Ningbo customs in East China's Zhejiang Province seized 523.7 tons of solid waste, according to a General Administration of Customs statement.

The seized garbage included five batches of sub-standard polyester flakes from Malaysia and Indonesia, which are banned imports. The statement added that the solid waste had been handed over to related departments for processing.

China began importing solid waste as a source of raw materials in the 1980s, and has been the world's largest importer for years, despite its weak capacity for garbage disposal. 

Some companies illegally bring foreign waste into the country for profit, posing a threat to the environment and public health.

Given rising public awareness of environmental protection and China's green development drive, the government decided to phase out and halt such imports by the end of 2019, except those containing resources that are not substitutable.

The Chinese government announced plans last year to ban 32 types of solid waste, including plastics and paper, and has imposed tough quality restrictions on other recyclable materials.