Facile fabrication of novel magnetic ZIF-67 MOF@aminated chitosan composite beads for the adsorptive removal of Cr(VI) from aqueous solutions.
Omer Ahmed M,Abd El-Monaem Eman M,Abd El-Latif Mona M,El-Subruiti Gehan M,Eltaweil Abdelazeem S
Carbohydrate polymers
Metal organic frameworks (MOFs) have become premium candidates for the removal of hazardous contaminants from wastewater. However, MOFs have a vast obstacle which is their poor recyclability. In this study, ZIF-67 was decorated with magnetic FeO nanoparticles, and then embedded into aminated chitosan (AmCs) matrix to form core-dual shell FeO/ZIF-67@AmCs composite beads. Diverse analysis tools were utilized to ensure the successful fabrication of the magnetic composite beads. The fabricated magnetic composite beads were examined their adsorptive removal aptitude towards toxic Cr(VI) ions. The gained results refereed that a maximum adsorption capacity of 119.05 mg/g was attained by magnetic FeO/ZIF-67@AmCs composite beads at 25 °C. The process obeyed both of Langmuir and Freundlich isotherm models, and the pseudo 2nd order was more suitable kinetic model to represent the adsorption process. Besides, FeO/ZIF-67@AmCs composite showed an excellent recyclability for the removal of Cr(VI) ions from their aqueous solutions for seven consecutive cycles.
10.1016/j.carbpol.2021.118084
Photocatalytic magnetic separable beads for chromium (VI) reduction.
Idris Ani,Hassan Nursia,Mohd Ismail Nur Suriani,Misran Effaliza,Yusof Noordin Mohd,Ngomsik Audrey-Flore,Bee Agnes
Water research
Magnetically separable photocatalyst beads containing nano-sized iron oxide in alginate polymer were prepared. This magnetic photocatalyst beads are used in slurry-type reactors. The magnetism of the catalyst arises from the nanostructured particles gamma-Fe(2)O(3), by which the catalyst can be easily recovered by the application of an external magnetic field. These synthesized beads are sunlight-driven photocatalyst. In the system without magnetic photocatalyst beads, no chromium reduction was observed under sunlight irradiation due to the stability of the chromium (VI). Upon the addition of magnetic photocatalyst beads, the photo-reduction of Cr(VI) was completed in just after only 50min under sunlight irradiation due to the photocatalytic activity of the beads. However when placed away from sunlight, the reduction rate of the chromium is just about 10%. These observations were explained in terms of absorption occurrence of chromium (VI) onto the catalyst surface which took place in this reaction. In addition, photo-reduction rate of chromium (VI) was more significant at lower pH. The results suggest that the use of magnetic separable photocatalyst beads is a feasible strategy for eliminating Cr(VI).
10.1016/j.watres.2009.11.026
Magnetic alginate beads for Pb(II) ions removal from wastewater.
Bée Agnès,Talbot Delphine,Abramson Sébastien,Dupuis Vincent
Journal of colloid and interface science
A magnetic adsorbent (called magsorbent) was developed by encapsulation of magnetic functionalized nanoparticles in calcium-alginate beads. The adsorption of Pb(II) ions by these magnetic beads was studied and the effect of different parameters, such as initial concentration, contact time and solution pH value on the adsorption of Pb(II) ions was investigated. Our magsorbent was found to be efficient to adsorb Pb(II) ions and maximal adsorption capacity occurred at pH 2.3-6. The classical Langmuir model used to fit the experimental adsorption data showed a maximum sorption capacity close to 100 mg g(-1). The experimental kinetic data were well correlated with a pseudo second-order model, 50% of the Pb(II) ions were removed within 20 min and the equilibrium was attained around 100 min. Moreover our magsorbent was easily collected from aqueous media by using an external magnetic field. These results permitted to conclude that magnetic alginate beads could be efficiently used to remove heavy metals in a water treatment process.
10.1016/j.jcis.2011.06.036
Adsorption of Pb (II) and Cu (II) by magnetic beads loaded with xanthan gum.
Environmental science and pollution research international
Green and environmentally friendly and efficient separation adsorbents have attracted much attention in the treatment of heavy metal ions wastewater. In this study, xanthan gum (XG) was supported by fly ash magnetic beads (FAMB) to prepare adsorbent XG@FAMB. The effects of XG@FAMB dosage, pH value of the solution, adsorption time, and initial Pb (II) and Cu (II) concentration on its adsorption performance for Pb (II) and Cu (II) were investigated. The results show that under the conditions of pH 6, dosage of XG@FAMB 4.0 g/L, adsorption time 120 min, and initial concentration 60 mg/L, the maximum adsorption capacity of XG@FAMB for Pb (II) and Cu (II) was 14.93 mg/g and 14.88 mg/g, respectively. The adsorption process of Pb (II) and Cu (II) by XG@FAMB could be better described by the quasi-second-order kinetic model and Langmuir isothermal adsorption model, that is, the adsorption process is monolayer adsorption controlled by chemical action. The adsorption mechanism is that Pb (II) and Cu (II) coordinate with oxygen-containing functional groups hydroxyl and carboxyl on XG@FAMB surface, accompanied by electrostatic adsorption. XG@FAMB has the advantages of environmental protection of XG and easy solid-liquid separation of FAMB, and has a good removal effect on Pb (II) and Cu (II).
10.1007/s11356-022-24620-2
Magnetic Beads of Zero Valent Iron Doped Polyethersolfun Developed for Removal of Arsenic from Apatite-Soil Treated Water.
International journal of environmental research and public health
The drop immerses calcium chloride aqueous solution was utilized to prepare the zero valent iron-doped polyethersulfone beads (PES/ZVI) for the efficient removal of arsenic from apatite-soil treated waters. The proposed beads can assist in promoting uptake efficiency by hindering ZVI agglomeration due to a high porosity and different active sites. The PES/ZVI beads were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and vibrating sample magnetism (VSM). The main objective of this study was to investigate the function of new PES/ZVI beads with an increased removal efficiency for the remediation of arsenic ions from the apatite-soil treated waters. A maximum adsorption removal of 82.39% was achieved when the experiment was performed with 80 mg of adsorbent for a contact time of 180 min. Based on the results, a removal efficiency >90% was obtained after 300 min of shaking time with an arsenic concentration of 20 mg·L. The experimental process was fitted with the Langmuir model due to the high R (0.99) value compared to the Freundlich model (0.91) with an adsorption capacity of 41.32 mg·g. The adsorption process speed was limited by pseudo-second-order (R = 0.999) and the adsorption mechanism nature was endothermic and physical.
10.3390/ijerph191912697
Gellan gel beads containing magnetic nanoparticles: an effective biosorbent for the removal of heavy metals from aqueous system.
Wang Xia,Zhao Chuanming,Zhao Peng,Dou Peipei,Ding Yi,Xu Ping
Bioresource technology
This study describes an efficient adsorbent consisting of magnetic Fe(3)O(4) and gellan gum, which couples magnetic separation with ionic exchange for heavy metal removal. Adsorption kinetics analysis showed that the adsorption capacities were in an order of Pb(2+)>Cr(3+)>Mn(2+). Different experimental parameters studies indicated that adsorbent dosage, initial metal concentration, temperature and initial pH played important roles in adsorption process. Additionally, the Freundlich model gave a better fit to the experimental data than the Langmuir model. Chemical analysis of calcium ions released into the bulk solutions demonstrated that carboxyl group is critical for binding Pb(2+), Mn(2+) and Cr(3+). Furthermore, a high desorption efficiency was obtained by sodium citrate.
10.1016/j.biortech.2008.10.042
Magnetic responsive mesoporous alginate/β-cyclodextrin polymer beads enhance selectivity and adsorption of heavy metal ions.
International journal of biological macromolecules
Mesoporous (~7-8 nm) biopolymer hydrogel beads (HNTs-FeNPs@Alg/β-CD) were synthesised via ionic polymerisation route to separate heavy metal ions. The adsorption capacity of HNTs-FeNPs@Alg/β-CD was higher than that of raw halloysite nano tubes (HNTs), iron nanoparticles (FeNPs), and bare alginate beads. FeNPs induce the magnetic properties of adsorbent and metal-based functional groups in and around the hydrogel beads. The mesoporous surface of the adsorbent permits access of heavy metal ions onto the polymer beads to interact with internal active sites and the mesoporous polymer network. Maximum adsorption capacities of lead (Pb), copper (Cu), cadmium (Cd), and nickel (Ni) were 21.09 mg/g, 15.54 mg/g, 2.47 mg/g, and 2.68 mg/g, respectively. HNTs-FeNPs@Alg/β-CD was able to adsorb heavy metals efficiently (75-99%) under environment-relevant concentrations (200 μg/L) from mixed metal contaminants. The adsorption and selectivity trends of heavy metals were Pb > Cu > Cd > Ni, despite electrostatic binding strength of Cd > Cu > Pb > Ni and covalent binding strength of Pb > Ni > Cu > Cd. It demonstrated that not only chemosorption but also physisorption acts as the sorption mechanism. The reduction in surface area, porosity, and pore volume of the expended adsorbent, along with sorption study results, confirmed that pore filling and intra-particle diffusion played a considerable role in removing heavy metals.
10.1016/j.ijbiomac.2022.03.159
Novel cationic polymer modified magnetic chitosan beads for efficient adsorption of heavy metals and dyes over a wide pH range.
Zhang Meng,Zhang Zhi,Peng Yazhou,Feng Li,Li Xuhao,Zhao Chuanliang,Sarfaraz Khan
International journal of biological macromolecules
Wastewater containing highly toxic and non-biodegradable heavy metals and organic dyes poses a serious threat to ecological environment and human health. Adsorption has been regarded as a promising technology to purify this kind of wastewater. Therefore, it is of great importance to develop efficient adsorbents. Herein, a magnetically recyclable adsorbent FeO-CS/PDAC was facilely fabricated by coating poly(acryloyloxyethyltrimethyl ammonium chloride)-modified chitosan on the surface of FeO nanoparticles. The morphology, physical-chemical and magnetic properties of as-prepared FeO-CS/PDAC was fully characterized by various techniques. Its adsorption behaviors towards heavy metal Cr(VI) and organic dye sunset yellow (SY) were systematically investigated. Evidently, FeO-CS/PDAC exhibited adsorption capacities of 163.93 and 769.23 mg/g for Cr(VI) and SY respectively, much higher than other reported adsorbents. Besides, batch experiment results showed that adsorption capacities decreased slightly with pH increasing from 2.0 to 10.0. Furthermore, FeO-CS/PDAC could be easily separated and effectively regenerated after adsorption. The superior adsorption performance of FeO-CS/PDAC could be attributed to the electrostatic interaction and ion exchange between target pollutants and the grafted cationic polymer. Owing to its high adsorption capacity over a wide pH range, rapid separation, easy regeneration and good reusability, FeO-CS/PDAC has great potential for practical application in water treatment.
10.1016/j.ijbiomac.2020.04.020