Wednesday, August 9, 2017

Antibiotics Come With 'Environmental Side Effects'

Report published in Microchemical Journal wins Elsevier's Atlas award

Date: July 25, 2017
Source: Elsevier
Summary: Researchers are bringing attention to the fact that commonly used antibiotic drugs are making their way out into the environment, where they can harm microbes that are essential to a healthy environment.

Researchers writing in Microchemical Journal are bringing attention to the fact that commonly used antibiotic drugs are making their way out into the environment, where they can harm microbes that are essential to a healthy environment. Their review article has been selected for the Elsevier Atlas Award, which recognizes research that could significantly impact people's lives around the world or has already done so.

"The amount of antibiotics is very, very low -- there are normally nanograms per liter of these molecules found in natural environments," said Dr. Paola Grenni, a microbial ecologist at the National Research Council's Water Research Institute in Italy. "But the antibiotics and also other pharmaceuticals can have an effect even in low concentrations, the so-called environmental side-effects."

When people take antibiotics, their bodies break down and metabolize only a portion of the drugs. The rest is excreted and enters wastewater. Because wastewater treatment plants aren't designed to fully remove antibiotic or other pharmaceutical compounds, many of those compounds reach natural systems where they can accumulate and harm microbes in nature.

That's a big concern, Dr. Grenni said, because many microbial species found in the environment are beneficial, playing important roles in natural cycles of nutrients, primary production and climate regulation. Some microbes also degrade organic contaminants, such as pesticides.

The review paper published by Dr. Grenni along with colleagues Drs. Valeria Ancona and Anna Barra Caracciolo highlights commonly used antibiotic compounds and their active ingredients. Some of those medications are used to treat people. Many others are used in veterinary medicine, especially to treat farm animals including cattle, pigs and poultry.

The release of antibiotics into natural systems is a "real-life experiment" with consequences that aren't yet fully known. Dr. Grenni and her colleagues say there's a need for more specific protections of environmental microbes given their importance to functioning ecosystems.

It's important for nations to work to reduce unnecessary antibiotic use and the release of those antibiotics that are needed into the environment. To that end, efforts should be made to equip wastewater treatment plants for removal of those compounds and to devise methods to improve the degradation of antibiotics once they reach natural environments. Members of the public can help by taking care to use antibiotics only when they are truly needed, and by disposing of expired medications properly.

"There are only a few researchers working in this field, but it's very important," Dr. Grenni said. "We need to know the different molecules we normally use that are in the environment and the effect they have. We need more research in this field."

Story Source: Elsevier. "Antibiotics come with 'environmental side effects': Report published in Microchemical Journal wins Elsevier's Atlas award." ScienceDaily. ScienceDaily, 25 July 2017. https://www.sciencedaily.com/releases/2017/07/170725122046.htm.

Friday, July 28, 2017

Heavy Metals in Water Meet Their Match

Reusable, Carbon Nanotube-Reinforced Filters Clean Toxins from Water, study shows

Date: July 27, 2017
Source: Rice University
Summary: A high school student's project removes more than 99 percent of heavy metal toxins from water. A new article demonstrates its potential for water remediation in developing nations around the world.



Plain quartz fiber, top, gains the ability to remove toxic metals from water when carbon nanotubes are added, bottom. The filters absorbed more than 99 percent of metals from test samples laden with cadmium, cobalt, copper, mercury, nickel and lead. Once saturated, the filters can be washed and reused.
Credit: Barron Research Group/Rice University


Carbon nanotubes immobilized in a tuft of quartz fiber have the power to remove toxic heavy metals from water, according to researchers at Rice University.

Prize-winning filters produced in the lab of Rice chemist Andrew Barron by then-high school student and lead author Perry Alagappan absorb more than 99 percent of metals from samples laden with cadmium, cobalt, copper, mercury, nickel and lead. Once saturated, the filters can be washed with a mild household chemical like vinegar and reused.

The researchers calculated one gram of the material could treat 83,000 liters of contaminated water to meet World Health Organization standards -- enough to supply the daily needs of 11,000 people.

The lab's analysis of the new filters appears this month in Nature's open-access Scientific Reports.

The robust filters consist of carbon nanotubes grown in place on quartz fibers that are then chemically epoxidized. Lab tests showed that scaled-up versions of the "supported-epoxidized carbon nanotube" (SENT) filters proved able to treat 5 liters of water in less than one minute and be renewed in 90 seconds. The material retained nearly 100 percent of its capacity to filter water for up to 70 liters per 100 grams of SENT, after which the metals contained could be extracted for reuse or turned into a solid for safe disposal.

While the quartz substrate gives the filter form and the carbon nanotube sheath makes it tough, the epoxidation via an oxidizing acid appears to be most responsible for adsorbing the metal, they determined.

Alagappan, now an undergraduate student at Stanford University, was inspired to start the project during a trip to India, where he learned about contamination of groundwater from the tons of electronic waste -- phones, computers and the like -- that improperly end up in landfills.

"Perry contacted me wanting to gain experience in laboratory research," Barron said. "Since we had an ongoing project started by Jessica Heimann, an undergraduate who was taking a semester at Jacobs University Bremen, this was a perfect match."

Barron said the raw materials for the filter are inexpensive and pointed out the conversion of acetic acid to vinegar is ubiquitous around the globe, which should simplify the process of recycling the filters for reuse even in remote locations. "Every culture on the planet knows how to make vinegar," he said.

"This would make the biggest social impact on village-scale units that could treat water in remote, developing regions," Barron said. "However, there is also the potential to scale up metal extraction, in particular from mine wastewater."

Alagappan's research won a series of awards while he was still a high school student in Clear Lake, a Houston suburb, as well as a visiting student in Barron's Rice lab. First was the top prize for environmental sciences at the Science and Engineering Fair of Houston in 2014. That qualified him to enter the Intel International Science and Engineering Fair in Los Angeles the next year, where he also took the top environmental award.

He booted that into the top prize at the 2015 Stockholm Junior Water Prize, where the crown princess of Sweden presented him with the honor.

"It's been a tremendous honor to be recognized on an international level for this research, and I am grateful for the opportunity to work on this project alongside such a talented group of individuals," Alagappan said. "I also especially appreciated being able to meet with other young researchers at the Intel International Science Fair and the Stockholm Junior Water Prize, who inspired me with their firm commitment to elevate society through science and technology."

Story Source: Rice University. "Heavy metals in water meet their match: Reusable, carbon nanotube-reinforced filters clean toxins from water, study shows." ScienceDaily. ScienceDaily, 27 July 2017. www.sciencedaily.com/releases/2017/07/170727083159.htm

Thursday, July 13, 2017

Release of Treated Wastewater From Hydraulic Fracturing Contaminates Lake

Date: July 12, 2017
Source: American Chemical Society
Summary: Hydraulic fracturing has enabled a domestic oil and gas boom in the US, but its rapid growth has raised questions about what to do with the billions of gallons of wastewater that result. Researchers now report that treating the wastewater and releasing it into surface waters has led to the contamination of a Pennsylvania watershed with radioactive material and endocrine-disrupting chemicals.


Treating fracking wastewater and releasing it into surface waters has led to the contamination of a Pennsylvania watershed with radioactive material and endocrine-disrupting chemicals, report investigators. (Stock image)
Credit: © John / Fotolia


Hydraulic fracturing has enabled a domestic oil and gas boom in the U.S., but its rapid growth has raised questions about what to do with the billions of gallons of wastewater that result. Researchers now report that treating the wastewater and releasing it into surface waters has led to the contamination of a Pennsylvania watershed with radioactive material and endocrine-disrupting chemicals. The study appears in ACS' journal Environmental Science & Technology.

In 2015, the unconventional oil and gas extraction method known as hydraulic fracturing, or "fracking," accounted for more than one-half of oil production and two-thirds of gas production in America, according to the U.S. Energy Information Administration. The method's market share is likely to increase even further. Although the technique has resulted in a shift away from coal, which could reduce greenhouse gas emissions, it produces large amounts of wastewater containing radioactive material, salts, metals, endocrine-disrupting chemicals and polycyclic aromatic hydrocarbons that could pose risks to the environment and human health. A Pennsylvania report estimates that in 2015, 10,000 unconventional oil and gas wells in the Marcellus Shale produced 1.7 billion gallons of wastewater. The facilities that collect the water provide only limited treatment before releasing it into surface waters. Bill Burgos and colleagues at Penn State, Colorado State and Dartmouth wanted to see what impact this strategy of treating and releasing fracking wastewater might be having.

The researchers sampled sediments and porewaters from a lake downstream from two facilities that treat fracking wastewater in Pennsylvania. Their analysis detected that peak concentrations of radium, alkaline earth metals, salts and organic chemicals all occurred in the same sediment layer. The two major classes of organic contaminants included nonylphenol ethoxylates, which are endocrine-disrupting chemicals, and polycyclic aromatic hydrocarbons, which are carcinogens. The highest concentrations coincided with sediment layers deposited five to 10 years ago during a peak period of fracking wastewater disposal. Elevated levels of radium were also found as far as 12 miles downstream of the treatment plants. The researchers say that the potential risks associated with this contamination are unknown, but they suggest tighter regulations of wastewater disposal could help protect the environment and human health.

Story Source:
American Chemical Society. "Release of treated wastewater from hydraulic fracturing contaminates lake." ScienceDaily. ScienceDaily, 12 July 2017. https://www.sciencedaily.com/releases/2017/07/170712110605.htm

Thursday, June 29, 2017

Bacteria-Coated Nanofiber Electrodes Clean Pollutants in Wastewater

Date: June 28, 2017
Source: Cornell University
Summary: Researchers may have created an innovative, cost-competitive electrode material for cleaning pollutants in wastewater.

Cornell University materials scientists and bioelectrochemical engineers may have created an innovative, cost-competitive electrode material for cleaning pollutants in wastewater.

The researchers created electro-spun carbon nanofiber electrodes and coated them with a conductive polymer, called PEDOT, to compete with carbon cloth electrodes available on the market. When the PEDOT coating is applied, an electrically active layer of bacteria -- Geobacter sulfurreducens -- naturally grows to create electricity and transfer electrons to the novel electrode.

The conducting nanofibers create a favorable surface for this bacteria, which digests pollutants from the wastewater and produces electricity, according to the research.

"Electrodes are expensive to make now, and this material could bring the price of electrodes way down, making it easier to clean up polluted water," said co-lead author Juan Guzman, a doctoral candidate in the field of biological and environmental engineering. Under a microscope, the carbon nanofiber electrode resembles a kitchen scrubber.

The electrode was made by co-lead author Meryem Pehlivaner, currently a doctoral student at Northeastern University, with senior author Margaret Frey, professor of fiber science and an associate dean of the College of Human Ecology. Pehlivaner fabricated the carbon nanofibers via electrospinning and carbonization processes. After a few hours electrospinning, a thick nanofiber sheet -- visible to the naked eye -- emerges.

Pehlivaner reached out to Guzman and senior author Lars Angenent, professor of biological and environmental engineering, for collaboration in applying the carbon nanofiber electrodes to simultaneous wastewater treatment and production of electrical energy.

The customizable carbon nanofiber electrode was used for its high porosity, surface area and biocompatibility with the bacteria. By adhering PEDOT, the material gets an improved function, according to the researchers.

Guzman said wastewater treatment plants do not employ this method -- yet. On a large scale, the bacteria at the electrode could capture and degrade pollutants from the wastewater that flows by it. Such a technology can improve wastewater treatment by allowing systems to take up less land and increase throughput.

Concepts like this happen on campuses where faculty and students want to communicate and collaborate, Angenent said. "This defines radical collaboration," he said. "We have fiber scientists talking to environmental engineers, from two very different Cornell colleges, to create reality from an idea -- that was more or less a hunch -- that will make cleaning wastewater better and a little more inexpensive."

Story Source: Cornell University. "Bacteria-coated nanofiber electrodes clean pollutants in wastewater." ScienceDaily. ScienceDaily, 28 June 2017. www.sciencedaily.com/releases/2017/06/170628144829.htm

Tuesday, June 27, 2017

Algae: The Final Frontier

Date: June 21, 2017
Source: Carnegie Institution for Science
Summary: Algae dominate the oceans that cover nearly three-quarters of our planet, and produce half of the oxygen that we breathe. And yet fewer than 10 percent of the algae have been formally described in the scientific literature, as noted in a new review.

Algae dominate the oceans that cover nearly three-quarters of our planet, and produce half of the oxygen that we breathe. And yet fewer than 10 percent of the algae have been formally described in the scientific literature, as noted in a new review co-authored by Carnegie's Arthur Grossman in Trends in Plant Science.

Algae are everywhere. They are part of crusts on desert surfaces and form massive blooms in lakes and oceans. They range in size from tiny single-celled organisms to giant kelp.

Algae also play crucial roles in human life. People have eaten "seaweed" (large macroalgae) for millennia. But algae can also represent a health hazard when toxic blooms suffocate lakes and coastlines.

Despite the pervasiveness of algae and their importance in our planet's ecology and in human health and nutrition, there is so much that scientists don't know about them. This lack of knowledge is mostly due to limited support and the need to develop methodologies for probing the various algal groups at the molecular level.

The term 'algae' is used informally to embrace a large variety of photosynthetic organisms that belong to a number of different taxa. To effectively reveal the mysteries of each of these organisms would require creating research processes that are effective for each of them (what works with one often doesn't work with another).

However, some of the latest molecular techniques have allowed scientists to elucidate major genetic processes that have shaped algal evolution. And this improved knowledge has implications beyond basic scientific discovery.

For example, in the future, algae may be used to produce biofuels or to synthesize high-value therapeutic compounds or plastics. Furthermore, with an improved understanding of metabolism in the various algal groups, scientists can better develop strategies to exploit algae for the production of materials -- using them as "cellular factories," in a sense.

Many studies have shown that algae can also adapt to changing environmental conditions. But what are the limits of this ability? And how will the effect of climate change on the world's oceans impact algae and the oxygen that we derive from them?

"In the process of reviewing the state of algal research, we feel that we are on the cusp of a revolution in understanding this group of organisms, their importance in shaping ecosystems worldwide, and the ways in which they can be used to enrich humankind," said Grossman.

Story Source: Carnegie Institution for Science. "Algae: The final frontier." ScienceDaily. ScienceDaily, 21 June 2017. www.sciencedaily.com/releases/2017/06/170621165931.htm

Tuesday, May 30, 2017

Water Efficiency in Rural Areas is Getting Worse, Even as it Improves in Urban Centers

Date: May 18, 2017
Source: North Carolina State University
Summary: A nationwide analysis of water use over the past 30 years finds that there is a disconnect between rural and urban areas, with most urban areas becoming more water efficient and most rural areas becoming less and less efficient over time.



This map shows spatio-temporal patterns of water-use efficiency (per-capita consumption) across the continental United States. Colors indicate the change in per-capita consumption, in gallons per day per person, computed as the difference between 2010 and 1985 estimates. The numbers shown in each state indicate the number of 5-year periods each state reduced its per-capita withdrawals from 1985 to 2010.
Credit: Sankar Arumugam


A nationwide analysis of water use over the past 30 years finds that there is a disconnect between rural and urban areas, with most urban areas becoming more water efficient and most rural areas becoming less and less efficient over time.

"Understanding water use is becoming increasingly important, given that climate change is likely to have a profound impact on the availability of water supplies," says Sankar Arumugam, lead author of a paper on the work. "This research helps us identify those areas that need the most help, and highlights the types of action that may be best suited to helping those areas." Arumugam is a University Faculty Scholar and professor of civil, construction and environmental engineering at North Carolina State University.

The new paper stems from a National Science Foundation-funded, interuniversity research project which focuses on understanding how water sustainability in the United States has changed over the past 30 years as a result of climate change and population growth.

For this paper, researchers evaluated water use data at the state and county level for the 48 contiguous states. Specifically, the researchers looked at water-use efficiency, measured as per capita consumption, in 5-year increments, from 1985 to 2010.

"This is the first systematic evaluation of water use across the continental U.S.," Arumugam says. "And we found that some states -- including Washington, Pennsylvania and Wyoming -- were becoming more efficient every five years. Meanwhile, other states -- such as South Carolina, Oklahoma and Mississippi -- have gotten worse every five years."

But a look at the county-level data reveals what may be the most important finding: most rural counties are getting less efficient, while most urban counties are getting more efficient.

"In other words, as we are facing a more uncertain future regarding water resources, rural counties are being left behind," Arumugam says.

The researchers found that investment in new water-efficiency technologies, and retrofitting existing water infrastructure, are big reasons for the improvement in urban areas.

"Rural counties appear to lack the resources, the political will, or both, to keep pace," Arumugam says.

Another important finding is that technologies and strategies focused on efficiency -- as opposed to large-scale projects, such as building new reservoirs -- have been extremely successful. These efforts have allowed urban areas to avoid sharp increases in water use, even as their populations have grown significantly.

"There may be a role for huge infrastructure projects at some point, but these findings underscore the value of focusing on efficiency measures -- and the need to pursue those measures in rural counties," Arumugam says.

Story Source: North Carolina State University. "Water efficiency in rural areas is getting worse, even as it improves in urban centers." ScienceDaily. ScienceDaily, 18 May 2017. http://www.sciencedaily.com/releases/2017/05/170518140246.htm

Tuesday, April 25, 2017

Wax Worm Caterpillar Will Eat Plastic Shopping Bags: New Solution to Plastic Waste?

Date: April 24, 2017
Source: Cell Press
Summary: Generally speaking, plastic is incredibly resistant to breaking down. That's certainly true of the trillion polyethylene plastic bags that people use each and every year. But researchers may be on track to find a solution to plastic waste. The key is a caterpillar commonly known as a wax worm.


This image shows a wax worm chewing a hole through plastic. Polyethylene debris can be seen attached to the caterpillar.
Credit: Federica Bertocchini, Paolo Bombelli, and Chris Howe


Generally speaking, plastic is incredibly resistant to breaking down. That's certainly true of the trillion polyethylene plastic bags that people use each and every year. But researchers reporting in Current Biology on April 24 may be on track to find a solution to plastic waste. The key is a caterpillar commonly known as a wax worm.

"We have found that the larva of a common insect, Galleria mellonella, is able to biodegrade one of the toughest, most resilient, and most used plastics: polyethylene," says Federica Bertocchini of the Institute of Biomedicine and Biotechnology of Cantabria in Spain. A previous study (doi: 10.1021/es504038a) has shown that Plodia interpunctella wax worms, the larvae of dian mealmoths, can also digest plastic.

Bertocchini and her colleagues made the discovery quite by accident, after noticing that plastic bags containing wax worms quickly became riddled with holes. Further study showed that the worms can do damage to a plastic bag in less than an hour.

After 12 hours, all that munching of plastic leads to an obvious reduction in plastic mass. The researchers showed that the wax worms were not only ingesting the plastic, they were also chemically transforming the polyethylene into ethylene glycol. This is suspected to be the case in Plodia interpunctella as well.

Although wax worms wouldn't normally eat plastic, the researchers suspect that their ability is a byproduct of their natural habits. Wax moths lay their eggs inside beehives. The worms hatch and grow on beeswax, which is composed of a highly diverse mixture of lipid compounds. The researchers say the molecular details of wax biodegradation require further investigation, but it's likely that digesting beeswax and polyethylene involves breaking down similar types of chemical bonds.

"Wax is a polymer, a sort of 'natural plastic,' and has a chemical structure not dissimilar to polyethylene," Bertocchini says.

As the molecular details of the process become known, the researchers say it could be used to devise a biotechnological solution to managing polyethylene waste. They'll continue to explore the process in search of such a strategy.

"We are planning to implement this finding into a viable way to get rid of plastic waste, working towards a solution to save our oceans, rivers, and all the environment from the unavoidable consequences of plastic accumulation," Bertocchini says. "However," she adds, "we should not feel justified to dump polyethylene deliberately in our environment just because we now know how to bio-degrade it."

Journal Reference:
Bombelli et al. Polyethylene bio-degradation by caterpillars of the wax moth Galleria mellonella. Current Biology, 2017 DOI: 10.1016/j.cub.2017.02.060

Story Source:
Cell Press. "Wax worm caterpillar will eat plastic shopping bags: New solution to plastic waste?." ScienceDaily. ScienceDaily, 24 April 2017. www.sciencedaily.com/releases/2017/04/170424141338.htm.