Equilibrium Sorption Data Research Articles

Adsorption of Crystal Violet onto Adsorbents Derived from Agricultural Wastes: Kinetic and Equilibrium Studies

Suitability of adsorbents derived from groundnut shell (GS) and bean pod (BP) in removing crystal violet from aqueous solution was evaluated in a series of batch experiments. Findings reveal that the points of zero charge (PZC) of GS and BP are 3.50 and 3.00 respectively. Findings also show that GS and BP exhibit maxima adsorption at pH values of 6.00 and 5.00 respectively. For both GS and BP, pseudo-second order model gives the best fit for the sorption kinetic data while Freundlich isotherm gives the best fit for the sorption equilibrium data. These findings suggest that the adsorption of crystal violent onto GS and BP probably involves chemisorption and the adsorption does not reach a plateau as the concentration of crystal violet in the aqueous solution increases. This study demonstrates the suitability of GS and BP as low-cost adsorbents for removing crystal violet from industrial wastewater.

Application of shrinking core model to the adsorption of oxytetracycline onto peanut hull-derived activated carbon in a closed-loop fixed-bed reactor

In the present paper, the ability of peanut hull-derived activated carbon AC(PH-800) to adsorb oxytetracycline (OTC) was investigated using batch adsorption with fixed-bed reactor. The factors influencing adsorption, such as contact time and sorbent concentration, were evaluated. Sorption kinetic and equilibrium data of OTC sorption onto AC(PH-800) were submitted to kinetics and equilibrium models in order to calculate the adsorption constant rate and the maximum capacity of the sorbent. The application of shrinking core model (SCM) for the removal of OTC was investigated with two assumptions finite and infinite volume solution. Oxytetracycline adsorption increased for increasing initial OTC concentrations, and equilibrium isotherms can be accurately described by the Freundlich equation. Experimental data were analyzed using the SCM and the analysis based on statistical and graphical method proved that the adsorption followed the product layer diffusion controlled equation of the model. The approach modeling considering a finite volume solution assumption was more successful than the modeling approach involving an infinite volume solution.

Sorption/release of bioactive species in/from cross-linked poly(ethyleneimine)/poly(N-isopropylacrylamide) films constructed onto solid surfaces

Multilayer thin films are useful materials in the fabrication of controlled drug delivery systems and in controlling drug release processes. Herein, we report the step-by-step deposition of polymer multilayers based on poly(ethyleneimine) (PEI) and poly( N-isopropylacrylamide) (PNIPAAm) mediated by pyromellitic dianhydride (PM), as cross-linker of PEI chains, onto Daisogel silica microparticles. The sorption/release properties of the resulting composite microparticles for indomethacin (IDM), diclofenac sodium salt (DS), and Ponceau SS (PSS) were followed as a function of PM concentration. The sorption properties of the [(PEI-PM)/PNIPAAm] n multilayer films for all anionic species (IDM, DS, and PSS) were influenced by the number of polymer layers and the weight ratio between cross-linker and Daisogel microparticles during the cross-linking steps. It was found that the sorbed amount of anionic compounds increased with the number of polymer layers and with the decrease of PM concentration. The Langmuir and Sips model isotherms fitted well the sorption equilibrium data. The maximum equilibrium sorption capacity ( qm) evaluated by the Langmuir model, at 25°C, was 41 mg IDM g−1 of Daisogel//[(PEI-PM)/PNIPAAm]8.5 and 40 mg PSS g−1 of Daisogel//[(PEI-PM)/PNIPAAm]8.5, for a weight percentage of PM/silica of 0.1% w/w. Cumulative release of IDM was faster and higher than PSS in the first 5 h, while PSS was desorbed with a constant rate for 30 h, supporting a sustained release from Daisogel//[(PEI-PM)/PNIPAAm] n composite microparticles.

Cadmium (II) Removal From Aqueous Solution Using Guar Gum-silica Nanocomposite

In present communication we report on Cd(II) adsorption using our recently reported material, the guar gum-silica nanocomposite. The equilibrium, thermodynamics and kinetics of Cd(II) adsorption onto composite from aqueous solution were investigated. Optimum experimental parameters were determined to be pH 8, contact time 2 hours, Cd(II) concentration 100 mg/L, temperature 30 o C and adsorbent dose 10 mg. The sorption equilibrium data were modeled using the Langmuir and Freundlich isotherms where the data fitted better to Langmuir model indicating unilayer sorption, the Qmax being 666 mg/g. The kinetic data indicated chemisorption in the rate-controlling step as the pseudo-second-order model was best suited (rate constant of 2.79 × 10-4 gmg -1 min -1 at 100 mg/L Cd 2+ ). The calculated thermodynamic parameters (ΔG°, ΔS°, ΔH°) showed the adsorption to be exothermic and spontaneous with decreased randomness at the solid–solution interface. The adsorbent could be recycled for six successive cycles with 31% loss in its efficiency.

Sorption heavy metal ions by activated carbons with well-developed microporosity and amino groups derived from Phragmites australis by ammonium phosphates activation

Activated carbons (ACs) were prepared from Phragmites australis impregnated with phosphoric acid (PPA) and ammonium phosphates (APs). APs include triammonium phosphate (TAP), diammonium phosphate (DAP), and monoammonium phosphate (MAP). The activation process of ACs was simulated by thermo-gravimetric analysis. The physicochemical properties of AC–PPA and AC–APs were systematically examined by N2 adsorption/desorption, elemental analysis, Boehm's titration, and XPS. AC–PPA exhibited much higher values of the BET surface area (894.5 m2/g) and total pore volume (1.108 cm3/g) than that of AC–APs (< 500 cm2/g and < 0.3 cm3/g), but less Smic/SBET (29.3%) and Vmic/Vtot (14.9%) of AC–PPA than that of AC–APs (> 60% and >50%). Nevertheless, the results of elemental analysis, Boehm's titration, and XPS showed that AC–APs contained much more surface nitrogen-containing functional groups. The sorption equilibrium data for heavy metal ions Ni(II), Cu(II), and Cd(II)) sorption onto the carbons was analyzed by the Langmuir and Freundlich model. The differences of the carbons in the physicochemical and adsorption properties suggested that AC–APs exhibited higher heavy metal ions sorption capacities than AC–PPA due to well-developed microporosity and abundant amino groups.

Fabrication and characterization of polyethyleneimine immobilized on chloropropyl- and silica-coated magnetic nanoparticles for Pb2+ removal from aqueous solution

A new surface polymeric functionalized magnetic adsorbent was synthesized through the grafting polyethyleneimine onto chloropropyl- and silica-coated magnetic nanoparticles and characterized by transmission electron microscopy, X-ray diffraction, IR, elemental analysis, and thermo gravimetric analysis. The relationship between grafting reaction conditions, such as solvent, reaction time, reaction temperature, and the polyethyleneimine amount added, and grafting percentage was investigated systematically. Under the optimized conditions, the magnetic adsorbent was fabricated and used for the removal of Pb2+ from the solutions for the first time. Batch experiments were carried out to examine the influence of different sorption parameters, for example, solution pH, initial concentration of Pb2+, contact time, and adsorbent dosage. The equilibrium sorption data fitted Langmuir adsorption isotherm well and the adsorbent–adsorbate kinetics followed pseudo-second-order model with a maximum adsorption capacity of 131 mg g−1, which revealed that the prepared polymeric magnetic adsorbent was attractive and effective material with high uptake capacity.

Assessment of the banana pseudostem as a low-cost biosorbent for the removal of reactive blue 5G dye

In this work, the removal of reactive blue 5G (RB5G) dye using the drying biomass of banana pseudostem (BPS) was investigated. The characterization of BPS particles was performed. Improvement in the RB5G dye removal performance at the following sorption conditions was evidenced: pH 1, 30°C sorption temperature and 40 rpm shaking, regardless of the particle size range. Kinetic RB5G dye sorption data obtained at better conditions fit well in an Elovich model. A combined Langmuir–BET isotherm model provides a good representation of the RB5G dye equilibrium sorption data, which shows the evidence of a physical sorption process on the BPS surface. Based on the results, the removal of RB5G dye molecules by BPS is based on a physical sorption process.

Physico-chemical studies in the removal of Sr(II) from aqueous solutions using activated sericite

Sericite, a mica based natural clay, was annealed at 800 °C for 4 h followed by acid activation using 3.0 mol/L of HCl at 100 °C in order to obtain activated sericite (AS). The activation of sericite causes a significant increase in specific surface area. Further, SEM images of the AS showed a disordered and heterogeneous surface structure with mesopores on its surface whereas the pristine sericite possessed a compact layered structure. The materials were further employed in the removal of Sr(II) from aqueous solutions in a batch reactor system. Removal of Sr(II) was studied as a function of pH, concentration of adsorbate, contact time, background electrolyte concentrations and dose of adsorbents using pristine sericite and AS. The removal of Sr(II) was favoured increasing the pH of the solution and the extent of Sr(II) removal was increased with increasing the sorbate concentration. Equilibrium sorption data obtained with pristine sericite were fitted well to Langmuir adsorption isotherm whereas the sorption data collected using AS better fitted to the Freundlich adsorption isotherm. The time dependence sorption data showed that the uptake of Sr(II) was very rapid and an apparent sorption equilibrium was achieved within 30 min and 60 min of contact for sericite and AS, respectively. The kinetic data were modelled to the pseudo-first order and pseudo-second order rate kinetics and sorption capacities as well as rate constants were evaluated. Increase in background electrolyte concentrations NaNO3 (0.001–0.1 mol/L) indicated that the presence of NaNO3 caused to decrease the percent removal of Sr(II) by sericite and AS. Furthermore, fixed-bed column reactor operations were performed to obtain the breakthrough data. The breakthrough data were fitted well to the non-linear Thomas equation. Therefore, the present study suggested that AS can be adequately applied for the removal of Sr(II) from the aquatic environment.

Sorption of uranium(VI) by Trapa bispinosa from aqueous solution: effect of pretreatments and modeling studies

In this study, the sorption of uranium(VI) from aqueous solution was investigated using Trapa bispinosa (Singhara) in batch system. Different physical and chemical treatments were given to native biomass for enhancing its sorption capacity for uranium(VI). The optimization of different experimental factors such as solution pH, dose of biosorbent, particle size, contact time, temperature, and initial uranium(VI) ion concentration was done. Maximum sorption (171 mg g−1) was observed at pH (5.0), particle size (0.25 mm), biosorbent dose (0.05 g), temperature (50°C), and initial uranium(VI) ion concentration (400 mg L−1) in 90 min. The obtained data were analyzed by applying equilibrium, kinetic, and thermodynamic models. The uranium(VI) sorption equilibrium data were best fitted in Freundlich adsorption isotherm. The rate of biosorption process was effectively described by applying different kinetic models and the well-fitted model found to be pseudo-second-order. The evaluation of thermodynamic parameters represented that the uranium(VI) sorption process was exothermic, spontaneous, and favorable. The process was made more economical through recovery of uranium(VI) ions using HNO3. FT-IR analysis of biosorbent confirmed the involvement of functional groups like hydroxyl, carbonyl, and carboxylic groups in the sorption process.

Kinetics and Equilibrium Models for Sorption of Cu(II) onto a Novel Manganese Nano-adsorbent

The studies of kinetics and equilibrium sorption of Cu(II) were undertaken using nanoscale zerovalent manganese (nZVMn) synthesized by chemical reduction in a single pot system. nZVMn was characterized using scanning electron microscopy, energy dispersive x-ray, and surface area determined by Brunauer–Emmett–Teller. The effect of pH, contact time, adsorbent dose, agitation speed, initial Cu(II) concentrations, temperature, and ionic strength on the sorption of Cu(II) onto nZVMn were investigated in a batch system. The kinetic data followed pseudo-second-order. The mechanism was governed by pore diffusion. The equilibrium sorption data were tested by Freundlich, Langmuir, Temkin, Dubinin–Kaganer–Raduskevich, and Halsey isotherm models. The Langmuir monolayer adsorption capacity (Qmax = 181.818 mg/g) is much greater compared to other nano-adsorbents used in sorption of Cu(II). The thermodynamic parameters (ΔH0, ΔS0, ΔG0) revealed a feasible, spontaneous, and endothermic adsorption process. nZVMn has a great potential for effective removal of copper (II) in aqueous solution.

Adsorption of reactive yellow 145 onto chitosan in aqueous solution: kinetic modeling and thermodynamic analysis

The adsorption of reactive yellow 145 (RY145) dye onto chitosan 8B in aqueous solution was investigated using batch method. Experiments were carried out at various pH, initial dye concentrations, ionic strengths and temperatures. The suitable pH was found to be 4 among the observed pH ranges between 4 and 11. The maximum amount of dye uptake onto chitosan 8B was found to be 129.87 µmol/g at 30 °C. Adsorption kinetic data acquired from various batch experiments were examined using pseudo-first-order, second-order, Elovich, intraparticle, and film diffusion kinetic models. The results revealed that the sorption process follows pseudo-second-order kinetics, whereas film diffusion and intraparticle diffusion are the rate-limiting steps. Freundlich, Temkin and Langmuir models were used to analyze the equilibrium sorption data. Langmuir model shows higher consistency than the other two models. The computed values of activation and apparent thermodynamic parameters confirm the conclusion that the adsorption of RY145 molecules onto chitosan 8B in aqueous solution is an endothermic spontaneous-physisorption process.

Characterization and adsorption kinetic study of surfactant treated oil palm (Elaeis guineensis) empty fruit bunches

Oil palm (Elaeis guineensis) empty fruit bunches (OPEFB) was treated with cetyltrimethylammonium bromide (CTAB) to make its surface suitable for methyl orange (MO) dye adsorption. CTAB-treated OPEFB samples were characterized for their surface functional groups using FTIR, pHzpc, proton-binding capacity, and Boehm titration techniques. The surface morphology and elemental composition of the sample were also studied, employing field emission scanning electron microscopy and energy dispersive X-ray spectroscopy (EDS). It was found that in totality, acidic surface functional group increased after CTAB treatment. The adsorption process was well explained with pseudo-second-order kinetic model. The obtained equilibrium sorption data were then analyzed using the Langmuir, Freundlich, Dubinin–Radushkevich, and Tempkin isotherms. The results showed that sorption was surfactant dose dependent and adsorption increased with an increase in the percentage of surfactant applied on the OPEFB. The maximum adsorption of MO was found at 1% surfactant treatment dose. It was also determined that MO adsorption onto the OPEFB treated with 1% CTAB solution (1% CTAB-OPEFB) followed the monolayer (Langmuir) adsorption. The maximum adsorption capacity of 1% CTAB-OPEFB for the removal of MO was found to be 18.08 mg/g at 298 K (at pH 6.3). Thermodynamic study revealed that the adsorption process was spontaneous and exothermic in nature. There was no energy barrier to initiate the adsorption of MO dye on the CTAB-treated OPFB.

Biosorption of Lead, Cadmium, and Zinc onto Sunflower Shell: Equilibrium, Kinetic, and Thermodynamic Studies

The present study deals with the application of an a bundant low cost biosorbent sunflower shell for metal ions removal. Lead, Cadmium and Zinc were chosen as model sorbates. The influences of initial pH, sorbent dosage, contact time, temperature and initial metal ions concentration on the removal efficiency were examined. The single ion equilibrium sorption data were fitted to the non-competitive Langmuir and Freundlich isotherm models. The Freundlich model represents the equilibrium data better than the Langmuir model. In single, binary and ternary component systems,Pb+2 ions was the most favorable component rather than Cd+2 and Zn+2 ions. The biosorption kinetics for the three metal ions followed the pseudo-second order kinetics indicating that the chemical sorption was the rate-limiting step. The thermodynamic parameters including free energy ( G0), enthalpy and entropy changes for Pb2+,Cd2+ and Zn2+ ions indicated that the sorption process was feasible,spontaneous,and endothermic in the temperature range 20-50 0 C .Desorption of the three metals ions from the biosorbent was effectively achieved in a 0.2 mol L-1 HCl solution.

Synthesis and application of a surface-grafted In (III) ion-imprinted polymer for selective separation and pre-concentration of indium (III) ion from aqueous solution

In (III) ion-imprinting polymer (In (III)-IIP) was prepared with the surface imprinting technique by using indium (III) ion as the template ion, vinylphosphonic acid (VPA) as the functional monomer and silica gel grafted as the support. The In (III)-IIP prepared was characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), Brunauer–Emmett–Teller (BET), thermogravimetric analysis and energy dispersive X-ray spectrometer (EDX). The adsorption behavior of the In (III) ion-imprinting polymer and non-imprinting polymer (In (III)-NIP) was investigated in detail by batch and column experiments. Optimum pH for maximum sorption was found to be 3.0. Kinetic studies revealed that both adsorption processes could be better described by pseudo-second-order kinetic model, while the sorption equilibrium data agreed well with the Langmuir isotherm model. The maximum adsorption capacities calculated from the Langmuir isotherm were 47.39 and 31.11mg·g−1 for In (III)-IIP and In (III)-NIP, respectively. The selectivity coefficients of the In (III)-IIP for indium (III) ion in the presence of Cu (II), Pb (II), Zn (II) and Fe (II) are found to be 189.17, 67.94, 886.63 and 2479.71, respectively. In addition, it was observed that the dynamic adsorption capacity of the In (III)-IIP was close to the static adsorption capacity due to the fast adsorption rate. Indium (III) ion can be separated selectively from the solution containing various foreign ions by column packed with the In (III)-IIP and can be pre-concentrated, and the enrichment factor reaches up to 80.0. The In (III)-IIP prepared was repeatedly used and regenerated six times without a significant decrease in adsorption capacity, demonstrating that the sorbent is of high stability and reusability. Moreover, the developed method was successfully applied to the selective extraction of indium (III) ion from the real water samples with satisfactory results.

A study of adsorption isotherms for the removal of herbicide Atlantis WG from aqueous solutions by using Bentonite clay

The subject of this research involves studying adsorption to removal herbicide Atlantis WG from aqueous solutions by bentonite clay. The equilibrium concentration have been determined spectra photometry by using UV-Vis spectrophotometer. The experimental equilibrium sorption data were analyzed by two widely, Langmuir and Freundlish isotherm models. The Langmuir model gave a better fit than Freundlich model The adsorption amount of (Atlantis WG) increased when the temperature and pH decreased. The thermodynamic parameters like ?G, ?H, and ?S have been calculated from the effect of temperature on adsorption process, is exothermic. The kinetic of adsorption process was studied depending on Lagergren ,Morris ? Weber and Rauschenberg equations.

A study of adsorption isotherms for the removal of herbicide Atlantis WG from aqueous solutions by using Bentonite clay

The subject of this research involves studying adsorption to removal herbicide Atlantis WG from aqueous solutions by bentonite clay. The equilibrium concentration have been determined spectra photometry by using UV-Vis spectrophotometer. The experimental equilibrium sorption data were analyzed by two widely, Langmuir and Freundlish isotherm models. The Langmuir model gave a better fit than Freundlich model The adsorption amount of (Atlantis WG) increased when the temperature and pH decreased. The thermodynamic parameters like ?G, ?H, and ?S have been calculated from the effect of temperature on adsorption process, is exothermic. The kinetic of adsorption process was studied depending on Lagergren ,Morris ? Weber and Rauschenberg equations.

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.

Inhibitory effect on the uptake and diffusion of Cd2+ onto soybean hull sorbent in Cd–Pb binary sorption systems

The uptake of Cd2+ and Pb2+ ions by a soybean hull (SH) biosorbent in single and binary systems has been investigated. Sorption tests regarding SH in natura and chemically treated were carried out testing a suitable value range of solution pH, sorption temperature and shaking velocity. Sorption capacity is improved at pH 4, 30 °C temperature and 100 rpm. When a strong base is applied, a related-to-untreated SH increasing of 20% in the sorption capacity of Pb2+ ions was observed, but with poor results for Cd2+ uptake. Additionally, a relatively strong decreasing in both sorption capacities of Pb2+ and Cd2+ ions was evidenced for all acidic treatments. Regarding untreated SH, kinetic sorption data of both metals were well-interpreted by a pseudo second-order model and a rate-limiting step on the basis of an intra-particle diffusion model was suggested to occur. An inhibitory effect of Pb2+ diffusion over Cd2+ one was observed, limiting to reach the obtained maximum sorption capacity in single system. Maximum adsorption capacities of 0.49 and 0.67mequivg−1 for Cd2+ and Pb2+, respectively, were predicted by the Langmuir isotherm model that reproduced well the equilibrium sorption data for single systems. The inhibitory effect of one metal over the other one was verified in equilibrium sorption data for binary systems interpreted on the basis of a modified extended Langmuir isotherm model, predicting changes in metal affinity onto the SH surface. Finally, SH is an alternative biosorbent with a great potential for the wastewater treatment containing cadmium and lead ions.

Lead Sorption by Carbon Nanofibers Grown on Powdered Activated Carbon — Kinetics and Equilibrium

Carbon nanofibers (CNFs) were synthesized by using a safe and less hazardous method, compared to using floating catalysts in chemical vapor deposition (CVD) process. This process used C 2 H 2 as carbon source and oil palm kernel shell-based powdered activated carbon (PAC) as cheap solid substrate. Use of nickel ( Ni 2+) impregnated PAC as fixed substrate for the synthesis of CNF is one of the novelties of the research work accomplished by the authors. The PAC–CNFs porous nanocomposite product was used for the sorption of lead ions ( Pb 2+) from synthetic aqueous solution. Kinetics of Pb 2+ adsorption and isotherms were investigated by varying initial concentration of lead and contact time. PAC–CNFs were found to remove Pb 2+ better at acidic pH of about 5.5. Langmuir and Freundlich isotherms were applied to the sorption equilibrium data to find the best fitted model. Langmuir isotherm model with R2 = 0.965 fitted the adsorption data better than the Freundlich isotherm. The kinetic processes of Pb 2+ adsorption on CNFs were investigated by applying different kinetic models, namely zero-order, pseudo-first-order and pseudo-second-order. The pseudo-second-order rate equation exhibited the best results with R2 = 0.999, qe = 74.79 (mg/g) and K2 = 0.029 (min ⋅ g/mg). The novel nanocomposite product seemed to have the potential to remove Pb 2+ ions from aqueous solution.

Green synthesis of graphene sand composite (GSC) as novel adsorbent for efficient removal of Cr (VI) ions from aqueous solution

Cr (VI) is one of the most toxic contaminants recognized as a carcinogenic and mutagenic agent and needs complete removal from wastewater before disposal. In the present study, a novel graphene based adsorbent was synthesized from sugar and sand using green chemistry approach and adsorption of Cr (VI) ions from aqueous solution was studied by batch adsorption technique under varying experimental conditions like contact time, pH, adsorbent dose, initial Cr (VI) concentration and temperature. The characterization of the prepared graphene sand composite (GSC) was accomplished by Fourier transform infrared (FTIR) spectroscopy, transmission electron microscopy (TEM), X-ray diffraction(XRD) analysis, Raman spectroscopy, electron diffraction measurements, X-ray photoelectron spectroscopy, energy dispersive X-ray spectroscopy (EDX) and surface area measurements. The specific surface area of the GSC before and after activation was determined to be 100m2/g and 157m2/g, respectively. The optimum adsorption of Cr (VI) by the new adsorbent, coined as GSC, was observed at pH 1.5 The maximum adsorption capacity of GSC for Cr (VI) was found to be 2859.38mg/g at room temperature which is claimed to be one of the exceptionally high values reported so far in the literature. The equilibrium sorption data were fitted satisfactorily to the Langmuir adsorption model with R2 value of 0.99108. The progress of the adsorption process was found to follow the second order kinetics. The results obtained in this study illustrated that the prepared graphenic material could be an effective and economically viable adsorbent for removal of Cr (VI) ions.