Thursday, March 5, 2009

Nanoparticle carbon molecules prevent bio-fouling

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.

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.

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.

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.

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.