Despite initial skepticism, the trash sorting program has been successfully implemented. According to last year's figures from the Shanghai municipal government, the amount of collected recyclables had grown 57.5 percent and kitchen waste 27.5 percent, while residual waste decreased 20 percent.

Similar laws and regulations were then adopted across the country, as the central government ordered 46 major cities to finish implementing a trash classification and treatment system by the end of last year. About 300 cities at the prefecture level and above should have similar systems to classify and dispose trash by 2025.

Huang Wei, the president of electronic waste recycling company TES-AMM China, said the waste the company collects has increased in recent years. "The country is getting more serious and is supportive of the recycling industry. … The e-waste we received grew around 10 to 20 percent every year," he said.

The company has been providing services since 2005 to manufacturers to recycle old computers, mobile phones and other home appliances. It now processes about 10,000 tons of e-waste a year, recycling 98 percent of the waste back into raw materials such as gold, copper and iron.

"As the trash sorting program is gradually implemented, we hope to expand our services to recycle more e-waste from domestic waste in the next five years," Huang said.

Around 200 billion yuan ($30.7 billion) in investment will be needed if the trash sorting program in Shanghai is to be implemented across China, according to a report by Orient Securities. Another report from market tracker Mordor Intelligence said China's overall waste management market is expected to grow at a compound annual growth rate of more than 7 percent from 2019 to 2024.

Data from Qichacha, a company that tracks business registrations, showed that around 500,000 companies operate in the waste management industry in China, and more than 300,000 companies were founded in the past three years.

Many companies are entering the trash separation and recycling market. Huazhan Environment in Jiangsu province launched a new brand, Maoxiansheng, or Mr Cat in English, selling intelligent trash stations and bins to local governments and residential communities.

Equipped with cameras, sensors and screens, the smart trash stations are interactive and help people to correctly dispose of different kinds of refuse. They can also alert waste transportation companies when bins are full.

Xue Tao, executive director of environmental think tank E20 Institute, said the hottest market segments in the waste management industry will be kitchen and food waste treatment.

"Since 2019, the growth of the trash incineration market has started to slow down after several years of rapidly constructing new incineration plants, which have basically met the needs of trash incineration in large cities, and future development will be in smaller cities," he said.

Statistics from the Ministry of Ecology and Environment show that the number of trash incineration plants in China has tripled to more than 400 in the past decade.

"The implementation of trash sorting programs across the country will separate a lot of wet waste, which demands more treatment facilities, and we estimate there will be a market of 213 billion yuan during the country's 14th Five-Year Plan (2021-25) period," Xue said.

Every day, about 15,000 tons of trash－or half of the domestic trash generated in Shanghai－is processed in the Laogang Ecological and Environmental Protection Base, the largest comprehensive trash treatment facility in Asia. There are also landfills, incineration and biomass energy plants at the base.

Since beginning operations in 1985, the base has evolved from a huge landfill into a modern waste treatment center. In 2019, the second phase of its incineration plant and a new biomass plant began operations. The incineration plant can burn 6,000 tons of dry trash a day, while the biomass plant can process 1,000 tons of wet trash.

"In the past, we dumped 3 million tons of trash into the landfill a year. But now, we have changed from dumping to incineration, and only the ashes and slag are sent to landfills," said Zhu Siliu, general manager of the Laogang Renewable Resource Recycling Center.

"By burning trash, we generate up to 1.2 billion kilowatt-hours of electricity a year," Zhu said.

The recycling and resource recovery sector, which deals with waste metal, paper, textiles, plastics glass and electronics, has also been expanding. According to a report by the Ministry of Commerce and the China National Resources Recycling Association, the total amount of recycled waste was 320 million tons in 2018, up 13.4 percent from the previous year.

As for the recyclable transfer center in Pujin, the expansion of China's recycling industry is only good news.

"When the transfer center opened in 2019, we could only collect 3 tons of recyclables per day. But by the end of 2020, the daily average rose to more than 15 tons, which makes our revenue break even," said Ma, deputy manager of the center. "Public awareness and government emphasis have contributed to the change. I cannot wait to see more breakthroughs in this field in 2021."