Guiyu in southern China was long considered the world's biggest electronics recycling site. And it was a highly polluting one at that. More than 5000 small family-run businesses recycled everything from screens to motherboards.

Poor workers did much of the recycling — dismantling, sorting and processing the components by hand. This work often took place in homes or by the side of the road, and frequently with little or no protective gear.

But the process was very dirty. People burned parts or used toxic chemicals to separate precious metals and other materials from the components. The air was filled with toxins and the ground water became so polluted that it wasn't suitable for drinking.

In 2013, the provincial government stepped in. It built a large industrial park on the city's outskirts. If recyclers wanted to stay in business, they had to move to the facility, which was equipped with modern air and water filtration systems to protect the environment.

By 2015, the facility was open for business. Having to rent space there cut into the profit margins of smaller companies. Some went bust, but the upside was that air quality improved dramatically. The streets are cleaner too, say residents.

This year, China decided it no longer wanted to be the world's dumping ground and banned imports of 24 kinds of waste. As a result, there are no more discarded and broken electronics arriving in Guiyu from Europe or the United States. Well, not officially.

For years, China neglected local waste because so much was flowing in from abroad. It arrived better sorted than domestic trash and was more economical to process. Even now, some recyclers are turning to more lucrative illegally imported electronic waste.

But now Beijing plans to invest billions in household waste treatment over the next few years to deal with its domestic trash problem. According to local media reports, Chinese authorities are trying to encourage people to sort their trash properly at home.