PNNL Researchers Develop Technology For Removing Perchlorate From Water
On July 21, researchers at Pacific Northwest National Laboratory (PNNL) announced the demonstration of a new, environmentally friendly process for treating water contaminated by perchlorate, a toxic chemical that has been found in drinking water in 35 states.

Perchlorate is used in rocket fuel, fireworks, and defense manufacturing, and groundwater contaminated by the chemical is difficult to treat. High levels of perchlorate have been associated with thyroid disease, and possibly cancer and other health problems. Contamination is especially widespread in California, which has a high number of U.S. military bases.

The conventional method for treating perchlorate-contaminated water employs an ion exchange resin. Regenerating the resin requires flushing with an acidic solution, which results in large quantities of secondary waste, the researchers said.
The PNNL method is an electrically controlled anion exchange process.

"The technology is unique in that it uses an electric current to regenerate the resin and release the perchlorate without producing a lot of secondary waste," said Yuehe Lin, lead researcher, adding that the process is "green" because it produces so little waste.
The technology is available for licensing and joint research opportunities through Battelle, which operates PNNL for the U.S. Department of Energy and facilitates the transfer of lab-created technologies to the marketplace.

To create the new process, Lin and his colleagues induced a positive charge to an electrically conducting polymer, such as a polypyrrole, that selectively attracts the negatively charged perchlorate ions. Application of an electric current releases the trapped perchlorate ions for disposal. Now neutral, the polymer can be reverted to a positively charged surface and reused.

The scientists increased the amount of perchlorate that can be captured by depositing the polymer as a polypyrrole thin film on a matrix of carbon nanotubes, creating a porous conductive nanocomposite.

"The high surface area of the carbon nanotubes provides an ideal matrix for the polymer," Lin said, noting that the polymer is electrodeposited on the carbon nanotubes through in-situ polymerization.

The porous surface created by the carbon nanotubes also gives the technology a longer life cycle because the polymer is more stable on the nanotube matrix than it would be on a flat, conducting substrate.

The electrically controlled anion exchange technology can be used to remove other contaminants, such as cesium and chromium. A radioactive material common to nuclear waste sites, cesium could be used by terrorists to build dirty bombs or contaminate drinking water. Chromate is a toxic form of chromium that is readily absorbed by the body.

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Marine 'dead zone' off Oregon is spreading
A hypoxic "dead zone" has formed off the Oregon Coast for the fifth time in five years, according to researchers at Oregon State University.
A fundamental new trend in atmospheric and ocean circulation patterns in the Pacific Northwest appears to have begun, scientists say, and apparently is expanding its scope beyond Oregon waters.

This year for the first time, the effect of the low-oxygen zone is also being seen in coastal waters off Washington, researchers at OSU and the Olympic Coast National Marine Sanctuary indicate.

There have been reports of dead crabs stretching from the central Oregon coast to the central Washington coast. Some dissolved oxygen levels at 180 feet have recently been measured as low as 0.55 milliliters per liter, and areas as shallow as 45 feet have been measured at 1 milliliter per liter.

These oxygen levels are several times lower than normal, and any dissolved oxygen level below 1.4 milliliters per liter is hypoxic, capable of suffocating a wide range of fish, crabs, and other marine life.

"There is a huge pool of low-oxygen water off the central Oregon coast with values as low as 0.46 milliliters per liter," said Francis Chan, marine ecologist in the OSU Department of Zoology and with the Partnership for Interdisciplinary Studies of Coastal Oceans (PISCO), a marine research consortium at OSU and other universities along the West Coast. "OSU researchers have documented this year's region of low-oxygen bottom waters from Florence to Cascade Head. The lack of consistent upwelling winds allowed a low-oxygen pool of deep water to build up. Now that the upwelling-favorable winds are blowing consistently, we're seeing that pool of water come close to shore and begin to suffocate marine life. If these winds continue to blow, we expect to see continued and possibly significant die-offs."

As events such as this become more regular, researchers say, they appear less like an anomaly and more like a fundamental shift in marine conditions and ocean behavior. In particular, a change in intensity and timing of coastal winds seems to play a significant role in these events.

"We're seeing wild swings from year to year in the timing and duration of winds favorable for upwelling," said Jack Barth, an oceanographer with PISCO and the OSU College of Oceanic and Atmospheric Sciences. "This change from normal seasonal patterns and the increased variability are both consistent with climate-change scenarios."

Barth and his colleagues are working on new circulation models that may allow scientists to predict when hypoxia and these "dead zones" will occur. No connection has been observed between these events and other major ocean cycles, such as El Niño or the Pacific Decadal Oscillation.

The lack of wide-scale ocean monitoring makes determining the size and movement of the dead zone difficult, although some new instrumentation being used this year seems to be helping. Dissolved oxygen sensors have been deployed on the sea floor, both close to shore and in 260 feet of water off Newport, some of which are sending data in near real-time.

In addition, a new underwater unmanned vehicle equipped with sensors to measure temperature, salinity, chlorophyll, and dissolved oxygen is routinely sampling across central Oregon waters.

During normal years, cold water rich in nutrients but low in oxygen upwells from the deep ocean off Oregon, mixes with oxygen-rich water near the surface, causes some phytoplankton growth, and provides the basis for a thriving fishery and healthy marine food chain. During dead zone periods, some of the normal processes -- including wind and current conditions -- can change. This allows huge masses of plant growth to die, decay, and in the process consume even more of the available oxygen near the sea floor, causing hypoxic conditions for marine life.

The first event in 2002 caused a massive die-off of fish and invertebrate marine species on the central Oregon coast. Less severe and somewhat different events occurred in 2003, 2004, and 2005.

The 2006 "dead zone" has a wider north-south extent. Some crabbers in the central Washington coast reported all dead crabs in pots at depths of about 45 to 90 feet, north of the Moclips River. Large numbers of dead Dungeness crab have been reported on the beach as far north as Kalaloch. Numerous species of bottom fish have been found dead on the beach south of the Quinault River in Washington.

In Oregon, the most vulnerable area in recent years has been the central third of the coast between about Newport and Florence, where conditions seem to be conducive to the development of low-oxygen waters. It's not always easy to measure the biological impact of the dead zones, because many dead animals may be washed out to the deep sea. But researchers say that this year's event may ultimately be as severe as the first one in 2002, although it reflects slightly different wind and ocean current conditions.

Researchers say that it's difficult to tell what long-term ecological impacts these dead zone events may have on marine ecosystems.

"Many marine species live in fairly specialized ecological niches and any time you change the fundamental physics, chemistry and nature of the system, it's a serious concern," Barth said.

Jane Lubchenco, the Valley Professor of Marine Biology at OSU and principle investigator for PISCO, also said that the biological monitoring of species health and impacts in the nearshore Pacific Ocean is "grossly inadequate," making it difficult to evaluate the long-term impacts of low-oxygen and other events.

Study Suggests Pharmaceuticals May Not Pose Major Risk To Aquatic Environment
A Canadian study of high-use drugs released from eight municipal wastewater treatment plants suggests that invertebrates, bacteria, and plants in the aquatic environment are unlikely to be affected.

In Canada, approximately 24,000 products -- including human pharmaceutical and biological drugs, veterinary drugs, and disinfectants -- are registered on Health Canada's Drug Product Database. None of these pharmaceuticals is absorbed entirely by the body; they often leave through urine and fecal matter. Domestic waste streams carry the excreted drugs to municipal wastewater treatment plants, private septic systems, or receiving waters without treatment.

Though sewage treatment plants can remove or degrade some of the drug compounds, many drugs and by-products are not removed effectively. Hence the major source of pharmaceuticals in the aquatic environment is from sewage treatment plants.
Across Atlantic Canada, the study's researchers found 10 acidic and two neutral pharmaceuticals in the effluents of eight sewage treatment plants. In the large bodies of receiving water, drugs generally were not detected at significant concentrations. However, in the small receiving streams, drug residues continued downstream for 17 kilometers. Based on the results of laboratory toxicity tests, the researchers concluded that the concentrations measured were not causing harm.

The study is published in the latest issue of Environmental Toxicology and Chemistry (Vol. 25(8): 2163-2176).

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U.S., Israel Collaborative Effort Targets Most Promising Areas For Water Treatment Using Nanotechnologies
Water researchers from leading institutions in Israel and the United States announced on July 10 they have targeted four "cutting-edge" projects for collaborative research between the two countries.

Their selection is one outcome of a bi-national workshop held in Washington, D.C., in mid-March, organized by the U.S. and Israeli national nanotechnology initiatives, and the Center of Advanced Materials for Purification of Water with Systems (WaterCAMPWS) at the University of Illinois.

Professor Rafi Semiat, director of the Grand Water Research Institute at the Technion Israel Institute of Technology and a workshop organizer, said that while the group will promote all 12 nanotech-based projects that were outlined at the workshop, special focus is being given to four projects that can provide extraordinary benefits for water purification, and that have the potential to be applied commercially within the next five years.

"Both countries see the target projects not only as very exciting, potential breakthroughs, but also as applied research that can get funded and get commercialized quickly," Semiat said.

The target projects focus on distinct nanotechnology-based solutions that were outlined at the bi-national workshop: membranes and membrane processes, biofouling and disinfection, contaminants removal, and environmental monitoring and sensors.

The four targeted projects are:

-- Development of new, porous polymer-based, ultra-filtration membranes with special coatings that exhibit higher flux and higher resistance to contamination, as well as robust molecular sieving abilities. The project will create and test self-assembling membranes with very stable transport channels that reduce biofouling and may also be capable of self-cleaning.

-- Development of coatings with antimicrobial capabilities that can minimize biological attachment and biofilm formation that can be applied to current generation membranes that are used for drinking water, wastewater, and desalination.

-- Study of mixed metal-oxide, nanostructured materials for the destruction of biological toxins in surface water and groundwater, using photocatalysis and oxidation. The project will provide data for optimizing the use of these materials in various environments.

-- Development of whole-cell microbial biosensors to detect minute metabolite excretions from newly forming biofilms. The project will examine the mechanisms of biological attachment to surfaces, identify its biochemical signals, and develop nanoscale sensors that can be applied to membrane surfaces, enabling optimized maintenance for water purification membranes and significant extension of membrane lifetimes.

Rich Sustich, industrial and governmental development manager for the WaterCAMPWS and a workshop organizer, said that there is special excitement over the proposed biosensor project, which may result in new tools and methods for water systems operation and reduction of long-term maintenance costs.

"Today's water infrastructure is run on a one-size-fits-all concept," Sustich noted. "Systems are assembled from standard components, and maintenance relies more on manufacturer's recommendations than on a direct understanding of what's really happening during treatment. This works, but it's very wasteful."

Adding biosensing devices throughout the water treatment system will provide direct awareness and interaction with the system in real time. The proposed biosensors can eventually lead beyond passive sensing to the development of "smart" membranes that react biologically to changes in the system's environment, and perhaps even prevent biofilm and toxics formation without the need for manual intervention, according to researchers.

Workshop participants agreed that such biosensing mechanisms could be applied within 5 to 10 years, given the needed development resources.

Workshop sponsors are seeking approximately $600,000 to support the costs of binational collaboration on all 12 projects, with funding to be matched equally between Israeli and U.S. sources. Additional workshops are also planned.

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Researchers: Gypsum Helps Curb Phosphorus Runoff
Gypsum showed the most promise in an Agricultural Research Service (ARS) study examining the ability of soil additives to curb runoff of phosphorus from farm fields into the nation's waters, ARS officials announced on June 20.

In research led by agronomist David Brauer of the ARS Dale Bumpers Small Farms Research Center in Booneville, Ark., the soft, widely distributed mineral was the only one of three soil amendments tested that reduced soluble soil phosphorus in a field containing more than 10 times the amount normally found in soils.

The study was done by Brauer, animal scientist Glen Aiken of the ARS Forage-Animal Production Research Unit in Lexington, Ky., soil scientist Daniel Pote of the Booneville center, and colleagues. The researchers examined how well gypsum, alum, and ground-up wastepaper kept phosphorus from leaching from farmland. Testing was done near Kurten, Texas, on land that has received manure applications from dairy and egg-laying operations for more than 40 years.

Excessive use of manures and other fertilizers can significantly increase phosphorus amounts in the soil. A valuable crop nutrient, phosphorus can run off and damage waterways by promoting accelerated growth of algae and plants in streams and lakes. This can deplete oxygen levels in water bodies and adversely impact living aquatic resources.

The researchers amended the soil annually for three years. They found that applying 5,000 pounds of gypsum per acre was most effective in reducing soil-test values for phosphorus. According to Brauer, reductions in dissolved reactive phosphorus seemed to be dependent on continual applications of gypsum.

Commonly found in sedimentary environments, gypsum is also a byproduct of coal-burning operations.

Brauer explained that gypsum curtails the amount of phosphorus lost by promoting the binding together of soil particles, thus reducing phosphorus carried along with sediment. He added that applying wastepaper product containing aluminum, the active ingredient in alum, can effectively curb phosphorus, but the large amounts necessary can be impractical.

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Catalytic Process Breaks Down Hormones In Wastewater
Scientists from Carnegie Mellon University and the U.S. Department of Agriculture (USDA) announced on June 26 they have found that a rapid, environmentally friendly catalytic process involving Fe-TAML® activators and hydrogen peroxide breaks down two types of estrogenic compounds. These natural and synthetic estrogenic compounds can mimic or block the activities of hormones in wildlife and humans, which may disrupt the normal functions of the endocrine system and impair development. They could also contaminate drinking water.

The results were presented by Nancy Shappell, a research physiologist with USDA's Agricultural Research Service (ARS), on June 29, at the tenth annual Green Chemistry and Engineering Conference in Washington, D.C. Shappell presented her paper, "Degradation of Estradiol and Ethinylestradiol With an Fe-TAML® Oxidant Activator and Hydrogen Peroxide," during the Frontiers in Green Chemistry and Green Engineering section of the conference. Estradiol is a natural form of the female hormone estrogen, and ethinylestradiol is a synthetic version used in contraceptives.

Fe-TAML (tetra-amido macrocyclic ligand) activators, which are synthetic catalysts made with elements found in nature, originated at Carnegie Mellon's Institute for Green Oxidation Chemistry under the leadership of Terry Collins, the Thomas Lord Professor of Chemistry in the Mellon College of Science.

"Environmental studies on various wildlife species have shown evidence that endocrine disruptors interfere with reproductive, immune, and neurological capabilities, and cause developmental abnormalities," Collins said. "We need to quickly develop a suite of standardized assays that test for estrogen-like activity of introduced chemicals and their byproducts so that anyone developing a new chemical technology can assess whether or not their technology is associated with endocrine disruption."

Waste from animal-rearing facilities across the United States constitutes a major concentrated source of estrogens. Millions of pigs housed in these facilities produce tons of waste products laden with estrogens that can enter the water. In addition, synthetic versions of estrogen found in birth control pills can enter surface water as a result of incomplete wastewater treatment, according to Shappell. Some scientists have suggested that these environmental estrogens could interfere with estrogen-controlled systems in wildlife and humans, disrupting innate regulatory mechanisms and leading to developmental disorders, infertility, and other reproductive complications.

"Our results show that Fe-TAML activators are capable of breaking down two types of estrogenic compounds found as contaminants in surface water," Shappell said. "These promising results also indicate the potential use of Fe-TAML activators to destroy estrogenic compounds in municipal and agricultural wastewaters."

Shappell and colleagues found that the Fe-TAML activator, used with hydrogen peroxide, almost completely degraded estradiol and ethinylestradiol in the laboratory. According to the researchers, ethinylestradiol is resistant to most biological degradation processes, but Fe-TAML activators break down more than 95 percent of this chemical within five minutes.

"Our next step would be to advance testing to the field. Fe-TAML activators have been field-tested in the pulp and paper industry and textile industry with promising results," said Colin Horwitz, research professor at Carnegie Mellon. ARS scientists Pat Hunt and Kyoung Ro from the Florence, S.C., Coastal Plains Plant, Soil and Water Research Center were instrumental in making the connection between Shappell and the Institute for Green Oxidation Chemistry, and will be involved in field-testing swine wastewater.

Past studies with Fe-TAML activators have shown their enormous potential to provide clean, safe alternatives to existing industrial practices and provide ways to remediate other pressing environmental problems that currently lack solutions. Specific applications of Fe-TAML activators have included cleaning wastewater from textile manufacturing, reducing fuel pollutants, treating pulp and paper processing byproducts, and decontaminating a benign simulant of anthrax.

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Soybean Scraps Used To Develop Filtering Agent For Contaminated Water
Scientists have discovered that soybean hulls -- as well as leftover stalks and stems from already-plucked corn and sugarcane plants -- could be used to develop a filtering agent that can adsorb harmful levels of lead, chromium, copper, and cadmium from contaminated water, Agricultural Research Service (ARS) officials stated on June 21.

ARS chemists Wayne Marshall and Lynda Wartelle -- who work at the ARS Southern Regional Research Center (SRRC) in New Orleans, La. -- have found that it takes just two steps to convert these abundant crop residues into a powerful magnet capable of snagging both positively and negatively charged particles of heavy metals in water.

The material that they've succeeded in creating is known as a dual-functioning ion-exchange resin. These resins -- which are commonly used for treating industrial and municipal wastewaters and for recycling heavy metals from solutions -- are typically effective in capturing only one kind of particle with either a positive or negative charge.
But the SRRC researchers' resins can grab both. Additionally, Marshall has found that they're more cost-effective than two synthetically made resins currently in use.

Ion exchange resins work by swapping, or exchanging, the undesirable ions in a water supply with benign ones. In a classic example of this interplay, water softeners work by drawing out and replacing unwanted "hard water" particles, like calcium and magnesium, with ions from sodium.

Marshall and Wartelle give their plant residues a negative charge by adding citric acid, a common food industry additive. The positive charge comes from choline chloride, which the researchers bind to plant fibers by adding DMDHEU (or dimethyloldihydroxyethylene urea) -- a chemical that's already known for making molecules stick. In the textile industry, it's the compound that helps dye cling to cotton and wool fibers.

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This article originally appeared in the 11/01/2006 issue of Environmental Protection.

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