New tech tackles soil contaminated with arsenic

For a few decades from the 1950s to the 1990s, Wenshan city in Southwest China's Yunnan province ranked first in terms of arsenic production in China.

Tao Guangfa, a 67-year-old villager, still remembers how people in his hometown used to be afraid of eating corn, rice and other crops from the fields and along a waterway around a local arsenic mine.

People even avoided herding around the arsenic mines for some time as grass for the cattle was poisoned due to soil pollution.

However, the latest technology is expected to reduce such concerns.

Chinese research institutions and enterprises have jointly developed a new technology with the aim of restoring soil contaminated with arsenic.

In the smelting process of nonferrous metals, heavy metals including lead, zinc, cadmium and arsenic may be found in various types of solid waste without proper treatment.

Though local arsenic manufacturers have all been shut down in recent years, arsenic residue in waste still continues to exist in mountains and gullies, affecting the environment and posing a health threat to locals.

The new technology on the remediation of arsenic contaminated sites on the plateau has recently passed expert evaluation.

Developed by the Yunnan Institute of Environmental Science, Kunming University of Science and Technology and Yunnan Investment Ecology, the technology improves the technical system of arsenic-containing waste disposal in cement kilns.

The researchers developed intelligent remediation equipment and an effective curing and stabilizing repair agent to provide key support in solving the arsenic pollution problem.

Based on preliminary research, Wenshan started a project on the disposal of eight arsenic slag sites with a total area of 6,130 cubic meters in May last year and completed landfill work on May 20 this year.

The project is currently in the final stage of ecological restoration, the local government said, adding that the contaminated soil is undergoing post-restoration treatment, which is expected to be completed in this month.

"Now, there's no need for us to worry about soil contaminated with arsenic," Tao said.

Xinhua