An efficient magnetic nanoadsorbent based on functionalized graphene oxide with gellan gum hydrogel embedded with MnFe layered double hydroxide for adsorption of Indigo carmine from water

The primary objective of this investigation was to synthesize a novel antibacterial nanocomposite consisting of natural gellan gum (GG) hydrogel, MnFe LDH, GO, and Fe3O4 nanoparticle, which was developed to adsorb Indigo carmine (IC). The GG hydrogel/MnFe LDH/GO/Fe3O4 nanocomposite was characterized through different analytical, microscopic, and biological methods. The results of adsorption experiments reveal that 0.004 g of the nanocomposite can remove 98.38 % of IC from a solution with an initial concentration of 100 mg/L, within 1 h at room temperature and under acidic pH conditions. Moreover, the nanocomposite material effectively suppressed the in vitro growth of both E. coli and S. aureus strains, with inhibitory rates of 62.33 % and 53.82 %, respectively. The isotherm data obtained in this investigation were fitted by linear and non-linear forms of Langmuir, Freundlich, and Dubinin-Radushkevich (D-R) isotherms equations. The results of the adsorption kinetics study indicated that the pseudo-second-order model best described the experimental data. The findings of this study suggest that the synthesized nanocomposites hold great potential as effective adsorbents for removing IC and bacteria from aqueous solutions.

Thermal and environmental optimization of an intercooled gas turbine toward a sustainable environment

In this article, in order to achieve a sustainable environment, the optimization of a GT equipped with intercooling of the compression process is discussed. To limit the exergy destruction in intercooling cooling process and also to reduce the heat dissipation in the environment, an ORC system is applied for heat recovery and more power generation. Decision variables include CPR, first stage CPR, TIT, intercooler effectiveness, HRVG pressure, and superheating degree. During a parametric study, the effect of decision variables on operating factors including exergy efficiency, TCR, and the normalized emission rate of environmental pollutants are investigated. Finally, by performing bi-objective optimization and considering exergy efficiency and TCR as OFs, optimal performance conditions are determined. Finally, it is observed that in optimum conditions, exergy efficiency is 33% and TCR is 0.9 $/s.