Removal of Malachite Green Dye Using IRMOF-3–MWCNT-OH–Pd-NPs as a Novel Adsorbent: Kinetic, Isotherm, and Thermodynamic Studies

Abstract

IRMOF-3 and its modifications, known as IRMOF-3−MWCNT-OH and IRMOF-3−MWCNT-OH−Pd-NPs, are prepared and characterized using Fourier transform infrared spectroscopy, infrared spectroscopy, field emission scanning electron microscopy, X-ray diffraction, energy dispersive spectroscopy, and Brunauer− Emmett−Teller (BET) analysis. These adsorbents, especially IRMOF-3−MWCNT-OH−Pd-NPs, are proposed as a novel adsorbent to remove malachite green (MG) dye from aqueous solutions. In this way, several parameters including initial dye concentration, pH, adsorbent mass, and sonication time are considered as the effective parameters that must be optimized. Using the optimized parameters obtained by the central composite design approach for the IRMOF-3, IRMOF-3−MWCNT-OH, and IRMOF-3−MWCNT-OH−Pd-NPs leads to maximum adsorption efficiencies of 37.20%, 55.50%, and 96.10%, respectively, while under the same conditions, the removal percentage significantly increases when the adsorbent is modified with MWCNT-OH and Pd-NPs. For instance, at 4 mg L −1 MG concentration, 5.5 for pH value, 12.5 min sonication time, and 0.01 g of adsorbent mass, an adsorption efficiency of 21.10%, 35.00%, and 96.80% is obtained, respectively. In addition, zero point charge analysis performed for IRMOF-3, IRMOF-3−MWCNT-OH, and IRMOF-3−MWCNT-OH−Pd-NPs demonstrates quantitative values of 3.30, 3.50, and 3.80, respectively. Besides, isotherms, kinetics, and thermodynamics investigations revealed that a pseudo-first-order, Langmuir isotherm model and endothermic reaction introduce the best modeling behaviors for MG adsorption onto the three aforementioned adsorbents. Moreover, the measured BET surface area reveals that the BET for IRMOF-3, IRMOF-3−MWCNT-OH, and IRMOF-3−MWCNT-OH−Pd-NPs before and after adsorptions are 52.03 and 41.39 m 2 g −1 , 207.51 and 205.18 m 2 g −1 , and 194.96 and 31.78 m 2 g −1 , respectively. Finally, reusability analysis results reveal that among the examined adsorbents, IRMOF-3 introduces no reusability potential, while IRMOF-3−MWCNT-OH and IRMOF-3−MWCNT-OH−Pd-NPs have three and five sequential recoveries, respectively.

Artificial neural network modelling and experimental investigations of malachite green adsorption on novel carboxymethyl cellulose/β-cyclodextrin/nickel cobaltite composite

“…Isoreticular MOFs (iso-M) and their modifications with multiwall CNTs and Pd are reported in Table 6 , the material exhibits a faster adsorption uptake for MG but the synthetic material is not so ecofriendly and suffers from low adsorption capacity. Moreover, MOFs often suffer from stability related issues [ 67 ]. The disadvantages and advantages of these adsorbents compared to CMC-SA- β -CD/NCO are reported in Table 6 .…”

Efficient adsorptive removal of paracetamol and thiazolyl blue from polluted water onto biosynthesized copper oxide nanoparticles

“…Additionally, the magnitude of ΔH° helps in the classification of the process as physisorption or chemisorption. The ΔH° values less than 40 kJ/mol is said to be dominated by physical adsorption while values higher than 40 kJ/mol can be as ascribed to chemisorption 77 . The ΔH° values obtained indicated that www.nature.com/scientificreports/ the adsorption of thiazolyl blue and paracetamol on the biosynthesized CuONPs conforms to physical adsorption, which supports the deduction of the isotherm model analysis.…”

Macro-Reticular Ion Exchange Resins for Recovery of Direct Dyes from Spent Dyeing and Soaping Liquors

“…Due to charge attraction and Van der Waals forces, dye molecules have a high affinity for adsorption on the surface of adsorbents, resulting in chemical and physical adsorption [ 34 ]. According to studies, adsorbents have the best removal rates and sorption capacities while being easy to operate and economically practical [ 35 ]. The literature contains valuable information about the applicability of IERs in the removal of dyes from aqueous solutions [ 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 ].…”