A novel synthesis route of peach blossom-like Dawsonite adsorbent for ultra-efficient removal of Congo red and Cu2+: Adsorption behavior and mechanism study
Zhonglin Li, Wenquan Li, Zonghui He, Jun Liang, Weiguang Zhang, Xuejiao Cao, Yibing Li
Abstract
To fully leverage the advantages of hierarchical adsorbents in structural design and selective adsorption performance, the sodium aluminate solution extracted from industrial waste fly ash was initially employed in generation of Peach Blossom-like Dawsonite (PBD) adsorbent with three-dimensional and hierarchical structure via hydrothermal method . A comprehensive series of material characterization methods and confirms the successful construction of PBD adsorbent, and the specificity of PBD adsorbent material morphology not only enhances the specific surface area and regulates the pore size distribution , but also significantly improves porosity, consequently, it leads to a notable enhancement in surface reactivity as well as mass transfer efficiency, thus generating excellent adsorption capacity for Cu(II) and CR. The impact of multiple factors on the adsorption process of PBD adsorbent material was investigated using the control variable method. The relevant results indicate that the saturation adsorption capacities of PBD for Cu(II) and CR are 169.875 mg g −1 (pH = 6 T = 298 K), and 6678.30 mg g −1 (pH = 3 T = 298 K), respectively. The pseudo-second-order kinetic model and Langmuir isotherm model are more suitable to describe the whole adsorption process, and the diffusion reaction belongs to a spontaneous process, endothermic procedure and entropy increased reaction. Moreover, the adsorption mechanisms of PBD adsorbent material for Cu(II) presumably involves electrostatic interaction , complexation between Cu(II) and CO 3 2– /OH – ions, as well as ion exchange in Cu(II) and Na(I). and the adsorption mechanism of PBD on CR primarily involves electrostatic interaction, hydrogen bonds . Hence, the preparation of PBD adsorbent from solid waste not only reduces the accumulation of industrial waste, but also realizes the high-value utilization of waste, thus positioning them as promising candidates for widespread adoption in large-scale wastewater treatment projects in the future.