Fly ash-based geopolymer: clean production, properties and applications

A comprehensive overview about the influence of different admixtures and additives on the properties of alkali-activated fly ash

Environmental chemistry of organosiloxanes.

A recent report from the United Nations has warned about the excessive CO2 emissions and the necessity of making efforts to keep the increase in global temperature below 2 °C. Current CO2 capture t...

Trends in Solid Adsorbent Materials Development for CO2 Capture

Chromium exists mainly in two forms in environmental matrices, namely, the hexavalent (Cr(VI)) and trivalent (Cr(III)) chromium. While Cr(III) is a micronutrient, Cr(VI) is a known carcinogen, and that warrants removal from environmental samples. Amongst the removal techniques reported in the literature, adsorption methods are viewed as superior to other methods because they use less chemicals; consequently, they are less toxic and easy to handle. Mitigation of chromium using adsorption methods has been achieved by exploiting the physical, chemical, and biological properties of Cr(VI) due to its dissolution tendencies in aqueous solutions. Many adsorbents, including synthetic polymers, activated carbons, biomass, graphene oxide, and nanoparticles as well as bioremediation, have been successfully applied in Cr(VI) remediation. Initially, adsorbents were used singly in their natural form, but recent literature shows that more composite materials are generated and applied. This review focused on the recent advances, insights, and project future directions for these adsorbents as well as compare and contrast the performances achieved by the mentioned adsorbents and their variants.

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Recent advances in hexavalent chromium removal from aqueous solutions by adsorptive methods

Low-reactive circulating fluidized bed combustion (CFBC) fly ashes as source material for geopolymer synthesis

The adsorption capacity of several kinds of activated carbons (ACs) for octamethylcyclotetrasiloxane (D4) in simulated landfill gas (LFG) was investigated and the main textural characteristics for AC adsorptive removal of siloxanes were studied. It was found that most of the ACs employed in this work showed good D4 adsorption capacity, and the D4 adsorption capacities of them ranged from 21.94 mg/g to 224.63 mg/g. Positive correlation was observed between D4 adsorption capacity and the BET surface area and the micropore volume of these ACs. Through analyzing nitrogen adsorption isotherms of these ACs, a conclusion was made that the super micropores and small mespores (pores of diameter ∼ 1.7–3.0 nm) in the ACs are the most favorable pores for siloxane adsorption.

Mengqun Zhang

Papers

Low-reactive circulating fluidized bed combustion (CFBC) fly ashes as source material for geopolymer synthesis

Adsorption characteristics of activated carbon for siloxanes

Surface modification of activated carbon for siloxane adsorption

Impact of using high-density polyethylene geomembrane layer as landfill intermediate cover on landfill gas extraction

Study on the deactivation of the deoxygen catalyst during the landfill gas upgrading process