Ocean-based carbon dioxide removal has gained immense attention as a countermeasure against climate change. The enhancement of ocean alkalinity and the creation of new blue carbon ecosystems are considered effective approaches for this. To evaluate the function of steelmaking slag from the viewpoints of CO reduction and creation of new blue carbon ecosystems, we conducted a comparative experiment using two mesocosms that replicated tidal-flats and shallow-water ecosystems. Initially, approximately 20 seagrasses (Zostera marina) were transplanted into the shallow-water area in the mesocosm tanks. The use of steelmaking slag is expected to increase the pH by releasing calcium and mitigate turbidity by solidifying dredged soil. In the experimental tank, where dredged soil and steelmaking slag were utilized as bed materials, the pH remained higher throughout the experimental period compared with the control tank, which utilized only dredged soil. As a result, pCO remained consistently lower in the experimental tank due to mainly its alkaline effect (March 2019: -10 ± 6 μatm, September 2019: -130 ± 47 μatm). The light environment in the control tank deteriorated due to high turbidity, whereas the turbidity in the experimental tank remained low throughout the year. The number of seagrass shoots in the experimental tank was consistently approximately 20, which was higher than that in the control tank. Additionally, more seaweed and benthic algae were observed in the experimental tank, indicating that it was more conducive to the growth of primary producers. In conclusion, tidal-flat and shallow-water ecosystems constructed using dredged soil and steelmaking slag are expected to enhance CO uptake and provide a habitat for primary producers that is superior to those constructed using dredged soil only.
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http://dx.doi.org/10.1016/j.marenvres.2023.106223 | DOI Listing |
Langmuir
November 2024
School of Metallurgy, Northeastern University, Shenyang 110819, Liaoning, China.
To reuse red mud and slag wastes as raw materials, a green type of porous spherical red mud/slag-based geopolymer (RSG) was synthesized by utilizing suspension curing and foaming techniques. Because methylene blue (MB) and nickel ion (Ni) were common and difficult to treat in wastewater, the adsorption characteristics of MB and Ni, as well as the phase and microstructure of the porous RSG spheres prior to and after adsorption, were thoroughly investigated. The porous RSG spheres showed a stable and mesoporous structure with a BET surface area of 31.
View Article and Find Full Text PDFEnviron Sci Pollut Res Int
September 2024
School of Materials Science and Engineering, Chang'an University, Xi'an, 710061, China.
As a byproduct of steelmaking, steel slag occupies significant land resources and poses potential environmental and safety challenges due to its extensive accumulation. Recently, steel slag has shown promising applications in the field of concrete. However, considering the complexity of the plateau environment, the utilization of steel slag is relatively lacking, and its low reactivity and poor volume stability remain the main factors restricting its application in plateau concrete.
View Article and Find Full Text PDFJ Hazard Mater
November 2024
Department of Civil and Environmental Engineering, Vanderbilt University, PMB 351826, Nashville, TN 37235-1826, USA. Electronic address:
Electric arc furnace (EAF) slag is the non-metallic byproduct of the primary U.S. steelmaking process.
View Article and Find Full Text PDFThe iron and steel-making industries have garnered significant attention in research related to low-carbon transitions and the reuse of steel slag. This industry is known for its high carbon emissions and the substantial amount of steel slag it generates. To address these challenges, a waste heat recovery process route has been developed for molten steel slag, which integrates CO capture and fixation as well as efficient utilization of steel slag.
View Article and Find Full Text PDFJ Environ Manage
August 2024
College of Water Conservancy and Architectural Engineering, Northwest A&F University, Yangling, 712100, China.
Steel slag (SS) is a byproduct that comes from the production of crude steel in alkaline oxidation furnaces. Resource utilization of steel slag, a calcium-silicon solid waste, is an urgent problem. This paper investigates a solid waste disposal method that applies different steel slag contents to modify dispersive soil.
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