Vivek Bhusari; Amit Bansiwal; Sadhana Rayalu
Abstract
Mixed oxide nanoparticles of iron and aluminium (FeAlO) were synthesized by combustion process and evaluated for the removal of chromium by adsorption from aqueous solution. The FeAlO were characterized for various physico-chemical properties using x ray diffraction, particle size, SEM, TEM, FTIR analysis. ...
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Mixed oxide nanoparticles of iron and aluminium (FeAlO) were synthesized by combustion process and evaluated for the removal of chromium by adsorption from aqueous solution. The FeAlO were characterized for various physico-chemical properties using x ray diffraction, particle size, SEM, TEM, FTIR analysis. The adsorbent was evaluated to study the effect of different parameters like dose, pH and interference of other ion on removal efficiency. The data was fitted in Langmuir and Freundlich adsorption parameters were computed to determine adsorption capacity. The adsorption isotherm was best fitted for Freundlich adsorption model and adsorption capacity was 0.824mg g-1 for Cr (VI). The FeAlO has good potential for the removal of Cr(VI) from water and wastewater.
Ayesha Dhawas; Dhananjay Bhatkhande; Shraddha Khamparia; Priya Nakade
Abstract
Substantial contamination of heavy metals in drinking water has been an issue to consumers since long. The persisting contamination level has been monitored by various agencies and researchers, which direct towards constant deterioration of water quality. The quality of water is degrading exponentially ...
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Substantial contamination of heavy metals in drinking water has been an issue to consumers since long. The persisting contamination level has been monitored by various agencies and researchers, which direct towards constant deterioration of water quality. The quality of water is degrading exponentially from rural to urban areas in a significant manner. Industrial effluents, sewage and agricultural waste are the prime sources of contamination of water resources. Various heavy metals such as nickel, chromium, lead, arsenic, cadmium, mercury and copper may be present in industrial effluents. Though different methods such as chemical precipitation, ion exchange, membrane filtration, coagulation – flocculation and electro dialysis are known, amongst which adsorption being the most versatile and economically viable has been extensively adopted by various researchers for trace level of concentrations. In this review, several low cost adsorbents are reported in the literature have been studied at length. Different types of adsorbents like nanosorbent, biosorbents, carbonaceous material and metal based adsorbents have been considered for the review paper. The review paper evaluates the possibilities of utilizing various adsorbents for efficient removal of different heavy metals from water. Study reflected towards remarkable adsorption capacity, efficiency and cost effectiveness of adsorbents utilized by researchers. The boundless use of low cost adsorbents for treatment of wastewater are strongly recommended due to their availability,
Masashi Hatanaka
Abstract
A useful formulation of ion-adsorption kinetics is introduced based on our recent researches. The chemical reaction kinetics and diffusion kinetics are simultaneously analyzed combining with the Einstein’s viscosity formula. The rate-determining steps are quantitatively determined by estimating ...
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A useful formulation of ion-adsorption kinetics is introduced based on our recent researches. The chemical reaction kinetics and diffusion kinetics are simultaneously analyzed combining with the Einstein’s viscosity formula. The rate-determining steps are quantitatively determined by estimating the relative magnitude of the kinetics resistances in the boundary film and the particle. The key concept of this method is an addition theorem of film-diffusion kinetic resistance and the particle-diffusion kinetic resistance. While in hydrophilic polymers, the thickness of boundary film decreases due to the attractive force between the ion and the surface, in hydrophobic polymers, it increases with the amount of hydrophobic components. This is confirmed by using chitosan resins with hydrophilic/hydrophobic components. The experiments are based on the batch method, and degree of film-diffusion control and particle-diffusion control is determined simultaneously. The film mass-transfer coefficient in the boundary film is also determined from a simple plotting of the experimental data. This method is also applicable to ion-exchange kinetics by summing the kinetic resistances at each step in the ion-exchange reaction and the mutual diffusion. Our method will serve as a guiding tool for designing of adsorption agents and ion-exchangers. Copyright © VBRI Press.
Sudhanshu Kanaujia; Sanjay K. Singh; Bharat Singh
Abstract
A comparative study was done for removal of fluoride by Al (III) modified Clinoptilolite (AC) and Carbonised Punica Granatum Carbon (CPGC) through batch techniques. The fluoride removal performance of both adsorbents AC and CPGC was evaluated as a function of the initial concentration, adsorbent ...
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A comparative study was done for removal of fluoride by Al (III) modified Clinoptilolite (AC) and Carbonised Punica Granatum Carbon (CPGC) through batch techniques. The fluoride removal performance of both adsorbents AC and CPGC was evaluated as a function of the initial concentration, adsorbent dose, contact time and pH. The equilibrium was attained at 90 and 75 minutes for AC and CPGC adsorbents, but percentage of removal was 76 and 65 for AC and CPGC respectively. The maximum adsorption of fluoride was found at pH 6.95 and 5.92 for AC and CPGC adsorbent respectively. The system followed the Freundlich isotherm model for both AC and CPGC with adsorption capacity 0.24 mg/g and 0.4 mg/g respectively. Copyright © 2018 VBRI Press.
Archana Sharma; Anu .; Mushahid Husain; Anurag Srivastava; Mohd. Shahid Khan
Abstract
Surface metal adsorption on 2D structures is demonstrated to be an effective tool for improving hydrogen storage capacity. In the current work, the behavior of Ca atom adsorption on monolayer MoS2 is studied and subsequently its hydrogen storage capacity is investigated computationally using van der ...
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Surface metal adsorption on 2D structures is demonstrated to be an effective tool for improving hydrogen storage capacity. In the current work, the behavior of Ca atom adsorption on monolayer MoS2 is studied and subsequently its hydrogen storage capacity is investigated computationally using van der Waals (vdW) revised Density Functional Theory. It is found that the Ca binds strongly with the MoS2 monolayer without being clustered, leading to high hydrogen storage capacity. It is further shown that five hydrogen molecules to each Ca atom can be adsorbed with the average adsorption energy of 0.23eV per hydrogen molecule, indicating it to be a good choice for reversible adsorption/desorption of H2 molecules at ambient conditions. It is revealed that hybridizations between s orbitals of H2 and p orbitals of S are also responsible for adsorption mechanism, along with coulomb interactions. It is demonstrated that a steady and uniform high Ca coverage can be achieved without clustering and with enhanced binding energy which can be used as high hydrogen capacity storage system. Copyright © 2018 VBRI Press.
Karuna Nalwa; Anupama Thakur; Neeta Sharma
Abstract
In the present study nanoparticles of zinc oxide (ZnO) were synthesized by simple solution based approach and used as an adsorbent for the removal of Cu(II) ions from aqueous solution. ZnO nanoparticles were characterized by X-Ray Diffraction (XRD), Transmission Electron Microscopy (TEM) and Dynamic ...
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In the present study nanoparticles of zinc oxide (ZnO) were synthesized by simple solution based approach and used as an adsorbent for the removal of Cu(II) ions from aqueous solution. ZnO nanoparticles were characterized by X-Ray Diffraction (XRD), Transmission Electron Microscopy (TEM) and Dynamic Light Scattering (DLS). TEM confirmed the formation of zinc oxide nanoparticles in the size range of 10-11 nm. Adsorption capacity of ZnO for removing Cu(II) ions from aqueous solutions was investigated at different pH, as a function of contact time, metal ion concentration and the amount of adsorbent. Moreover, adsorption isotherms and kinetics was studied to understand the nature and mechanism of adsorption. A high percentage removal (98.71%) of Cu(II) from its aqueous solutions at pH 5 and at initial heavy metal ion concentration of 300 mg/l by ZnO particles was achieved. The adsorption isotherm was well described by Freundlich isotherm model(R2= 0.999). The adsorption kinetics data was well fitted by the pseudo-second-order rate model with a high regression coefficient. The above results suggest that ZnO nanoparticles can be used as potential adsorbent for the efficient removal of heavy metals from aqueous solutions. Copyright © 2017 VBRI Press
