Adsorption Capacity For Copper Ions Research Articles

A novel nanocomposite membrane containing modified cellulose nanocrystals for copper ion removal and dye adsorption from water

The aim of this study was developing novel membranes based on polyethersulfone (PES) as matrix and amine functionalized cellulose nanocrystals (CNC) as nanofiller for copper ion and direct red-16 removal from water. The surface modification of CNC was performed using (3-aminopropyl)triethoxysilane (APTES) and confirmed by Fourier transform infrared spectroscopy and energy dispersive X-ray spectroscopy. Then, PES membranes were prepared by embedding various concentrations (0, 0.1, 0.5, and 1 wt%) of modified CNC (MCNC). The results showed that the maximum adsorption capacity of copper ions was 90% for membranes containing 1 wt% MCNC. Dye removal percentage was 89% for neat PES and increased to 99% for 1 wt% MCNC loading. The outcomes of this study demonstrated that incorporating this type of modified CNC in PES membranes improved the efficacy of impurities removal from water and can be suggested as a simple technique for water filtration.

Magnetic silica coated iron carbide/alginate beads: Synthesis and application for adsorption of Cu (II) from aqueous solutions.

In the present study, a novel and high efficient magnetic alginate beads containing Fe5C2@SiO2 nanoparticles (NPs) were synthesized and applied to remove Cu (II) ions from water. The synthesized Fe5C2@SiO2 NPs were characterized by scanning electron microscopy (SEM) and Transmission electron microscopy (TEM). The elemental content of the magnetic/alginate beads before and after Cu(II) adsorption was analyzed using energy dispersive X-ray spectroscopy (EDS). The influence of important factors such as pH, contact time and initial Cu (II) concentration on the adsorption capacity of magnetic/alginate beads was investigated. The maximum adsorption percent (97.4%) was attained in the pH range of 3-4 and the adsorbent dosage of 0.41 g/L in the Cu (II) concentration of 200 mg/L. Moreover, the maximum capacity of adsorption was compared with silica coated iron carbide alginate and alginate alone. The results showed with adding a 1 mg of silica coated iron carbide NPs to sodium alginate enhanced the adsorption capacity of copper ions to ca. 2 times. The Sips isotherm model was best fitted to the experimental data with the maximum adsorption capacity of 37.73 mg/g for each layer. The adsorption kinetic followed the pseudo-second order kinetic model. These results reveal that the alginate Fe5C2@SiO2 beads could be a candidate for copper ions removal from aqueous solutions.

Large scale fabrication of porous boron nitride microrods with tunable pore size for superior copper (II) ion adsorption

Herein, large scale fabrication of porous boron nitride (BN) microrods has been achieved via a facile process, which involves the synthesis of melamine diborate precursors and subsequent thermal treatment process. The fabrication can be scaled up to ultra-large scale which is limited by the furnace. The characterization results show that the as-obtained products are porous BN microrods with diameters in the range of ten to tens of micrometers and length of a few millimeters, respectively. The specific surface area and porosity of these porous BN microrods are tunable by adjusting the synthesis processes of precursors. A highest specific surface area of 653.66 m2/g is obtained for the sample of BN-4, corresponding to the differential pore volume of 0.289 cm3/(g nm) and pore size of about 1.928 nm. Further measurement shows that the as-obtained porous BN microrods possess excellent copper ion adsorption property with a highest adsorption capacity of 365.4 mg/g. This adsorption capacity is superior to those of most copper ion adsorbents reported in recent literature. The high copper ion adsorption capacity combining with the unique properties of hexagonal BN makes them promising candidates for copper ions adsorption in practical wastewater treatment.

Chitosan Functionalization with Amino Acids Yields to Higher Copper Ions Adsorption Capacity

Chitosan (Chi) beads were conjugated with three different amino acids [namely, glutamic acid (GLU), methionine (MET), and taurine (TAU)] aiming to increase the divalent copper ions uptake in aqueous media. Scanning Electron Microscopy evidenced the development of a large porous structure after amino acid functionalization, associated with the increase in a number of amino groups in the polymer backbone. X-Ray Photoelectron Spectroscopy and Fourier-Transform Infrared Spectra analyses were also employed to assess the conjugation of these three different amino acids in chitosan backbone. Adsorption experiments were conducted in a batch process, at 298 K, and kinetic data indicated a slightly better fitting for the pseudo-first-order model when compared to pseudo-second order. Intraparticle diffusion model suggested a three-step mechanism for Cu(II) adsorption kinetics, limited by the third step, the intraparticle diffusion. The isotherm data fitting to the traditional Langmuir and Freundlich models indicated a better fit for the former case. The amino acid conjugation resulted in the increase of the maximum adsorption capacity for Cu(II) from 1.30 mmol g−1 prior to amino acid conjugation to values as high as 2.31 mmol g−1, 2.40 mmol g−1 and 2.68 mmol g−1 for Chi–TAU, Chi–GLU, and Chi–MET, respectively. These results are attributed to the introduction of additional amino groups and new carboxylate and amino acid residues into the chitosan backbone, which might also be explored for amino acid demanding applications.

Free radical synthesis of nanosilver/gelatin-poly (acrylic acid) nanocomposite hydrogels employed for antibacterial activity and removal of Cu(II) metal ions

The present work involves the synthesis of porous gelatin/AcA (PGE-AcA) hydrogel and novel porous gelatin-silver/AcA (NPGESNC-AcA) nanocomposite hydrogel, and their ability as effective biosorbents for the removal of Cu2+ ions from contaminated water. The formation of the samples was confirmed by UV–Vis, TEM, SEM, EDX, DLS, AFM, XRD, TGA/DTG and FTIR techniques. The adsorption studies results showed that maximum monolayer adsorption capacity of copper ions for PGE-AcA was achieved about 130.50 mg g−1 in pH 6.0 for 50 min, and adsorption capacity for the NPGESNC-AcA was nearly 147.10 mg g−1 in pH 5.5 for 40 min by atomic absorption spectroscopy technique. The Cu2+ ions loaded on the PGE-AcA and NPGESNC-AcA could be recovered by HCl above 65.8% and 78.7% after five consecutive cycles of adsorption/desorption, respectively. The results showed that the both of biosorbents loaded by Cu2+ ions could be easily regenerated and reusable. On the other hand, the results of adsorption kinetics and equilibrium isotherms were indicated high correlation coefficient (closer to a unit) for the pseudo-second-order and excellent fitted the adsorption data with the Langmuir isotherm model. Furthermore, the antimicrobial efficiency of the synthesized samples were tested on the Staphylococcus aureus and the Escherichia coli.

Treatment of Wastewater Contaminated with Cu(II) by Adsorption onto Acacia Activated Carbon

In this study, the adsorption of Cu(II) ions from aqueous solutions onto Activated Carbon prepared from Acacia leaves. (AAC) was investigated. The experiments were performed in a batch system at different parameters (contact time, adsorbent dosage, initial concentration of adsorbate, agitation rate, temperature, particle diameter, and solution pH) were varied in order to establish the optimum conditions for copper removal using AAC, and the copper ions adsorption capacity was evaluated after equilibrium was attained. The results indicate that the removal was effective at low Cu(II) concentrations and a natural pH value, and the optimum conditions for Cu(II) removal operation from the synthetic solution investigated were 120 minutes, 300 rpm, and 0.375 mm as a contact time, agitation rate, and particle diameter respectively, and pH value equals to 6 at the temperature 30 1 oC. Also, the adsorbent dose of 0.5 g/100 ml was sufficient for the high removal of Cu(II) from the solution for studied batches which reaches up to 95.3, 77.42, 53.4, 37.6, 26.5, 18.4, 15.4, and 12.15% respectively for studied batches 100, 200, 300, 400, 500, 600, 800, and 1000 ppm respectively. The results obtained from this study show that the AAC can be used as a low-cost adsorbent for the complete removal of Cu(II) from an aqueous solution especially at low concentrations.

Response surface methodology for optimization of the adsorption capability of ball-milled pomegranate peel for different pollutants

Pomegranate peel waste was milled using ball milling to get particles of size of 90μm and used for adsorption of toxic pollutants. The response surface methodology was used for modeling of the adsorption capacity of copper ions and C.I. Reactive Yellow 145 (3RS) from wastewater using ball-milled pomegranate peel (BMPP). The predicted removal capacities obtained from the model are in a good agreement within the experimental results with correlation regression of 0.94 for dye adsorption and 0.92 for metal adsorption. The maximum removal capacity over adsorbent biomass is expected to be 209.7103mgg−1 for dye and 103mgg−1 for metal at optimal values of the independent variables. The analogue experimental results are 224mgg−1 for dye and 106mgg−1 for metal. Conclusively, the obtained results confirm the applicability of used model for predicting the adsorptive capacity of ball-milled pomegranate peel of dye and metals. As well ball-milled pomegranate peel is considering a powerful, cost effective and anionic/cationic adsorbent for decontamination of wastewater.

Influence of Salt and Surfactant on Copper Removal by Xanthan Gum-g-Itaconic Acid/Bentonite Hydrogel Composite from Water Using Fractional Factorial Design

A novel xanthan gum-g-itaconic acid/bentonite (XG-g-PIA/BET) hydrogel composite was synthesized using free radical polymerization in the presence of ammonium persulfate as initiator and N,N’-methylenebis(acrylamide) as crosslinker. The Fourier transform infrared spectroscopy spectra of XG-g-PIA/BET composite before and after adsorption gave strong evidence of the successful adsorbance of copper ions with COOH groups. Influence of the presence of three typical salts (NaCl, CaCl2, and FeCl3) and three types of surfactants including anionic (Brij 35), cationic (N-Cetyl-N,N,N-trimethyl ammonium bromide), anionic (sodium dodecyl sulfate), and their two-term interactions on copper ions adsorption capacity were investigated using 32 experiments with fractional factorial experimental design. The analysis of variance (ANOVA) showed that the fitted model had a significant p value (<0.0001), and except FeCl3, all other variables present in the aqueous solution increased the copper adsorption capacity. In addition, there was no significant two-term interaction between different variables.

Cu(II) adsorption from copper mine water by chitosan films and the matrix effects.

Adsorption of copper ions onto chitosan films was studied, and the matrix effect was evaluated using a synthetic solution and a real effluent from closed copper mine. Chitosan films were prepared by casting technique and characterized. The adsorption study was carried out by equilibrium isotherms, thermodynamics, and kinetics. The thermodynamic parameters indicated that the copper adsorption onto chitosan film was favorable, spontaneous, and exothermic, suggesting an increased randomness at the solid/solution interface. The matrix effect was evaluated in kinetic assays, where a synthetic solution and a real system were carried out at different stirring rates. The highest values of adsorption capacity reached in all stirring rates were about 20% lower in the real effluent, and this reduction in the competitiveness was due to the presence of other ions in the matrix of the real effluent. The maximum adsorption capacity of copper ions onto chitosan films for the synthetic solution was of 450mgg-1, and the removal percentage was in the range from 78 to 96%, and these values for the real effluent were of 360mgg-1 and removal ranging from 62 to 76%. The mapping done of ions present in the water adsorbed of the mine in the films showed that the same was homogeneously distributed in the films' surfaces.

Microfiltration/ultrafiltration polyamide-6 membranes for copper removal from aqueous solutions

Microfiltration/ultrafiltration (MF/UF) Adsorptive polyamide-6 (PA-6) membranes were prepared using wet phase inversion process. The prepared PA-6 membranes are characterized by scanning electron microscopy (SEM), porosity and swelling degree. In this study, the membranes performance has examined by adsorptive removal of copper ions from aqueous solutions in a batch adsorption mode. The PA-6/H2O membranes display sponge like and highly porous structures, with porosities of 41-73%. Under the conditions examined, the adsorption experiments have showed that the PA-6/H2O membranes had a good adsorption capacity (up to 120-280 mg/g at the initial copper ion concentration (C0) = 680 mg/L, pH7), fast adsorption rates and short adsorption equilibrium times (less than 1.5-2 hrs) for copper ions. The fast adsorption in this study may be attributed to the high porosities and large pore sizes of the PA-6/H2O membranes, which have facilitated the transport of copper ions to the adsorption. The results obtained from the study illustrated that the copper ions which have adsorbed on the polyamide membranes can be effectively desorbed in an Ethylene dinitrilotetra acetic acid Di sodium salt (Na2 EDTA) solution from initial concentration (up to 92% desorption efficiency) and the PA-6 membranes can be reused almost without loss of the adsorption capacity for copper ions. The results obtained from the study suggested that the PA-6/H2O membranes can be effectively applied for the adsorptive removal of copper ions from aqueous solutions.

Copper ions removal from aqueous solutions using acid-chitosan functionalized carbon nanotubes sheets

Copper ions (Cu2+) removal from aqueous solutions using carbon nanotubes (CNTs) sheets was performed. CNTs sheets were synthesized via chemical vapor deposition of cyclohexanol and ferrocene in nitrogen atmosphere at 750°C, and functionalized with concentrated nitric acid and chitosan. The as-synthesized and functionalized CNTs sheets were used as adsorbents for copper ions removal from water. The results demonstrated that functionalization with concentrated nitric acid and chitosan improves copper ions adsorption capacity of CNTs sheets from 23.32 to 57.34 mg/g at initial copper ions concentration of 800 mg/l. Therefore, the acid–chitosan-functionalized CNTs sheets can be used as an effective adsorbent for copper ions removal from water and have a good potential application in the environmental protection. Langmuir and Freundlich isotherm models were used to describe the adsorption behavior of copper ions by CNTs sheets. Two kinetics models including the pseudo-first-order and the pseudo-second-order equations were applied to fit the experimental data.

The Potential of Sargassum oligocystum Harvested From Persian Gulf for the Adsorption of Copper Ions From Aqueous Solutions

This study revealed the potential of a brown alga, Sargassum oligocystum, harvested from Persian Gulf for the Cu 2+ adsorption from aqueous solutions. The adsorption kinetic and isotherm and the characteristics of the biomass prepared from S. oligocystum (BSO) were investigated. The BSO was a mesoporous adsorbent with Brunauer, Emmett, and Teller (BET) surface area, a total pore volume, and an average pore diameter of 0.487 m 2 /g, 1.423 cm 3 /g and 12.5 nm, respectively. Fourier transform infrared spectroscopy (FTIR) analysis showed that there were many active functional groups such as alcohol and phenol groups, carbonyl, ethers, and esters on the BSO. Batch tests demonstrated that the Langmuir isotherm model best represented the equilibrium data with maximum copper ions adsorption capacity of 8.23 mg/g. Pseudo-second-order kinetic model was found to satisfactory describe the adsorption process. BSO is an easy-prepared adsorbent and could be an option for the treatment of Cu 2+ -laden wastewaters.

Removal of copper ions from aqueous solution by adsorption onto novel polyelectrolyte film-coated nanofibrous silk fibroin non-wovens

In this approach, polyelectrolyte film-coated nanofibrous silk fibroin (SF) nonwovens were prepared from the alternate deposition of positively charged polyethylenimine (PEI) and negatively charged SF using electrostatic layer-by-layer (LBL) self-assembled technology. The composite membranes were characterized by scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectrometer. The SF-PEI multilayer-assembled nanofibers (less than five layers) were fine and uniform with the fiber diameter from 400nm to 600nm, and had very large surface area and high porosity (more than 70%). The amino groups of PEI were proved to be deposited onto SF nonwovens, which granted the coated nonwovens with potential applicability for copper ions adsorption. The PEI films coated SF substrate showed much higher copper ions adsorption capacity than that of ethanol treated SF nanofibers. Adding the number of PEI coated could enhance the Cu2+ adsorption capacity significantly. The maximum milligrams per gram of copper ions adsorbed reached 59.7mg/g when the SF substrate was coated with 5 bilayers of SF-PEI. However, the copper ions adsorption capacity had no obvious change as the number of PEI continued to increase. These results suggest potential for PEL film-coated nanofibrous nonwovens as a new adsorbent for metal ions.

Amino-functionalized adsorbent prepared by means of Cu(II) imprinted method and its selective removal of copper from aqueous solutions

An amino-functionalized modified metal ion imprinting adsorbent was newly synthesized for the selective extraction and the removal of Cu(II) from aqueous solution. The adsorption capacity of the amino-functionalized ion-imprinted adsorbent was found to be significantly more than the several adsorbents reported in the literatures. The carbon based adsorbent was characterized by SEM, TEM, XPS, Elemental analysis and FTIR respectively. The optimum pH for Cu(II) adsorption was found to be 5. The adsorption equilibrium isotherm could be described by Langmuir model, the Langmuir isotherm has shown an agreement with experimental data, and the maximum adsorption capacity of copper ions for Cu(II) imprinted adsorbent was 33.33mg/g. The selectivity coefficients of the imprinted material for Cu(II)/Cd(II), Cu(II)/Co(II), Cu(II)/Ni(II) and Cu(II)/Zn(II) were 31.8, 90.2, 38.6 and 36.1, respectively. Those were 10.6, 6.22, 7.11 and 39.2 times greater than that of non-imprinted material, respectively. The high adsorption capacity and selectivity coefficient indicated that this amino-functionalized ion-imprinted adsorbent can be used as the selective adsorbent for the removal of copper ions from wastewater. In this work, glucose, tetraethylene pentamine (TEPA) and copper ions as template are combined together with specific mole radio for preparing carbon-based adsorbent by means of hydrothermal synthesis method.

Copper ions removal from water using functionalized carbon nanotubes–mullite composite as adsorbent

Carbon nanotubes–mullite composite was synthesized by direct growth of carbon nanotubes on mullite particles via chemical vapor deposition method using cyclohexanol and ferrocene as carbon precursor and catalyst, respectively. The carbon nanotubes–mullite composite was oxidized with concentrated nitric acid and functionalized with chitosan and then used as a novel adsorbent for copper ions removal from water. The results demonstrated that modification with concentrated nitric acid and chitosan improves copper ions adsorption capacity of the prepared composite, significantly. Langmuir and Freundlich isotherms and two kinetic models were applied to fit the experimental data. The carbon nanotubes growth on mullite particles to form the carbon nanotubes–mullite composite with further modification is an inherently safe approach for many promising environmental applications to avoid some concerns regarding environment, health and safety. It was found that the modified carbon nanotubes–mullite composite can be considered as an excellent adsorbent for copper ions removal from water.

Preparation of carbon adsorbents from lignosulfonate by phosphoric acid activation for the adsorption of metal ions

Activated carbons were prepared from sodium lignosulfonate by phosphoric acid activation at carbonization temperatures of 400–1000°C. The resulting materials were characterized with regard to their surface area, pore volume, pore size distribution, distribution of surface groups and ability to adsorb copper ions. Activated carbons were characterized by nitrogen adsorption, scanning electron microscopy, Fourier transform infrared spectroscopy and thermal gravimetric analyses. The results indicate that with increasing carbonization temperature, the surface area decreased from 770m2/g at 400°C to 180m2/g at 700°C and increased at higher temperatures to 1370m2/g at 1000°C. The phosphorus content peaked at 11% for carbon obtained by carbonization at 800°C. Potentiometric titration revealed the acidic character of all the phosphoric acid-activated carbons, which were found to have total concentrations of surface groups of up to 3.3mmol/g. The carbons showed a high adsorption capacity for copper ions even at pH values as low as 2.

Synthesis of functionalized mesoporous silica and its application for Cu(II) removal

The amine-grafted and mercapto-grafted SBA-15 mesoporous silica were synthesized successfully via hydrothermal method. These functionalized mesoporous silica were prepared by direct co-condensation and post-synthesis grafting processes and then used as adsorbents to remove the Cu2+ from the simulated water. The obtained mesoporous adsorbent was characterized by X-ray diffraction, nitrogen adsorption–desorption analysis, Fourier transform infrared spectroscopy, transmission electron microscopy, and scanning electron microscopy. The experimental results showed that mesoporous materials can be grafted functional groups successfully without significant change of the hexagonal mesostructure after the functionalization process, but the adsorption capacity of copper ions was greatly enhanced and the adsorption amount was up to 99.68%. Compared with post-synthesis grafting processes, because the direct co-condensation templating agent was not completely removed which affects the adsorption capacity. It was demonstrated that the functionalized mesoporous silica could be used as a promising adsorbent for removing and recovering heavy metal ions in water.

Equilibrium studies of copper ion adsorption onto modified kernel of date (Fructus dactylus)

Heavy metal pollution of water is a serious problem because of its toxic effects on the human health and living organism. Therefore, there is a need to develop technologies to remove toxic pollutants found in polluted water. There are different ways to remove the toxic metals from wastewater. Among all treatments proposed, the adsorption process is one of the most promising technologies in water pollution control. Recently, numerous approaches have been studied for the development of cheaper and effective adsorbents. Many low-cost adsorbents, including natural materials, biosorbents and waste materials from industry and agriculture, have been proposed by several researchers. In this study, removal of copper from aqueous solution by using powdered and modified kernel of date (Fructus dactylus) with apocarbonic anhydrase enzyme has been investigated. The operating variables studied were contact time, initial solution pH, initial metal concentration, temperature and adsorbent dosage. The experimental investigation results showed that modified and powdered kernel of date (F. dactylus) has a high level of adsorption capacity for copper ions. The adsorption data were correlated with the Langmuir and Freundlich isotherm models. It was found that the Langmuir and Freundlich isotherms fitted well to the data. The results revealed that copper is considerably adsorbed on modified and powdered kernel of date (F. dactylus). Consequently, it is concluded that the modified and powdered kernel of date (F. dactylus) can be successfully used for the removal of the copper ions from the aqueous solutions.

Preparation of Sugarcane Bagasse/Poly(Acrylic Acid-co-Acrylamide) Hydrogels and their Application

In this work, sugarcane bagasse, being an abundant and renewable resource, was used as a raw material to prepare sugarcane bagasse-g-poly(acrylic acid-co-acrylamide) (SB/P(AA-co-AM)) hydrogels. The hydrogels were prepared by free radical graft copolymerization of SB with AA and AM using N,N-methylene-bis-acrylamide (MBA) as a crosslinker. The optimal synthesis conditions were determined by investigating the water absorbency of the hydrogels. The maximum water absorbency reached 269 g/g in deionized water, and the corresponding copper ions adsorption capacity was 265 mg/g. These grafted hydrogels showed a pH-sensitive swelling behavior. Furthermore, they also exhibited excellent water retention capacity, which reserved 92.7%, 81.7%, and 76.8% for 44 h, and 83.7%, 58.6%, and 47.1% for 116 h at 5 °C, 25 °C, and 35 °C, respectively. FTIR spectroscopy and SEM were used to reveal the chemical structure and the morphology of the hydrogels. SEM/EDS further confirmed the adsorption of the copper(II) on the resulting hydrogels. Therefore, SB/P(AA-co-AM) hydrogels could have promising applications as water retention agents and metal ions adsorbents in water treatment and agricultural industries.

Fast, selective adsorption of Cu2+ from aqueous mixed metal ions solution using 1,4,7-triazacyclononane modified SBA-15 silica adsorbent (SBA-TACN)

A new SBA-15 supported 1,4,7-triazacyclononane modified mesoporous silica adsorbent (SBA-TACN) has been synthesized using post grafting route and has thoroughly been characterized by small angle X-ray scattering (SAXS), N2 adsorption–desorption measurements, Fourier-transform infrared (FT-IR), solid-state 29Si MAS and 13C CP MAS NMR spectroscopy, transmission electron (TEM) and scanning electron microscopy (SEM), elemental analysis (EA) and thermogravimetric analysis (TGA). The synthesized material shows excellent copper (II) ion adsorption selectivity at pH 5 in mixed metal ion solution containing Cu2+, Cr3+, Ni2+, Co2+ and Li+. The copper ion adsorption capacity of the SBA-TACN can reach a maximum value of 0.67mmol/g. Possible adsorption mechanism of metal ions on SBA-TACN has been discussed. The adsorbent can be readily regenerated by HNO3–NH3 treatment.