Hereon Study Highlights CO₂ Sequestration Potential of Alkaline Industrial Wastewater

Researchers at Helmholtz-Zentrum Hereon have developed a method to chemically bind carbon dioxide (CO₂) using alkaline industrial wastewater, such as that produced in cement and steel manufacturing. This process involves neutralizing the wastewater with CO₂, forming bicarbonate that sequesters the greenhouse gas in water for the long term.

Traditionally, these wastewaters are neutralized with strong acids like sulfuric or hydrochloric acid before being discharged into rivers, a practice that overlooks their potential for CO₂ sequestration. By substituting CO₂ for these acids, the process not only neutralizes the wastewater but also captures significant amounts of CO₂.

The study estimates that implementing this method globally could sequester approximately 30 million tons of CO₂ annually. The necessary technology is already available, allowing for immediate application. Additionally, the process meets environmental and regulatory constraints, particularly concerning pH levels, by automatically adjusting the released waters to match the original conditions of the receiving rivers.

This approach offers a practical and scalable solution for reducing atmospheric CO₂ levels by leveraging existing industrial processes and waste streams.