Chongqing Lab Develops Four Pollution Fighters That Go Straight to the Source

Chongqing - From the air people breathe at home to emissions from traffic and waste, researchers at the Chongqing Research Academy of Eco-Environmental Sciences are developing technologies to reduce everyday exposure to urban air pollution.

Chongqing is home to over 31 million people and nearly 10 million motor vehicles. In 2025, the municipality recorded over 300 days of good or excellent air quality, and the annual average PM2.5 concentration dropped to a record low. However, air pollution remains a challenge, particularly in densely populated urban areas. And in the river valleys that carve up the city, adverse winter meteorological conditions can cause pollutants to accumulate.

The lab is tasked with developing technologies for atmospheric environmental protection. The team includes inspection engineer Li Ling, R&D engineer Hu Wei, materials engineer Pang Shanxiang, process engineer Hu Yi, among others.

To begin with, Chongqing's dense roads and waterways are the city's economic arteries, but that also means vehicle and vessel exhaust travels through them. To tackle emissions from mobile sources, the team developed vanadium‑based and copper‑based catalytic materials. 

"Many people think that controlling ship exhaust is extremely challenging, but in fact we already have mature, intelligent, and efficient treatment technology," said Hu Wei. The devices are installed at exhaust outlets, using the heat of the exhaust itself along with small amounts of auxiliary agents to convert nitrogen oxides into harmless nitrogen and water. 

Portable monitoring devices are also deployed along major urban roads and at riverside docks to detect excessive emissions in real time.

Other sources of air pollution are stationary but equally challenging to control.

"During refueling or storage at service stations, a large amount of volatile organic compounds, what we commonly call 'VOCs,' are silently released," said Li Ling. Li noted that these pollutants are colorless and odorless, invisible to the naked eye, yet they diffuse quickly and contribute to ozone and fine particulate matter, making them tricky to contain conventionally.

To address gasoline vapor emissions, the team developed a high‑porosity, carbon‑based adsorption material shaped like tiny black balls. The captured VOCs can be quickly desorbed, regenerated, and even recycled, while dedicated monitoring equipment picks up minor leaks in facilities.

While gasoline vapor may be odorless, the pungent smell at waste stations is much harder to ignore, particularly during Chongqing's long summers. 

"These are sulfur‑containing gases like hydrogen sulfide and methanethiol," explained Pang Shanxiang. "The smell draws complaints from residents, but it is difficult to pinpoint the exact source during inspections." 

The team developed an absorption material to be installed on waste management equipment.

Pang added that its composition essentially makes it an "odor detector" that accurately identifies and adsorbs sulfur‑containing malodorous molecules, even in Chongqing's humid weather.

Another common indoor air pollutant is formaldehyde, an invisible health hazard often found in new homes, new cars and enclosed public spaces. The team suggested that many existing commercial solutions only temporarily mask or adsorb the pollutant, only to be released when temperatures rise. 

The team’s material works differently. It uses a multi‑valent metal cycle that draws oxygen from air to continuously break formaldehyde down into harmless water and carbon dioxide. The material does not get used up, so there is no filter to replace, and it leaves no residue. 

The decomposition is permanent, so the formaldehyde does not reform or escape later. “It runs on its own and keeps working without any ongoing effort,” said process engineer Hu Yi.