No abstract

Economic development in many developing countries is leading to a significant increase in atmospheric CO2 in recent decades, exacerbating global climate change. One of the solutions being vigorously researched is the use of cheap and environmentally friendly CO2 adsorbents. In this study, solid residues from gasification of bagasse, and pyrolysis of macadamia nut shells were used for CO2 adsorption. The N2 adsorption/desorption results showed that the post-gasification residue was much more porous compared to the post-pyrolysis residue. The CO2 adsorption experiments were carried out in laboratory conditions (100 % CO2, 25 °C) and flue gas conditions (15 % CO2, 40 °C). The bagasse residue achieved a high and stable CO2 adsorption value at 2.3 mmol/g, 2.5 times more than that of macadamia nut shells residue. This result showed that residues from thermal conversion processes could be re-used as cheap and environmentally friendly materials for CO2 capture.

Global challenges in removing heavy metal ions from aquatic reservoirs require novel solutions, especially the application of environmentally friendly materials. This paper presented the efficient removal of Fe3+ and Pb2+ ions from wastewater by apatite ore-based nanostructures. The synthesized material exhibited a nanostructure with high thermal stability, high porosity and negative surface potential, suitable for heavy metal removal in wastewater. The adsorption measurements performed in varying conditions (pH, mass of the adsorbent, and contact time onto the adsorbent) proved that even a few milligrams of the synthesized material could effectively absorb the lead and iron ions from the solution, reaching an effectiveness of about 90%. The maximum adsorption capacity followed the Langmuir isotherm model, estimated at 341 mg.g− 1 for Pb2+, and 1092 mg.g− 1 for Fe3+. Experiments conducted with industrial and craft-village’s wastewaters confirmed the high potential of the nanostructural chemically modified apatite as an efficient and affordable material for the removal of various pollutants from aqueous solutions in practical conditions.