Earthworms soak up heavy metal

Earthworms soak up heavy metal

7:09 AM, 17th August 2012
Earthworms soak up heavy metal
Bioremediation of toxic metals using worms.

GENEVA, SWITZERLAND: Earthworms could be used to extract toxic heavy metals, including cadmium and lead, from solid waste from domestic refuse collection and waste from vegetable and flower markets, according to researchers writing in the International Journal of Environment and Waste Management. Swati Pattnaik and M Vikram Reddy of the Department of Ecology and Environmental Sciences, at Pondicherry University, in Puducherry, India, explain how three species of earthworm, Eudrilus eugeniae, Eisenia fetida and Perionyx excavates can be used to assist in the composting of urban waste and to extract heavy metals, cadmium, copper, lead, manganese, zinc, prior to subsequent processing.

With rapid increases in urban populations particularly in the developing world, there is a growing problem of how to manage organic waste and to find alternatives to landfill disposal particularly for domestic food waste and that from vegetable markets. According to the research team, it is an unfortunate fact of life that much of this waste is currently dumped on the outskirts of many towns and cities and is causing serious pollution, disease risk and general ecological harm. It also represents a considerable wasted resource, whereas the organic matter might be exploited usefully in growing food crops.

The process of vermicomposting in this way allows such waste materials to be remediated and the compost used subsequently for use in growing human food without the risk of accumulating heavy metals in crops. The team said that up to about three-quarters of the various heavy metals can be removed by the worms from solid waste. The E. eugeniae species was the most effective worm at remediating solid waste and producing rich compost. The team’s tests on vermicomposting reveal that the heavy metal content of such waste can be reduced to levels significantly below the permissible safe limits.

The worms’ digestive system is apparently capable of detaching heavy metal ions from the complex aggregates between these ions and humic substances in the waste as it rots. Various enzyme-driven process then seem to lead to assimilation of the metal ions by the worms so that they are locked up in the organism’s tissues rather than being released back into the compost as worm casts. The separation of dead worms from compost is a relatively straightforward process allowing the heavy metal to be removed from the organic waste.

© Inderscience Publishers News

0 Comments

Login

Your Comments (Up to 2000 characters)
Please respect our community and the integrity of its participants. WOC reserves the right to moderate and approve your comment.

Related News


Scientists find new form of carbon

WASHINGTON DC, US: A team of scientists led by Lin Wang, Carnegie Institution has observed a new form of very hard carbon clusters, which are unusual ...

Read more
BASF sells RELIUS decorative paints business to PROSOL

MUNSTER/ASCHAFFENBURG, GERMANY: BASF and PROSOL Lacke+Farben GmbH signed a contract regarding the sale of the decorative paints business of RELIUS Coa ...

Read more
Reliance Industries in talks to buy BP’s Malaysia plant

MUMBAI, INDIA: India’s largest private sector company, Reliance Industries (RIL) is in talks with British oil giant, British Petroleum (BP) to b ...

Read more
ADM appoints Todd Werpy as Vice President, Research and Development

DECATUR, US: Archer Daniels Midland Company (ADM) appointed Todd Werpy, PhD, as Vice President, Research and Development. Werpy, previously the comp ...

Read more
Segetis raises $25.5 million in Series C financing

GOLDEN VALLEY, US: Segetis Inc has raised $25.5 million in its Series C financing. Saudi Basic Industries Corporation (SABIC) Ventures BV led the inve ...

Read more
KiOR receives fuel registration from EPA for renewable diesel

PASADENA, US: KiOR Inc, a next-generation renewable fuels company, has been granted Part 79 registration for its Renewable Diesel Blendstock 5 by the ...

Read more
www.worldofchemicals.com uses cookies to ensure that we give you the best experience on our website. By using this site, you agree to our Privacy Policy and our Terms of Use. X