Date: July 2, 2019
Source: University of Colorado at Boulder
Summary: Sand is a key ingredient in the recipe of modern life, and yet it is being extracted faster than it can be replaced.
What links the building you live in, the glass you drink from and the computer you work on? The answer is smaller than you think and is something we are rapidly running out of: sand.
In a commentary published today in the journal Nature, a group of scientists from the University of Colorado Boulder, the University of Illinois, the University of Hull and Arizona State University highlight the urgent need for a global agenda for sand.
Sand is a key ingredient in the recipe of modern life, and yet it might be our most overlooked natural resource, the authors argue. Sand and gravel are being extracted faster than they can be replaced. Rapid urbanization and global population growth have fueled the demand for sand and gravel, with between 32 and 50 billion tons extracted globally each year.
"From 2000-2100 it is projected there will be a 300 percent increase in sand demand and 400 percent increase in prices," said Mette Bendixen, a researcher at CU Boulder's Institute of Arctic and Alpine Research (INSTAAR). "We urgently require a monitoring program to address the current data and knowledge gap, and thus fully assess the magnitude of sand scarcity. It is up to the scientific community, governments and policy makers to take the steps needed to make this happen."
A lack of oversight and monitoring is leading to unsustainable exploitation, planning and trade. Removal of sand from rivers and beaches has far-reaching impacts on ecology, infrastructure, national economies and the livelihoods of the 3 billion people who live along the world's river corridors. Illegal sand mining has been documented in 70 countries across the globe, and battles over sand have reportedly killed hundreds in recent years, including local citizens, police officers and government officials.
"Politically and socially, we must ask: If we can send probes to the depths of the oceans or the furthest regions of the solar system, is it too much to expect that we possess a reliable understanding of sand mining in the world's great rivers, and on which so much of the world's human population, rely?" said Jim Best, a professor at the University of Illinois Department of Geology. "Now is the time to commit to gaining such knowledge by fully grasping and utilizing the new techniques that are at our disposal."
In order to move towards globally sustainable sand extraction, the authors argue that we must fully understand the occurrence of sustainable sources and reduce current extraction rates and sand needs, by recycling concrete and developing alternative to sand (such as crushed rocks or plastic waste materials). This will rely on a knowledge of the location and extent of sand mining, as well as the natural variations in sand flux in the world's rivers.
"The fact that sand is such a fundamental component of modern society, and yet we have no clear idea of how much sand we remove from our rivers every year, or even how much sand is naturally available, makes ensuring this industry is sustainable very, very difficult" said Chris Hackney, research fellow at the University of Hull's Energy and Environment Institute. "It's time that sand was given the same focus on the world stage as other global commodities such as oil, gas and precious metals."
"The issue of sand scarcity cannot be studied in geographical isolation as it has worldwide implications," said Lars L. Iversen, a research fellow at Arizona State University's Julie Ann Wrigley Global Institute of Sustainability. "The reality and size of the problem must be acknowledged -- and action must be taken -- on a global stage. In a rapidly changing world, we cannot afford blind spots."
The Carlsberg Foundation and the Danish National Research Foundation provided funding for the study.
Story Source: University of Colorado at Boulder. "The world needs a global agenda for sand." ScienceDaily. ScienceDaily, 2 July 2019. https://www.sciencedaily.com/releases/2019/07/190702112726.htm.
Wednesday, July 10, 2019
Wednesday, June 19, 2019
Alarming Study Finds Plastic Ocean Pollution Harms Bacteria That Produce The Oxygen We Breathe
Rich Haridy | May 15th, 2019
Chemicals that leach out of plastic rubbish were found to impair the growth of bacteria in the ocean responsible for producing a large volume of the oxygen in our atmosphere (Credit: ead72/Depositphotos)
An important new study is raising novel concerns over the effects of plastic pollution in our oceans. For the first time researchers investigated how a common ocean bacteria, responsible for producing over 10 percent of oxygen in the atmosphere, is negatively impaired by chemicals that can leach out of plastic products.
Prochlorococcus is a tiny cyanobacterial genus that was only discovered a little over 30 years ago. This remarkable cyanobacterium is not only the smallest photosynthesizing organism on the planet, but also one of the most abundant. Some estimates suggest there are as much as three octillion Prochlorococcus in the ocean, where they not only help keep the waters healthy, but also produce a substantial volume of the oxygen we breathe.
"These tiny microorganisms are critical to the marine food web, contribute to carbon cycling and are thought to be responsible for up to 10 per cent of the total global oxygen production," says Lisa Moore, from Australia's Macquarie University and co-author on the new study. "So one in every 10 breaths of oxygen you breathe in is thanks to these little guys, yet almost nothing is known about how marine bacteria, such as Prochlorococcus respond to human pollutants."
To fill this substantial gap in scientific knowledge, the researchers took two different strains of the cyanobacteria and in laboratory conditions exposed them to chemicals known to leach out of common plastic products. The results were striking with the chemicals impairing the Prochlorococcus' growth, reducing its ability to photosynthesize, and altering the expression of a large number of its genes.
The study obviously has a number of limitations if one is trying to extrapolate these results to the general effect of plastics in the ocean. The researchers do note that their experiments do not equate to specific concentrations of plastics in the ocean, but instead they're designed to try to better understand what the impact of plastic pollution could be on this vitally important population of microorganisms in our marine systems.
"Our data shows that plastic pollution may have widespread ecosystem impacts beyond the known effects on macro-organisms, such as seabirds and turtles," says lead author on the study, Sasha Tetu. "If we truly want to understand the full impact of plastic pollution in the marine environment and find ways to mitigate it, we need to consider its impact on key microbial groups, including photosynthetic microbes."
While a great deal of activity currently circles the problem of plastics, and microplastics, in our ocean ecosystems, very little is known about what actual damage these pollutants are causing. Further study will be necessary to investigate the effects of these plastics on microorganisms in the actual ocean, but the researchers hypothesize this to potentially be a significant global issue.
The new study notes the nearly two trillion plastic pieces that make up the infamous Great Pacific Garbage Patch cross over an area where the Prochlorococcus cyanobacterium is most abundant. Alongside this, a recent study did reveal that floating plastic rubbish can leach chemicals into ambient seawater in volumes high enough to alter the activity of local microbial populations. So, although this new research was completed in laboratory environments in generally hypothetical scenarios, the problem of plastic chemicals leaching into the ocean is one that certainly needs attention.
The new study was published in the journal Communications Biology.
Source: Macquarie University
Story Source: https://newatlas.com/plastic-ocean-pollution-bacteria-photosynthesis-oxygen/59688/
Chemicals that leach out of plastic rubbish were found to impair the growth of bacteria in the ocean responsible for producing a large volume of the oxygen in our atmosphere (Credit: ead72/Depositphotos)
An important new study is raising novel concerns over the effects of plastic pollution in our oceans. For the first time researchers investigated how a common ocean bacteria, responsible for producing over 10 percent of oxygen in the atmosphere, is negatively impaired by chemicals that can leach out of plastic products.
Prochlorococcus is a tiny cyanobacterial genus that was only discovered a little over 30 years ago. This remarkable cyanobacterium is not only the smallest photosynthesizing organism on the planet, but also one of the most abundant. Some estimates suggest there are as much as three octillion Prochlorococcus in the ocean, where they not only help keep the waters healthy, but also produce a substantial volume of the oxygen we breathe.
"These tiny microorganisms are critical to the marine food web, contribute to carbon cycling and are thought to be responsible for up to 10 per cent of the total global oxygen production," says Lisa Moore, from Australia's Macquarie University and co-author on the new study. "So one in every 10 breaths of oxygen you breathe in is thanks to these little guys, yet almost nothing is known about how marine bacteria, such as Prochlorococcus respond to human pollutants."
To fill this substantial gap in scientific knowledge, the researchers took two different strains of the cyanobacteria and in laboratory conditions exposed them to chemicals known to leach out of common plastic products. The results were striking with the chemicals impairing the Prochlorococcus' growth, reducing its ability to photosynthesize, and altering the expression of a large number of its genes.
The study obviously has a number of limitations if one is trying to extrapolate these results to the general effect of plastics in the ocean. The researchers do note that their experiments do not equate to specific concentrations of plastics in the ocean, but instead they're designed to try to better understand what the impact of plastic pollution could be on this vitally important population of microorganisms in our marine systems.
"Our data shows that plastic pollution may have widespread ecosystem impacts beyond the known effects on macro-organisms, such as seabirds and turtles," says lead author on the study, Sasha Tetu. "If we truly want to understand the full impact of plastic pollution in the marine environment and find ways to mitigate it, we need to consider its impact on key microbial groups, including photosynthetic microbes."
While a great deal of activity currently circles the problem of plastics, and microplastics, in our ocean ecosystems, very little is known about what actual damage these pollutants are causing. Further study will be necessary to investigate the effects of these plastics on microorganisms in the actual ocean, but the researchers hypothesize this to potentially be a significant global issue.
The new study notes the nearly two trillion plastic pieces that make up the infamous Great Pacific Garbage Patch cross over an area where the Prochlorococcus cyanobacterium is most abundant. Alongside this, a recent study did reveal that floating plastic rubbish can leach chemicals into ambient seawater in volumes high enough to alter the activity of local microbial populations. So, although this new research was completed in laboratory environments in generally hypothetical scenarios, the problem of plastic chemicals leaching into the ocean is one that certainly needs attention.
The new study was published in the journal Communications Biology.
Source: Macquarie University
Story Source: https://newatlas.com/plastic-ocean-pollution-bacteria-photosynthesis-oxygen/59688/
Wednesday, May 8, 2019
Radical Desalination Approach May Disrupt the Water Industry
Date: May 6, 2019
Source: Columbia University School of Engineering and Applied Science
Summary: Researchers report that they have developed a radically different desalination approach--''temperature swing solvent extraction (TSSE)''--for hypersaline brines. Their study demonstrates that TSSE can desalinate very high-salinity brines, up to seven times the concentration of seawater.
This is an illustration describing fresh water production from hypersaline brines by temperature swing solvent extraction.
Credit: Chanhee Boo/Columbia Engineering
Hypersaline brines -- water that contains high concentrations of dissolved salts and whose saline levels are higher than ocean water -- are a growing environmental concern around the world. Very challenging and costly to treat, they result from water produced during oil and gas production, inland desalination concentrate, landfill leachate (a major problem for municipal solid waste landfills), flue gas desulfurization wastewater from fossil-fuel power plants, and effluent from industrial processes.
If hypersaline brines are improperly managed, they can pollute both surface and groundwater resources. But if there were a simple, inexpensive way to desalinate the brines, vast quantities of water would be available for all kinds of uses, from agriculture to industrial applications, and possibly even for human consumption.
A Columbia Engineering team led by Ngai Yin Yip, assistant professor of earth and environmental engineering, reports that they have developed a radically different desalination approach -- "temperature swing solvent extraction (TSSE)" -- for hypersaline brines. The study, published online in Environmental Science & Technology Letters, demonstrates that TSSE can desalinate very high-salinity brines, up to seven times the concentration of seawater. This is a good deal more than reverse osmosis, the gold-standard for seawater desalination, and can hold handle approximately twice seawater salt concentrations.
VIDEO: https://youtu.be/P8VPVdZm0r8
Currently, hypersaline brines are desalinated either by membrane (reverse osmosis) or water evaporation (distillation). Each approach has limitations. Reverse osmosis methods are ineffective for high-saline brines because the pressures applied in reverse osmosis scale with the amount of salt: hypersaline brines require prohibitively high pressurizations. Distillation techniques, which evaporate the brine, are very energy-intensive.
Yip has been working on solvent extraction, a separation method widely employed for chemical engineering processes. The relatively inexpensive, simple, and effective separation technique is used in a wide range of industries, including production of fine organic compounds, purification of natural products, and extraction of valuable metal complexes.
"I thought solvent extraction could be a good alternative desalination approach that is radically different from conventional methods because it is membrane-less and not based on evaporative phase-change," Yip says. "Our results show that TSSE could be a disruptive technology -- it's effective, efficient, scalable, and can be sustainably powered."
TSSE utilizes a low-polarity solvent with temperature-dependent water solubility for the selective extraction of water over salt from saline feeds. Because it is membrane-less and not based on evaporation of water, it can sidestep the technical constraints that limit the more traditional methods. Importantly, TSSE is powered by low-grade heat (< 70 C) that is inexpensive and sometimes even free. In the study, TSSE removed up to 98.4% of the salt, which is comparable to reverse osmosis, the gold standard for seawater desalination. The findings also demonstrated high water recovery >50% for the hypersaline brines, also comparable to current seawater desalination operations. But, unlike TSSE, reverse osmosis cannot handle hypersaline brines.
"We think TSSE will be transformational for the water industry," he adds. "It can displace the prevailing practice of costly distillation for desalination of high-salinity brines and tackle higher salinities that RO cannot handle," Yip adds. "This will radically improve the sustainability in the treatment of produced water, inland desalination concentrate, landfill leachate, and other hypersaline streams of emerging importance. We can eliminate the pollution problems from these brines and create cleaner, more useable water for our planet."
Yip's TSSE approach has a clear path to commercialization. The heat input can be sustainably supplied by low-grade thermal sources such as industrial waste heat, shallow-well geothermal, and low-concentration solar collectors. He is now working on further refining how TSSE works as a desalination method so that he can engineer further improvements in performance and test it with real-world samples in the field.
Story Source:
Columbia University School of Engineering and Applied Science. "Radical desalination approach may disrupt the water industry." ScienceDaily. ScienceDaily, 6 May 2019. https://www.sciencedaily.com/releases/2019/05/190506151839.htm
Source: Columbia University School of Engineering and Applied Science
Summary: Researchers report that they have developed a radically different desalination approach--''temperature swing solvent extraction (TSSE)''--for hypersaline brines. Their study demonstrates that TSSE can desalinate very high-salinity brines, up to seven times the concentration of seawater.
This is an illustration describing fresh water production from hypersaline brines by temperature swing solvent extraction.
Credit: Chanhee Boo/Columbia Engineering
Hypersaline brines -- water that contains high concentrations of dissolved salts and whose saline levels are higher than ocean water -- are a growing environmental concern around the world. Very challenging and costly to treat, they result from water produced during oil and gas production, inland desalination concentrate, landfill leachate (a major problem for municipal solid waste landfills), flue gas desulfurization wastewater from fossil-fuel power plants, and effluent from industrial processes.
If hypersaline brines are improperly managed, they can pollute both surface and groundwater resources. But if there were a simple, inexpensive way to desalinate the brines, vast quantities of water would be available for all kinds of uses, from agriculture to industrial applications, and possibly even for human consumption.
A Columbia Engineering team led by Ngai Yin Yip, assistant professor of earth and environmental engineering, reports that they have developed a radically different desalination approach -- "temperature swing solvent extraction (TSSE)" -- for hypersaline brines. The study, published online in Environmental Science & Technology Letters, demonstrates that TSSE can desalinate very high-salinity brines, up to seven times the concentration of seawater. This is a good deal more than reverse osmosis, the gold-standard for seawater desalination, and can hold handle approximately twice seawater salt concentrations.
VIDEO: https://youtu.be/P8VPVdZm0r8
Currently, hypersaline brines are desalinated either by membrane (reverse osmosis) or water evaporation (distillation). Each approach has limitations. Reverse osmosis methods are ineffective for high-saline brines because the pressures applied in reverse osmosis scale with the amount of salt: hypersaline brines require prohibitively high pressurizations. Distillation techniques, which evaporate the brine, are very energy-intensive.
Yip has been working on solvent extraction, a separation method widely employed for chemical engineering processes. The relatively inexpensive, simple, and effective separation technique is used in a wide range of industries, including production of fine organic compounds, purification of natural products, and extraction of valuable metal complexes.
"I thought solvent extraction could be a good alternative desalination approach that is radically different from conventional methods because it is membrane-less and not based on evaporative phase-change," Yip says. "Our results show that TSSE could be a disruptive technology -- it's effective, efficient, scalable, and can be sustainably powered."
TSSE utilizes a low-polarity solvent with temperature-dependent water solubility for the selective extraction of water over salt from saline feeds. Because it is membrane-less and not based on evaporation of water, it can sidestep the technical constraints that limit the more traditional methods. Importantly, TSSE is powered by low-grade heat (< 70 C) that is inexpensive and sometimes even free. In the study, TSSE removed up to 98.4% of the salt, which is comparable to reverse osmosis, the gold standard for seawater desalination. The findings also demonstrated high water recovery >50% for the hypersaline brines, also comparable to current seawater desalination operations. But, unlike TSSE, reverse osmosis cannot handle hypersaline brines.
"We think TSSE will be transformational for the water industry," he adds. "It can displace the prevailing practice of costly distillation for desalination of high-salinity brines and tackle higher salinities that RO cannot handle," Yip adds. "This will radically improve the sustainability in the treatment of produced water, inland desalination concentrate, landfill leachate, and other hypersaline streams of emerging importance. We can eliminate the pollution problems from these brines and create cleaner, more useable water for our planet."
Yip's TSSE approach has a clear path to commercialization. The heat input can be sustainably supplied by low-grade thermal sources such as industrial waste heat, shallow-well geothermal, and low-concentration solar collectors. He is now working on further refining how TSSE works as a desalination method so that he can engineer further improvements in performance and test it with real-world samples in the field.
Story Source:
Columbia University School of Engineering and Applied Science. "Radical desalination approach may disrupt the water industry." ScienceDaily. ScienceDaily, 6 May 2019. https://www.sciencedaily.com/releases/2019/05/190506151839.htm
Tuesday, October 23, 2018
Atmospheric Water Harvester Takes out $1.5m XPrize
By Nick Lavars | October 20th, 2018
Skysource/Skywater Alliance develops deployable machines that can harvest freshwater from the air
(Credit: Skysource/Skywater Alliance)
Two years ago, XPrize extended its list of pioneering technology competitions with a new contest aimed at the problem of global water security. After revealing the five finalists earlier in the year, the foundation has today announced the grand prize winner, which outshone almost 100 competitors with its superior ability to harvest fresh water from thin air.
The Water Abundance XPrize drew 98 competing teams from 25 countries, who were asked to develop and demonstrate technologies capable of harvesting 2,000 L (528 gal) of water from the atmosphere each day. They needed to be powered entirely by renewable energy, and produce water at a cost of no more than two cents per liter (0.26 gal).
Over the month of September, two finalists were made to fully demonstrate their devices satisfying these requirements, with LA-based Skysource/Skywater Alliance coming up trumps. Its range of deployable machines pull moisture from the air, condense it and then filter it into fresh water, with outputs ranging from 30 gal (113 L) to 300 gal (1,135 L) per day.
Skysource/Skywater Alliance claims its device harvests atmospheric water more efficiently than any other method
(Credit: Skysource/Skywater Alliance)
The company's website states that it harvests atmospheric water more efficiently than any other method, and we guess it now has the accolades to back up its claims, along with US$1.5 million in prize money.
Coming in second place was Hawaii's JMCC WING, whose solution combines a high torque wind energy system with an atmospheric water harvester as a way of keeping energy requirements, and thereby costs per liter, to a minimum. JMCC WING has received $150,000 for its efforts.
JMCC WING's solution combines a high torque wind energy system with an atmospheric water harvester
(Credit: JMCC WING)
Story Source: https://newatlas.com/xprize-water-abundance-winner/56860/
Skysource/Skywater Alliance develops deployable machines that can harvest freshwater from the air
(Credit: Skysource/Skywater Alliance)
Two years ago, XPrize extended its list of pioneering technology competitions with a new contest aimed at the problem of global water security. After revealing the five finalists earlier in the year, the foundation has today announced the grand prize winner, which outshone almost 100 competitors with its superior ability to harvest fresh water from thin air.
The Water Abundance XPrize drew 98 competing teams from 25 countries, who were asked to develop and demonstrate technologies capable of harvesting 2,000 L (528 gal) of water from the atmosphere each day. They needed to be powered entirely by renewable energy, and produce water at a cost of no more than two cents per liter (0.26 gal).
Over the month of September, two finalists were made to fully demonstrate their devices satisfying these requirements, with LA-based Skysource/Skywater Alliance coming up trumps. Its range of deployable machines pull moisture from the air, condense it and then filter it into fresh water, with outputs ranging from 30 gal (113 L) to 300 gal (1,135 L) per day.
Skysource/Skywater Alliance claims its device harvests atmospheric water more efficiently than any other method
(Credit: Skysource/Skywater Alliance)
The company's website states that it harvests atmospheric water more efficiently than any other method, and we guess it now has the accolades to back up its claims, along with US$1.5 million in prize money.
Coming in second place was Hawaii's JMCC WING, whose solution combines a high torque wind energy system with an atmospheric water harvester as a way of keeping energy requirements, and thereby costs per liter, to a minimum. JMCC WING has received $150,000 for its efforts.
JMCC WING's solution combines a high torque wind energy system with an atmospheric water harvester
(Credit: JMCC WING)
Story Source: https://newatlas.com/xprize-water-abundance-winner/56860/
Tuesday, October 16, 2018
Newly Discovered Bacterium Rids Problematic Pair of Toxic Groundwater Contaminants
Date: October 9, 2018
Source: New Jersey Institute of Technology
Summary: Researchers have detailed the discovery of the first bacterium known capable of simultaneously degrading the pair of chemical contaminants -- 1,4-Dioxane and 1,1-DCE.
Image of DD4 cells.
Credit: NJIT, Mengyan Li
Known as a chemical manufacturing by-product of many cosmetics and home cleaning products, the industrial solvent 1,4-Dioxane is now considered by the Environmental Protection Agency to be an "emerging contaminant" and "likely human carcinogen" that can be found at thousands of groundwater sites nationally -- potentially representing a multi-billion dollar environmental remediation challenge.
However, it is the contaminant's frequent co-existence with another toxic chemical -- 1,1-Dichloroethylene (1,1-DCE) -- that has been found to aid in 1,4-dioxane's resistance to certain remediation strategies, including degradation by naturally-occurring microbes.
Now, New Jersey Institute of Technology (NJIT) researchers have detailed the discovery of the first bacterium known capable of simultaneously degrading the pair of chemical contaminants -- 1,4-Dioxane and 1,1-DCE. The study, published in Environmental Science & Technology Letters, also showcases the efficiency of the microbe, called Azoarcus sp. DD4 (DD4), in reducing 1,4-dioxane and 1,1-DCE levels in co-contaminated groundwater samples.
"Nationwide, researchers have found that more than 80% of the groundwater sites contaminated with 1,4-dioxane also contain 1,1-DCE," said Mengyan Li, assistant professor of chemistry and environmental science at NJIT. "This pair of chemicals are toxic and costly to remove from the environment because the pair have very different properties that typically require separate treatment solutions. Biodegradation by DD4 is the first biological method we have found for treating both compounds concurrently, and it is also environmentally-friendly and cost-efficient."
Li's research team initially discovered the DD4 microbe from activated sludge samples collected from a municipal wastewater treatment facility. In the lab, Li's team was able to isolate and analyze DD4's ability to degrade 1,4-dioxane and 1,1-DCE simultaneously in contaminated groundwater samples over a two-week period.
Applying the microbe to the field samples, Li's team observed that concentration of 1,4-dioxane was degraded from 10 parts-per-million (10 ppm) -- or 3,000 times the limit of the EPA's guidance level of 0.35 parts-per-billion (0.35 ppb) -- to under 0.38 ppb. The lab also found 1,1-DCE concentration levels reduced from over 3 ppm to below 0.02 ppm.
Notably, DD4 displayed resistance to cellular toxicity produced by the metabolites of 1,1-DCE, which typically inhibit the ability of other bacteria capable of degrading 1,4-dioxane. Li's team observed that although DD4 was partially inhibited in its ability to degrade 1,4-dioxane when excessive amounts of 1,1-DCE were artificially spiked in the water samples, 1,4-dioxane degradation capability immediately recovered once the microbe had depleted 1,1-DCE.
"Overall, we were impressed by the performance of DD4," said Li. "We did not add nutrients like ammonia for the microbe to feed on, or other facilitators that might enhance the bacterium's activity. This demonstrated to us the potential of this bacterium for future use in the field."
In an analysis of the genetic makeup of DD4, Li's lab identified a potentially key gene related to the microbe's chemical degradation activity. Li says that the gene encodes for an enzyme, called soluble di-iron monooxygenase (SDIMO), with versatile capabilities of breaking down chemical pollutants. "We want to characterize it (this enzyme) further to see if we can better learn the mechanism underlying how DD4 degrades these contaminants." said Li.
Along with DD4's 1,1-DCE-resistance and ability to degrade the co-contaminants concurrently, Li says the bacterium possesses several other key traits that make it conducive as a potential bioremediation solution at contaminated groundwater sites -- such as its ability to disperse freely through water to remediate larger areas of contamination, rather than aggregating like other bacterial treatments. The microbe can also be cultured rapidly and can sustain for extended periods with limited nutrient source.
"We tested the bacterium in normal refrigerated temperature over three days and its viability remained above 80%," said Li. "After a week, half were still alive. This makes it even more desirable because it would be able to survive the delivery time from the lab to contaminated sites."
Li's lab is now conducting further tests of the bacterium in the lab to better understand how DD4 might perform at contaminated water sites. With feasibility tests already underway, Li says his team could begin field demonstrations of DD4 as a water treatment solution for 1,4-dioxane and 1,1-DCE contamination sites as early as next year.
"Ideally, we may inject the bacteria into the center of a contamination zone, or try growing them on the surface of bio-barriers that help stop spread of contamination," said Li. "First, we'd like to do more tests and possibly develop a gene marker that helps us assess the bacteria's performance. Then, we would like to move into the field."
Story Source:
New Jersey Institute of Technology. "Newly discovered bacterium rids problematic pair of toxic groundwater contaminants." ScienceDaily. ScienceDaily, 9 October 2018. https://www.sciencedaily.com/releases/2018/10/181009115019.htm
Source: New Jersey Institute of Technology
Summary: Researchers have detailed the discovery of the first bacterium known capable of simultaneously degrading the pair of chemical contaminants -- 1,4-Dioxane and 1,1-DCE.
Image of DD4 cells.
Credit: NJIT, Mengyan Li
Known as a chemical manufacturing by-product of many cosmetics and home cleaning products, the industrial solvent 1,4-Dioxane is now considered by the Environmental Protection Agency to be an "emerging contaminant" and "likely human carcinogen" that can be found at thousands of groundwater sites nationally -- potentially representing a multi-billion dollar environmental remediation challenge.
However, it is the contaminant's frequent co-existence with another toxic chemical -- 1,1-Dichloroethylene (1,1-DCE) -- that has been found to aid in 1,4-dioxane's resistance to certain remediation strategies, including degradation by naturally-occurring microbes.
Now, New Jersey Institute of Technology (NJIT) researchers have detailed the discovery of the first bacterium known capable of simultaneously degrading the pair of chemical contaminants -- 1,4-Dioxane and 1,1-DCE. The study, published in Environmental Science & Technology Letters, also showcases the efficiency of the microbe, called Azoarcus sp. DD4 (DD4), in reducing 1,4-dioxane and 1,1-DCE levels in co-contaminated groundwater samples.
"Nationwide, researchers have found that more than 80% of the groundwater sites contaminated with 1,4-dioxane also contain 1,1-DCE," said Mengyan Li, assistant professor of chemistry and environmental science at NJIT. "This pair of chemicals are toxic and costly to remove from the environment because the pair have very different properties that typically require separate treatment solutions. Biodegradation by DD4 is the first biological method we have found for treating both compounds concurrently, and it is also environmentally-friendly and cost-efficient."
Li's research team initially discovered the DD4 microbe from activated sludge samples collected from a municipal wastewater treatment facility. In the lab, Li's team was able to isolate and analyze DD4's ability to degrade 1,4-dioxane and 1,1-DCE simultaneously in contaminated groundwater samples over a two-week period.
Applying the microbe to the field samples, Li's team observed that concentration of 1,4-dioxane was degraded from 10 parts-per-million (10 ppm) -- or 3,000 times the limit of the EPA's guidance level of 0.35 parts-per-billion (0.35 ppb) -- to under 0.38 ppb. The lab also found 1,1-DCE concentration levels reduced from over 3 ppm to below 0.02 ppm.
Notably, DD4 displayed resistance to cellular toxicity produced by the metabolites of 1,1-DCE, which typically inhibit the ability of other bacteria capable of degrading 1,4-dioxane. Li's team observed that although DD4 was partially inhibited in its ability to degrade 1,4-dioxane when excessive amounts of 1,1-DCE were artificially spiked in the water samples, 1,4-dioxane degradation capability immediately recovered once the microbe had depleted 1,1-DCE.
"Overall, we were impressed by the performance of DD4," said Li. "We did not add nutrients like ammonia for the microbe to feed on, or other facilitators that might enhance the bacterium's activity. This demonstrated to us the potential of this bacterium for future use in the field."
In an analysis of the genetic makeup of DD4, Li's lab identified a potentially key gene related to the microbe's chemical degradation activity. Li says that the gene encodes for an enzyme, called soluble di-iron monooxygenase (SDIMO), with versatile capabilities of breaking down chemical pollutants. "We want to characterize it (this enzyme) further to see if we can better learn the mechanism underlying how DD4 degrades these contaminants." said Li.
Along with DD4's 1,1-DCE-resistance and ability to degrade the co-contaminants concurrently, Li says the bacterium possesses several other key traits that make it conducive as a potential bioremediation solution at contaminated groundwater sites -- such as its ability to disperse freely through water to remediate larger areas of contamination, rather than aggregating like other bacterial treatments. The microbe can also be cultured rapidly and can sustain for extended periods with limited nutrient source.
"We tested the bacterium in normal refrigerated temperature over three days and its viability remained above 80%," said Li. "After a week, half were still alive. This makes it even more desirable because it would be able to survive the delivery time from the lab to contaminated sites."
Li's lab is now conducting further tests of the bacterium in the lab to better understand how DD4 might perform at contaminated water sites. With feasibility tests already underway, Li says his team could begin field demonstrations of DD4 as a water treatment solution for 1,4-dioxane and 1,1-DCE contamination sites as early as next year.
"Ideally, we may inject the bacteria into the center of a contamination zone, or try growing them on the surface of bio-barriers that help stop spread of contamination," said Li. "First, we'd like to do more tests and possibly develop a gene marker that helps us assess the bacteria's performance. Then, we would like to move into the field."
Story Source:
New Jersey Institute of Technology. "Newly discovered bacterium rids problematic pair of toxic groundwater contaminants." ScienceDaily. ScienceDaily, 9 October 2018. https://www.sciencedaily.com/releases/2018/10/181009115019.htm
Monday, August 13, 2018
Rethinking Ketchup Packets: New Approach to Slippery Packaging Aims to Cut Food Waste
Benefits Also Include Consumer Safety and Comfort
Date: August 3, 2018
Source: Virginia Tech
Summary: New research aims to cut down on waste -- and consumer frustration -- with a novel approach to creating super slippery industrial packaging. The study establishes a method for wicking chemically compatible vegetable oils into the surfaces of common extruded plastics, like those used for ketchup packets and other condiments.
Virginia Tech doctoral student Ranit Mukherjee observes a dollop of ketchup as it moves on a super slippery plastic film. Mukherjee is the lead author on a study that yielded a novel approach to creating super slippery industrial packaging.
Credit: Virginia Tech
Almost everyone who eats fast food is familiar with the frustration of trying to squeeze every last drop of ketchup out of the small packets that accompany french fries.
What most consumers don't realize, however, is that food left behind in plastic packaging is not simply a nuisance. It also contributes to the millions of pounds of perfectly edible food that Americans throw out every year. These small, incremental amounts of sticky foods like condiments, dairy products, beverages, and some meat products that remain trapped in their packaging can add up to big numbers over time, even for a single household.
New research from Virginia Tech aims to cut down on that waste -- and consumer frustration -- with a novel approach to creating super slippery industrial packaging.
The study, which was published in Scientific Reports and has yielded a provisional patent, establishes a method for wicking chemically compatible vegetable oils into the surfaces of common extruded plastics.
Not only will the technique help sticky foods release from their packaging much more easily, but for the first time, it can also be applied to inexpensive and readily available plastics such as polyethylene and polypropylene.
These hydrocarbon-based polymers make up 55 percent of the total demand for plastics in the world today, meaning potential applications for the research stretch far beyond just ketchup packets. They're also among the easiest plastics to recycle.
"Previous SLIPS, or slippery liquid-infused porous surfaces, have been made using silicon- or fluorine-based polymers, which are very expensive," said Ranit Mukherjee, a doctoral student in the Department of Biomedical Engineering and Mechanics within the College of Engineering and the study's lead author. "But we can make our SLIPS out of these hydrocarbon-based polymers, which are widely applicable to everyday packaged products."
First created by Harvard University researchers in 2011, SLIPS are porous surfaces or absorbent polymers that can hold a chemically compatible oil within their surfaces via the process of wicking. These surfaces are not only very slippery, but they're also self-cleaning, self-healing, and more durable than traditional superhydrophobic surfaces.
In order for SLIPS to hold these oils, the surfaces must have some sort of nano- or micro-roughness, which keeps the oil in place by way of surface tension. This roughness can be achieved two ways: the surface material is roughened with a type of applied coating, or the surface material consists of an absorbent polymer. In the latter case, the molecular structure of the material itself exhibits the necessary nano-roughness.
Both techniques have recently gained traction with startups and in limited commercial applications. But current SLIPS that use silicone- and fluorine-based absorbent polymers aren't attractive for industrial applications due to their high cost, while the method of adding roughness to surfaces can likewise be an expensive and complicated process.
"We had two big breakthroughs," said Jonathan Boreyko, an assistant professor of biomedical engineering and mechanics and a study co-author. "Not only are we using these hydrocarbon-based polymers that are cheap and in high demand, but we don't have to add any surface roughness, either. We actually found oils that are naturally compatible with the plastics, so these oils are wicking into the plastic itself, not into a roughness we have to apply."
In addition to minimizing food waste, Boreyko cited other benefits to the improved design, including consumer safety and comfort.
"We're not adding any mystery nanoparticles to the surfaces of these plastics that could make people uncomfortable," he said. "We use natural oils like cottonseed oil, so there are no health concerns whatsoever. There's no fancy recipe required."
While the method has obvious implications for industrial food and product packaging, it could also find widespread use in the pharmaceutical industry. The oil-infused plastic surfaces are naturally anti-fouling, meaning they resist bacterial adhesion and growth.
Although the technique may sound very high-tech, it actually finds its roots in the pitcher plant, a carnivorous plant that entices insects to the edge of a deep cavity filled with nectar and digestive enzymes. The leaves that form the plant's eponymous shape have a slippery ring, created by a secreted liquid, around the periphery of the cavity. When the insects move onto this slippery ring, they slide into the belly of the plants.
"This slippery periphery on the pitcher plant actually inspired our SLIPS product," said Mukherjee.
The pitcher plant's innovation -- which engineers are now copying with great success -- is the combination of a lubricant with some type of surface roughness that can lock that lubricant into place very stably with surface tension.
"We're taking that same concept, but the roughness we're using is just a common attribute of everyday plastics, which means maximal practicality," said Boreyko.
This research was funded through an industrial collaboration with Bemis North America. Additional co-authors of the study include Mohammad Habibi, a Virginia Tech mechanical engineering graduate student; Ziad Rashed, an engineering science and mechanics 2018 graduate from Virginia Tech's undergraduate program; and Otacilio Berbert and Xiangke Shi, both of Bemis North America.
Reprinted From:
Virginia Tech. "Rethinking ketchup packets: New approach to slippery packaging aims to cut food waste: Benefits also include consumer safety and comfort." ScienceDaily. ScienceDaily, 3 August 2018. https://www.sciencedaily.com/releases/2018/08/180803103302.htm
Date: August 3, 2018
Source: Virginia Tech
Summary: New research aims to cut down on waste -- and consumer frustration -- with a novel approach to creating super slippery industrial packaging. The study establishes a method for wicking chemically compatible vegetable oils into the surfaces of common extruded plastics, like those used for ketchup packets and other condiments.
Virginia Tech doctoral student Ranit Mukherjee observes a dollop of ketchup as it moves on a super slippery plastic film. Mukherjee is the lead author on a study that yielded a novel approach to creating super slippery industrial packaging.
Credit: Virginia Tech
Almost everyone who eats fast food is familiar with the frustration of trying to squeeze every last drop of ketchup out of the small packets that accompany french fries.
What most consumers don't realize, however, is that food left behind in plastic packaging is not simply a nuisance. It also contributes to the millions of pounds of perfectly edible food that Americans throw out every year. These small, incremental amounts of sticky foods like condiments, dairy products, beverages, and some meat products that remain trapped in their packaging can add up to big numbers over time, even for a single household.
New research from Virginia Tech aims to cut down on that waste -- and consumer frustration -- with a novel approach to creating super slippery industrial packaging.
The study, which was published in Scientific Reports and has yielded a provisional patent, establishes a method for wicking chemically compatible vegetable oils into the surfaces of common extruded plastics.
Not only will the technique help sticky foods release from their packaging much more easily, but for the first time, it can also be applied to inexpensive and readily available plastics such as polyethylene and polypropylene.
These hydrocarbon-based polymers make up 55 percent of the total demand for plastics in the world today, meaning potential applications for the research stretch far beyond just ketchup packets. They're also among the easiest plastics to recycle.
"Previous SLIPS, or slippery liquid-infused porous surfaces, have been made using silicon- or fluorine-based polymers, which are very expensive," said Ranit Mukherjee, a doctoral student in the Department of Biomedical Engineering and Mechanics within the College of Engineering and the study's lead author. "But we can make our SLIPS out of these hydrocarbon-based polymers, which are widely applicable to everyday packaged products."
First created by Harvard University researchers in 2011, SLIPS are porous surfaces or absorbent polymers that can hold a chemically compatible oil within their surfaces via the process of wicking. These surfaces are not only very slippery, but they're also self-cleaning, self-healing, and more durable than traditional superhydrophobic surfaces.
In order for SLIPS to hold these oils, the surfaces must have some sort of nano- or micro-roughness, which keeps the oil in place by way of surface tension. This roughness can be achieved two ways: the surface material is roughened with a type of applied coating, or the surface material consists of an absorbent polymer. In the latter case, the molecular structure of the material itself exhibits the necessary nano-roughness.
Both techniques have recently gained traction with startups and in limited commercial applications. But current SLIPS that use silicone- and fluorine-based absorbent polymers aren't attractive for industrial applications due to their high cost, while the method of adding roughness to surfaces can likewise be an expensive and complicated process.
"We had two big breakthroughs," said Jonathan Boreyko, an assistant professor of biomedical engineering and mechanics and a study co-author. "Not only are we using these hydrocarbon-based polymers that are cheap and in high demand, but we don't have to add any surface roughness, either. We actually found oils that are naturally compatible with the plastics, so these oils are wicking into the plastic itself, not into a roughness we have to apply."
In addition to minimizing food waste, Boreyko cited other benefits to the improved design, including consumer safety and comfort.
"We're not adding any mystery nanoparticles to the surfaces of these plastics that could make people uncomfortable," he said. "We use natural oils like cottonseed oil, so there are no health concerns whatsoever. There's no fancy recipe required."
While the method has obvious implications for industrial food and product packaging, it could also find widespread use in the pharmaceutical industry. The oil-infused plastic surfaces are naturally anti-fouling, meaning they resist bacterial adhesion and growth.
Although the technique may sound very high-tech, it actually finds its roots in the pitcher plant, a carnivorous plant that entices insects to the edge of a deep cavity filled with nectar and digestive enzymes. The leaves that form the plant's eponymous shape have a slippery ring, created by a secreted liquid, around the periphery of the cavity. When the insects move onto this slippery ring, they slide into the belly of the plants.
"This slippery periphery on the pitcher plant actually inspired our SLIPS product," said Mukherjee.
The pitcher plant's innovation -- which engineers are now copying with great success -- is the combination of a lubricant with some type of surface roughness that can lock that lubricant into place very stably with surface tension.
"We're taking that same concept, but the roughness we're using is just a common attribute of everyday plastics, which means maximal practicality," said Boreyko.
This research was funded through an industrial collaboration with Bemis North America. Additional co-authors of the study include Mohammad Habibi, a Virginia Tech mechanical engineering graduate student; Ziad Rashed, an engineering science and mechanics 2018 graduate from Virginia Tech's undergraduate program; and Otacilio Berbert and Xiangke Shi, both of Bemis North America.
Reprinted From:
Virginia Tech. "Rethinking ketchup packets: New approach to slippery packaging aims to cut food waste: Benefits also include consumer safety and comfort." ScienceDaily. ScienceDaily, 3 August 2018. https://www.sciencedaily.com/releases/2018/08/180803103302.htm
Friday, August 3, 2018
Small Amounts of Pharmaceuticals Found in North Central Pa. Rural Well Water
Date: July 31, 2018
Source: Penn State
Summary: Drinking water from wells in rural north central Pennsylvania had low levels of pharmaceuticals, according to a new study.
While septic tanks are generally installed downgradient of wells, contaminant from septic systems can impact well water quality, especially if the septic systems are not maintained or were improperly installed. Pharmaceuticals that are incompletely degraded in septic tanks and leaching fields can travel with wastewater and infiltrate groundwater.
Credit: Heather Gall Research Group / Penn State
Drinking water from wells in rural north central Pennsylvania had low levels of pharmaceuticals, according to a study led by Penn State researchers.
Partnering with volunteers in the University's Pennsylvania Master Well Owner Network, researchers tested water samples from 26 households with private wells in nine counties in the basin of the West Branch of the Susquehanna River. All samples were analyzed for seven over-the-counter and prescription pharmaceuticals: acetaminophen, ampicillin, caffeine, naproxen, ofloxacin, sulfamethoxazole and trimethoprim.
At least one compound was detected at all sites. Ofloxacin and sulfamethoxazole -- antibiotics prescribed for the treatment of a number of bacterial infections -- were the most frequently detected compounds. Caffeine was detected in approximately half of the samples, while naproxen -- an anti-inflammatory drug used for the management of pain, fever and inflammation -- was not detected in any samples.
"It is now widely known that over-the-counter and prescription medications are routinely present at detectable levels in surface and groundwater bodies," said Heather Gall, assistant professor of agricultural and biological engineering, whose research group in the Penn State's College of Agricultural Sciences conducted the study. "The presence of these emerging contaminants has raised both environmental and public health concerns, particularly when these water supplies are used as drinking water sources."
The good news, Gall pointed out, is that the concentrations of the pharmaceuticals in groundwater sampled were extremely low -- at parts per billion levels. However, given that sampling with the Master Well Owner Network only occurred once, the frequency of occurrence, range of concentrations and potential health risks are not yet well understood, especially for these private groundwater supplies.
The researchers used a simple modeling approach based on the pharmaceuticals' physicochemical parameters -- degradation rates and sorption factors -- to provide insight into the differences in frequency of detection for the target pharmaceuticals, noted lead researcher Faith Kibuye, who will graduate with a doctoral degree in biorenewable systems next year.
She explained that calculations revealed that none of the concentrations observed in the groundwater wells posed any significant human health risk, with risk quotients that are well below the minimal value. However, the risk assessment does not address the potential effect of exposure to mixtures of pharmaceuticals that are likely present in water simultaneously, she said. For example, as many as six of the analyzed pharmaceuticals were detected in some groundwater samples.
"There remains a major concern that even at low concentrations, pharmaceuticals could interact together and influence the biochemical functioning of the human body, so even at very low concentrations they might have some kind of synergistic effect," Kibuye said. "We only analyzed for seven pharmaceuticals but the chances are that there may have been many more."
The findings of the research -- which Kibuye will present today (July 31) at the annual meeting of the American Association of Agricultural and Biological Engineers in Detroit -- should be of interest the world over because groundwater is a critical supply of drinking water globally.
It is estimated that half of the population accesses potable water from groundwater aquifers. In the United States, approximately 13 million households use private wells as their drinking water source, according to the U.S. Environmental Protection Agency. In Pennsylvania, approximately one-third of the residents receive their drinking water from private groundwater wells, Penn State Extension surveys show.
It is common for homeowners with private wells to also have septic tanks on their properties for treatment of their wastewater. And while septic tanks are generally installed downgradient of the well, it is possible that contaminant from septic systems can impact well-water quality, especially if the septic systems are not maintained or were improperly installed.
"While common contaminant issues include fecal coliform, E. coli and nitrate, pharmaceuticals and other compounds of emerging concern pose potential threats to well water quality," Kibuye said. "Pharmaceuticals that are incompletely degraded in septic tanks and leaching fields can therefore travel with wastewater plumes and impact groundwater, potentially making septic systems important point sources to surrounding domestic groundwater sources."
Story Source:
Penn State. "Small amounts of pharmaceuticals found in north central Pa. rural well water." ScienceDaily. ScienceDaily, 31 July 2018. https://www.sciencedaily.com/releases/2018/07/180731141630.htm
Source: Penn State
Summary: Drinking water from wells in rural north central Pennsylvania had low levels of pharmaceuticals, according to a new study.
While septic tanks are generally installed downgradient of wells, contaminant from septic systems can impact well water quality, especially if the septic systems are not maintained or were improperly installed. Pharmaceuticals that are incompletely degraded in septic tanks and leaching fields can travel with wastewater and infiltrate groundwater.
Credit: Heather Gall Research Group / Penn State
Drinking water from wells in rural north central Pennsylvania had low levels of pharmaceuticals, according to a study led by Penn State researchers.
Partnering with volunteers in the University's Pennsylvania Master Well Owner Network, researchers tested water samples from 26 households with private wells in nine counties in the basin of the West Branch of the Susquehanna River. All samples were analyzed for seven over-the-counter and prescription pharmaceuticals: acetaminophen, ampicillin, caffeine, naproxen, ofloxacin, sulfamethoxazole and trimethoprim.
At least one compound was detected at all sites. Ofloxacin and sulfamethoxazole -- antibiotics prescribed for the treatment of a number of bacterial infections -- were the most frequently detected compounds. Caffeine was detected in approximately half of the samples, while naproxen -- an anti-inflammatory drug used for the management of pain, fever and inflammation -- was not detected in any samples.
"It is now widely known that over-the-counter and prescription medications are routinely present at detectable levels in surface and groundwater bodies," said Heather Gall, assistant professor of agricultural and biological engineering, whose research group in the Penn State's College of Agricultural Sciences conducted the study. "The presence of these emerging contaminants has raised both environmental and public health concerns, particularly when these water supplies are used as drinking water sources."
The good news, Gall pointed out, is that the concentrations of the pharmaceuticals in groundwater sampled were extremely low -- at parts per billion levels. However, given that sampling with the Master Well Owner Network only occurred once, the frequency of occurrence, range of concentrations and potential health risks are not yet well understood, especially for these private groundwater supplies.
The researchers used a simple modeling approach based on the pharmaceuticals' physicochemical parameters -- degradation rates and sorption factors -- to provide insight into the differences in frequency of detection for the target pharmaceuticals, noted lead researcher Faith Kibuye, who will graduate with a doctoral degree in biorenewable systems next year.
She explained that calculations revealed that none of the concentrations observed in the groundwater wells posed any significant human health risk, with risk quotients that are well below the minimal value. However, the risk assessment does not address the potential effect of exposure to mixtures of pharmaceuticals that are likely present in water simultaneously, she said. For example, as many as six of the analyzed pharmaceuticals were detected in some groundwater samples.
"There remains a major concern that even at low concentrations, pharmaceuticals could interact together and influence the biochemical functioning of the human body, so even at very low concentrations they might have some kind of synergistic effect," Kibuye said. "We only analyzed for seven pharmaceuticals but the chances are that there may have been many more."
The findings of the research -- which Kibuye will present today (July 31) at the annual meeting of the American Association of Agricultural and Biological Engineers in Detroit -- should be of interest the world over because groundwater is a critical supply of drinking water globally.
It is estimated that half of the population accesses potable water from groundwater aquifers. In the United States, approximately 13 million households use private wells as their drinking water source, according to the U.S. Environmental Protection Agency. In Pennsylvania, approximately one-third of the residents receive their drinking water from private groundwater wells, Penn State Extension surveys show.
It is common for homeowners with private wells to also have septic tanks on their properties for treatment of their wastewater. And while septic tanks are generally installed downgradient of the well, it is possible that contaminant from septic systems can impact well-water quality, especially if the septic systems are not maintained or were improperly installed.
"While common contaminant issues include fecal coliform, E. coli and nitrate, pharmaceuticals and other compounds of emerging concern pose potential threats to well water quality," Kibuye said. "Pharmaceuticals that are incompletely degraded in septic tanks and leaching fields can therefore travel with wastewater plumes and impact groundwater, potentially making septic systems important point sources to surrounding domestic groundwater sources."
Story Source:
Penn State. "Small amounts of pharmaceuticals found in north central Pa. rural well water." ScienceDaily. ScienceDaily, 31 July 2018. https://www.sciencedaily.com/releases/2018/07/180731141630.htm
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