A landfill that has been dormant for more than 20 years is finally stirring. Looming over Shenzhen in south China's Guangdong Province, the Yulong Landfill is a titan of a bygone era. It holds a staggering 2.5 million cubic meters of waste—a volume that can fill 1,000 Olympic-sized swimming pools. For decades, this 50-meter-high mountain of refuse sat hushed—a stark, grim monument to the city's raw industrial beginnings.

Built in 1983, decommissioned in 1997, and officially capped in late 2005, the site has, for more than two decades, been a festering sore on Shenzhen's landscape. "When the landfill was first built, it was still on the city's fringe. But as the city grew, this site has gradually evolved from desolate wilderness to what is now the urban core," Cao Yongmin, lead designer of the Yulong Landfill Environmental Remediation Project, told CCTV News on January 18.

In late 2024, local authorities officially launched the environmental restoration of the Yulong landfill, embarking on a full-scale excavation, relocation and treatment of the massive site. Cao said the most important factor enabling the cleanup is that today's waste treatment technology has finally reached a level capable of eradicating this stubborn environmental blight at its root.

Scar to launchpad 

The entire excavation has been operating under a colossal canopy—a span of a maximum 280 meters makes it the largest canopy system in China. This hi-tech shroud acts like a giant tent, shielding the gritty reality of the landfill from the public eye. Inside, an integrated misting system silently neutralizes odors and dust, ensuring that while a mountain is being moved, the city barely catches a scent of its past.

Just 500 meters away, the sorting facility hums with mechanical precision. Six massive conveyor belts, resembling industrial slides, move 6,000 tons of waste every day—the most ambitious sorting operation in the country. Here, the mountain of trash is meticulously dissected into three distinct streams: organic waste for composting or refining, inorganic aggregates for recycling, and light combustibles destined for the furnace.

The journey of this "golden fuel" ends a few dozen km away at a state-of-the-art waste-to-energy plant. Inside the belly of the furnace, the waste is subjected to a 1,100-degree-Celsius inferno for two hours. But the real scientific triumph happens at 850 degrees Celsius: by maintaining this heat for at least two seconds, dioxins—the most feared toxic byproducts—are systematically obliterated.

"Our emission levels aren't just low; they are virtually undetectable," Zhao Lichao, project manager at Shenzhen Energy Environment, a leader in hi-tech waste solutions, told Xinhua News Agency. While the national limit is 0.1 nanograms per cubic meter, this facility operates at a mere 0.004.

This is about more than just disposal; it's about power. Zhao introduced that utilizing a self-developed, seven-stage filtration system that is 100 percent domestically manufactured, the plant processes 5,100 tons of trash daily. Estimates show that the landfill will yield approximately 330,000 tons of light combustible materials through screening, which are expected to generate 100 million kilowatt-hours of electricity, enough to power 26,000 households for a full year.

Even the leftover slag (bottom ash) finds a second life. Instead of returning to a hole in the ground, it is transported to a specialized factory and compressed into "eco-bricks." These bricks are tougher and cheaper than traditional clay, forming the foundation of Shenzhen's roads and infrastructure. If they break, they can simply be recycled again.

Overseeing this entire "industrial ballet" is a digital watchdog. Every furnace is equipped with automatic sensors linked directly to environmental authorities, providing real-time, traceable data to ensure the process remains transparent and safe.

The project is set to be completed late this year. Once the land is restored and the last of the trash is transformed, this site will become a launchpad. In place of the landfill, a new ecosystem of AI, life sciences and the digital economy will rise.

Beyond the furnace 

The excavation currently underway in Shenzhen is far from a solitary endeavor. Over the past two years, several other Chinese cities have begun unearthing landfills that have sat dormant for decades, reclaiming aged waste, which will be repurposed and recycled.

Across China, a quiet alchemy is turning the discarded into the desired. In a radical reversal that borders on the surreal, yesterday's filth has been rebranded as "golden fuel," a leap driven by the technological evolution of waste-to-energy incineration.

This journey has not been without its hurdles. In the 1980s, China began importing foreign incineration equipment, but the high costs and technical mismatches posed problems. "Western garbage is 'dry' and burns like a cracker. But Chinese garbage is 'wet,' mixed with large amounts of leftover food," Yan Jianhua, a professor at Zhejiang University's College of Energy Engineering, told newspaper Zhejiang Daily.

In an era before widespread sorting, the waste entering Chinese incinerators had a moisture content of over 50 percent. For imported equipment, attempting to burn this was essentially like "boiling water." To maintain the critical 850-degree-Celsius threshold, early incineration plants had to pour tons of diesel fuel into their furnaces as a supplement—driving up costs and defeating the purpose.

To overcome this challenge of "technological indigestion," Chinese scientists, including Yan, began a drive for localization in the 1990s. Yan led his team to develop a heterogeneous circulating fluidized bed incineration technology specifically tailored to China's high-moisture waste.

By re-engineering the furnace structure, they ensured that even damp refuse could burn stably and trigger the critical "two-second moment," the window of high-temperature combustion that destroys toxins, without requiring massive amounts of external fuel.

Thanks to decades of research and development by these scientists, China's waste-to-energy technology and equipment are now 100 percent domestically produced, driving down costs. Over the past decade, supported by policies like electricity subsidies, the industry has grown into a complete industrial chain with a mature commercial model.

China's independently developed waste-to-energy technology is currently empowering several partner countries under the Belt and Road Initiative, a China-proposed framework to boost connectivity along and beyond the ancient Silk Road routes. According to data from the All-China Environment Federation, as of May 2025, Chinese enterprises were involved in 79 overseas waste incineration projects, including those already under contract.

"Waste is simply a resource that has been put in the wrong place," Du Xiangwan, former Vice President of the Chinese Academy of Engineering and a key figure in the Waste-Free City initiative, told newspaper Guangming Daily.

He added that despite the sophistication of modern incineration, front-end waste sorting remains far from obsolete. Separated kitchen waste can undergo anaerobic digestion, a natural process where microorganisms break down organic matter (including food waste) in an oxygen-free environment, to produce biogas, while recyclables can be reintegrated into industrial production chains. Only the true remnants, aka the waste that has absolutely nowhere else to go, should be destined for the flames.

The core of the Waste-Free City initiative is not about building more furnaces; it is about waste reduction at the beginning of the cycle, he emphasized. "We are aiming to build a closed loop of resource circulation, not merely a sophisticated discharge point for waste," he said.

Copyedited by Elsbeth van Paridon 

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