DURHAM, NC — Engineers at Duke University have found that spherical carbon molecules known as “buckyballs” hinder the ability of bacteria and other microorganisms to accumulate on membranes used to filter water in treatment plants, according to a March 5 Duke University news release.
According to the engineers, coating pipes and membranes with these nanoparticles may prove to be an effective strategy for addressing biofouling.
So-Ryong Chae, post-doctoral fellow in Duke’s environmental and civil engineering department, explains in the release: “Just as plaque can build up inside arteries and reduce the flow of blood, bacteria and other microorganisms can over time attach and accumulate on water treatment membranes and along water pipes. As the bacteria build up on these surfaces, they attract other organic matter, creating a biofilm that slowly builds up over time.
“The results of our experiments in the laboratory indicate that buckyballs may be able to prevent this clogging, known as biofouling. The only other options to address biofouling are digging up the pipes and replacing the membranes, which can be expensive and inconvenient.”
Results of Chae’s experiments were published March 5 in the Journal of Membrane Sciences.
The researchers concluded that because buckyballs are one of the most widely used nanoparticles, additional research is needed to determine if they have any detrimental effects on humans or the environment. Buckyballs are named after the spherical geodesic domes designed by architect R. Buckminster Fuller.
To read the full article, click here.
Thursday, March 5, 2009
Shrimp protein removes heavy metals in water
LONG BEACH, CA — A Cal State Long Beach biochemistry and chemistry professor has turned his attention toward brine shrimp, also known as sea monkeys, in an effort to develop a more efficient, more economical water treatment technology for removing heavy metals, according to a March 2 daily49er.com article.
Roger Acey said a protein found in brine shrimp (Artemia salina), when placed on a membrane, instantaneously binds to heavy metals such as lead, arsenic and mercury as a solution containing the toxic metals is passed through the membrane.
Acey said one advantage of the process is that biologically essential metals pass through the membrane.
The gene for the protein, a metallothinein-like protein (MT), was cloned from brine shrimp, and then placed into bacteria to produce the protein, the article said.
Acey said he hopes to adapt the technology into a point-of-use water filter.
Roger Acey said a protein found in brine shrimp (Artemia salina), when placed on a membrane, instantaneously binds to heavy metals such as lead, arsenic and mercury as a solution containing the toxic metals is passed through the membrane.
Acey said one advantage of the process is that biologically essential metals pass through the membrane.
The gene for the protein, a metallothinein-like protein (MT), was cloned from brine shrimp, and then placed into bacteria to produce the protein, the article said.
Acey said he hopes to adapt the technology into a point-of-use water filter.
Algae by-products to blame for bad-taste water
ALLIANCE, OH — An off-taste and off-odor to this city’s municipal water has continued to linger since an algae outbreak late last year, but now officials from the Alliance Water Department are moving toward a solution, saying the situation is improving, according to a March 2 CantonRep.com article.
CantonRep.com reported that while city administration officials declined an interview offer on February 27, they supplied details from a recent community forum on the issue. A PowerPoint presentation by Water Treatment Superintendent Dean Reynolds pinpoints the culprits as algae byproducts or metabolites called methylisoborneol (MIB) and geosmin.
The city has addressed the increased algae growth with additional powdered activated carbon. The system serves 10,000 people.
Ohio regulatory officials said the water is safe to drink.
To read the full article, click here.
CantonRep.com reported that while city administration officials declined an interview offer on February 27, they supplied details from a recent community forum on the issue. A PowerPoint presentation by Water Treatment Superintendent Dean Reynolds pinpoints the culprits as algae byproducts or metabolites called methylisoborneol (MIB) and geosmin.
The city has addressed the increased algae growth with additional powdered activated carbon. The system serves 10,000 people.
Ohio regulatory officials said the water is safe to drink.
To read the full article, click here.
Chromium hexavalent is carcinogenic in water
Charlottesville, VA — National Toxicology Program scientists have concluded at the end of a two-year animal study that the compound hexavalent chromium is carcinogenic in drinking water, Environmental Health News reported on February 20.
Hexavalent chromium, also known as chromium 6 or chromium VI, was brought to the general public’s attention by the movie “Erin Brockovich,” which chronicles a lawyer’s crusade on behalf of citizens of a small California town battling a cover-up involving chromium 6-contaminated water. It has been known for about 20 years that hexavalent chromium is carcinogenic when inhaled.
In the National Toxicology Program study, scientists found that mice and rats contracted malignant tumors in their small intestines and mouths when they drank water containing several different doses of hexavalent chromium, Environmental Health News reported.
California and US Environmental Protection Agency officials now are reevaluating what concentration is safe in water supplies, the article said. California is expected to announce within a few weeks a proposal to set a new health guideline for hexavalent chromium in drinking water.
Roberto Gwiazda, an assistant researcher at University of California at Santa Cruz’s Department of Environmental Toxicology, called the new study a “milestone,” saying it “settles the issue.” However, Gwiazda said in the article that using the new research “to support a drinking water standard is a different matter” because extrapolating it to humans remains controversial.
To read the full report, click here.
Hexavalent chromium, also known as chromium 6 or chromium VI, was brought to the general public’s attention by the movie “Erin Brockovich,” which chronicles a lawyer’s crusade on behalf of citizens of a small California town battling a cover-up involving chromium 6-contaminated water. It has been known for about 20 years that hexavalent chromium is carcinogenic when inhaled.
In the National Toxicology Program study, scientists found that mice and rats contracted malignant tumors in their small intestines and mouths when they drank water containing several different doses of hexavalent chromium, Environmental Health News reported.
California and US Environmental Protection Agency officials now are reevaluating what concentration is safe in water supplies, the article said. California is expected to announce within a few weeks a proposal to set a new health guideline for hexavalent chromium in drinking water.
Roberto Gwiazda, an assistant researcher at University of California at Santa Cruz’s Department of Environmental Toxicology, called the new study a “milestone,” saying it “settles the issue.” However, Gwiazda said in the article that using the new research “to support a drinking water standard is a different matter” because extrapolating it to humans remains controversial.
To read the full report, click here.
Saturday, January 10, 2009
Legionella Bacteria Found At Maryland General Hospital
Bacteria Found In Water System; No Patients Affected
BALTIMORE — Routine testing has revealed low levels of Legionella bacteria in the water system of Maryland General Hospital, located here, according to a January 7 WBAL TV 11 News report on msnbc.com.
The bacteria were found in a shower area during a routine test. No cases of infection have been reported.
Maryland General Hospital has begun disinfecting its water system, according to hospital officials. Bottled water has been made available to patients and access to showers has been reduced.
11 News reported that this is at least the second time in the last 22 months that Legionella bacteria have been found at the hospital.
To read the full report, click here.
BALTIMORE — Routine testing has revealed low levels of Legionella bacteria in the water system of Maryland General Hospital, located here, according to a January 7 WBAL TV 11 News report on msnbc.com.
The bacteria were found in a shower area during a routine test. No cases of infection have been reported.
Maryland General Hospital has begun disinfecting its water system, according to hospital officials. Bottled water has been made available to patients and access to showers has been reduced.
11 News reported that this is at least the second time in the last 22 months that Legionella bacteria have been found at the hospital.
To read the full report, click here.
Saturday, December 27, 2008
Solving problem for very high iron content water
When experienced water treatment professional Mark St. Hilaire first received the lab results for a point–of–entry (POE) system at an indoor athletic facility in New Hampshire, he thought there was a mistake: The iron was at 270 parts per million (ppm).
“We said, ‘It can’t be,’” says St. Hilaire, director of the residential systems group for Waltham, MA–headquartered Atlas Watersystems, Inc. So he sent out another sample, and the results were pretty much the same. That lab report on the facility’s private well water revealed:
Iron at 209 ppm
pH of 5.5
Hardness of 354 ppm, about 21 grains per gallon (gpg)
Sediment — positive
Conductivity of 1,570 microsiemens.
In addition, the naturally occurring iron had caused the water to have “tremendous color” in an orangey tint, and an awful taste.
“It was exciting and frightening at the same time,” recounts St. Hilaire. “To take on the job was somewhat frightening in the beginning, looking at the initial test result. It became exciting when you realized that the chemistry that was coming back was going to support being able to fix it.”
A system ‘making mud’
Earlier this year, Atlas was called in to correct problems the facility was having with its existing POE system, which was about five to six years old. That system was designed to oxidize the water via chlorine injection, and then filter it.
That’s a common and often acceptable method for iron treatment: soluble ferrous iron (Fe+2) is oxidized into ferric iron (Fe+3), a particulate in suspension which can be removed with a filter.
However, according to St. Hilaire’s account, in this case there was simply too much iron in the athletic facility’s water: “It just couldn’t work with what it was trying to deal with. … Not gonna happen. They were just making mud.”
St. Hilaire says his first reaction upon seeing the results of the lab water analysis was to suggest the customer drill another well. The customer told him they had done that already, but the water in the new well was of about the same quality.
“Under normal circumstances, we would not attempt to treat this water,” St. Hilaire says. But he adds, “They were desperate.”
Iron like never before
The water was essentially unusable. St. Hilaire was faced with an athletic facility housing workout rooms, an indoor soccer field, showers, a concession stand and more, and the water was so bad, no one could shower there. The owner supplied bottled water for drinking.
What tipped Atlas off and made it decide to attempt to treat the water was that it had samples of the high–iron water sitting on desks for two or three weeks that weren’t oxidizing “the way normal samples oxidize when there is that much iron,” says St. Hilaire.
“Typically when you pull a sample that has iron in it, in a day or two the iron will start to convert all by itself and drop out. We had a bottle that was sitting in the refrigerator, and it just didn’t turn. Over the period of two weeks, it never turned,” according to St. Hilaire.
“This was the most iron anybody here had ever seen dissolved in water; you fully expect the sample to turn color in a matter of hours, but it didn’t,” he adds.
A unique solution for tough iron
After reviewing the samples of water in the refrigerator, the Atlas people decided they might have a chance of using ion exchange to remove the iron without oxidizing it.
The company began by getting to know its water user. Atlas installed a water meter to determine how much water the facility was using on a daily basis. That figure was compared with engineering specifications for water use.
With that data in hand, Atlas personnel installed a small POE pilot softening system to see what it would do. “It caught the iron down to about 0.6 [ppm],” St. Hilaire says.
The pilot system afforded enough information for St. Hilaire and his team to design a permanent solution. Working in a confined space that essentially is a boxed–in stairway, the company designed and installed a quad–flow system using AvantaPure countercurrent regenerating water softeners. The softeners rely on a standard cation exchange resin, St. Hilaire says.
Of the unique system design, St. Hilaire explains: “We put four AvantaPure systems in parallel, and essentially they clean each other out because you would not be able to backwash them with water that has 270 parts per million iron. … So every tank is pulling from the other when it is in its cleaning cycle, so they are always cleaning with clean water. We modified the valves to make that happen.”
The system, installed by six technicians, includes sediment filters before the water softeners. The softeners are followed by a chemical feed system injecting chlorine and soda ash into a large retention and settling tank. “We had to deal with the color, the pH still, a little bit of iron bacteria still,” St. Hilaire says.
The water then goes through a series of two multimedia filters. After all the equipment, a booster pump was installed to maintain pressure throughout the facility at an even 70 pounds per square inch (psi).
The result: “The water is clear at the tap. Iron is consistently below 0.3 [ppm], pH neutral. The state came in and did their compliance testing and was shocked,” St. Hilaire says.
A little POU for good measure
While the facility owners removed the bottled water, they wanted to provide the highest quality drinking water possible for their members. Not only is the water used for drinking, but it is used to make coffee, protein drinks and more. To address this, Atlas installed two point–of–use (POU) undersink reverse osmosis (RO) units with faucets.
After four months of service, the system was delivering water with an iron level of 0.2 ppm, hardness of 0–1 gpg, and a pH of 7.4.
St. Hilaire says the facility does the daily/weekly maintenance required for the salt, chlorine and soda ash. Once a month, Atlas technicians perform on–site system maintenance, which includes testing each piece individually to make sure it is doing what it is supposed to.“There has been not even a hiccup yet,” St. Hilaire says.
“We said, ‘It can’t be,’” says St. Hilaire, director of the residential systems group for Waltham, MA–headquartered Atlas Watersystems, Inc. So he sent out another sample, and the results were pretty much the same. That lab report on the facility’s private well water revealed:
Iron at 209 ppm
pH of 5.5
Hardness of 354 ppm, about 21 grains per gallon (gpg)
Sediment — positive
Conductivity of 1,570 microsiemens.
In addition, the naturally occurring iron had caused the water to have “tremendous color” in an orangey tint, and an awful taste.
“It was exciting and frightening at the same time,” recounts St. Hilaire. “To take on the job was somewhat frightening in the beginning, looking at the initial test result. It became exciting when you realized that the chemistry that was coming back was going to support being able to fix it.”
A system ‘making mud’
Earlier this year, Atlas was called in to correct problems the facility was having with its existing POE system, which was about five to six years old. That system was designed to oxidize the water via chlorine injection, and then filter it.
That’s a common and often acceptable method for iron treatment: soluble ferrous iron (Fe+2) is oxidized into ferric iron (Fe+3), a particulate in suspension which can be removed with a filter.
However, according to St. Hilaire’s account, in this case there was simply too much iron in the athletic facility’s water: “It just couldn’t work with what it was trying to deal with. … Not gonna happen. They were just making mud.”
St. Hilaire says his first reaction upon seeing the results of the lab water analysis was to suggest the customer drill another well. The customer told him they had done that already, but the water in the new well was of about the same quality.
“Under normal circumstances, we would not attempt to treat this water,” St. Hilaire says. But he adds, “They were desperate.”
Iron like never before
The water was essentially unusable. St. Hilaire was faced with an athletic facility housing workout rooms, an indoor soccer field, showers, a concession stand and more, and the water was so bad, no one could shower there. The owner supplied bottled water for drinking.
What tipped Atlas off and made it decide to attempt to treat the water was that it had samples of the high–iron water sitting on desks for two or three weeks that weren’t oxidizing “the way normal samples oxidize when there is that much iron,” says St. Hilaire.
“Typically when you pull a sample that has iron in it, in a day or two the iron will start to convert all by itself and drop out. We had a bottle that was sitting in the refrigerator, and it just didn’t turn. Over the period of two weeks, it never turned,” according to St. Hilaire.
“This was the most iron anybody here had ever seen dissolved in water; you fully expect the sample to turn color in a matter of hours, but it didn’t,” he adds.
A unique solution for tough iron
After reviewing the samples of water in the refrigerator, the Atlas people decided they might have a chance of using ion exchange to remove the iron without oxidizing it.
The company began by getting to know its water user. Atlas installed a water meter to determine how much water the facility was using on a daily basis. That figure was compared with engineering specifications for water use.
With that data in hand, Atlas personnel installed a small POE pilot softening system to see what it would do. “It caught the iron down to about 0.6 [ppm],” St. Hilaire says.
The pilot system afforded enough information for St. Hilaire and his team to design a permanent solution. Working in a confined space that essentially is a boxed–in stairway, the company designed and installed a quad–flow system using AvantaPure countercurrent regenerating water softeners. The softeners rely on a standard cation exchange resin, St. Hilaire says.
Of the unique system design, St. Hilaire explains: “We put four AvantaPure systems in parallel, and essentially they clean each other out because you would not be able to backwash them with water that has 270 parts per million iron. … So every tank is pulling from the other when it is in its cleaning cycle, so they are always cleaning with clean water. We modified the valves to make that happen.”
The system, installed by six technicians, includes sediment filters before the water softeners. The softeners are followed by a chemical feed system injecting chlorine and soda ash into a large retention and settling tank. “We had to deal with the color, the pH still, a little bit of iron bacteria still,” St. Hilaire says.
The water then goes through a series of two multimedia filters. After all the equipment, a booster pump was installed to maintain pressure throughout the facility at an even 70 pounds per square inch (psi).
The result: “The water is clear at the tap. Iron is consistently below 0.3 [ppm], pH neutral. The state came in and did their compliance testing and was shocked,” St. Hilaire says.
A little POU for good measure
While the facility owners removed the bottled water, they wanted to provide the highest quality drinking water possible for their members. Not only is the water used for drinking, but it is used to make coffee, protein drinks and more. To address this, Atlas installed two point–of–use (POU) undersink reverse osmosis (RO) units with faucets.
After four months of service, the system was delivering water with an iron level of 0.2 ppm, hardness of 0–1 gpg, and a pH of 7.4.
St. Hilaire says the facility does the daily/weekly maintenance required for the salt, chlorine and soda ash. Once a month, Atlas technicians perform on–site system maintenance, which includes testing each piece individually to make sure it is doing what it is supposed to.“There has been not even a hiccup yet,” St. Hilaire says.
Monday, November 24, 2008
EPA seeking comments on proposed guidelines to control construction site pollution
WASHINGTON, DC, Nov. 19, 2008 -- EPA is seeking comments on its proposed guidelines to control the discharge of pollutants from construction sites. The proposal would require all construction sites to implement erosion and sediment control best management practices to reduce pollutants in stormwater discharges.
"This proposal builds a foundation for cleaner streams and greener neighborhoods through improved treatment technologies and prevention practices," said Benjamin H. Grumbles, EPA's assistant administrator for water.
Click here for more information about the proposal.
"This proposal builds a foundation for cleaner streams and greener neighborhoods through improved treatment technologies and prevention practices," said Benjamin H. Grumbles, EPA's assistant administrator for water.
Click here for more information about the proposal.
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