No abstract

No abstract

In the present study, a porous concrete with alkali activated slag (AAS) and coal bottom ash was developed and the effect of carbonation on the physical property, microstructural characteristic, and heavy metal leaching behavior of the porous concrete were investigated. Independent variables, such as the type of the alkali activator and binder, the amount of paste, and CO 2 concentration, were considered. The experimental test results showed that the measured void ratio and compressive strength of the carbonated porous concrete exceeded minimum level stated in ACI 522 for general porous concrete. A new quantitative TG analysis for evaluating CO 2 uptake in AAS was proposed, and the result showed that the CO 2 uptake in AAS paste was approximately twice as high as that in OPC paste. The leached concentrations of heavy metals from carbonated porous concrete were below the relevant environmental criteria.

No abstract

Chlorine is a critical element with respect to the use of fossil fuel, recycling of industrial wastes, and water purification. Chlorine could form toxic chemical compounds, corrode pipe systems and boilers, and contaminate surface and ground waters. Calcium aluminate-layered double hydroxides are one of the most promising materials to remove chlorides due to the chemisorption mechanism, since the phases have positively charged interlayers. Many studies on the synthesis and the characterization of calcium aluminate-layered double hydroxides have been extensively conducted, whereas few studies have been conducted on the chloride removal characteristics of the phases. The state-of-the-art studies on the synthesis methods and the structural characteristics of CaAl-LDH phases, the underlying mechanism on the removal of chlorides, and the potential removal rate and the capacity in the present study were thoroughly reviewed.

No abstract

No abstract

No abstract