costs while confronting lower use and revenue. Essentially, water prices must rise to cover rising fixed costs despite declining volumes.

What if we turned this thinking around? Lower water use results in paying less driven by technology innovation?

There was a thought-provoking column in the September 2015 Global Water Intelligence issue from Debra Coy exploring that very idea. And it touches on two key issues — the cost to replace US water infrastructure and the price of water.