Effect of moist content on the bio-carbonated steel slag bricks

To deal with the problem of increasing serious environmental pollution caused by industrial solid waste such as steel slag, microbial carbonated steel slag bricks are studied in order to promote their utilization. Carbonic anhydrase (CA) bacteria are used to accelerate the carbonation process. The addition of CA bacteria improves the carbonation rate by accelerating the hydration of CO2. Water plays a significant role in the diffusion of CO2, the survival of bacteria as well as the carbonation reaction between carbon dioxide and the alkaline substance. The concept of residual water-cement ratio (R-e) is adopted to study the influence of moisture content on the carbonation process of microbial carbonated steel slag bricks. Results indicate that a proper value of R-e is vital for steel slag bricks to be well-carbonated. As R-e decreases, the acceleration effect of bacteria on the carbonation process is weakened while the diffusion of CO2 is enhanced, as a result, the final carbonation depth decreases. (C) 2020 Elsevier Ltd. All rights reserved.

Automated summary

This study focused on using microbial carbonation technology to address environmental pollution caused by industrial solid waste, and found that water and carbonic anhydrase bacteria play crucial roles in the carbonation process. Optimal moisture content is essential for achieving proper carbonation of steel slag bricks.