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Tuesday, December 16, 2014

Hazy Road to Mecca

Date: December 15, 2014

Source: University of California - Irvine

Summary: Dangerously high levels of air pollutants are being released in Mecca during the hajj, the annual holy pilgrimage in which millions of Muslims on foot and in vehicles converge on the Saudi Arabian city, according to new findings.



UC Irvine and other researchers are testing air pollution in the Middle East, including in Mecca during the annual hajj, at burning landfills and elsewhere. Dangerously high levels of smog forming contaminants are being released, the scientists have found.
Credit: Image courtesy of Dr. Azhar Siddique


Dangerously high levels of air pollutants are being released in Mecca during the hajj, the annual holy pilgrimage in which millions of Muslims on foot and in vehicles converge on the Saudi Arabian city, according to findings reported today at the American Geophysical Union meeting in San Francisco.

"Hajj is like nothing else on the planet. You have 3 to 4 million people -- a whole good-sized city -- coming into an already existing city," said Isobel Simpson, a UC Irvine research chemist in the Nobel Prize-winning Rowland-Blake atmospheric chemistry laboratory. "The problem is that this intensifies the pollution that already exists. We measured among the highest concentrations our group has ever measured in urban areas -- and we've studied 75 cities around the world in the past two decades."

Scientists from UCI, King Abdulaziz University in Saudi Arabia, the University of Karachi in Pakistan, the New York State Department of Health's Wadsworth Center, and the University at Albany in New York captured and analyzed air samples during the 2012 and 2013 hajjes on roadsides; near massive, air-conditioned tents; and in narrow tunnels that funnel people to the Grand Mosque, the world's largest, in the heart of Mecca.

The worst spot was inside the Al-Masjid Al-Haram tunnel, where pilgrims on foot, hotel workers and security personnel are exposed to fumes from idling vehicles, often for hours. The highest carbon monoxide level -- 57,000 parts per billion -- was recorded in this tunnel during October 2012. That's more than 300 times regional background levels.

Heart attacks are a major concern linked to such exposure: The risk of heart failure hospitalization or death rises sharply as the amount of carbon monoxide in the air escalates, the researchers note in a paper published in the journal Environmental Science & Technology. Headaches, dizziness and nausea have also been associated with inhaling carbon monoxide.

"There's carbon monoxide that increases the risk of heart failure. There's benzene that causes narcosis and leukemia," Simpson said. "But the other way to look at it is that people are not just breathing in benzene or CO, they're breathing in hundreds of components of smog and soot."

The scientists detected a stew of unhealthy chemicals, many connected to serious illnesses by the World Health Organization and others.

"Air pollution is the cause of one in eight deaths and has now become the single biggest environmental health risk globally," said Haider Khwaja of the University at Albany. "There were 4.3 million deaths in 2012 due to indoor air pollution and 3.7 million deaths because of outdoor air pollution, according to WHO. And more than 90 percent of those deaths and lost life years occur in developing countries."

Khwaja experienced sooty air pollution firsthand as a child in Karachi, Pakistan, and saw his elderly father return from the hajj with a wracking cough that took weeks to clear. He and fellow researchers braved the tunnels and roads to take air samples and install continuous monitors in Mecca.

"Suffocating," he said of the air quality.

In addition to the high smog-forming measurements, the team in follow-up work found alarming levels of black carbon and fine particulates that sink deep into lungs. Once the hajj was over, concentrations of all contaminants fell but were still comparable to those in other large cities with poor air quality. Just as unhealthy "bad air" days once plagued Greater Los Angeles, research is now showing degraded air in the oil-rich, sunny Arabian Peninsula and elsewhere in the Middle East. Because the number of pilgrims and permanent residents is increasing, the scientists recommend reducing emissions by targeting fossil fuel sources.

Besides vehicle exhaust, other likely culprits include gasoline high in benzene, a lack of vapor locks around gas station fuel nozzles, and older cars with disintegrating brake liners and other parts. Coolants used for air-conditioned tents sleeping up to 40 people also contribute to greenhouse gas buildup. And the dearth of regulations exacerbates these problems.

The researchers said that Saudi officials are aware of the issues and taking steps to address them, such as working to reduce benzene in area gasoline supplies. Directing Mecca pedestrians and vehicles to separate tunnels would be optimal. In addition, clearing the region's air with time-tested technologies used elsewhere in the world could sharply reduce pollution and save lives.

"This is a major public health problem, and the positive news is that some of the answers are very much within reach, like putting rubber seals on nozzles at gas stations to reduce leaks," Simpson said. "It's a simple, doable solution."

Story Source:
The above story is based on materials provided by University of California - Irvine.

Tuesday, December 9, 2014

Fracking and Pollution: Technology-Dependent Emissions of Gas Extraction in the US

Date: December 8, 2014
Source: Karlsruhe Institute of Technology. "Fracking and pollution: Technology-dependent emissions of gas extraction in the US." ScienceDaily. ScienceDaily, 8 December 2014. www.sciencedaily.com/releases/2014/12/141208074327.htm.

Summary: Not all boreholes are the same. Scientists used mobile measurement equipment to analyze gaseous compounds emitted by the extraction of oil and natural gas in the US. For the first time, organic pollutants emitted during a fracking process were measured at a high temporal resolution using a vapor capture system. The highest values measured by this process exceeded typical mean values in urban air by a factor of about one thousand.


The KIT measurement instrument on board of a minivan directly measures atmospheric emissions on site with a high temporal resolution.
Credit: Photo: F. Geiger/KIT.

Not all boreholes are the same. Scientists of the Karlsruhe Institute of Technology (KIT) used mobile measurement equipment to analyze gaseous compounds emitted by the extraction of oil and natural gas in the USA. For the first time, organic pollutants emitted during a fracking process were measured at a high temporal resolution using a vapor capture system. The highest values measured by this process exceeded typical mean values in urban air by a factor of about one thousand, as was reported in the ACP journal.

Emission of trace gases by oil and gas fields was studied by the KIT researchers in the USA (Utah and Colorado) together with US institutes. Background concentrations and the waste gas plumes of single extraction plants and fracking facilities were analyzed. The air quality measurements of several weeks duration took place under the "Uintah Basin Winter Ozone Study" coordinated by the National Oceanic and Atmospheric Administration (NOAA).

The KIT measurements focused on health-damaging aromatic hydrocarbons in air, such as carcinogenic benzene. Maximum concentrations were determined in the waste gas plumes of boreholes. Some extraction plants emitted up to about a hundred times more benzene than others. The highest values of some milligrams of benzene per cubic meter air were measured downstream of an open fracking facility, where returning drilling fluid is stored in open tanks and basins. Much better results were reached by oil and gas extraction plants and plants with closed production processes. In Germany, benzene concentration at the workplace is subject to strict limits: The Federal Emission Control Ordinance gives an annual benzene limit of five micrograms per cubic meter for the protection of human health, which is smaller than the values now measured at the open fracking facility in the US by a factor of about one thousand. The researchers published the results measured in the journal Atmospheric Chemistry and Physics ACP.

"Characteristic emissions of trace gases are encountered everywhere. These are symptomatic of gas and gas extraction. But the values measured for different technologies differ considerably," Felix Geiger of the Institute of Meteorology and Climate Research (IMK) of KIT explains. He is one of the first authors of the study. By means of closed collection tanks and so-called vapor capture systems, for instance, the gases released during operation can be collected and reduced significantly.

"The gas fields in the sparsely populated areas of North America are a good showcase for estimating the range of impacts of different extraction and fracking technologies," explains Professor Johannes Orphal, Head of IMK. "In the densely populated Germany, framework conditions are much stricter and much more attention is paid to reducing and monitoring emissions."

Fracking is increasingly discussed as a technology to extract fossil resources from unconventional deposits. Hydraulic breaking of suitable shale stone layers opens up the fossil fuels stored there and makes them accessible for economically efficient use. For this purpose, boreholes are drilled into these rock formations. Then, they are subjected to high pressure using large amounts of water and auxiliary materials, such as sand, cement, and chemicals. The oil or gas can flow to the surface through the opened microstructures in the rock. Typically, the return flow of the aqueous fracking liquid with the dissolved oil and gas constituents to the surface lasts several days until the production phase proper of purer oil or natural gas. This return flow is collected and then reused until it finally has to be disposed of. Air pollution mainly depends on the treatment of this return flow at the extraction plant. In this respect, currently practiced fracking technologies differ considerably. For the first time now, the resulting local atmospheric emissions were studied at a high temporary resolution. Based on the results, emissions can be assigned directly to the different plant sections of an extraction plant. For measurement, the newly developed, compact, and highly sensitive instrument, a so-called proton transfer reaction mass spectrometer (PTR-MS), of KIT was installed on board of a minivan and driven closer to the different extraction points, the distances being a few tens of meters. In this way, the waste gas plumes of individual extraction sources and fracking processes were studied in detail.

Thursday, December 4, 2014

Gut Bacteria from a Worm Can Degrade Plastic

Date: December 3, 2014

Source: American Chemical Society

Summary: Plastic is well-known for sticking around in the environment for years without breaking down, contributing significantly to litter and landfills. But scientists have now discovered that bacteria from the guts of a worm known to munch on food packaging can degrade polyethylene, the most common plastic.The finding could lead to new ways to help get rid of the otherwise persistent waste, the scientists say.


Some bacteria from the guts of waxworms could help us eliminate plastic trash.
Credit: ACS

Plastic is well-known for sticking around in the environment for years without breaking down, contributing significantly to litter and landfills. But scientists have now discovered that bacteria from the guts of a worm known to munch on food packaging can degrade polyethylene, the most common plastic. Reported in the ACS journal Environmental Science & Technology, the finding could lead to new ways to help get rid of the otherwise persistent waste, the scientists say.

Jun Yang and colleagues point out that the global plastics industry churns out about 140 million tons of polyethylene every year. Much of it goes into the bags, bottles and boxes that many of us use regularly -- and then throw out. Scientists have been trying to figure out for years how to make this plastic trash go away. Some of the most recent studies have tried siccing bacteria on plastic to degrade it, but these required first exposing the plastic to light or heat. Yang's team wanted to find bacteria that could degrade polyethylene in one step.

The researchers turned to a plastic-eating moth larva, known as a waxworm. They found that at least two strains of the waxworm's gut microbes could degrade polyethylene without a pretreatment step. They say the results point toward a new, more direct way to biodegrade plastic.

The authors acknowledge funding from the National Natural Science Foundation of China, the National Basic Research Program of China and the Shenzhen Key Laboratory of Bioenergy.

Story Source: The above story is based on materials provided by American Chemical Society.

Monday, November 17, 2014

Major Class of Fracking Chemicals No More Toxic Than Common Household Substances, analysis finds

Date: November 12, 2014
Source: University of Colorado at Boulder

Summary: The 'surfactant' chemicals found in samples of fracking fluid collected in five states were no more toxic than substances commonly found in homes, according to a first-of-its-kind analysis.


Fracking fluid is largely composed of water and sand, but oil and gas companies also add a variety of other chemicals, including anti-bacterial agents, corrosion inhibitors and surfactants. Surfactants reduce the surface tension between water and oil, allowing for more oil to be extracted from porous rock underground.

In a new study published in the journal Analytical Chemistry, the research team identified the surfactants found in fracking fluid samples from Colorado, Louisiana, Nevada, Pennsylvania and Texas. The results showed that the chemicals found in the fluid samples were also commonly found in everyday products, from toothpaste to laxatives to detergent to ice cream.

"This is the first published paper that identifies some of the organic fracking chemicals going down the well that companies use," said Michael Thurman, lead author of the paper and a co-founder of the Laboratory for Environmental Mass Spectrometry in CU-Boulder's College of Engineering and Applied Science. "We found chemicals in the samples we were running that most of us are putting down our drains at home."

Imma Ferrer, chief scientist at the mass spectrometry laboratory and co-author of the paper said, "Our unique instrumentation with accurate mass and intimate knowledge of ion chemistry was used to identify these chemicals." The mass spectrometry laboratory is sponsored by Agilent Technologies, Inc., which provides state-of-the art instrumentation and support.

The fluid samples analyzed for the study were provided through partnerships with Colorado State University and colleagues at CU-Boulder.

Hydraulic fracturing, or "fracking," is a technique used to increase the amount of oil and gas that can be extracted from the ground by forcing fluid down the well. Fracking has allowed for an explosion of oil and gas operations across the country. In the U.S. the number of natural gas wells has increased by 200,000 in the last two decades, according to the U.S. Energy Information Administration.

Among the concerns raised by the fracking boom is that the chemicals used in the fracking fluid might contaminate ground and surface water supplies. But determining the risk of contamination--or proving that any contamination has occurred in the past--has been difficult because oil and gas companies have been reluctant to share exactly what's in their proprietary fluid mixtures, citing stiff competition within the industry.

Recent state and federal regulations require companies to disclose what is being used in their fracking fluids, but the resulting lists typically use broad chemical categories to describe the actual ingredients.

The results of the new study are important not only because they give a picture of the possible toxicity of the fluid but because a detailed list of the ingredients can be used as a "fingerprint" to trace whether suspected contamination of water supplies actually originated from a fracking operation.

The authors caution that their results may not be applicable to all wells. Individual well operators use unique fracking fluid mixtures that may be modified depending on the underlying geology. Ferrer and Thurman are now working to analyze more water samples collected from other wells as part of a larger study at CU-Boulder exploring the impacts of natural gas development.

Thurman notes that there are other concerns about fracking--including air pollution, the antimicrobial biocides used in fracking fluids, wastewater disposal triggering earthquakes and the large amount of water used--that are important to investigate and ameliorate. But water pollution from surfactants in fracking fluid may not be as big a concern as previously thought.

"What we have learned in this piece of work is that the really toxic surfactants aren't being used in the wells we have tested," he said.

Monday, November 10, 2014

Nutrients That Feed Red Tide 'Under the Microscope' in Major Study

Date: November 6, 2014
Source: Bigelow Laboratory for Ocean Sciences

Summary:
The 'food' sources that support Florida red tides are more diverse and complex than previously realized, according to five years' worth of research on red tide and nutrients. The microbiology, physiology, ecology and physical oceanography factors affecting red tides were documented in new detail and suggestions for resource managers addressing red tide in the coastal waters of southwest Florida were offered.


The rosette of Niskin bottles is submerged to collect water samples.

The multi-partner project was funded by the National Oceanic and Atmospheric Administration's ECOHAB program and included 14 research papers from seven institutions.

The research team studied four red tide blooms caused by the harmful algae species Karenia brevis in 2001, '07, '08 and '09, plus the non-bloom year 2010. Their goal was to understand which nutrients supported these red tides and the extent to which coastal pollution might contribute, helping reveal what drives red tide in southwest Florida.

Study partners documented 12 sources of nutrients in southwest Florida waters -- including some never before associated with K. brevis. Results supported the consensus that blooms start 10-40 miles offshore, away from the direct influence of land-based nutrient pollution, but once moved inshore blooms can use both human-contributed and natural nutrients for growth.

The project documented the microbiology, physiology, ecology and physical oceanography factors affecting red tides in new detail, provided a synthesis of results and offered suggestions for resource managers addressing red tide in the coastal waters of southwest Florida.

Florida red tide blooms -- which occur naturally in the Gulf of Mexico and most frequently off southwest Florida -- are higher-than-normal concentrations of the microscopic algae species K. brevis, a plant-like organism whose toxins can kill fish and other marine species, make shellfish toxic to eat and cause respiratory irritation in humans. These blooms occurred centuries before the mid-to-late twentieth century population boom along Florida's coast. Now, with large numbers of coastal residents and visitors in Florida, blooms can significantly affect public health and the economy.

Public information and short-term forecasts help mitigate red tide impacts, but ongoing research is critical to inform resource managers working to understand and potentially reduce nutrients available to blooms.

"Data go a long way toward increasing our understanding," said Dr. Cynthia Heil, Senior Research Scientist at Bigelow Laboratory for Ocean Sciences in Maine, who co-edited the special issue of Harmful Algae and was formerly with FWC's Fish and Wildlife Research Institute. "This report, which includes data from four different red tides and numerous laboratory studies and modeling efforts by biological, chemical and physical oceanographers, shows the collaborative efforts needed to understand why Florida red tides are so frequent and harmful in this region."

Co-editor Dr. Judith O'Neil, Research Associate Professor at the University of Maryland Center for Environmental Science, added, "We learned that K. brevis is an adaptable and flexible organism. We identified 12 different sources of nutrients that it can take up and use. One of the most interesting things that hadn't previously been taken into account is this organism's ability to not just use sunlight, like plants, but to also consume other single-celled organisms as a nutrient source. Additionally, its migratory behavior and directed swimming allows K. brevis access to nutrient sources everywhere it finds them -- at the surface, bottom and throughout the water column."

According to the study, K. brevis can get the nutrients nitrogen and/or phosphorus from the following sources (bold sources were newly linked to K. brevis blooms through the ECOHAB project):

  • Undersea sediments
  • Decaying fish
  • Water flowing out of estuaries
  • Deposits from the atmosphere
  • Nitrogen from the air transformed, or "fixed," into a more useable form by the naturally occurring bacteria Trichodesmium. (They are a type of cyanobacteria, which use energy from sun to make food, like plants. They can multiply and form blooms.)
  • Waste from zooplankton -- small aquatic animals visible to the naked eye
  • The "grazing" of smaller zooplankton, dubbed "microzooplankton" because they can only be seen under a microscope. (Grazing includes their "sloppy eating" of other tiny life forms, along with their waste.)
  • Picoplankton -- tiny life forms that K. brevis consumes
  • Bacteria transforming nitrogen in the water into more useful forms
  • Light creating available nutrients from natural, dissolved compounds like tannins in the water
  • Decay of Trichodesmium blooms (newly documented as a long-term nutrient source for K. brevis blooms)
  • Nitrogen from the air "fixed" by other cyanobacteria that are NOT Trichodesmium

The researchers concluded that many of these nutrient sources are individually more than enough to support observed blooms, but no single nutrient source is solely responsible.

Naturally occurring Trichodesmium (defined above) provided the most nitrogen, but not all, for K. brevis blooms developing offshore. Nearer to shore and within estuaries, major nitrogen sources believed to support blooms included estuary water carrying land-based nutrients to sea, underwater sediments and dead fish decomposing, in addition to other sources.

A few coastal sources -- estuary water, deposits from the atmosphere and underwater sediments -- are known to carry natural nutrients as well as some enhanced levels due to human activity. With other nutrient sources -- such as microscopic life forms -- connections with human activities are less direct, so it is harder to predict how they might be influencing red tides.

"Nature is messy, but this project has put several new pieces in place," said Dr. Kellie Dixon, Senior Scientist at Mote Marine Laboratory and Co-Principal Investigator for the ECOHAB project. "Until now we had not looked at this many of the 12 sources and their specific quantities simultaneously. Some of the sources, like nutrients released from the sediments, had never been measured in southwest Florida's coastal waters until we studied them for ECOHAB."

The project blended nutrient studies with physical oceanography, shedding new light on how blooms are brought to shore.

"Until now, effective management of harmful algal blooms caused by K. brevis was complicated because we didn't know enough about how different nutrient sources and forms taken up by K. brevis interacted with the physical environment," said Matt Garrett of the Fish and Wildlife Research Institute, who managed the ECOHAB project. "This project provides data that can help inform management recommendations on how to control nutrient sources and possibly improve forecasting models."

The special issue of Harmful Algae includes the following management recommendations:

  • Maximize efforts to reduce potentially controllable nutrient inputs and sources that contribute to K. brevis blooms.
  • Monitor for known physical conditions that favor/disfavor the initiation, transport and export of K. brevis blooms in the southwest Florida region.
  • Identify and provide necessary funding at state and federal levels to maintain the southwest Florida coastal observing system infrastructure on an operational basis.

Thursday, November 6, 2014

National Water-Use at Lowest Levels Since Before 1970

Released: 11/5/2014 9:16:23 AM

Contact Information:
U.S. Department of the Interior, U.S. Geological Survey
Office of Communications and Publishing
12201 Sunrise Valley Dr, MS 119
Reston, VA 20192
Ethan Alpern
Phone: 703-648-4406


Water use across the country reached its lowest recorded level in nearly 45 years. According to a new USGS report, about 355 billion gallons of water per day (Bgal/d) were withdrawn for use in the entire United States during 2010.

This represents a 13 percent reduction of water use from 2005 when about 410 Bgal/d were withdrawn and the lowest level since before 1970.

“Reaching this 45-year low shows the positive trends in conservation that stem from improvements in water-use technologies and management,” said Mike Connor, deputy secretary of the Interior. “Even as the U.S. population continues to grow, people are learning to be more water conscious and do their part to help sustain the limited freshwater resources in the country.”


Total water withdrawals by State and barchart showing categories by State from west to east, 2010. (Larger image.)

In 2010, more than 50 percent of the total withdrawals in the United States were accounted for by 12 states in order of withdrawal amounts: California, Texas, Idaho, Florida, Illinois, North Carolina, Arkansas, Colorado, Michigan, New York, Alabama and Ohio.

California accounted for 11 percent of the total withdrawals for all categories and 10 percent of total freshwater withdrawals for all categories nationwide. Texas accounted for about 7 percent of total withdrawals for all categories, predominantly for thermoelectric power, irrigation and public supply.

Florida had the largest saline withdrawals, accounting for 18 percent of the total in the country, mostly saline surface-water withdrawals for thermoelectric power. Oklahoma and Texas accounted for about 70 percent of the total saline groundwater withdrawals in the United States, mostly for mining.

“Since 1950, the USGS has tracked the national water-use statistics,” said Suzette Kimball, acting USGS director. “By providing data down to the county level, we are able to ensure that water resource managers across the nation have the information necessary to make strong water-use and conservation decisions.”


Trends in total water withdrawals by water-use category, 1950–2010.
(Larger image.)

Water withdrawn for thermoelectric power was the largest use nationally, with the other leading uses being irrigation, public supply and self-supplied industrial water, respectively. Withdrawals declined in each of these categories. Collectively, all of these uses represented 94 percent of total withdrawals from 2005-2010.

  • Thermoelectric power declined 20 percent, the largest percent decline.
  • Irrigation withdrawals (all freshwater) declined 9 percent.
  • Public-supply withdrawals declined 5 percent.

Self-supplied industrial withdrawals declined 12 percent.

A number of factors can be attributed to the 20 percent decline in thermoelectric-power withdrawals, including an increase in the number of power plants built or converted since the 1970’s that use more efficient cooling-system technologies, declines in withdrawals to protect aquatic habitat and environments, power plant closures and a decline in the use of coal to fuel power plants.

"Irrigation withdrawals in the United States continued to decline since 2005, and more croplands were reported as using higher-efficiency irrigation systems in 2010,” said Molly Maupin, USGS hydrologist. “Shifts toward more sprinkler and micro-irrigation systems nationally and declining withdrawals in the West have contributed to a drop in the national average application rate from 2.32 acre-feet per acre in 2005 to 2.07 acre-feet per acre in 2010."

For the first time, withdrawals for public water supply declined between 2005 and 2010, despite a 4 percent increase in the nation’s total population. The number of people served by public-supply systems continued to increase and the public-supply per capita use declined to 89 gallons per day in 2010 from 100 gallons per day in 2005.

Declines in industrial withdrawals can be attributed to factors such as greater efficiencies in industrial processes, more emphasis on water reuse and recycling, and the 2008 U.S. recession, resulting in lower industrial production in major water-using industries.

In a separate report, USGS estimated thermoelectric-power withdrawals and consumptive use for 2010, based on linked heat- and water-budget models that integrated power plant characteristics, cooling system types and data on heat flows into and out of 1,290 power plants in the United States. These data include the first national estimates of consumptive use for thermoelectric power since 1995, and the models offer a new approach for nationally consistent estimates.

In August, USGS released the 2010 water-use estimates for California in advance of the national report. The estimates showed that in 2010, Californians withdrew an estimated total of 38 Bgal/day, compared with 46 Bgal/day in 2005. Surface water withdrawals in the state were down whereas groundwater withdrawals and freshwater withdrawals were up. Most freshwater withdrawals in California are for irrigation.

The USGS is the world’s largest provider of water data and the premier water research agency in the federal government.

Tuesday, October 28, 2014

Electrodialysis Identified as Potential Way to Remove Salt from Fracking Waste Water

Fracking is a highly controversial and divisive issue. Proponents argue that it could be the biggest energy boom since the Arabian oil fields were opened almost 80 years ago, but this comes at a serious cost to the environment. Among the detrimental effects of the process is that the waste water it produces is over five times saltier than seawater, which is, to put it mildly, not good. A research team led by MIT that has found an economical way of removing salt from fracking waste water that promises to not only reduce pollution, but conserve water as well.

Hydraulic fracturing, or fracking uses water pressure to shatter oil shale formations, releasing oil and natural gas from deposits that would otherwise be uneconomical to exploit. One of the major problems with this process is that as the water is pumped through the oil shale, it picks up salt, and by the time it’s pumped back to the surface, it’s extremely salty – in the order of 192,000 parts per million (ppm). In contrast, seawater is only 35,000 ppm. This makes it not only too salty to be disposed of without reprocessing, but it’s also too salty to be reused in fracking.

The MIT research team sought to find the most cost effective means of desalinating fracking water. They found that electrodialysis is not only a promising way of cleaning up fracking waste water, but could also provide oil explorers with a closed-loop system that places less demand on local water supplies.


Diagram of the MIT desalinating process (Image: Jose-Luis Olivares/MIT)


Electrodialysis is not a new technology. It was developed half a century ago and is currently used to desalinate brackish water and seawater, for small-scale drinking water plants, in food processing, greenhouses, hydroponics, and desalinating various chemicals.

In electrodialysis, a series of membranes divide streams of water of different salinity into stacks. An electric current on either side of the stack draws the sodium and chlorine ions of the salt across the membranes, leaving the water behind. The end result is a very salty stream of water, and a relatively pure stream.

According to MIT, electrodialysis has been overlooked as a way of treating fracking waste water until now because the process was thought to only be effective on water that wasn't of such high salinity. However, the team’s research found that electrodialysis is not only practical, but economically viable – not the least because water conducts electricity better as it gets saltier, therefore the electrodialysis process works better.

The team found that the key was to desalinate the water in stages and rather than making the water potable, it only had to be cleaned up enough to be pumped back into a fracking well and used again. This not only has the potential to reduce the costs, but also alleviate pressure on local water supplies and minimize the need for disposal of contaminated water.

In addition, the process described by MIT is extremely flexible, allowing engineers to "dial" the saline output. This is important, because reusing the water will mean finding the most effective level of salinity for fracking, which is a question still to be answered.

According to the team, there’s still a lot of work to be done before the process is practical. In addition to tweaking the electrodialysis design, laboratory work needs to be done on removing oil, gas, and mineral contaminants that may clog the membranes, and new equipment needs to be designed, built, and tested to apply the new technology.