Onion soaks up heavy metal, researchers find

Dec 10, 2012

Onion and garlic waste from the food industry could be used to mop up hazardous heavy metals, including arsenic, cadmium, iron, lead, mercury and tin in contaminated materials, according to a research paper published in the International Journal of Environment and Pollution.

Biotechnologists Rahul Negi, Gouri Satpathy, Yogesh Tyagi and Rajinder Gupta of the GGS Indraprastha University in Delhi, India, explain how waste from the processing and canning of onion (Allium cepa L.) and garlic (Allium sativum L.) could be used as an alternative remediation material for removing from contaminated materials including industrial effluent. The team has studies the influence of acidity or alkalinity, contact time, temperature and concentration of the different materials present to optimize conditions for making a biological heavy metal filter for industrial-scale decontamination.

They have found that at 50 Celsius (122 Fahrenheit), the efficiency of the clean-up process is largely dependent on pH (acidity or alkalinity) and equilibration time usually occurs within half an hour; a pH of 5 was optimal. They demonstrated the maximum extraction was achievable for lead, one of the most troublesome metallic . They could extract more than 10 milligrams per gram of Allium material from a test solution containing 5 grams per liter of mixed solution, amounting to recovery efficiency of more than 70%. The absorbed metals can be released into a collecting vessel using nitric acid and the biomass reused.

The team experimented with Allium biomass to demonstrated effective removal of from both simulated and actual industrial effluents. "The technique appears to be industrially applicable and viable," they suggest. "This may provide an affordable, environmental friendly and low maintenance technology for small and medium scale industries in developing countries," they conclude.

Explore further: Germany restricts fracking but doesn't ban it

More information: Biosorption of heavy metals by utilising onion and garlic wastes, Int. J. Environment and Pollution, 2012, 49, 179-196. www.inderscience.com/jhome.php?jcode=ijep

Related Stories

The worm that turned on heavy metal

Dec 06, 2010

Researchers in South America have studied the viability of using earthworms to process hazardous material containing high concentrations of heavy metal for the bioremediation of old industrial sites, landfill and other potentially ...

Earthworms soak up heavy metal

Aug 16, 2012

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 Jo ...

Novel device removes heavy metals from water

Dec 16, 2011

An unfortunate consequence of many industrial and manufacturing practices, from textile factories to metalworking operations, is the release of heavy metals in waterways. Those metals can remain for decades, even centuries, ...

Recommended for you

Germany restricts fracking but doesn't ban it

2 hours ago

The German cabinet drew up rules Wednesday on the hitherto unregulated technology of "fracking" in Germany, narrowly restricting its use, but stopping short of an outright ban.

Life in the poisonous breath of sleeping volcanos

3 hours ago

Researchers of the University Jena analyze the microbial community in volcanically active soils. In a mofette close to the Czech river Plesná in north-western Bohemia, the team around Prof. Dr. Kirsten Küsel ...

Eggs and chicken instead of beef reap major climate gains

4 hours ago

Beef on our plates is one of the biggest climate villains, but that does not mean we have to adopt a vegan diet to reach climate goals. Research results from Chalmers University of Technology show that adopting ...

Local action needed to protect nature from global warming

6 hours ago

Stronger local management can increase the resilience of nature to the impacts of climate change, writes an international team of researchers in Science. The authors examined three UNESCO World Heritage Sites: ...

Deforestation is messing with our weather and our food

6 hours ago

Today, the National Socio-Environmental Synthesis Center (SESYNC) at the University of Maryland published new research in Nature Communications providing insight into how large-scale deforestation could ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.