{"id":198,"date":"2025-06-20T08:32:27","date_gmt":"2025-06-20T15:32:27","guid":{"rendered":"https:\/\/scienceblog.com\/sciencechina\/?p=198"},"modified":"2025-06-20T08:32:27","modified_gmt":"2025-06-20T15:32:27","slug":"bacteria-turn-steel-waste-into-carbon-capturing-cement","status":"publish","type":"post","link":"https:\/\/scienceblog.com\/sciencechina\/2025\/06\/20\/bacteria-turn-steel-waste-into-carbon-capturing-cement\/","title":{"rendered":"Bacteria Turn Steel Waste Into Carbon-Capturing Cement"},"content":{"rendered":"

Chinese researchers have developed a microbial system that transforms steel industry waste into useful construction materials while simultaneously capturing carbon dioxide from cement plant emissions. The technology addresses two major environmental challenges with a single biological solution.<\/p>\n

The study, published in Engineering, demonstrates how bacteria can accelerate the conversion of steel slag\u2014a massive industrial byproduct\u2014into supplementary cement materials that actively remove CO2 from the atmosphere. Over 400 million metric tons of steel slag accumulate globally each year, with less than 30% finding productive use.<\/p>\n

Microbial Engineering at Work<\/h2>\n

The research team, led by Professor Chunxiang Qian from Southeast University, employed Bacillus mucilaginosus bacteria in a rotating reactor system that processes cement kiln flue gas. The microorganisms accelerate chemical reactions that would normally require high temperatures and pressures, making the process energy-efficient and scalable.<\/p>\n

Within just one hour, the microbial system achieved a CO2 fixation ratio of approximately 10%\u2014nearly double the rate achieved without bacterial assistance. The process remained consistent across different seasons and varying flue gas compositions, demonstrating remarkable stability for industrial applications.<\/p>\n

Solving Multiple Problems<\/h2>\n

Steel slag presents significant challenges for the construction industry. Its expansion-prone compounds make it unsafe for widespread use, while its low reactivity limits its effectiveness as a cement substitute. The microbial carbonation process addresses both issues simultaneously.<\/p>\n

“When the CO2-fixation ratio exceeds 8% and the specific surface area is at least 300 m\u00b2\/kg, the soundness issue of steel slag can be effectively addressed, facilitating the safe utilization of steel slag,” the researchers found.<\/p>\n

Key Performance Metrics<\/h2>\n