Filter cleans arsenic-tainted water
March 19, 1998
Nik P. Nikolaidis and colleagues are working on a filter for arsenic-contaminated groundwater
Web posted at: 2:51 a.m. EST (0751 GMT)
By Environmental News Network staff
(ENN) -- A filter developed by University of Connecticut engineers may help end a worldwide problem of arsenic-contaminated groundwater.
Nik P. Nikolaidis, an associate professor of civil and environmental engineering, and colleagues in the university's Critical Technologies Program have developed a filter that removes arsenic from water.
Arsenic, a poisonous chemical element, is found as compounds with oxygen, chlorine, sulfur, carbon, hydrogen, lead, gold and iron, and is present in many rock-forming minerals. It also occurs as a result of geological processes, manufacturing, smelting and agriculture. Arsenic poisoning has become an epidemic in many areas in Asia, but it also may be a problem in our own backyards. It is used in insecticides and was exposed by gold mining in many states, such as Montana.
"Arsenic poisoning is one of the most widespread problems in the world," says Nikolaidis. "It's a major problem in many countries such as Bangladesh, where 77 million people are at risk for arsenic contamination."
The filter has at least a 20-year life span
Sixty percent of the people in Bangladesh are affected in the largest mass poisoning case in the world currently. Also affected by arsenic poisoning are millions in West Bengal, India; Mongolia; Mexico; Chile; Argentina; Taiwan and Thailand, he says.
When people drink arsenic-contaminated groundwater, it begins to kill slowly and painfully.
Arsenic poisoning leads to a host of problems including a change of skin complexion; lesions; tumors; possible cancer; damage to blood vessels, liver or kidney; gangrenous ulcers; abnormal heart function and impaired nerve functions. Symptoms of arsenic poisoning can take eight to 14 years to manifest in a person. If caught early, however, the poisoning can be reversed.
The filter material developed by Nikolaidis and his colleagues, with funding from the Critical Technologies Program and industry, has at least a 20-year life span. It attaches to well tubes like a regular filter or is placed in a trench to intercept the contaminated groundwater from a landfill. The filter consists of iron filings, cut in small pieces, and sand. When the iron corrodes, it takes all the arsenic out of the water. Nikolaidis is designing filters for larger use such as local water systems.
Nikolaidis has been researching arsenic for the past four years, having come across the problem while working at a contaminated landfill in central Maine. Most landfills here have arsenic problems stemming from unchecked disposal of chemicals containing arsenic, such as herbicides.
Scientists and governments are only now realizing how widespread the problem is, he says.
"We're talking about water, a basic part of our life," Nikolaidis says. "In Asia, they drink much more water than we do because of the heat. In Bangladesh, they also do not have the amenities that we do and certainly cannot afford expensive technologies to treat their drinking water."
The World Health Organization's standard is set at 10 micrograms per liter. In Bangladesh and West Bengal, the water has anywhere from 300 micrograms per liter to 4,000 micrograms per liter of arsenic.
Arsenic levels higher than the current EPA standard have been discovered in private wells in New England, especially southeastern New Hampshire, Maine and Massachusetts. It has been discovered in Ohio, Alaska, California, Hawaii, Idaho, Nevada, Oregon, Washington and Montana.
The EPA will decide soon on changing the standards for arsenic by 2000, lowering the acceptable limit of arsenic from 50 micrograms per liter to possibly 10 micrograms per liter. If the standard were set at 10 micrograms per liter, Nikolaidis said thousands of local water systems and private wells in the country would have to filter the arsenic out to be in compliance. The EPA estimates that the cost would be in the millions, but many cases of skin cancer would be avoided in the United States.
Most private well owners in the United States have not tested their water for arsenic levels, according to Jeff Lackovic, a graduate student majoring in environmental engineering, who has worked with Nikolaidis on the project since they began analyzing how arsenic moves in groundwater in 1994.
"Arsenic has not been adequately surveyed in local water systems, so we don't know how widespread the problem is in Connecticut or New England," he said.
The filter will get its first use next month in a pilot project at a landfill in central Maine. Nikolaidis and colleagues have submitted a patent application for the filter they developed. The patent is expected to be final in a few years.
Nikolaidis was invited to present his invention at an international conference on arsenic in Dhaka, Bangladesh, in early February. The United States joined Japan, India, France, United Kingdom, Chile and China among other countries in pledging to help end the problem.
"I hope we will be able to create an inexpensive technology that can be used here and in countries like Bangladesh to save people's lives," Nikolaidis said.
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