A heavily polluted river flows through Nanjing in 2017. The liquids dumped by Wang contained hazardous chemicals including aniline, bromine, sulfide and silver, which combined can lead to physical deformities and cancer after a long period of exposure. Photo: VCG

A man in the eastern city of Nanjing has been sentenced to two years in prison for dumping more than 200 metric tons (22 tons) of toxic waste into local rivers and drainage systems.

The self-employed businessman, surnamed Wang, collected chemicals used to treat photo film from several photo studios from 2007 and extracted silver sulfide from the toxic liquid before discharging the waste into drainage systems, streams and trenches near his home, trial documents from Nanjing’s Xuanwu District People’s Court showed.

A kilogram (2.2 pounds) of silver sulfide can be sold for 1,600 yuan ($254), according to a research paper published in Chinese journal Frontiers of Engineering Management in 2014. Between three to 20 kilograms of silver sulfide can be extracted from 1,000 kilograms of photo processing liquid, according to the article.

Wang didn’t have a license to collect or dispose of hazardous chemicals. He was ordered to pay 1.94 million yuan in fines and fees to cover costs linked to environmental damages.

The ruling is the latest in a string of cases where reckless business owners were caught discharging untreated toxic waste in recent years.

Used photo treatment liquid contains many hazardous chemicals including aniline, bromine, sulfide and silver, which combined can lead to physical deformities and cancer after a long period of exposure.

Samples of wastewater dumped by Wang contained 2.3 micrograms of sulfide per liter, 2.3 times what is allowed by the law, and 139 micrograms of silver per liter, which is 278 times the safe limit set by the law, according to the district court.

Companies that use chemicals to process photo film should contract licensed waste treatment businesses to dispose of the residue and should notify district or city environmental authorities about their waste disposal contracts, according to an employee at the privately-owned Shanghai 365 Waste Management Service Center

Photo studios that contracted Wang to get rid of their waste should also be held liable, the district court said without elaborating.

Contact reporter Li Rongde (rongdeli@caixin.com)