'Red mud' disaster's main threat to crops is not toxic metals

Feb 02, 2011

As farmers in Hungary ponder spring planting on hundreds of acres of farmland affected by last October's red mud disaster, scientists are reporting that high alkalinity is the main threat to a bountiful harvest, not toxic metals. In a study in the ACS journal Environmental Science & Technology, they also describe an inexpensive decontamination strategy using the mineral gypsum, an ingredient in plaster.

Erik Smolders and colleagues note that a dam burst at a factory processing aluminum ore, flooding the surrounding land with more than 700,000 cubic yards of a byproduct termed red mud. At least 10 people died and hundreds were injured in Hungary's worst-ever environmental disaster. Red mud contains toxic metals like arsenic, chromium, cadmium and nickel. The mud also contains radioactive elements and is highly alkaline, caustic enough to burn skin and eyes. On the scale for measuring acidity or alkalinity, 7 is neutral, anything above 7 is alkaline and below is acid. Red mud is about one million times more alkaline than a neutral material. With up to 4 inches of red mud coating , concerns arose about red mud's potential impact on the 2011 planting of corn, alfalfa, and other crops. With little scientific knowledge about red mud's effects on plant growth, much of the concern focused on toxic metals.

The scientists' tests showed that plants in contaminated soil grew about 25 percent slower than crops grown in uncontaminated soil. The main culprit, however, appeared to be not or radioactivity, but red mud's intense alkalinity and salt content. Adding gypsum to the red mud can reduce alkalinity and will accelerate the removal of the salts, the scientists add, recommending long-term monitoring of metals in the crops to remove any concerns with food chain contamination.

Explore further: New research on Earth's carbon budget

More information: "The Red Mud Accident in Ajka (Hungary): Plant Toxicity and Trace Bioavailability in Red Mud Contaminated Soil" Environmental Science & Technology

add to favorites email to friend print save as pdf

Related Stories

Hungary's red sludge nearly equals Gulf oil spill

Oct 08, 2010

(AP) -- The mighty Danube apparently absorbed Hungary's massive red sludge spill with little immediate damage Friday but laboratory tests heightened concerns about possible longer-term harm caused by toxic ...

Can Hungary's red sludge be made less toxic with carbon?

Oct 13, 2010

The red, metal-laden sludge that escaped a containment pond in Hungary last week could be made less toxic with the help of carbon sequestration, says an Indiana University Bloomington geologist who has a patent ...

Toxic mud spill kills four in Hungary

Oct 05, 2010

Hungary declared a state of emergency on Tuesday after a toxic mud spill killed four people and injured 120 in what officials described as Hungary's worst-ever chemical accident.

Hungary toxic sludge spill reaches Danube (Update)

Oct 08, 2010

The company at the centre of Hungary's toxic sludge leak that killed four people defended itself Friday, as fears increased over the threat to marine life in Europe's second longest river.

Toxicity of Hungary's red sludge flow drops

Oct 08, 2010

(AP) -- The concentration of toxic heavy metals where Hungary's massive red sludge spill entered the Danube has dropped to the level allowed in drinking water, authorities said Friday, easing fears that Europe's ...

Crews struggle to clear toxic Hungary sludge flood

Oct 06, 2010

(AP) -- There was no stopping the avalanche of toxic red sludge when it rammed into Kati Holtzer's home: It smashed through the main door and trapped the woman and her 3-year-old boy in a churning sea of ...

Recommended for you

US delays decision on Keystone pipeline project

14 hours ago

The United States announced Friday a fresh delay on a final decision regarding a controversial Canada to US oil pipeline, saying more time was needed to carry out a review.

New research on Earth's carbon budget

21 hours ago

(Phys.org) —Results from a research project involving scientists from the Desert Research Institute have generated new findings surrounding some of the unknowns of changes in climate and the degree to which ...

User comments : 0

More news stories

Magnitude-7.2 earthquake shakes Mexican capital

A powerful magnitude-7.2 earthquake shook central and southern Mexico on Friday, sending panicked people into the streets. Some walls cracked and fell, but there were no reports of major damage or casualties.

There's something ancient in the icebox

Glaciers are commonly thought to work like a belt sander. As they move over the land they scrape off everything—vegetation, soil, and even the top layer of bedrock. So scientists were greatly surprised ...

Health care site flagged in Heartbleed review

People with accounts on the enrollment website for President Barack Obama's signature health care law are being told to change their passwords following an administration-wide review of the government's vulnerability to the ...

Airbnb rental site raises $450 mn

Online lodging listings website Airbnb inked a $450 million funding deal with investors led by TPG, a source close to the matter said Friday.