CHN Energy has successfully developed China’s first microalgae-based biological carbon sequestration system designed for ecological restoration in mining areas, marking a technological breakthrough in low-carbon mine rehabilitation.
Centered on microalgae, the technology utilizes raw pit water from coal mines and carbon dioxide generated from agricultural and livestock waste as cultivation media, integrating microalgae carbon sequestration with pit water purification and soil regeneration.
In a pilot experiment conducted on a 2,100-square-meter desertified waste dump at the Baorixile mining area, vegetation restoration was achieved without on the use of external topsoil. Test results showed that vegetation coverage increased from 38 percent to 54 percent, soil moisture content rose from 14 percent to 85 percent, and total soil organic carbon content recorded a maximum increase of 613.2 percent.
Through microalgae cultivation, the system purifies pit water by absorbing nitrogen and phosphorus pollutants and immobilizing heavy metals. The restored vegetation system forms sustained carbon sink, creating a circular restoration model that links water, soil and vegetation within mining areas.
The technology is primarily to address ecological restoration challenges in northern regions characterized by water scarcity and limited soil resources. Its application offers a replicable technical pathway for ecological rehabilitation in similar mining environments.
