engineers are plugging holes in drinking water treatment

by:Purewell     2020-01-07
On the gravel road on the edge of the university campus --
Next to the town\'s stray dog fence-
It is a busy testing place for the latest technology of drinking water treatment.
In the shedturned-
David Reckhow, lab engineer at the University of Massachusetts Amherst, launched a campaign.
More people would like to use his lab to test new water treatment techniques instead of having space in the building.
This is a story of success in revitalization.
In the 1970 s, when the Clean Water Act put new limits on water pollution, a small gray building in Amherst, Massachusetts.
It\'s where the pollution is tested.
Control measures.
But the funds are fickle and the building has been out of repair for years.
In 2015, Reckhow brings the site back to life.
He and a group of researchers cleaned up the garbage, cleared the weeds that swallowed the building, and installed monitoring equipment worth hundreds of billions of dollars, most of which were donated or purchased second-hand equipment.
\"We recognize that there is a lot of demand for drinking water technology,\" Reckhow said . \".
Researchers, students and start-ups
Up companies all want test methods for sanitizing drinking water, filtering contaminants, or detecting waterGood quality.
On a Monday afternoon in October, the lab was busy.
The student processes the data on a large table in the main room. Small-
Scale testing using the technology of electrochemical clean water, connected to a monitor that tracks water quality.
A graduate student sits on a bench in a lab.
A cost replica of expensive monitoring equipment.
When by-the device reminds the water treatment plant
Products that disinfect chemicals in water supply reach dangerous levels.
In an attached garage, both startups are expanding in size.
Scale test of new membrane for filtering pollutants.
Behind the shed is almostready-to-roll newcomer.
Starting in 2019, the mobile water Innovation Lab will provide promising new technologies and affordable testing to local communities.
This is important, says Reckhow, because there are many differences in the water quality of drinking water treatment plants. On-
Field testing is the only way to know if a new method works, especially for new technologies that don\'t have long-term use, he said
Track Records regularly.
The popularity of the facility reflects a continuing concern in the United States: How to ensure affordable clean, safe drinking water. Although U. S.
Drinking water is strictly regulated and very clean overall
Pollution ,()
, Exposed weaknesses in the system, shaken people\'s trust in tap water.
In 2013 and 2014, 42 outbreaks related to drinking water resulted in more than 1,000 diseases and 13 deaths. S.
Centers for Disease Control and Prevention.
According to the data released in November 2017, the culprit is bacteria and some form of chemicals, toxins or parasites.
However, these numbers are only part of the story.
Many pollutants in the United States. S.
The Environmental Protection Agency has passed the 1974 Safe Drinking Water Act, which will cause problems only if it is exposed for a long time;
The effects of contaminants like lead do not appear immediately after exposure.
The EPA\'s record of violation of the rules shows that in 2015, researchers reported in a study in February that drinking water systems did not meet the standards.
The report tracks trends in violations of drinking water between 1982 and 2015.
David Sedlak, an environmental engineer at the University of California, Berkeley, said the current technology can remove most pollutants.
Including microorganisms, arsenic, nitrate and lead.
\"There are also some industrial chemicals that are difficult to degrade or transform,\" such as those known as PFAS.
Small communities in particular can\'t afford to buy topof-the-
For example, maintenance of line equipment or infrastructure.
So Reckhow\'s facility is testing ways to help the community solve water problems
Solve quality problems in an affordable way.
Some researchers are adding technologies to deal with new potentially harmful pollutants.
Others are designing ways to work with existing water infrastructure or to clean up contaminants from the source.
A typical drinking water treatment plant passes through.
First, add a condensate to the water.
The deposits that these chemicals gather together can cloud the water or make it taste interesting, so they are bigger and easier to remove.
The slight shaking or rotation of the water, known as the pleadings, contributes to the formation of these lumps.
Next, the water flows into the large tank and is placed for a period of time so that the deposit falls to the bottom.
The cleaner water then moves by filtering the membrane of the smaller contaminants.
Disinfection by chemicals or ultraviolet rays can kill harmful bacteria and viruses.
Then the water can be distributed.
There is a lot of room for change in the basic water treatment process.
Chemicals added at different stages can trigger a reaction, breaking down a large number of toxic organic molecules into less harmful parts. Ion-
The exchange system of charge separation pollutants can remove ions that \"harden\" the water, such as magnesium or calcium, as well as heavy metals such as lead and arsenic, nitrate lost by fertilizers.
The city adjusts the chemicals according to the precise chemical quality of the local water supply, mixes and matches these strategies, and sets priorities for the treatment components.
Some water companies are simplifying the treatment process by installing technologies such as reverse osmosis, a technology that forces water molecules to remove almost everything from water through selective permeable membranes with tiny holes.
Reverse osmosis can replace some steps in the water treatment process, or reduce the amount of chemicals added in the water.
But the cost of installation and operation is high, which makes it inaccessible to many cities.
14% of the United StatesS.
Residents obtain water from wells and other private sources not regulated by the Safe Drinking Water Act.
These people face the same pollution challenges as the municipal water supply system, but do not have regulation, community support or funding.
\"When it comes to the leadership of private wells . . . . . . You can only rely on yourself.
No one will help you, \"said Mark Edwards, an engineer at Virginia Tech, who helped spot the Flint water crisis.
Edwards and colleagues from Virginia Tech, Kelsey Pipper, were in 2012 and 2013.
Some are OK, but others have more than 100 lead per billion.
When the 15 ppb threshold is exceeded, EPA requires the city to take measures to control the corrosion and inform the public about the contamination.
The researchers reported the findings in 2015.
In order to remove lead and other contaminants, users usually rely onof-use treatments.
The filter on the tap can remove most but not all contaminants.
Some people choose expensive reverse osmosis systems.
These three new waters
The cleaning method does not require expensive infrastructure overhaul.
The Reckhow team at UMass Amherst is an iron ion that can replace several water treatment steps.
First, the high-speed rail will kill bacteria in the water.
Next, it breaks down carbon.
Convert chemical contaminants into smaller, less harmful molecules.
Reckhow and his colleagues reported in 2016 that in the end, it was in the water, so it was easier for them to filter out.
The high-speed rail salts have a wide range of effects and may simplify the process of drinking water treatment, or reduce the use of chemicals such as chlorine, which can produce dangerous by-products
Joseph Goodwill, environmental engineer at Rhode Island University in Kingston, said.
Bullet train can be a useful disinfectant for small drinking water systems that do not have infrastructure, expertise or funding to implement methods such as ozone treatment, this method uses ozone gas to break down contaminants, says reckhow.
Early next year, in his maiden voyage to the mobile water treatment Laboratory, Reckhow plans to test the high-speed rail method in Gloucester, Massachusetts. In the 36-
The foot trailer is squeaky.
Clean array of plastic pipes and storage tanks.
Set to route water intake through the same series of steps-
Purification, filtration and disinfection
This can be found in a standard drinking water treatment plant.
With two sets of everything, scientists can runby-
Compare the performance of a new technology with standard methods.
Patrick Wittbold, research engineer at UMass Amherst, who is responsible for the design of the trailer, said so that researchers can see if the new technology is better than the existing options.
The filter film is easily blocked by small particles.
\"This is a fatal weakness in membrane therapy,\" said Brian Chaplin, an engineer at the University of Illinois in Chicago.
Dredging filters will waste energy and increase costs.
Chaplin believes that electricity can solve this problem and provide some side benefits.
His team tested an electrolytic film made of titanium oxide or titanium dioxide that filters both water and acts as an electrode.
A chemical reaction occurring on a charged membrane can convert nitrate into nitrogen or decompose water molecules to produce active ions that can oxidized pollutants in water.
These reactions can also prevent particles from sticking to the film. Large carbon-
Basic molecules like benzene are getting smaller and less harmful.
In laboratory tests, the membrane effectively filters and destroys contaminants, says Chaplin.
In one test, the membrane converts 67% of the nitrate in the solution into other molecules.
In July, he and his colleagues reported that the finished water was ten parts per million.
Chaplin is expected to transfer the film to the pilot in the next two years.
Industrial chemicals known as PFAS face two challenges.
Only the larger filter is valid, which is the active material in many household filters.
Christopher Higgins, environmental engineer at the Golden Colorado School of Mines, said the smaller PFAS remained in the water.
In addition, filtration is not enough because these bulky chemicals are difficult to break down for safe disposal.
Higgins and colleague Timothy Strasman, also at the Colorado School of Mines, are working on the process of destroying PFAS.
First, a dedicated filter with small holes grabs molecules from the water.
Then, the sulfuric acid root is added to the concentrated mixture of the pollutant.
When exposed to ultraviolet rays, the sulfuric acid root produces active electrons that break down the tough carbon-
Fluorine Bonds in PFAS molecules.
Other researchers reported in 2016 that UV radiation combined with sulfuric acid in 30 minutes.
Soon, Higgins and Strasman will test the process at the Petersen Air Force Base in Colorado, where groundwater is known to be contaminated with PFAS.
Clearing these sites will remove contaminants from groundwater, which may also provide water sources for wells or urban water supply systems.
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