PPI-Dendrimer-Functionalized Magnetic Metal–Organic Framework (Fe3O4@MOF@PPI) with High Adsorption Capacity for Sustainable Wastewater Treatment (original) (raw)
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Nanochemistry Research, 2023
Magnetic nanocomposites of nickel ferrite nanoparticles, uniformly dispersed in the silica matrix, were synthesized successfully by a sol-gel process using tetraethyl orthosilicate (TEOS) and metallic nitrates as precursors. NiFe2O4@SiO2@HKUST-1 magnetic nanocomposites were synthesized and characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectrometry (FTIR), vibrating sample magnetometry (VSM), nitrogen adsorption porosimetry, Thermal Analysis (TGA), photoluminescence analysis, and UV-visible. The more acidic pHs and lower concentrations of the dye solution, the less the dye molecules are present in the solution; therefore, the pore volumes and surface areas will be filled slowly and with higher removal efficiency. Magnetic nanocomposite of metal-organic, ferrite-nickel, and silica framework have high efficiency and absorbability for cationic dyes such as methylene blue. Within 60 minutes, approximately 98% of the dye molecules were removed using the magnetic metal-organic framework nanocomposite 30% NiFe2O4@SiO2@HKUST-1 under optimum condition. Adsorption isotherms, kinetics, and adsorption studies have shown that R2 is the most frequent Freundlich isotherm, which means that the adsorption process was mainly multilayered on heterogeneous surfaces of the metal-organic framework nanocomposites.
Magnetochemistry
In the present study, a ternary magnetic nanocomposite (SiO2/MnFe2O4/ZIF-8) was synthesized via the embedding of the SiO2/MnFe2O4 nanocomposite within the metal–organic framework (ZIF-8). The synthesized nanocomposite was characterized using suitable techniques including FT-IR, XRD, SEM, TEM, VSM, and BET. The nanocomposite showed a high surface area (SBET = 831 m2·g−1) and superparamagnetic behavior (23.7 emu·g−1). All characterization techniques confirmed the successful combination of three nanocomposite parts (MnFe2O4, SiO2, and ZIF-8). The nanocomposite was examined for the adsorption of organic dyes, malachite green (MG) and methyl red (MR), from aqueous solutions. The adsorption conditions including ionic strength, contact time, pH, and adsorbent dosage were optimized by studying their change effect. The SiO2/MnFe2O4/ZIF-8 nanocomposite showed high adsorption capacities (1000.03 and 1111.12 mg/g) for the removal of MG and MR, respectively, from water. The isotherm and kinetics...
Efficient removal of some anionic dyes from aqueous solution using a polymer-coated magnetic nano-adsorbent
For the efficient removal of some anionic dyes, a novel adsorbent was developed. The adsorbent was prepared by coating a synthetic polymer on magnetite nanosphere surface as a magnetic carrier. The synthesized nano-adsorbent was fully characterized using Fourier transform infrared spectroscopy (FT-IR), vibrating sample magnetometer, X-ray diffractometer, scanning electron microscope, and transmission electronic microscopy measurements. The synthesized nano-adsorbent showed high adsorption capacity towards removal of some anionic dyes (221.4, 201.6, and 135.3 mg g1 for reactive red 195, reactive yellow 145, and reactive blue 19 dye, respectively) from aqueous samples. The dye adsorption was thoroughly studied from both kinetic and equilibrium points of view. It was found that the Langmuir isotherm showed a better correlation with the experimental data. The kinetic data showed that the process was very fast, and the adsorption process followed pseudo-second order kinetic models for the modified magnetic nano-adsorbent. Furthermore, the results showed that a stable and reusable (up to 20 cycles) nano-adsorbent for dye removal purposes was synthesized.
CrytEnggComm, 2019
Herein, two metal organic frameworks (MOFs), namely, [{Cu 2 IJμ-OH)IJμ-OAc)IJH 2 O)IJOAc)IJbpy) 2 }NO 3 ·4H 2 O] n (CuMOF-1) and [{CoIJbpy)IJClO 4) 2 IJH 2 O) 2 }·bpy] n (CoMOF-2), where bpy = 4,4′-bipyridine, were synthesized, characterized and explored for their material importance in magnetism and dye adsorption. Under solvothermal conditions, two different metal salts (nitrate and perchlorate) were reacted with a simple bench chemical, i.e., a dipyridine derivative, namely, bpy to afford two MOFs having different yet interesting topologies and adsorption properties. The structure of CuMOF-1 was built from the repeating building blocks of the dinuclear cationic CuIJII) units composed of two CuIJII) ions, two bpy ligands, two acetate ions (OAc), one hydroxide ion (OH −) and a water molecule. Interestingly, two different Cu atoms existed in the structure with two different coordination geometries, i.e., octahedral and trigonal bipyramidal. The sql to-pology of the resulting 4-c uninodal net with point symbol {4 4 ·6 2 } was obtained for CuMOF-1. The cluster representation of CuMOF-1 further gave hxl topology with 6-c uninodal nets (point symbol: {3 6 ·4 6 ·5 3 }). CoMOF-2 was built from repeating mononuclear CoIJII) units, where each Co atom coordinated with two bpy ligands, two perchlorate ions and two water molecules, resulting in octahedral geometry around the CoIJII) ions. The surprising nature of the structure of CoMOF-2 was that one bpy ligand was coordinated with cobalt, while the second bpy ligand was present in the lattice in between layers, thus consolidating the structure by strong hydrogen bonding with the coordinated water molecules of the neighboring units. The resulting underlying net in CoMOF-2 was 2C1 with sql topology. The magnetic data indicated the presence of strong antiferromagnetic interactions in MOFs (J = −98.21 cm −1 in CuMOF-1 and θ = −8.8 K in CoMOF-2). The present MOFs were exploited for the adsorption of two dyes, namely, methylene blue (MB) and methyl orange (MO), which are organic pollutants. The adsorption studies confirmed that CoMOF-2 is a more selective adsorbent for MB. The kinetic data disclosed the pseudo-second-order mechanism of ad-sorption in both cases. The cation/anion-π interaction between the dyes and π-electron-rich bpy was responsible for the adsorption behaviour of MOFs. Moreover, the presence of free bpy in the lattice of CoMOF-2 gave rise to the strongest interactions, making CoMOF-2 the best adsorbent.
Recent Advances in MOF-Based Adsorbents for Dye Removal from the Aquatic Environment
Energies
The adsorptive removal of dyes from industrial wastewater using commercially available adsorbents is not significantly efficient. Metal–organic frameworks (MOFs) offer outstanding properties which can boost the separation performance over current commercial adsorbents and hence, these materials represent a milestone in improving treatment methods for dye removal from water. Accordingly, in this paper, the recent studies in the modification of MOF structures in dye removal from the aquatic environment have been discussed. This study aims to elaborate on the synthetic strategies applied to improve the adsorption efficiency and to discuss the major adsorption mechanisms as well as the most influential parameters in the adsorptive removal of dyes using MOFs. More particularly, the advanced separation performance of MOF-based adsorbents will be comprehensively explained. The introduction of various functional groups and nanomaterials, such as amine functional groups, magnetic nanoparticl...
Waste Water Treatment Through Dendrimer -Conjugated Magnetic Nanoparticles
International Journal of Chem Tech Research, 2013
Water treatment by the use of nano technology has been an encouraging progress, though nano membranes and nanofilters are used in the treatment of water, the technology of metal ion removal by the use of a nanoadsorbant is at a neonatal stage in India, though it has been proposed that the nanoadsorbants have a tremendous potential for effective physical as well chemical treatment of water. The aim of the present study was to synthesize silica based PAMAM dendrimer (nanoadsorbant) with ester and amino groups at the outer surface, to evaluate its metal binding properties from tannery effluent using Atomic Absorption Spectroscopy. The synthesis of dendrimer is usually carried out in two ways namely convergent technique and divergent technique. In the divergent technique, the dendrimer is assembled from a multifunctional core, which is extended outward by a series of reactions, commonly a Michael reaction. In the case of convergent technique, Dendrimers are built from small molecules that end up at the surface of the sphere, and reactions precede inward building inward and are eventually attached to a core. PAMAM is normally synthesized by divergent methods starting from ammonia or ethylenediamine initiator core reagents. PAMAM is found to have high surface functionality, which is very helpful in the adsorption of metal ions. PAMAM belong to the class of water soluble polymers which is a criteria much needed for the agent in the treatment of water. They can act as flocculants for dye industry waste water treatment. Amine terminated PAMAM dendrimers exhibit and high affinity for adsorption of metal ions to their surface via co ordination to the amine or the acid functionality. It is pH independent in its action. Silica gel being an adsorbent with excellent thermal and mechanical stability, used in most chromatographic techniques. All of the ester and amino terminated PAMAM dendrimer presented regularities in adsorption of metals like chromium, zinc and iron. The adsorption of ester and the amino terminated products increased with the increase in the increase in the grafting percentage and the addition of the surface functional groups. From this it can be concluded that the amine and the ester groups are alone responsible for the easy and efficient adsorption of the metal ions, the amine terminated groups exhibiting higher adsorption due to its co ordination and acid functionality. E.Gomathi et al/Int.J.ChemTech Res.2013,5(3) 1240
2018
Dyes are the most abundant hazardous components existing in the environment because of their extensive use in industries. So, in the present study, two isoreticular Zn(II)-MOFs, TMU-16 and TMU-16-NH2, were used for the adsorptive removal of harmful cationic dyes from aquatic medium. In order to improve the removal efficiency, optimization of the experimental conditions was carried out as a function of pH, MOF dosage, dye concentration and contact time. The maximum removal capacity was obtained at pH 12, 10 mg of MOF and 20 min as the contact time. The adsorption isotherms of each dye over both sorbents matched with the Langmuir model, and the adsorption kinetics followed the pseudo-second order kinetic model. The dye adsorption over TMU-16-NH2 is higher than that over TMU-16, indicating that the addition of amine groups in MOF network played an important role in the adsorption process, because of electrostatic interactions and hydrogen bonding. Thermodynamic studies indicated that a...
Journal of Water and Wastewater, 2022
Disposal of dyes containing dyes from related industries has caused global concern. Therefore, removing dyes from aqueous solution is very important and necessary. In this work, a novel magnetic glycodendrimer is introduced as effective adsorbent for malachite green adsorption. Firstly, magnetic graphene oxide was prepared by co-precipitation method and then modified with ethylenediamine to generate amine group on the surface which was further reacted with mercaptoacetic acid to provide polymerizable MGO nanosheets. Thereafter, Allylamine was grafted onto nanosheets and subsequently, reacted with methacrylate in a Michael type reaction to generate methyl ester groups. Finally, amidation of the terminal methyl ester groups with chitosan resulted in the formation of glycodendrimer. The properties of the synthesized adsorbent were investigated using XRD, FTIR, BET, FESEM and TEM. The results showed that pH=5, temperature of 40 °C, initial concentration of 600 mg/mL and contact time of 10 min as optimal values for removing malachite green dye with nanosorbent (MGD) were obtained. The maximum adsorption capacity of green malachite was 452.97 μg/mg. The high correlation coefficient (R2=0.9947) for the Freundlich model confirms that the Freundlich model is suitable for fitting laboratory data. According to the compliance model, the heat absorption for malachite green is B=8.1447 j/mol and indicates that the process of dye adsorption with nanosorbent is physical. According to the results of fitting the kinetic models of dye adsorption kinetics by nanosorbent shows that Hu and McKay model with higher correlation coefficient (R2=0.994) than other models is more consistent with experimental data. Due to the fact that a large decrease in dye removal is not observed in 10 consecutive recovery cycles and therefore nanosorbent has a high stability and can be used several times.