Across China: Chinese scientists develop tech to treat contaminated soils

Source: Xinhua| 2019-07-01 20:03:43|Editor: ZX
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KUNMING, July 1 (Xinhua) -- Tao Guangfa, a 67-year-old Chinese villager, still remembers how people used to be afraid to eat corn, rice and other crops in the fields and along a waterway around a local arsenic mine.

Tao's hometown, the city of Wenshan in southwest China's Yunnan Province, ranked first in China in terms of arsenic production for many years from the 1950s to the 1990s.

For some time, people even avoided herding around the arsenic mines as the grass for the cattle was poisoned due to soil pollution. Such concerns that once surrounded Tao and his fellow villagers are now expected to be reduced with the latest technology.

Chinese research institutions and enterprises have jointly developed a new technology that aims at restoring arsenic-contaminated soils.

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

In recent years, local arsenic manufacturers have all been shut down, but the waste arsenic residues still existed in mountainsides, mountaintops and gullies, affecting the environment and posing a threat to the health of local residents.

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

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

The researchers developed an effective curing and stabilizing repair agent and intelligent remediation equipment, which provides key support for solving the problem of arsenic pollution.

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 2018, and has completed its landfill work on May 20.

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 and is expected to be completed in early July.

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