TY - JOUR ID - 128376 TI - ZnO-MgFe2O4/(Mg)- or (Zn)-Al-LDH Composites: Adsorption Efficiency, Kinetics, and Adsorption Isotherm for Congo Red Removal JO - Physical Chemistry Research JA - PCR LA - en SN - 2322-5521 AU - Yarahmadi, Pegah AU - Movadedi, Maryam AU - Salavti, Hossein AD - Department of Chemistry, Payame Noor University, P. O. Box: 19395-3697 Tehran, Iran Y1 - 2021 PY - 2021 VL - 9 IS - 2 SP - 311 EP - 325 KW - ZnO-MgFe2O4 KW - ZnAl-LDH KW - MgAl-LDH KW - Adsorbent KW - Composite DO - 10.22036/pcr.2021.247509.1830 N2 - In this research, the ZnO-MgFe2O4/ZnAl-LDH, ZnO-MgFe2O4/MgAl-LDH, ZnO-MgFe2O4, ZnAl-LDH, and MgAl-LDH were prepared and characterized using X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), and FT-IR spectrometer analysis. The samples were synthesized by the co-precipitation method. The efficiency of the samples was investigated for the Congo red dye removal from the aqueous solution. According to the results, a similar efficiency for the LDHs samples and ZnO-MgFe2O4/LDHs composites was observed. The experimental data for the ZnO-MgFe2O4/ZnAl-LDH and ZnO-MgFe2O4/MgAl-LDH composites were analyzed by adsorption isotherm (Langmuir and Freundlich) and kinetic models (pseudo-first-order, pseudo-second-order, and intra-particle diffusion). The results showed more than >90% of the Congo red dye was removed from the solution after 90 min contact time. The experimental results showed the adsorption process fitted well with the Langmuir isotherm model and pseudo-second-order kinetic model. For the ZnO-MgFe2O4/ZnAl-LDH and ZnO-MgFe2O4/MgAl-LDH samples, the RL value close to zero (0.024 and 0.037) was obtained. This result indicates that the adsorption of the CR dye molecules on the surface of the samples is an almost irreversible process. The low RL value indicates that the interactions between Congo red dye molecules and LDH composites might be relatively strong. UR - https://www.physchemres.org/article_128376.html L1 - https://www.physchemres.org/article_128376_ce0d00ad91472edcf7c4a5a8a368dcb7.pdf ER -