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New
Approach To Purifying Drinking Water
 DURHAM,
NC -- A genetic tool used by medical researchers may also be
used in a novel approach to remove harmful microbes and
viruses from drinking water.
In a series of proof-of-concept
experiments, Duke University engineers demonstrated that
short strands of genetic material could successfully target
a matching portion of a gene in a common fungus found in
water and make it stop working. If this new approach can be
perfected, the researchers believe that it could serve as
the basis for a device to help solve the problem of safe
drinking water in Third World countries that lack water
treatment facilities.
The relatively new technology,
known as RNA interference (RNAi), makes use of short
snippets of genetic material that match -- like a lock and
key -- a corresponding segment of a gene in the target. When
these snippets enter a cell and attach to the corresponding
segment, they can inhibit or block the action of the target
gene. This approach is increasingly being used as a tool in
biomedical research, but has not previously been applied to
environmental issues.
“Pathogens, whether bacterial or
viral, represent one of the major threats to drinking water
in developed and undeveloped countries,” said Sara Morey, a
Ph.D. candidate in the lab of Claudia Gunsch, assistant
professor of civil engineering at Duke’s Pratt School of
Engineering. “Our data showed that we could silence the
action of a specific gene in a fungus in water, leading us
to believe that RNAi shows promise as a gene-silencing tool
for controlling the proliferation of waterborne bacteria and
viruses.”
Morey presented the results of
her experiments on June 3, 2008, during the annual meeting
of the American Society of Microbiology in Boston.
In addition to helping solve
drinking water issues in underdeveloped countries, this new
approach could address some of the drawbacks associated with
treated drinking water in more developed nations, Morey
said. Methods currently used to treat water -- chlorine and
ultraviolet (UV) light -- can be expensive to operate and
the results of the treatment itself can affect the taste and
smell of the water.
Although these methods have been
employed for years, problems can emerge once the treated
water enters the distribution system, where pathogens are
also present. For this reason, water is often
over-chlorinated at the plant so that it remains in high
enough concentrations in the pipes to neutralize pathogens.
This explains why people living closer to a treatment plant
will be more likely to taste or smell the chemical than
those farthest away from the plant, the researchers said.
Additionally, chlorine can react with other organic matter
in the system, leading to potentially harmful by-products.
UV light, while also effective in
neutralizing pathogens at the plant, has no effect once the
water is pumped out of the plant. Gunsch said that many
pathogens are developing a resistance to the effects of
chlorine and UV light, so newer options are needed.
“We envision creating a system
based on RNAi technology that would look from the outside
just like the water filters commonly used now,” Gunsch said.
“This approach would be especially attractive in less
industrialized countries without water treatment systems.
This ‘point-of-use’ strategy would allow these countries to
make safe water without the expense of water purification
infrastructure.”
The first prototypes would likely
involve a filter “seeded” with RNAi that would eliminate
pathogens as the water passed through it. These filters
would likely need to be replaced regularly, Gunsch said,
adding that she believes it would theoretically be possible
to create a living, or self-replicating system, which would
not require replacement.
The researchers are currently
conducting additional experiments targeting other regions of
the fungus’ genome. For their proof-of-concept experiments,
they tested RNAi on a non-essential, yet easy to monitor,
gene. They are now testing this approach to silence or block
genes essential to the viability of the pathogen.
They are also planning to test
this strategy in water that contains a number of different
pathogens at the same time, as well as trying to determine
the optimal concentration needed in the water to be
effective. The experiments were funded by Duke's
Pratt School of Engineering.
Source:
http://www.duke.edu/
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Orange County Wins Stockholm
Award
 Stockholm,
Sweden -- Pioneering work to develop the world's largest
water purification plant for groundwater recharge has earned
the Orange County Water District and the Orange County
Sanitation District, California, the 2008 Stockholm Industry
Water Award. The prestigious distinction will be presented
on August 21 during the 2008 World Water Week in Stockholm.
People expect water to be there
when they turn on the faucet. But in growing arid regions
like Orange County in Southern California, sufficient water
is not naturally guaranteed. Fortunately for the 2.3 million
residents living there, the Orange County Water District and
the Orange County Sanitation District jointly developed the
Groundwater Replenishment (GWR) system, a water purification
system which will provide enough water to meet the needs of
an additional 500 000 people without diminishing groundwater
resources for current or future generations.
The GWR System diverts highly
treated sewer water that is currently discharged into the
ocean and purifies it through a series of advanced
techniques: microfiltration, reverse osmosis, ultraviolet
disinfection and hydrogen peroxide. The cleaned water is
returned to the groundwater basin to increase both water
supply and quality. The GWR system has established a
blueprint for large-scale wastewater purification that is
already being emulated in dry regions and nations, such as
Singapore.
"Both agencies have demonstrated
how communities can develop, implement and achieve
sustainable water reuse," says Mr. Lars Gunnarsson, chairman
of the Award Committee. "Their extensive involvement of
private sector companies such as CDM and Trojan and Siemens,
long-term commitment to research and development, and
utilization of cutting-edge technologies has established a
model for water-stressed regions to replenish groundwater
resources and improve water security."
About the Stockholm Industry
Water Award
The Stockholm Industry Water
Award honors and encourages business sector contributions to
sustainable development in the water sector and is presented
each August at the World Water Week in Stockholm. It was
established in 2000 by the Stockholm Water Foundation in
collaboration with the Royal Swedish Academy of Engineering
Sciences and the World Business Council for Sustainable
Development.
Previous recipients include PUB
Singapore; the Sydney Water Corporation, Australia; Procter
& Gamble; the Staple Fibre Division of Grasim Industries
Ltd, India; ZENON Environmental Inc, Canada; Kaldnes
Miljöteknologi AS, Norway; The General Motors de Mexico
Ramos Arizpe Complex, Mexico; and Northumbrian Water
Limited, United Kingdom.
Source:
http://www.siwi.org/
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Wastewater Sludge : A New
Alternative Energy
 Alexandria,
VA -- Wastewater treatment plants are net users of energy.
In the U.S. they consume an estimated 21 billion kilowatt
hours per year. There are important reasons for this energy
use, as society demands increasingly intensive treatment to
remove nutrients and chemicals from wastewater before it is
discharged back into water bodies or is reused. But energy
use is coming under increasing scrutiny, with the financial
cost of energy and the environment cost of energy generation
driving new interest in the conversion of sewage sludge to
energy.
Researchers are exploring sustainable wastewater treatment
with a reduced carbon footprint. The view of municipal
sewage has shifted, from a waste to be treated and disposed
of, to a resource that can be processed for recovery of
energy, nutrients, and other constituents.
Research has demonstrated that sewage actually contains 10
times the energy needed to treat it, and it is technically
feasible to recover energy from sludge. As renewable energy,
it can be directly used for wastewater treatment, reducing
the facility’s dependency on conventional electricity. The
greater the quantity of energy produced by the industry, the
more the industry can help reduce emissions of greenhouse
gases.
Using
solids as a resource rather than a waste may help stressed
public budgets as well. Wastewater solids must be processed
prior to disposal, and solids handling accounts for as much
as 30 percent of a wastewater treatment facility’s costs.
According to “State of the Science Report: Energy and
Resource Recovery from Sludge,” published by the Global
Water Research Coalition,” converting solids to energy is
feasible and desirable, from a treatment perspective. The
challenge is finding a process that meets social, economic
and environmental objectives, as well as being affordable
and cost effective. For instance, chemical use may be
required in certain processes, but it may not always be the
best option in terms of health protection and life cycle
impacts (energy use and emissions during production and
transportation).
There
are about 2,000 central sludge processing facilities in the
U.S. As of 2004, 650 of those facilities used anaerobic
digesters to process its sludge. When sludge is digested, it
produces methane gas. The Water Environment Research
Foundation developed the Life Cycle Assessment Manager for
Energy Recovery (LCAMER) model to helps wastewater agencies
determine the feasibility of recovering energy from
anaerobic digestion of wastewater solids.
Other
examples of energy conversion:
- The city of Watsonville, California uses restaurant grease
to increase sewage sludge digester gas production by over 50
percent.
- The use of methane as a source of hydrogen has been
demonstrated at King County (WA) South Treatment Plant.
-In 2005 in the U.K., waste (including sewer sludge)
combustion and biogas production accounted for 10.8 percent
and 4.2 percent respectively of all UK renewable energy.
- A German plant produces excess energy. In 2005, an average
of 113 percent of the electricity consumed in the operation
of the plant was generated onsite by gas engines.
- A Swedish treatment plant produces and sells biogas to
Stockholm’s bus company, which uses it to run at least 30
buses.
- Stockholm’s energy company uses heat recovery pumps to
extract heat from treated sewage to provide hot water and
heating to 80,000 apartments.
- The Sewerage Bureau of Tokyo Metropolitan Government turns
dewatered sewage sludge into fuel charcoal for thermal power
generation.
While
the current technology is promising, none of the processes
can fully extract all the energy available in wastewater.
The exploration of new technological developments, or
improvements of current
Source: Water Environment Research Foundation
Web site:
http://www.werf.org/
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Strategic Marketing : Targeted to Your Audience
 How
can you reach the world's water and wastewater top
executives, engineers, managers and service personnel?
By purchasing a banner advertising package on our
industry's most popular web site.
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your videos with everyone - promote your plant, your
product and your company, free. Industry-related
videos have been watched
over 250,000+ times in our Video Center.
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| Help Forum :
Hot Messages from the Help Forum
People post their requests
for help and offer their suggestions to others in our open
forum.
Mr. Deshpande has a problem
with sludge washout:
Sludge wash out is a commonly
faced problems in Sugar Wastewater Plant. The most obvious
reason is higher COD load causing increase in gas production
rate.
In order to trap the gas can
we increase the distance between first and second stage of
GLSS (Gas Liquid Solid Separator) which a 3 tier
arrangement. The first or the lowermost dome can be
placed just over granulated suspended sludge bed?
Mostly we take liquid rise
velocity of 0.6 to 0.7 m/hr with gas combined velocity may
go up to 1.0 m/hr. Or is there any other way to hinder
the gas from causing turbulence.
(Click
here to post a reply)
Thanks and regards,
Ashish Deshpande
ashish.deshpande@hotmail.com
Otava needs help with biogas
creation:
I have a question about
biogas production from granular. These granular were
collected for more than 3 month ago, after collected, have
been kept on service water (used in laboratory) in a bottle.
This morning, after I shook
the bottle, biogas was released. Why the granular can
produce biogas?
(Click
here to post a reply)
Thanks,
Otava
Thai Beverage Plc.
eakpong.t@thaibev.com
Help Forum:
Share your
expertise with others in our
Help
Forum. |
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| From the Job
Fair: Industrial
Water/Wastewater Engineers - St. Louis
Jacobs is integral in
creating the world of tomorrow as one of the largest and
most diverse providers of architecture, engineering,
construction, and other professional technical services. We
have immediate opportunities for experienced Industrial
Water/Wastewater Engineers in our St. Louis office.
Selected professionals will
perform project planning, detailed design, project
specification, construction drawing development, project
review, equipment sizing and specification, coordinating
with multiple engineering disciplines and specialty
sub-consultants, as well as hydraulic analysis, cost
estimating, field studies and site investigations in support
of industrial water and wastewater treatment and conveyance
projects.
Specific projects include:
sewer, water pipelines, pump stations, water and wastewater
treatment plants, sewer rehabilitation, inflow/infiltration
reduction, combined sewer overflow control, flow monitoring,
water and wastewater system modeling and master planning.
BS (MS preferred) in
Environmental or Civil Engineering, EIT required and PE
preferred. Minimum 4 years related design experience in
industrial wastewater treatment facilities.
Please visit us at:
www.jacobs.com
If interested please forward
resume to:
theresa.czolgosz@jacobs.com
for immediate consideration.
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their staff.
Do you have a position
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Fair. |
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| About Us :
Water and Wastewater Newsletter
© 1999-2008 Water and Wastewater.com
Home page: http://www.waterandwastewater.com
Joseph Taylor, Editor
Water and Wastewater Newsletter
3948 South Third Street, No. 121
Jacksonville Beach, FL 32250
Phone: 904-280-4656
Fax: 904-273-1399
Email: jtaylor@waterandwastewater.com
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Newsletter is a 100% opt-in e-mail list of information for
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you have company news, a new product, new service or other
information you would like to share with our subscribers?
Please submit articles via e-mail, only to: news@waterandwastewater.com |
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::
New Approach To Purifying
Drinking Water
::
Orange County Wins Stockholm
Award
::
Wastewater Sludge : A New
Alternative Energy
::
Strategic Marketing : Targeted to
Your Audience
:: The News Center : More headlines
:: The Water and Wastewater Blog
:: Video Center
:: Help Forum
::
Water and Wastewater Plant
Directory : Featured Plant
:: The Job Fair
:: Top Picks at Amazon.com
:: Ask Tom! Column!
:: 262,000+ visitors in May !
:: Call For Photographs!
:: Subscribe, Unsubscribe
:: Archive Information
:: About Us
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| Hi Everyone,
Hope you are surviving the gas
crisis and having a great Summer. Interesting news for
water and wastewater treatment this month, read on!
With over 10,000+ subscribers,
our goal is to provide information
to improve your business by using the resources available on the
Internet.
Thanks,
Joe Taylor, Editor
jtaylor@waterandwastewater.com
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| This
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Featured
Case History |
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Case Study : City of
Sanford, Florida
In order to meet the demand of growth within the
city and to achieve stringent effluent limits, the
City of Sanford worked with CPH Engineers to design
the Sanford South Water Resource Center (WRC),
located in the heart of Central Florida. The
facility produces a high quality effluent, as well
as reclaimed water, which is distributed throughout
the region. The plant is a 2.0 MGD “Advanced
Secondary plus Filtration Facility.” The plant is
easily expandable to 6.0 MGD plus tertiary treatment...(more) |
More case histories...
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placing a banner ad on the industry's most popular web
site.
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| Call For
Photographs
This weeks photo
is of ozone generators installed at the Wiggins Water Works
in Durban, South Africa. The plant has a design capacity for
treating 350Ml/day (92MGD). The three ozone generators (2
depicted) produce 30 kg/hour of ozone each are manufactured
by
Trailigaz and sold by Ozonic.
Photo courtesy
of Leon de Goede of Ozonic - South Africa.
Send us
your photos: We would love to have your photo of
a water or wastewater treatment "action shot" for
inclusion on our home page, free of charge. Send your
photograph and description to: news@waterandwastewater.com
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