Official statistics show that more than 3 million hectares of Chinese farmland is polluted with heavy metals. With growing concern over the country's food security, the government is investing billions of yuan a year to try to rehabilitate the soil. The new funding has attracted a number of scientists and companies that are developing new techniques for making the land safe again.
Professor Pan Genxing and his team started a pilot project to clean contaminated farmland in Yixing City of Jiangsu Province in 2009. The land was so contaminated by emissions from a nearby oil refinery the crops on this land were dying before they matured.
Their tests show that heavy metals, like cadmium and lead, were not naturally decomposing, so they've come up with a way to absorb the contaminates using treated straw.
"First we developed a technique to char the straw before putting it on the land. The straw keeps the heavily metals from the roots of the crops and the straw mulch also benefits the soil," said Pan with Nanjing Agricultural University.
Pan says crops from the plots treated with the straw were not only free from heavy metals, they were also more abundant. He has received two national patents for his technology.
Other scientists and entrepreneurs are hoping the soil cleansing techniques they develop will lead to lucrative contracts and a share of the billions of dollars the government is spending to rehabilitate poisoned land.
Gu Xiaoping is the director of one of first companies to clean contaminated soil in Jiangsu. The company has already invested millions of yuan and expects to spend millions more developing effective methods of reclaiming contaminated soil.
"We are cooperating with international experts and companies on the best ways to clean the polluted soil." said Gu from Jiangsu Ddbs Environment Remediation Co., Ltd.
Gu's company has concentrated on cleaning polluted soil in urban centers but plans to expand business to rehabilitating farmland. While the need and opportunities are great, the problem, he says, is a lack of government standards.
"Despite the technical difficulties, China does not have a specific law on the soil contamination and rehabilitation. So companies don't have technical standards or regulations for reference,"Gu said.
Experts say without regulations and standards, companies won't know if the techniques they develop will be good enough to qualify them for a share of the government's huge land rehabilitation fund.
Soil rehabilitation in China is still in its early stages. It requires advanced technology, heavy investment and a customized solution. China's absence of regulation or standard on the matter has prompted calls for more legal efforts to tackle the problem.
(CNTV.cn January 20, 2014) |