Onion soaks up heavy metal

December 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 toxic elements 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 environmental pollutants. They could extract more than 10 milligrams per gram of Allium material from a test solution containing 5 grams per liter of mixed metal ion 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 heavy metals 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.
-end-
"Biosorption of heavy metals by utilising onion and garlic wastes" in Int. J. Environment and Pollution, 2012, 49, 179-196

Inderscience Publishers

Related Heavy Metals Articles from Brightsurf:

Dairy cows exposed to heavy metals worsen antibiotic-resistant pathogen crisis
Dairy cows, exposed for a few years to drinking water contaminated with heavy metals, carry more pathogens loaded with antimicrobial-resistance genes able to tolerate and survive various antibiotics.

Liquid metals come to the rescue of semiconductors
Two-dimensional semiconductors offer a possible solution to the limited potential for further shrinking of traditional silicon-based electronics: the long-predicted end of 'Moore's Law'.

Heavy metals make soil enzymes 3 times weaker, says a soil scientist from RUDN University
Heavy metals suppress enzyme activity in the soil by 3-3.5 times and have especially prominent effect on the enzymes that support carbon and sulfur circulation.

Semiconductors can behave like metals and even like superconductors
The crystal structure at the surface of semiconductor materials can make them behave like metals and even like superconductors, a joint Swansea/Rostock research team has shown.

Metals could be the link to new antibiotics
Compounds containing metals could hold the key to the next generation of antibiotics to combat the growing threat of global antibiotic resistance.

Instrument may enable mail-in testing to detect heavy metals in water
MIT researchers have developed an approach called SEPSTAT, for solid-phase extraction, preservation, storage, transportation, and analysis of trace contaminants.

A new look at 'strange metals'
'Strange metals' could be the key to finally understanding high-temperature superconductors.

Flame retardants and pesticides overtake heavy metals as biggest contributors to IQ loss
Adverse outcomes from childhood exposures to lead and mercury are on the decline in the United States, likely due to decades of restrictions on the use of heavy metals, a new study finds.

Stellar heavy metals can trace history of galaxies
Astronomers have cataloged signs of nine heavy metals in the infrared light from supergiant and giant stars.

Microwave treatment is an inexpensive way to clean heavy metals from treated sewage
A team of Florida State University researchers studying new methods to remove toxic heavy metals from biosolids -- the solid waste left over after sewage treatment -- found the key is a brief spin through a microwave.

Read More: Heavy Metals News and Heavy Metals Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.