Featured Research

from universities, journals, and other organizations

Sandia Attenuation Technology May Help Resolve Arsenic Environmental Crisis In Bangladesh

Date:
April 20, 2000
Source:
Sandia National Laboratories
Summary:
Technology developed at the Department of Energy's Sandia National Laboratories to remove toxins from groundwater contaminated by nuclear waste may offer clues about how to resolve a catastrophic environmental crisis in Bangladesh where arsenic-polluted wells are slowly poisoning and killing hundreds of thousands of people.

ALBUQUERQUE, N.M. -- Technology developed at the Department of Energy's Sandia National Laboratories to remove toxins from groundwater contaminated by nuclear waste may offer clues about how to resolve a catastrophic environmental crisis in Bangladesh where arsenic-polluted wells are slowly poisoning and killing hundreds of thousands of people.

This spring Sandia geochemist Pat Brady will travel to Vienna to meet with scientists from the International Atomic Energy Agency (IAEA) and help them understand the origins of the arsenic in the Bangladeshi wells. The IAEA is one of several world organizations striving to put an end to the poisoning.

Brady was invited to join in the IAEA scientists' efforts because of his work in natural attenuation, a naturally occurring process that adsorbs soluble heavy metals onto a mineral surface, thus eliminating it from water or soil. Scientists speculate that the mirror image of the process is providing arsenic to the wells in Bangladesh, and that mineral uptake might conceivably be used to remove arsenic from drinking water -- if the right mineral can be found.

Mass poisoning

The water contamination, which The New York Times has described as "the biggest mass poisoning in history," began innocently in the late 1970s when the United Nations International Children's Emergency Fund (UNICEF) dug about one million wells to provide clean water in rural areas of Bangladesh. Most of the surface water was polluted, and the new wells were seen as the solution to the water dilemma. Villagers dug an additional three million wells at their own expense, mostly used for crop irrigation. No one knew the new wells were polluted because they were not tested for arsenic contamination.

Arsenic poisoning started showing up in the mid-1980s, and today it is estimated that hundreds of thousands of people throughout Bangladesh are suffering from it and millions more are at great risk. It can cause breathing difficulties, skin discoloration, lesions, cancer, and ultimately death. The World Bank surveyed 10 percent of the four million wells in Bangladesh and found that 40 percent contained significant contamination.

Scientists have been struggling to determine the cause. Originally they believed arsenic might be coming from pyrite (iron sulfide -- "fool's gold") in groundwater. More recently they concluded the arsenic originated in iron oxide coatings of rocks lining the aquifer. Arsenic may be on surface coatings, whereupon fresh water can easily wash it off. Or it may be buried deep inside the mineral coating with the arsenic seeping out at weak points, like cracks, in the coatings.

"It's important to understand the origins of the arsenic," Brady says. "Once we do that, we can figure out how persistent the problem is likely to be, and it might give clues as to how to get it out."

'Getters' sought

In the meantime the quest continues to find a way to eliminate the arsenic from the water. Brady and several other Sandia scientists have been designing "getters" -- mineral solids that "suck" much of a particular contaminant out of the water. The getters would be external to the wells. Contaminants are attracted to a specific type of mineral and then eventually become entrapped in it, freeing the water or soil of the metal molecules.

The Sandia researchers have been successful in using this technique to remove iodide -- a contaminant emitted by nuclear waste -- from groundwater. Both iodide and arsenic are anions, negatively charged ions. In theory, similar methods could be used to clean up both.

Brady says the team has identified at least two types of minerals that they believe might pull out arsenic. This was accomplished through molecular modeling of arsenic interaction with mineral surfaces.

"This helped us rule out certain minerals and told us which ones might be getters," Brady says. "As a result, we don't have to test every mineral."

Brady says the next step will be to run arsenic-contaminated water through the selected minerals and determine if and how fast the arsenic sorbs.

If this works, they will have found a cheap and easy way to remove arsenic from drinking water.

"Existing methods of arsenic cleanup, including distillation, would cost hundreds of millions of dollars," Brady says. "That is well out of the price range of Bangladesh, a country where the per capita income is roughly $250. A less expensive method of cleanup must be found. Maybe the Sandia-designed getters will be the one."


Story Source:

The above story is based on materials provided by Sandia National Laboratories. Note: Materials may be edited for content and length.


Cite This Page:

Sandia National Laboratories. "Sandia Attenuation Technology May Help Resolve Arsenic Environmental Crisis In Bangladesh." ScienceDaily. ScienceDaily, 20 April 2000. <www.sciencedaily.com/releases/2000/04/000420074303.htm>.
Sandia National Laboratories. (2000, April 20). Sandia Attenuation Technology May Help Resolve Arsenic Environmental Crisis In Bangladesh. ScienceDaily. Retrieved July 25, 2014 from www.sciencedaily.com/releases/2000/04/000420074303.htm
Sandia National Laboratories. "Sandia Attenuation Technology May Help Resolve Arsenic Environmental Crisis In Bangladesh." ScienceDaily. www.sciencedaily.com/releases/2000/04/000420074303.htm (accessed July 25, 2014).

Share This




More Earth & Climate News

Friday, July 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Goma Cheese Brings Whiff of New Hope to DRC

Goma Cheese Brings Whiff of New Hope to DRC

Reuters - Business Video Online (July 24, 2014) The eastern region of the Democratic Republic of Congo, mainly known for conflict and instability, is an unlikely place for the production of fine cheese. But a farm in the village of Masisi, in North Kivu is slowly transforming perceptions of the area. Known simply as Goma cheese, the Congolese version of Dutch gouda has gained popularity through out the region. Ciara Sutton reports. Video provided by Reuters
Powered by NewsLook.com
Bill Gates: Health, Agriculture Key to Africa's Development

Bill Gates: Health, Agriculture Key to Africa's Development

AFP (July 24, 2014) Health and agriculture development are key if African countries are to overcome poverty and grow, US software billionaire Bill Gates said Thursday, as he received an honourary degree in Ethiopia. Duration: 00:36 Video provided by AFP
Powered by NewsLook.com
Higgins Breaks Record at Mt. Washington

Higgins Breaks Record at Mt. Washington

Driving Sports (July 24, 2014) Subaru Rally Team USA drivers David Higgins and Travis Pastrana face off against a global contingent of racers at the annual Mt. Washington Hillclimb in New Hampshire. Includes exclusive in-car footage from Higgins' record attempt. Video provided by Driving Sports
Powered by NewsLook.com
Storm Kills Three, Injures 20 at Virginia Campground

Storm Kills Three, Injures 20 at Virginia Campground

Reuters - US Online Video (July 24, 2014) A likely tornado tears through an eastern Virginia campground, killing three and injuring at least 20. Linda So reports. Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

    Health News

      Environment News

        Technology News



          Save/Print:
          Share:

          Free Subscriptions


          Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

          Get Social & Mobile


          Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

          Have Feedback?


          Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
          Mobile: iPhone Android Web
          Follow: Facebook Twitter Google+
          Subscribe: RSS Feeds Email Newsletters
          Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins