GUANGZHOU - Guiyu, China's largest disposal center for electronic trash, on Thursday told all electronic recycling firms they must relocate to an industrial park so pollution can be managed.

Due to severe pollution, the town in the southern province of Guangdong has given small recycling businesses until the end of 2015 the move to the industrial park, said Lin Dingliang, head of Chaoyang District of Shantou City, which administers Guiyu.

The park offers standardized disposal of effluent, waste and emissions services and does not allow any hazardous rubbish.

By November, the town had closed more than 400 workshops, while persuading the over 3,000 businesses to move to the park.

Guiyu began recycling electronic trash in the 1980s. The industry now employs 100,000 people, who dismantle 450,000 tonnes of electronic trash annually.

Due to the explosion of this industry, however, thousands of small workshops have emerged causing serious soil, water and air pollution.

"The town's river used to test as strong acid, and copper levels in the riverbed sludge were almost on par with copper mines," said Huang Tengyuan, director of the environmental protection bureau of Shantou.

Since recycling business began to be relocated to the park in 2013 there have been noticeable improvements, according to Huang.

Data from the bureau shows that compared with 2012 levels, the heavy metal content in Guiyu's air had declined by 94 percent in the first three quarters of this year, while lead, nickel and copper content in the local river had dropped by 37 percent, 78 percent and 94 percent, respectively.