Adsorption Of Zinc Ions Research Articles

The Adsorption of Cadmium and Zinc Ions from Waste Waters in Agricultural Argilaceous Soils

The adsorption of cadmium and zinc ions from waste waters in agricultural argilaceaus soils have been studied, using a thermodynamic method in order to put in evidence the influence of adsorption conditions on adsorption degree. The adsorption isotherms, Langmuir and Freundlich, have been used to describe the adsorption equilibrium. The experimental data put in evidence that Cd2+ ions are more adsorbable (about 300 mmol/g) than Zn2+ ones (about 200 mmol/g). The Langmuir isotherms reflect more exactly the adsorption process of both Cd2+and Zn2+ ions, being recommended for thermodynamic parameters determination.

Synthesis and Characterization of Ion-Imprinted Polymer for Selective Adsorption of Zinc Ions in Aqueous media

Synthesis and Characterization of Ion-Imprinted Polymer for Selective Adsorption of Zinc Ions in Aqueous media

Equilibrium, kinetic, and thermodynamic studies of lead ion and zinc ion adsorption from aqueous solution onto activated carbon prepared from palm oil mill effluent

An efficient activated carbon was prepared using palm oil mill effluent as a precursor. The adsorption capacity of activated carbon for lead ion and zinc ion from aqueous media was investigated under equilibrium conditions between 303.15 and 353.15 K. The activated carbon was analyzed using fourier transform infrared spectroscopy, field emission scanning electron microscope, energy dispersive X-Ray, and Nitrogen adsorption-desorption analysis. The adsorption capacity of activated carbon was studied by varying adsorbent dosage, contact time, and temperature. The equilibrium time was attained after 50 min for both ions. The data analysis was performed with different isotherm and kinetic models. Pseudo-second-order kinetic rather than pseudo first-order model is best fitted for both lead ion and zinc ion removal from wastewater. Further, the rate-determining step for both metal ions is chemisorption based on the suitability of the Elovich equation. Langmuir model provides the best fit for both removal of lead ion and zinc ion. The thermodynamic parameters shows the feasibility of adsorption of both ions is endothermic.

Modelling of adsorption of zinc and silver ions on analcime and modified analcime zeolites using Central Composite design

In this study, Response Surface Methodology (RSM) using Central Composite Design (CCD) was employed to optimize the conditions of independent variables (adsorption time and ion solution concentration) for the removal of Zinc (II) and Ag ions from the aqueous solutions using analcime and modified analcime zeolites (Fe-ANA and Ni-ANA) as efficient and low cost adsorbent. The operation conditions were contact time of 1-13 h and ion concentration of 25-250 ppm at ambient temperature. Under these conditions, the response (the adsorption capacity of zinc (II) and Ag ions) was fitted by a quadratic polynomial regression model and linear model analysis in five-level-two-factor CCD using Design Expert software. The optimal conditions (high removal efficiency) for zinc (II) and Ag+ adsorption were achieved. The analysis of variance demonstrated that ion concentration effect was found to be significant in the adsorption process. Moreover, actual and predicted response plot of ion adsorption in zeolites were investigated.

Metakaolin based geopolymer as an effective adsorbent for adsorption of zinc(II) and nickel(II) ions from aqueous solutions

Metakaolin based geopolymer (MKG) was investigated as an adsorbent to remove Zn(II) and Ni(II) ions from aqueous solution. The parameters of initial pH, adsorbent amount, time of contact and initial metal ion concentration on the metal removal performance of MKG were studied using a batch method at 25°C. The amount of Zn(II) and Ni(II) ions adsorbed onto MKG increased with increasing contact time with an adsorption equilibrium being reached within 40min and 50min for Zn(II) and Ni(II), respectively. The optimum values of initial pH were 6.39 for Zn(II) and 7.25 for Ni(II). The uptake of Zn(II) and Ni(II) ions by MKG was observed to decrease by increasing the adsorbent amount. The Langmuir isotherm described the adsorption data very well and the maximum monolayer adsorption capacities determined from the Langmuir adsorption isotherm were found to be 1.14×10−3 and 7.26×10−4molg−1 for Zn(II) and Ni(II), respectively. The kinetic studies showed that adsorption followed the pseudo-second-order kinetic model. The continuous mode adsorption studies showed the optimum flow rates were 2.0mLmin−1 for Zn(II) and 1.0mLmin−1 for Ni(II). The breakthrough points were observed at 150 and 280min for Zn(II) and Ni(II), respectively. It is concluded that Zn(II) and Ni(II) ions in aqueous solutions are efficiently removed by MKG which could be employed as a low-cost and excellent alternative for wastewater treatment.

Preparation and characterization of bioadsorbent beads for chromium and zinc ions adsorption

Low-cost chitosan beads were prepared by dropping chitosan solution into an alkaline bath and then were used for Cr(VI) and Zn(II) ions adsorption from aqueous solution. Prepared chitosan beads wer...

Adsorption of copper(II) and zinc(II) ions from aqueous solution by activated carbon derived from halophytes (Suaeda maritime)

Adsorption of copper(II) and zinc(II) ions from aqueous solution by activated carbon derived from halophytes (Suaeda maritime)

Characterization and Geochemical Modeling of Cu and Zn Sorption Using Mineral Systems Injected with Iron Sulfide: Case Study of Mine Waste Water, Wales, United Kingdom

Sorption of Cu and Zn was investigated using single and mixed mineral systems under sulfidic-anoxic condition to treat wastewater obtained from disused mine pits at Parys Mountain in, United Kingdom. Water courses are the recipients of these contaminants. In these water courses fishing activities exist. Attempt was made to reduce the Cu and Zn levels intake in the watercourses using mineral systems of clays and goethite. These were tested with the mine waste water for characterization of copper and zinc removal at variable pH, solid concentration and contact time. In addition, levels of saturation of hydroxyl complexes were modeled. Batch reactions conducted at ambient temperature (23±2°C) reveal all systems of assorted minerals sorbed more Cu than Zn. In addition, Cu sorbed on iron sulfide exhibited increase in sorption with increasing pH. There was cross cutting effect of Cu and Zn sorbed on iron sulfide at pH 6 and Cu sorbed on goethite at about pH 7, These indicate similar metal removal characteristics. Differences in removal of copper and zinc ions may be assigned to outer sphere complexation and specific adsorption of copper and zinc ions. Non-promotive Cp effect (i.e. decrease in metal removal with increase in concentration of particle) was observed in all minerals. This effect may be assigned to increase in aggregation of the mineral particle size. Ageing characterization progresses as residence time was increased. This may be assigned thiol (=S-H) and hydroxyl (=Me-OH) groups and sites of reactions. There is no link to stable hydroxylation of copper and zinc species that could significantly contribute to the removal of these metals.

Adsorption Activity of Materials Derived from Copolymers of Acrylonitrile with Various Acid Comonomers

A study was carried out on the adsorption of zinc ions by ion-exchange materials derived from fibrous copolymers of acrylonitrile (AN) with 2-acrylamide-2-methylpropanesulfonic acid (AMPS), acrylic acid (AA), or itaconic acid (ItA) as the ionogenic component. The adsorption activity of materials derived from poly[AN-co-AMPS] containing sulfo groups is somewhat reminiscent of the behavior of carboxyl ion-exchange resins. The amount of zinc adsorbed by materials derived from poly[AN-co-AMPS] may exceed the static exchange capacity (SEC) for sulfo groups. It was proposed that the amide groups affect the adsorption behavior of ion exchangers derived from poly[AN-co-AMPS].

Effect of nanotechnology on heavy metal removal from aqueous solution

The effect of nanotechnology on cadmium and zinc removal from aqueous solution was investigated. In order to characterize micro and nano phragmites australis adsorbent, we analyzed the data via FTIR, SEM, PSA, and EDX. The effect of various parameters such as pH, contact time, amount of adsorbent and initial concentration, was investigated. The optimum pH for the removal of cadmium for micro and nano phragmites australis adsorbent was 7, and for the removal of zinc by the micro adsorbent was 7 and by nano adsorbent was 6. The equilibrium time of zinc was 90 min and for the adsorption of cadmium by micro and nano adsorbent were 90 and 30 min, respectively. The optimum dose of micro adsorbent for the removal of cadmium was 0.7 g, and the other dose for the removal of zinc and cadmium was 0.5 g. The evaluation of adsorbent’s distribution coefficient showed that the highest rates of distribution coefficient with initial concentration of 5, 10, 30, and 50 mg/L were 394.83, 587.62, 759.39 and 1101.52 L/kg, respectively, which were observed in nano adsorbent. Desorption experiments for the nano adsorbent in three cycles were done. Among kinetics models, our experimental data were more consistent with Hoo kinetic model and for isotherm models, Freundlich isotherm was more consistent. The results show that nanotechnology could increase the performance of adsorbents and enhance the efficiency of the adsorption of cadmium and zinc ions.

Critical analysis of adsorption data statistically

Experimental data can be presented, computed, and critically analysed in a different way using statistics. A variety of statistical tests are used to make decisions about the significance and validity of the experimental data. In the present study, adsorption was carried out to remove zinc ions from contaminated aqueous solution using mango leaf powder. The experimental data was analysed statistically by hypothesis testing applying t test, paired t test and Chi-square test to (a) test the optimum value of the process pH, (b) verify the success of experiment and (c) study the effect of adsorbent dose in zinc ion removal from aqueous solutions. Comparison of calculated and tabulated values of t and χ2 showed the results in favour of the data collected from the experiment and this has been shown on probability charts. K value for Langmuir isotherm was 0.8582 and m value for Freundlich adsorption isotherm obtained was 0.725, both are <1, indicating favourable isotherms. Karl Pearson’s correlation coefficient values for Langmuir and Freundlich adsorption isotherms were obtained as 0.99 and 0.95 respectively, which show higher degree of correlation between the variables. This validates the data obtained for adsorption of zinc ions from the contaminated aqueous solution with the help of mango leaf powder.

Application of nanochitosan and chitosan particles for adsorption of Zn(II) ions pollutant from aqueous solution to protect environment

Existence of heavy metals like zinc within water source is considered as one of the most important environmental problems. Accumulating within alive tissues, zinc raises various diseases and disorders. Chitosan is a hydrophilic polymer which is raised from acetyl groups of chitin from alkaline solution: it is employed widely as a well- known adsorbent for removing heavy metal ions. Present study aimed at optimizing the production of chitosan nano size particles by method of calvo and compared the adsorption of Zn (II) ions by chitosan macro and nano size particles. Adsorption experiments were conducted in a batch system and the effects of temperature, pH, contact time and initial concentration of metal ions on productivity of adsorption of zinc ions have been considered. Performing analysis DLS revealed that mean size of nano chitosan particles is 19.84 nm. Optimal adsorption by chitosan and nano chitosan has been done in pH 7 and about of 5. Efficiencies of both adsorbent were increased by increasing contact time. Both adsorbent had maximum efficiency at the temperature of 25 °C. At the concentration of 10 mg/L of zinc metal ions, maximum effective removal of chitosan macro and nano size particles were 90.80 and 99.10 %, respectively. Maximum capacity of adsorption by chitosan macro and nano size particle was 196.07 and 370.37 mg/g, respectively. Adsorption kinetics followed a pseudo second order model. Nanochitosan compared to chitosan particles had higher removal efficiency for Zinc metal ions due to nano size of particles, larger adsorption surfaces and more functional groups.

Adsorption of zinc ions on bone char using helical coil-packed bed columns and its mass transfer modeling

AbstractThis study reports the assessment of helical coil-packed bed columns for Zn2+ adsorption on bone char. Zn2+ adsorption breakthrough curves have been obtained using helical coil columns with different characteristics and a comparison has been conducted with respect to the results of straight fixed-bed columns. Results showed that the helical coil adsorption columns may offer an equivalent removal performance than that obtained for the traditional packed bed columns but using a compact structure. However, the coil diameter, number of turns, and feed flow appear to be crucial parameters for obtaining the best performance in this packed-bed geometry. A mass transfer model for a mobile fluid flowing through a porous media was used for fitting and predicting the Zn2+ breakthrough curves in helical coil bed columns. Results of adsorbent physicochemical characterization showed that Zn2+ adsorption on bone char can be attributed to an ion-exchange mechanism. In summary, helical coil columns appear to be a ...

Zinc and nickel adsorption onto a low-cost mineral adsorbent: kinetic, isotherm, and thermodynamic studies

In this study, adsorption of zinc and nickel ions from aqueous solutions by low-cost dolomite was investigated. Dolomite, as a mineral adsorbent, is ample in most countries of the world. Morphology of adsorbent surface and the nature of the dolomite powder were examined using the scanning electron microscope. The process has been studied as a function of contact time, pH, initial concentrations, temperature, and adsorbent dosage. The experimental data were evaluated using three isotherm and kinetic models, including the pseudo-first-order, pseudo-second-order, and intraparticle diffusion models for kinetics and Freundlich, Langmuir and Temkin for isotherms. The results showed that the adsorption isotherm data were fitted well by the Langmuir isotherm and adsorption kinetics followed the pseudo-second-order model for both metal ions. The thermodynamic parameters, such as the change in standard free energy, enthalpy, and entropy, were also determined. The calculated parameters indicated that adsorption process was spontaneous and endothermic in nature. The adsorption capacity of zinc and nickel onto dolomite powder found to be 21.85 and 20.09 mg/g, respectively.

Zinc-dependent mechanical properties of Staphylococcus aureus biofilm-forming surface protein SasG

Staphylococcus aureus surface protein SasG promotes cell-cell adhesion during the accumulation phase of biofilm formation, but the molecular basis of this interaction remains poorly understood. Here, we unravel the mechanical properties of SasG on the surface of living bacteria, that is, in its native cellular environment. Nanoscale multiparametric imaging of living bacteria reveals that Zn(2+) strongly increases cell wall rigidity and activates the adhesive function of SasG. Single-cell force measurements show that SasG mediates cell-cell adhesion via specific Zn(2+)-dependent homophilic bonds between β-sheet-rich G5-E domains on neighboring cells. The force required to unfold individual domains is remarkably strong, up to ∼500 pN, thus explaining how SasG can withstand physiological shear forces. We also observe that SasG forms homophilic bonds with the structurally related accumulation-associated protein of Staphylococcus epidermidis, suggesting the possibility of multispecies biofilms during host colonization and infection. Collectively, our findings support a model in which zinc plays a dual role in activating cell-cell adhesion: adsorption of zinc ions to the bacterial cell surface increases cell wall cohesion and favors the projection of elongated SasG proteins away from the cell surface, thereby enabling zinc-dependent homophilic bonds between opposing cells. This work demonstrates an unexpected relationship between mechanics and adhesion in a staphylococcal surface protein, which may represent a general mechanism among bacterial pathogens for activating cell association.

Zinc Adsorption Properties of Alginate-SBA-15 Nanocomposite

Assessment of adsorption zinc (II) ions from aqueous solution using alginate-SBA-15 sorbent nanocomposite was investigated as a function of zinc concentration, solution pH, and contact time. For that purpose, the alginate-SBA-15 nanocomposite adsorbent was prepared through encapsulation method by immobilization mesoporous SBA-15 into a polymeric matrix. Identification of functional groups and surface morphology of the obtained nanocomposite was carried out by X-Ray diffraction (XRD), scanning electron microscopy (SEM), fourier transform infrared spectroscopy (FTIR) and nitrogen porosimetry experiments. Sorption performance of the alginate-SBA-15 adsorbent during batch experiments was studied. A mathematically explanation of adsorption process using kinetics and isotherm models was also performed. Kinetic study was revealed that the pseudo second-order model has good agreement with the experimental results than the pseudo first-order model. Therefore, it indicates that the concentration of both alginate-SBA-15 and zinc metal ions are involved in the rate determining step of the sorption process. The qmax value for zinc (II) ions adsorption onto alginate-SBA-15 was found 46.3 mg g-1. According to thermodynamic analysis, physisorption and the endothermic of the sorption process nature of Zn(II) ions onto alginate-SBA-15 nanocomposite was revealed.

The mechanism of adsorption of zinc and cadmium ions onto bentonite clay

Adsorption of zinc and cadmium ions onto bentonite clays from the Zyryanskoe deposit (Kurgan region, Russia) was studied as a function of contact duration, pH, and temperature. Silanol and aluminol groups of the clay were found to participate in ion exchange and in complex formation with zinc and cadmium ions; a certain process prevails depending on pH. Adsorption of zinc and cadmium ions from equimolar binary solutions was studied. Adsorption of ions onto clay increases with temperature increasing from 293 to 333 K. Adsorption mechanisms of Zn(II) and Cd(II) ions were proposed.

Application of laboratory prepared and commercially available biochars to adsorption of cadmium, copper and zinc ions from water

The goal of the presented work was the evaluation and comparison of two biochars (produced from Sida hermaphrodita – BCSH/laboratory produced and from wheatstraw – BCS/commercial available) to adsorb heavy metal ions (Cd(II), Cu(II) and Zn(II)) from water. Kinetics of the sorption as well as sorption isotherms, the influence of solution pH and interfering ions were investigated. Different physico-chemical properties of biochars had the great influence on adsorption capacity. The greater adsorption efficiency was observed for BCSH than for BCS in the case of all investigated metals. The adsorption efficiency of BCSH was correlated with higher content of carbon and oxygen, what is equal with higher content of polar-groups on the BCSH surface e.g., –COOH. Furthermore, the molar ratio of O/C as well as polarity index (which was higher for BCSH) was also important parameters.

Design analysis of fixed-bed synergic adsorption of heavy metals and acid blue 25 on activated carbon

This study reports the multicomponent adsorption of dye AB25, nickel (Ni2+) and zinc (Zn2+) ions on an activated carbon using binary mixtures of metal and dye, and packed bed columns at different operating conditions. Design parameters of packed bed adsorption columns have been calculated using the breakthrough curves and Thomas model, and an analysis has been performed to determine the effect and magnitude of the synergistic adsorption on the design parameters and adsorbent performance. Results showed that there is a strong synergistic adsorption of heavy metals on activated carbon caused by the presence of dye AB25 in binary mixtures. The magnitude of this synergistic adsorption effect depends on the dynamic operating conditions and type of heavy metal present in the binary system. The presence of dye AB25 in the binary mixtures caused a better degree of column utilization because the values of mass transfer zone decreased with respect to the results obtained with mono-component solutions. Metal adsorption capacities may increase up to 20 times if the binary mixture with dye AB25 is used as a column feed. In addition, the removal of heavy metal ions in adsorption columns packed with dye-loaded activated carbon is also an effective treatment process. This improvement in metal adsorption capacities is due to dye AB25 loaded in activated carbon may act as an additional active site for binding the metallic ions. In summary, this study showed that an adsorbent with a lower adsorption capacity for the removal of heavy metals can be employed, without comprising the process efficacy, in the treatment of multicomponent mixtures of dyes and heavy metals under dynamic operating conditions.

Synthesis of amino-functionalized mesoporous silica sheets and their application for metal ion capture

Novel mesoporous silica sheets with surface amino-functional groups (sheet-NH2) were prepared for the efficient adsorption of aqueous metal ions. The sheet-NH2 were synthesized by a dual-templating process using Pluronic P123 and N-palmitoyl-l-alanine as templates. Two silicone regents were used to form the silica framework: tetraethoxysilane and 3-aminopropyltriethoxysilane. In the synthetic process, the as-prepared silicate was refluxed in ethanol to remove the organic templates remaining from the surface amino groups derived from APTES. The prepared sheet-NH2 showed widths of several micrometres and small thicknesses of approximately 50 nm. The pore diameter, pore volume and BET surface area of sheet-NH2 were determined by nitrogen adsorption–desorption isotherms to be 3.1 nm, 0.73 cm3 g−1 and 189.9 m2 g−1, respectively. TEM, XRD, FT-IR and TG–DTA analysis demonstrated that the sheet material had a disordered mesoporous structure and contained organic chains. The adsorptions of aqueous zinc(II) and copper(II) metal ions were examined and compared with amino-functionalized conventional mesoporous silica (MCM-NH2), calcined mesoporous silica sheets and silica beads with no porous structures. Notably, the sheet-NH2 exhibited the highest adsorption of both zinc and copper ions among the examined materials. In addition, the metal ion sorption equilibrium data of sheet-NH2 were fitted to the Langmuir isotherm model.