Application of response surface methodology for uranium(VI) adsorption using hydroxyapatite prepared from eggshells waste material: study of influencing factors and mechanism

Abstract Hydroxyapatite (HAp) was synthesized from biowaste hen eggshells by wet precipitation method in which calcium hydroxide and phosphoric acid were used as precursors. The effectiveness of uranium(VI) adsorption onto HAp was investigated by batch adsorption experiments from aqueous solutions. The obtained HAp powder was characterized by X-ray diffraction, Fourier transform infrared spectroscopy, Raman spectrometry, point of zero charge and Scanning electron microscope. The factors and levels used during the experiments were pH (2–5), adsorbent mass (0.01–0.05 g), and initial U(VI) concentration (100–310 mg L−1). A Box–Behnken design combined with analysis of variance was used to interpret the main effect influencing the adsorption. The results showed that pH was the most significant parameter affecting U(VI). The kinetic data correlates well with the pseudo-second-order model. The adsorption isotherms fitted the Langmuir-1 type model with the qmax = 175.22 mg g−1 at 25 °C. The calculated value of the mean free energy indicates the chemisorption process. Under optimal conditions, the uranium effluent derived from the precipitation of ammonium uranyl carbonate removal performance of 98% was achieved. This study proved that HAp prepared from eggshell was an ecofriendly and low-cost adsorbent and was very effective for the adsorption of U(VI) from aqueous solutions.

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Isotherms and kinetic studies on adsorption of Hg(II) ions onto Ziziphus spina-christi L. from aqueous solutions

Green Processing and Synthesis ◽

10.1515/gps-2015-0103 ◽

2016 ◽

Vol 5 (2) ◽

Cited By ~ 4

Author(s):

Ali Hashem ◽

Alaauddin Al-Anwar ◽

Negma M. Nagy ◽

Doaa M. Hussein ◽

Sara Eisa

Keyword(s):

Experimental Data ◽

Aqueous Solutions ◽

Low Cost ◽

Kinetic Studies ◽

Plant Residue ◽

Batch Adsorption ◽

Pseudo First Order Reaction ◽

Solution Ph ◽

Equilibrium Data ◽

Pseudo Second Order

AbstractL. (ZscL) is a plant residue that has been used as adsorbent for the removal of Hg(II) ions from an aqueous solution. The ability of ZscL to adsorb Hg(II) ions was investigated by using the batch adsorption procedure. It was characterized by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) to support the adsorption of Hg(II) ions. The effects of various parameters on the adsorption process, such as contact time, adsorbent concentration, solution pH and initial concentrations of metal ions were studied to optimize the conditions for maximum adsorption. Experimental equilibrium data were fitted to the Freundlich, Langmuir, Dubinin-Radushkevich, Halsey and Temkin (two parameter models), Redlich-Peterson, Sips, Khan, Hill, Radke-Prausnitz, Langmuir-Freundlich and Toth (three parameter models), Fritz-Schlunder and Baudu (four parameter models) and Fritz-Schlunder (five parameter model) at 30°C by using nonlinear regression analysis. The examination of error analysis methods showed that the Halsey model provides the best fit for experimental data compared with the other isotherms. Various kinetic models have been applied to the experimental data to predict the adsorption kinetics. It was found that pseudo-second-order rate was better obeyed than pseudo-first-order reaction, supporting that the chemisorption process was involved. The obtained results show that ZscL can be used as an effective and natural low-cost adsorbent for the removal of Hg(II) ions from aqueous solutions.

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Adsorption Removal of Eriochrome Black T (EBT) and Rose Bengal (RB) from Aqueous Solutions Using Bio-Sorbents Combination

Chemistry & Chemical Technology ◽

10.23939/chcht15.02.299 ◽

2021 ◽

Vol 15 (2) ◽

pp. 299-311

Author(s):

Miada Benkartoussa ◽

◽

Mossaab Bencheikh Lehocine ◽

Sihem Arris ◽

Hassen Abdeslam Meniai ◽

...

Keyword(s):

Aqueous Solutions ◽

Rose Bengal ◽

Low Cost ◽

Point Of Zero Charge ◽

Order Kinetic ◽

Solution Ph ◽

Eriochrome Black T ◽

Order Kinetic Model ◽

Pseudo Second Order ◽

Potato Peels

Adsorption of eriochrome black T (EBT) and rose bengal (RB) mixture from aqueous solutions was investigated using a mixture of low-cost biosorbents – 50 % of raw state potato peels and 50 % of raw state eggshell (M 50%). The surface charge distribution was determined by acid-base titration and the point of zero charge of the M 50% was found to be 8.5. The adsorbent materials were characterized by Fourier transform infrared spectroscopy and X-ray diffraction. It was confirmed that M 50% was mainly composed of calcite and cellulose. The effect of various operating parameters such as contact time, pH, temperature, etc., was studied. The amount of the adsorption decreased when solution pH increased. The pseudo-second order kinetic model provided the best fit to the experimental data for the adsorption of EBT and RB. The obtained thermodynamic parameters indicate that the adsorption process is endothermic one. According to the obtained results, the new biosorbent may be recommended as an industrial adsorbent for the treatment of effluents containing EBT and RB.

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Preparation and sorption property study of Fe3O4/Al2O3/ZrO2 composite for the removal of cadmium, lead and chromium ions from aqueous solutions

Bulletin of the Chemical Society of Ethiopia ◽

10.4314/bcse.v34i1.10 ◽

2020 ◽

Vol 34 (1) ◽

pp. 105-121

Author(s):

Fekadu Tsegaye ◽

Abi M. Taddesse ◽

Endale Teju ◽

Minbale Aschalew

Keyword(s):

Aqueous Solutions ◽

Mixed Oxides ◽

Sorption Property ◽

Freundlich Isotherm ◽

Experimental Results ◽

Point Of Zero Charge ◽

Precipitation Method ◽

Order Kinetic ◽

X Ray Diffraction ◽

X Ray

Fe-Al-Zr ternary mixed oxides composite was synthesized via co-precipitation method for the removal Pb(II), Cd(II) and Cr(VI) ions from aqueous solutions. The as-synthesized materials were characterized by X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET), scanning electron microscope hyphenated with energy dispersive X-ray diffraction (SEM-EDX) and Fourier transform infrared (FTIR) techniques. The pH at the point of zero charge (pHpzc) of the sorbent and effect of ionic strength on sorption were also determined. The batch tests were conducted to optimize the various sorption parameters such as pH, adsorbent dose, contact time, speed of agitation and initial metal concentration. The experimental results showed that the adsorbed amounts of Pb(II), Cd(II) and Cr(VI) tend to decrease with increase in pH. Freundlich isotherm model fits better the equilibrium data for the adsorbent. Kinetic data correlated better with both pseudo first order and pseudo second order kinetic models. The spontaneous nature of the adsorption process was also confirmed from thermodynamic grounds. The nanosized adsorbent exhibited an adsorption efficiency of 96.65%, 96.55% and 97.2% for Cd(II), Cr(VI) and Pb(II), respectively, at optimum condition. Experimental results showed that the nanocomposite was effective for the removal of the title heavy metals from aqueous solution. Bull. Chem. Soc. Ethiop. 2020, 34(1), 105-121. DOI: https://dx.doi.org/10.4314/bcse.v34i1.10

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Sorption of Pb(II) from Aqueous Solutions by Acid-Modified Clinoptilolite-Rich Tuffs with Different Si/Al Ratios

Applied Sciences ◽

10.3390/app9122415 ◽

2019 ◽

Vol 9 (12) ◽

pp. 2415 ◽

Cited By ~ 4

Author(s):

Mohamed Abatal ◽

Atl V. Córdova Quiroz ◽

María T. Olguín ◽

América R. Vázquez-Olmos ◽

Joel Vargas ◽

...

Keyword(s):

Aqueous Solutions ◽

Contact Time ◽

Point Of Zero Charge ◽

X Ray Diffraction ◽

Solution Ph ◽

Batch Studies ◽

X Ray ◽

Pseudo Second Order ◽

Modified Clinoptilolite ◽

Adsorbent Dose

The removal of Pb(II) from aqueous solutions by acid-modified clinoptilolite-rich tuff was investigated in this work. Clinoptilolite-rich tuff samples were treated using H2SO4 at different concentrations. Prior to and following acid treatment, the samples were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), and Fourier-transform infrared spectroscopy (FTIR). The pH of the point of zero charge (pHPZC) was also determined as part of this characterization. Batch studies were studied to investigate Pb(II) removal as a function of contact time, initial Pb(II) concentration, adsorbent dosage, and solution pH. The results of the XRD and SEM techniques showed that clinoptilolite is the main mineral of the non- and acid-treated natural zeolite samples. However, EDS analysis indicated that the Si/Al ratio increases as the exchangeable ions decrease with increasing acid concentrations. The optimum conditions for Pb(II) removal for samples with 4.37 ≤ Si/Al ≤ 7.9 were found to be as follows: Contact time of 60–360 min, pH: 6–8, and adsorbent dose of 6 mg g−1; whereas for acid-modified clinoptilolite-rich tuffs with 9.01 ≤ Si/Al ≤ 9.52, these conditions were as follows: Contact time of 1440 min, pH: 8–10, and adsorbent dose of 10 mg g−1. The experimental data were analyzed by kinetic and isotherms models. The results showed that the sorption of Pb(II) on samples with Si/Al ratios of 4.37, 5.31, and 7.91 were in agreement with the pseudo-second order and Langmuir isotherm with qm = 48.54, 37.04, and 14.99 mg g−1, respectively, while the kinetic data and isotherm for samples with 9.01 ≤ Si/Al ≤ 9.52 were found to fit the pseudo-first order and Freundlich model.

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Removal of Copper (II) from Aqueous Solutions Using Cuttlebone as Bio-adsorbent

Applied Environmental Research ◽

10.35762/aer.2016.38.3.4 ◽

2016 ◽

pp. 39-48

Author(s):

Pathompong Vibhatabandhu ◽

Sarawut Srithongouthai

Keyword(s):

Aqueous Solutions ◽

Low Cost ◽

Batch Adsorption ◽

Order Kinetic ◽

Optimal Conditions ◽

Optimum Conditions ◽

Adsorption Data ◽

Initial Ph ◽

Order Kinetic Model ◽

Pseudo Second Order

Biosorptionis an effective process for removal and recovery of heavy metal ions from aqueous solutions. In the present study, batch adsorption experiments were carried out for the removal of copper (Cu II) from aqueous solutions using cuttlebone powder (<100 μm)as a bio-adsorbent. The effects of initial pH, adsorbent dosage, initial concentration, and contact time on adsorption efficiency and capacity were studied to evaluate the optimum conditions for copper removal.The results found optimal conditions at initial pH of 5.0, 10 g L-1cuttlebone, 500 mg L-1initial concentration of Cu II in solution, and 150 min of equilibrium time.The Langmuir isotherm and pseudo-second order kinetic model were fitted to the experimental adsorption data. The maxi-mum adsorption capacity calculated from theLangmuir isotherm was 54.05 mg g-1. This result shows that cuttlebone is an effective bio-adsorbent, constituting a promising, efficient, low-cost, and eco-friendly technology bio-sorbent for reducing copper pollution during wastewater treatment.

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Use of Lignite as a Low-Cost Material for Cadmium and Copper Removal from Aqueous Solutions: Assessment of Adsorption Characteristics and Exploration of Involved Mechanisms

Water ◽

10.3390/w13020164 ◽

2021 ◽

Vol 13 (2) ◽

pp. 164

Author(s):

Salah Jellali ◽

Ahmed Amine Azzaz ◽

Mejdi Jeguirim ◽

Helmi Hamdi ◽

Ammar Mlayah

Keyword(s):

Aqueous Solutions ◽

Low Cost ◽

X Ray Diffraction ◽

High Adsorption ◽

Experimental Conditions ◽

X Ray ◽

Ph Values ◽

Adsorption Capacities ◽

Or Groups ◽

Pseudo Second Order

Lignite, as an available and low-cost material, was tested for cadmium (Cd) and copper (Cu) removal from aqueous solutions under various static experimental conditions. Experimental results showed that the removal efficiency of both metals was improved by increasing their initial concentrations, adsorbent dosage and aqueous pH values. The adsorption kinetic was very rapid for Cd since about 78% of the totally adsorbed amounts were removed after a contact time of only 1 min. For Cd and Cu, the kinetic and isothermal data were well fitted with pseudo-second order and Freundlich models, respectively, which suggests that Cd/Cu removal by lignite occurs heterogeneously on multilayers surfaces. The maximum Langmuir’s adsorption capacities of Cd and Cu were assessed to 38.0 and 21.4 mg g−1 and are relatively important compared to some other lignites and raw natural materials. Results of proximate, scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDS), Fourier transform infrared spectroscopy (FTIR) and X-Ray diffraction (XRD) showed that the removal of these metals occurs most likely through a combination of cation exchange and complexation with specific functional groups. The relatively high adsorption capacity of the used lignite promotes its future use as a low cost material for Cd and Cu removal from effluents, and possibly for other heavy metals or groups of pollutants.

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Kinetics and isotherm modeling of Pb(II) and Cd(II) sequestration from polluted water onto tropical ultisol obtained from Enugu Nigeria

Applied Water Science ◽

10.1007/s13201-021-01402-8 ◽

2021 ◽

Vol 11 (4) ◽

Author(s):

Theresa C. Umeh ◽

John K. Nduka ◽

Kovo G. Akpomie

Keyword(s):

Metal Ions ◽

Low Cost ◽

Water Environment ◽

Standard Technique ◽

Soil Surface ◽

Cost Effective ◽

Polluted Water ◽

Batch Adsorption ◽

Lead And Cadmium ◽

Pseudo Second Order

AbstractDeterioration in soil–water environment severely contributed by heavy metal bioavailability and mobility on soil surface and sub-surface due to irrational increase in wastewater discharge and agrochemical activities. Therefore, the feasibility of adsorption characteristics of the soil is paramount in curbing the problem of micropollutant contamination in the farming vicinity. Soil from a farming site in a populated area in Enugu, Nigeria was collected and tested to measure the lead and cadmium contents using atomic absorption spectrophotometer (AAS). The adsorption potency of the ultisol soil was estimated for identifiable physicochemical properties by standard technique. The mean activity concentration of Pb2+ and Cd2+ was 15.68 mg/kg and 3.01 mg/kg. The pH, temperature, metal concentration and contact time adsorptive effect on the Pb2+ and Cd2+ uptake was evaluated by batch adsorption technique. The Langmuir, Freundlich and Temkin models were fitted into equilibrium adsorption data and the calculated results depict a better and satisfactory correlation for Langmuir with higher linear regression coefficients (Pb2+, 0.935 and Cd2+, 0.971). On the basis of sorption capacity mechanism of the soil, pseudo-second-order model best described the kinetics of both metal ions retention process. The results of the present study indicated that the soil being a low cost-effective adsorbent can be utilized to minimize the environmental risk impact of these metal ions.

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Adsorptive Removal of Phosphate from Aqueous Solutions Using Low-Cost Volcanic Rocks: Kinetics and Equilibrium Approaches

Materials ◽

10.3390/ma14051312 ◽

2021 ◽

Vol 14 (5) ◽

pp. 1312

Author(s):

Dereje Tadesse Mekonnen ◽

Esayas Alemayehu ◽

Bernd Lennartz

Keyword(s):

Aqueous Solutions ◽

Low Income ◽

Low Cost ◽

Volcanic Rocks ◽

Phosphate Removal ◽

Phosphate Adsorption ◽

Adsorptive Capacity ◽

Batch Adsorption ◽

Order Kinetic ◽

Adsorptive Removal

The contamination of surface and groundwater with phosphate originating from industrial and household wastewater remains a serious environmental issue in low-income countries. Herein, phosphate removal from aqueous solutions was studied using low-cost volcanic rocks such as pumice (VPum) and scoria (VSco), obtained from the Ethiopian Great Rift Valley. Batch adsorption experiments were conducted using phosphate solutions with concentrations of 0.5 to 25 mg·L−1 to examine the adsorption kinetic as well as equilibrium conditions. The experimental adsorption data were tested by employing various equilibrium adsorption models, and the Freundlich and Dubinin-Radushkevich (D-R) isotherms best depicted the observations. The maximum phosphate adsorption capacities of VPum and VSco were calculated and found to be 294 mg·kg−1 and 169 mg·kg−1, respectively. A pseudo-second-order kinetic model best described the experimental data with a coefficient of correlation of R2 > 0.99 for both VPum and VSco; however, VPum showed a slightly better selectivity for phosphate removal than VSco. The presence of competitive anions markedly reduced the removal efficiency of phosphate from the aqueous solution. The adsorptive removal of phosphate was affected by competitive anions in the order: HCO3− >F− > SO4−2 > NO3− > Cl− for VPum and HCO3− > F− > Cl− > SO4−2 > NO3− for VSco. The results indicate that the readily available volcanic rocks have a good adsorptive capacity for phosphate and shall be considered in future studies as test materials for phosphate removal from water in technical-scale experiments.

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Insights into Starch Coated Nanozero Valent Iron-Graphene Composite for Cr(VI) Removal from Aqueous Medium

Journal of Nanomaterials ◽

10.1155/2016/2813289 ◽

2016 ◽

Vol 2016 ◽

pp. 1-10 ◽

Cited By ~ 5

Author(s):

Prasanna Kumarathilaka ◽

Vimukthi Jayaweera ◽

Hasintha Wijesekara ◽

I. R. M. Kottegoda ◽

S. R. D. Rosa ◽

...

Keyword(s):

Point Of Zero Charge ◽

Inert Material ◽

Maximum Adsorption Capacity ◽

Order Kinetic ◽

X Ray Diffraction ◽

Graphene Composite ◽

Removal Capacity ◽

Order Kinetic Model ◽

Pseudo Second Order ◽

First Time

Embedding nanoparticles into an inert material like graphene is a viable option since hybrid materials are more capable than those based on pure nanoparticulates for the removal of toxic pollutants. This study reports for the first time on Cr(VI) removal capacity of novel starch stabilized nanozero valent iron-graphene composite (NZVI-Gn) under different pHs, contact time, and initial concentrations. Starch coated NZVI-Gn composite was developed through borohydrate reduction method. The structure and surface of the composite were characterized by scanning electron microscopy (SEM), X-ray diffraction spectroscopy (XRD), Fourier transform infrared spectroscopy (FTIR), Brunauer-Emmett-Teller (BET), and point of zero charge (pHpzc). The surface area and pHpzc of NZVI-Gn composite were reported as 525 m2 g−1 and 8.5, respectively. Highest Cr(VI) removal was achieved at pH 3, whereas 67.3% was removed within first few minutes and reached its equilibrium within 20 min obeying pseudo-second-order kinetic model, suggesting chemisorption as the rate limiting process. The partitioning of Cr(VI) at equilibrium is perfectly matched with Langmuir isotherm and maximum adsorption capacity of the NZVI-Gn composite is 143.28 mg g−1. Overall, these findings indicated that NZVI-Gn composite could be utilized as an efficient and magnetically separable adsorbent for removal of Cr(VI).

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Removal of Heavy Metals from Aqueous Solution by Hydroxyapatite/Chitosan Composite

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.789.176 ◽

2013 ◽

Vol 789 ◽

pp. 176-179 ◽

Cited By ~ 3

Author(s):

Eny Kusrini ◽

Nofrijon Sofyan ◽

Dwi Marta Nurjaya ◽

Santoso Santoso ◽

Dewi Tristantini

Keyword(s):

Heavy Metals ◽

Aqueous Solution ◽

Metal Ions ◽

Precipitation Method ◽

X Ray Diffraction ◽

X Ray ◽

Removal Of Heavy Metals ◽

Sem Micrograph ◽

Pseudo Second Order ◽

Chitosan Composite

Hydroxyapatite/chitosan (HApC) composite has been prepared by precipitation method and used for removal of heavy metals (Cr6+, Zn2+and Cd2+) from aqueous solution. The HAp and 3H7C composite with HAp:chitosan ratio of 3:7 (wt%) were characterized by Fourier transform infrared spectroscopy, X-ray diffraction and scanning electron microscopy-energy dispersive X-ray spectroscopy. The SEM results showed that HAp is spherical-shaped and crystalline, while chitosan has a flat structure. SEM micrograph of 3H7C composite reveals crystalline of HAp uniformly spread over the surface of chitosan. The crystal structure of HAp is maintained in 3H7C composite. Chitosan affects the adsorption capacity of HAp for heavy metal ions; it binds the metal ions as well as HAp. The kinetic data was best described by the pseudo-second order. Surface adsorption and intraparticle diffusion take place in the mechanism of adsorption process. The binding of HAp powder with chitosan made the capability of composite to removal of Cr6+, Zn2+and Cd2+from aqueous solution effective. The order of removal efficiency (Cr6+> Cd2+> Zn2+) was observed.

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