Bioremediation can restore China's polluted land

Want China Times, Staff Reporter 2014-10-12

A field surrounded by factories in Hebei. (File photo/CNS)

Microbes, including bacteria and fungi, are increasingly being used by local governments in China to treat soil that has been polluted by waste products, Shanghai's China Business News reports.

Henan and Jiansu provinces have been attaching great importance to bioremediation technology–the use of microorganisms to degrade contaminants that pose risks to the environment or to human health.

The ability of microbes to degrade a vast array of pollutants means they can be applied to different soil conditions, the report stated.

Using a technique that involves the use of organisms to remove or neutralize pollutants from a contaminated site, some paddy fields in the two provinces have been restored to produce crops, according to the report.

For instance, a 29,000 hectare oil field in Puyang, Henan which had not been arable for years has been transformed into arable land after it was treated in this way over recent years to degrade 85% of contaminants and reduce salt levels by 85% at the site.

After being treated between 2008 and 2010, a portion of polluted farmland in Jiangsu was also restored and made arable.

An official report published in April stated that pollution caused by heavy metals, such as cadmium, mercury, copper and arsenic, is the most serious type of soil contamination in China.

With China's rapid economic development and growing population, the country's soil pollution problem has become more serious, an expert said.

The country has about 50 million hectares of land that is moderately or strongly polluted by heavy metals, according to data.

The Ministry of Agriculture estimates that 3.3 million hectares of arable land is contaminated and said that farming on land almost the size of Belgium has been stopped so that the the land can be "rehabilitated". The vice minister of land and resources, Wang Shiyuan, said that much of the contaminated land is in grain-producing areas.

According to state media this accounts for approximately 2% of China's total farmland. The environmental protection ministry has estimated that 12 million tonnes of grain are polluted by heavy metals every year.

However, through bioremediation, soil pollution has been reduced significantly.

The technology has been applied to agricultural areas in more than 20 provinces and cities over the past nine years to restore soil fertility. It is expected to boost farm production by 15%-80%.

Bioremediation can also be used to contain pollution caused by oil spillovers and can have a limited effect on human beings and the environment, at only about 30%-50% of the cost of other waste management techniques.

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