Initial Copper Ion Concentration Research Articles

Chitosan-rectorite nanospheres immobilized on polystyrene fibrous mats via alternate electrospinning/electrospraying techniques for copper ions adsorption

Chitosan (CS), as a kind of well characterized biopolymer, has been used for heavy metal adsorption due to its low cost and high efficacy. However, when used directly, chitosan particles had small surface area and weak mechanical strength which is unfavorable to metal adsorption and reused. Besides, it cannot be easily recycled that may cause a secondary pollution. In this paper, CS and layered silicate rectorite (REC) were fully mixed and the mixtures were subsequently electrosprayed nano-sized spheres, which were immobilized on the surface of electrospun polystyrene (PS) mats for metal adsorption. The morphology analysis taken from SEM confirmed that CS-REC nanospheres were loaded on the surface of PS fibrous mats. Small Angle X-ray diffraction patterns showed that the interlayer distance of REC in composite mats was enlarged by the intercalation of CS chains; such structure meant bigger surface area which was helpful for metal adsorption. The data of contact angle implied that PS mats coated with CS-REC nanospheres exhibited better hydrophilicity than PS mats, which was conductive to adsorption rate. Besides, the copper ions adsorption of composite mats was tested at different conditions including the adsorption time, the initial pH and the initial concentration of copper ion. The results demonstrated that PS mats coated with CS-REC nanospheres had the adsorption capacity up to 134mg/g. In addition, the addition of REC containing Ca2+ could also improve the metal adsorption because of cation exchange. The desorption assay indicated that PS mats immobilized with CS and CS-REC still kept high adsorption ability which retained 74% and 78% after three adsorption-desorption cycles.

Cu(II) ions removal from aqueous solution by synthesized Phragmites australis/emeraldine base biocomposite

In this paper the influence of in situ synthesized biocomposite consisted of Phragmites australis (common reed) and emeraldine base on the removal of copper ions from aqueous media is discussed. Physico-chemical parameters such as initial copper ion concentration, composite dosage and contact time between composites and Cu(II) ions in the water solution were studied. An assessment of the equilibrium and the kinetics of sorption of copper ions has been made. For preparation of the biocomposites two different ratios of common reed/aniline were used. The results show that in all cases were achieved high removal efficiencies. The copper ions removal efficiency increases up to an optimal dose (0.5 g) above which the removal efficiency does not significantly change. Using 0.5 g of Pha/Emb1 and initial copper ions concentration 50 mg L -1 for a period of 360 minutes 99.6 % removal efficiency was achieved, while using the same amount of Pha/Emb2 for the same period of time was obtained 91.9 % removal efficiency. The obtained data were fitted into the isotherms of Langmuir, Freundlich, Temkin and Dubinin-Raduskevich. Applying the Dubinin–Radushkevich model to the experimental data, it was found that the removal of copper ions from the aqueous medium using the synthesized composites is probably due to physical adsorption and ion exchange process. It was found that the Cu(II) adsorption onto used biocomposites followed pseudo second-order kinetics and copper ions were adsorbed onto the Pha/Emb1 and Pha/Emb2 surfaces via chemical interaction.

PENGGUNAAN SELULOSA-DIETILENTRIAMINA SEBAGAI LAPISAN PENGIKAT LOGAM Cu(II) DENGAN METODE GRADIEN DIFUSI DALAM FILM TIPIS

This researh aims to application of cellulose-diethylenetriamine as a binding layer on the diffusive gradients in thin films method with modification of cellulose with diethylenetriamine. The method of diffusive gradients in thin films in principle uses a simple instrument such as round plastic with a diameter of 2.5 cm, which is filled with metal binding gel, diffusive gel, and membrane filter of 0.45 µm. The metal ions were diffuse through the membrane filter and diffusive gel according to the Fick's Law I, and then is accumulated in the binding layer gel. Based on the results of FTIR analysis, the formation of the binders of the copper ions at the binding layer of cellulose-dietilentriamina involves amine and hydroxyl functional groups.The results of the application of cellulose- diethylenetriamine using as binding layer with polyacrylamide diffusive gel showed a liniar concentration up to 12 hours of contact time and initial copper ion concentration up to 1000 mg/L. The maximum concentration of copper was obtained at pH 4.Keywords: copper, cellulose- diethylenetriamine, polyacrylamide gel.

A novel recovery method of copper from waste printed circuit boards by supercritical methanol process: Preparation of ultrafine copper materials

In this study, supercritical methanol (SCM) process was successfully used for the preparation of ultrafine copper materials from waste printed circuit boards (PCBs) after nitric acid pretreatment. Waste PCBs were pretreated twice in nitric acid. Sn and Pb were recovered by the first nitric acid pretreatment. The leach liquor with a high concentration of copper ions after the second nitric acid leaching was subjected to SCM process. The mixture of Cu and Cu2O with poor uniformity of particle size was formed due to the effect of ferric iron contained in the leach liquor of waste PCBs, while more uniform and spherical Cu particles with high monodispersity and smaller size could be prepared after the removal of Fe. The size of Cu particles increased obviously with the decline of SCM temperature, and particles became highly aggregated when the reaction temperature decreased to 300°C. The size of Cu particles decreased markedly with the decrease of initial concentration of copper ion in the leach liquor of waste PCBs. It is believed that the process developed in this study is simple and practical for the preparation of ultrafine copper materials from waste PCBs with the aim of recycling these waste resources as a high value-added product.

Modeling of batch sorber system: kinetic, mechanistic, and thermodynamic modeling

The present investigation has dealt with the biosorption of copper and zinc ions on the surface of egg-shell particles in the liquid phase. Various rate models were evaluated to elucidate the kinetics of copper and zinc biosorptions, and the results indicated that the pseudo-second-order model was more appropriate than the pseudo-first-order model. The curve of the initial sorption rate versus the initial concentration of copper and zinc ions also complemented the results of the pseudo-second-order model. Models used for the mechanistic modeling were the intra-particle model of pore diffusion and Bangham’s model of film diffusion. The results of the mechanistic modeling together with the values of pore and film diffusivities indicated that the preferential mode of the biosorption of copper and zinc ions on the surface of egg-shell particles in the liquid phase was film diffusion. The results of the intra-particle model showed that the biosorption of the copper and zinc ions was not dominated by the pore diffusion, which was due to macro-pores with open-void spaces present on the surface of egg-shell particles. The thermodynamic modeling reproduced the fact that the sorption of copper and zinc was spontaneous, exothermic with the increased order of the randomness at the solid–liquid interface.

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.

A novel zerovalent manganese for removal of copper ions: synthesis, characterization and adsorption studies

Synthesis of nanoscale zerovalent manganese (nZVMn) by chemical reduction was carried out in a single pot system under inert environment. nZVMn was characterized using a combination of analytical techniques: Ultraviolet–Visible Spectroscopy, Fourier Transform Infrared Spectroscopy, Scanning Electron Microscopy, Transmission Electron Microscopy, Energy Dispersive X-ray, BET surface area and Point of Zero Charge. The adsorption physicochemical factors: pH, contact time, adsorbent dose, agitation speed, initial copper ion concentration and temperature were optimized. The kinetic data fitted better to Pseudo second-order, Elovich, fractional power and intraparticle diffusion models and their validity was tested by three statistical models: sum of square error, Chi-square (χ2) and normalized standard deviation (Δq). Seven of the two-parameter isotherm models [Freundlich, Langmuir, Temkin, Dubinin–Kaganer–Raduskevich (DKR), Halsey, Harkin–Jura and Flory–Huggins] were used to analyse the equilibrium adsorption data. The Langmuir monolayer adsorption capacity (Qmax = 181.818 mg/g) obtained is greater than other those of nano-adsorbents utilized in adsorption of copper ions. The equilibrium adsorption data were better described by Langmuir, Freundlich, Temkin, DKR and Halsey isotherm models considering their coefficient of regression (R2 > 0.90). The values of the thermodynamic parameters: standard enthalpy change ∆H° (+50.27848 kJ mol−1), standard entropy change ∆S° (203.5724 J mol−1 K−1) and the Gibbs free energy change ∆G° revealed that the adsorption process was feasible, spontaneous, and endothermic in nature. The performance of this novel nanoscale zerovalent manganese (nZVMn) suggested that it has a great potential for effective removal of copper ions from aqueous solution.

Biosorption of Copper Ions from Aqueous Solution by Flammulina velutipes Spent Substrate

To remove heavy metals from aqueous solution and reclaim valuable materials from mushroom byproducts, Flammulina velutipes spent substrate (FVSS) was developed as a novel biosorbent for copper ion removal. Batch experiments demonstrated that ion removal was pH-, biosorbent dosage- and initial metal concentration dependent. The maximum removal capacity of 15.56 mg/g was achieved at pH 6.0 with a biomass dosage of 3.0 g/L and initial copper ion concentration of 50 mg/L. The adsorption data were in compliance with the Langmuir isotherm and a pseudo-second-order kinetic model. Thermodynamic studies revealed the biosorption process was endothermic, random, and spontaneous. FT-IR spectral analysis confirmed that hydroxyl, amino, carbonyl, and phosphate groups on the biosorbent surface were involved in the biosorption. The uneven surface and porous structure of the biosorbent was propitious for quickly capturing the metal ions from aqueous solution. EDX spectra revealed that the copper ions were loaded on the surface of the biosorbent. XRD patterns showed the formation of copper-containing compounds.

Usage of Iranian scoria for copper and cadmium removal from aqueous solutions

The competitive removal of copper and cadmium from aqueous solutions using scoria has been investigated. Scoria was characterized by various methods, such as XRD, XRF, FT-IR and SEM. The results show that scoria sample contained augite, enstatite, diopside, and olivine. These minerals were separated from each other and each mineral was then subjected to the adsorption experiments. It was found that the main absorbent constituent in scoria was augite. Finally, statistical experimental method was used to optimization of adsorption conditions (Initial concentration of copper and cadmium ions, the amount of scoria and temperature) for removal of Cu (II) and Cd (II) ions from solution in optimum conditions. The optimum conditions are obtained as follows: concentrations of Cu (II) and Cd (II) of 400×10−6 and 554×10−6, respectively; amount of scoria of 7 g; temperature of 38 °C. Under these conditions Cu (II) and Cd (II) ions are absorbed onto the scoria more than 79% and 16%, respectively.

Recovery of Copper from Effluents by Cementation on Aluminum in a Multirotating Cylinder-Agitated Vessel

Recovery of copper from synthetic waste solution using cementation technique in a new agitated vessel employing multirotating aluminum cylinders impeller was investigated. Parameters studied are cylinder diameter, rotation speed, initial copper ion concentrations, and effect of surfactants. Solution analysis and scanning electron microscopy were employed to investigate the kinetic and mechanism of the process. The rate of recovery was found to be at its maximum value at the operating conditions of 350 rpm rotation speed, 5000 ppm initial CuSO4 concentration, and 1.2 cm cylinder diameter. All data were correlated by the dimensionless equation: $$ {\text{Sh}} = 1.16 {\text{Sc}}^{0.33} {\text{Re}}^{0.63} \left( {\frac{{d_{\text{c}} }}{L}} \right)^{0.54}, $$ with an average deviation of ±8.5 pct and a standard deviation of 5.88 pct. Presence of nonylphenol ethoxylate surfactant in the solution decreased the rate of recovery by an amount ranging from 2.94 to 38.57 pct depending on the operating conditions. The present geometry gave higher rates of recovery compared to both the single rotating cylinder and rotating disc reactor.

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.

Synthesis of platy potassium magnesium titanate and its application in removal of copper ions from aqueous solution

Platy potassium magnesium titanate (K0.8Mg0.4Ti1.6O4, KMTO) was synthesized by a flux method. The potential application of KMTO in removing copper ions from water pollutants was investigated. The crystal phases of specimens were identified by XRD. The morphology and structural information were characterized by SEM and TEM. The adsorption behavior under different conditions was investigated, including different pH values and different initial copper ion concentrations. The results show that the maximum adsorption capacity of Cu(II) ions is 290.697 mg/g, and almost 99.9% of Cu(II) ions can be removed, which is much higher than that of other sorbents reported. The kinetics of KMTO for the adsorption of Cu(II) ions was studied and the best fit can be obtained by the pseudo-second-order model. Adsorption isothermal data can be well interpreted by the Freundlich equation (R2=0.991). In conclusion, this study highlights that KMTO is a potential material for the efficient removal of heavy metal ions in polluted water. It also opens up a new opportunity for the applications of platy KMTO.

Adsorption of copper ions onto nano-scale zero-valent iron impregnated cashew nut shell

In this work, the synthesis and characterization of a new low-cost adsorbent such as nano-scale zero-valent iron impregnated cashew nut shell (NZVI-CNS) was studied for the removal of copper ions. The prepared adsorbent was characterized by Fourier Transform Infrared Spectroscop, Scanning Electron Microscopy/Energy Dispersive X-ray Spectroscopy, Transmission Electron Microscopy, and X-ray diffraction. The adsorption parameters such as solution pH, adsorbent dose, initial copper ions concentration, contact time, and temperature were optimized. The adsorption kinetics of copper ions removal by NZVI-CNS have been studied by pseudo-first-order, pseudo-second-order, intraparticle diffusion, Boyd kinetic, and shrinking core models. The adsorption isotherms of copper ions removal by NZVI-CNS have been studied by Langmuir, Freundlich, Temkin, and Dubinin–Radushkevich models. The adsorption experimental data were best fitted with the pseudo-second-order and Freundlich models. The thermodynamic studies showed the adsorption process was spontaneous, feasible, and exothermic in nature. The results indicated that NZVI-CNS can act as an effective adsorbent for the removal of heavy metal ions from the water/wastewater by reducing its intake in the human food chain.

Copper adsorption by natural manganese dioxide

The adsorption of copper ions was investigated using pyrolusite ore as a low-cost alternative adsorbent source. Pyrolusite, which contains mainly MnO2, is a manganese ore. The effects of the initial concentration of copper(II) ions, initial pH of solution, adsorbent dosage and particle size on the adsorption process were examined. It was found that the percentage of the adsorbed copper increases with increasing the amount of adsorbent. It was observed that the maximum adsorption occurred at natural initial pH values for all copper concentrations. While the initial solution concentration, initial pH, contact time, stirring speed, particle size and adsorbent dosage were 2.5 mmol/L, natural, 180 min, 200 r/min, 120 μm and 6 g/L, respectively, the efficiency of copper adsorption on pyrolusite ore was 96.5%. The isotherm and kinetic studies relating to this adsorption process were also made. It was determined that the equilibrium data followed the Langmuir isotherm model while the process kinetic could be described by the pseudo-second order kinetic model.

Removal of copper ion in aqueous solution by activated carbon from sewage sludge

Activated carbon has been prepared from sewage sludge of the municipal wastewater treatment plant using chemical activation method. Porous structure of activated carbon was characterised by nitrogen adsorption and scanning electron microscopy. And activated carbon was also characterised by its surface area and porosity. Its surface is an irregular and porous structure. The BET surface area is 432.45 m2/g, the total pore volume is 0.43 cm3/g and the nominal pore size is 0.53 nm. Then, it was used as an adsorbent for the removal of copper ions from aqueous solution. The effects of parameters such as pH, temperature, contact time and initial copper ion concentration were investigated. The adsorption kinetics and adsorption isotherms of copper ions in aqueous solution onto activated carbon were investigated through experimental data. The results showed that the adsorption processes were perfectly fitted to the pseudo-second order model with very high regression coefficients. It may be evaluated as an environmentally friendly and extra economic treatment of copper ions in aqueous solution. The Langmuir isotherm fitted better than the Freundlich isotherm for the adsorption of copper ion on the activated carbon. The adsorption process is heterogeneity of the adsorbents and favourable adsorption.

Removal of Copper From Wastewater By Cementation From Simulated Leach Liquors

Every year, tons of precious and/or toxic metals are thrown away in industrial liquid effluents and most frequently directly in natural environment. The recovery of those metals in dilute solutions is an everyday problem associating both ecology and economy. Copper is among the most prevalent and valuable metal used by industry. Cementation is one of the most effective and economic techniques for recovering toxic and or valuable metals from industrial waste solution and from leach liquors obtained by leaching low grade copper ore. The present study was carried out to investigate the removal of copper metal ions from synthetic waste water by cementation using a rotating iron cylinder. The study covered the effect of different parameters in batch mode which are: Initial copper concentrations, pH values, rotational speed, and reaction temperature on the rate of cementation. The rate of cementation was found to increase with increasing rotational speed, temperature, and pH till a value of 2.1 and then starts to decrease .On the other hand as the initial copper ions concentration increases from 0.2 to 0.4 M the rate of copper ions removal increase. The rate of copper recovery ranged from 10% to 90% per hour depending on the operating conditions Rates of cementation which can be expressed in terms of the rate of mass transfer were correlated to the controlling parameters by dimensionless equation: Sh=0.18 SC0.33 Re0.961. This equation can be used in the design and operation of high-productivity cementation reactor.

Recovery of Copper by Electrodeposition Method from Electroplating Wastewater

Electrodeposition method was applied to recover copper from the simulation of copper-containing electroplating wastewater. Stainless steel plate is used as the cathode and the anode is made of titanium plate coated with RnO2+IrO2, titanium mesh coated with RnO2+IrO2 or stainless steel plate. The electrode potential of copper in electrolyte was calculated, and the effect of initial concentration of copper ions, temperature of electrolyte, voltage, electrode spacing, initial pH value and additive concentration on the recovery of copper was studied in detail. The experimental results showed that the proper anode is titanium plate coated with RnO2+IrO2.Under the condition ofinitial concentration of copper ions 25g/L, temperature of electrolyte 40°C, voltage 3.8V, electrode spacing 25mm, initial pH value 3.60, additive concentration 7.1g/L,the recovery rate of copper can achieve 99.4% and the current efficiency can achieve 88.5%.

Adsorption of copper ions onto activated carbon from capsicum straw

Activated carbon was obtained from capsicum straw by chemical activation using KOH as an activator. Then, it was used as an adsorbent for the removal of copper ions from aqueous solution. The effects of various parameters such as contact time, initial copper ion concentration, and temperature on copper ions adsorption by activated carbon were investigated. The experimental data were analyzed by the Langmuir and Freundlich models of adsorption. Kinetic adsorption data were analyzed by the pseudo-first-order kinetic model, the pseudo-second-order model, and the intraparticle diffusion model, respectively. The thermodynamics parameters were also calculated. The activated carbon was found to be both effective and economical.

Improving the Diffusion Controlled Cementation of Copper Ions on a Fixed Bed of Zinc Raschig Rings Using Flow Pulses in a Batch Reactor

This work investigates the possibility of improving the kinetics of the diffusion controlled cementation of copper on a fixed bed of zinc Raschig rings in a batch reactor by using flow pulses induced through the bed by a pulsating perforated disc. The kinetics of the cementation reaction was investigated under different conditions of initial concentration of copper ions, frequency and amplitude of oscillation (vibration velocity), zinc ring diameter, bed height and temperature. The effect of temperature was found to fit the Arrhenius equation with an activation energy of 5.5 kcal/mole which confirms the diffusion controlled nature of the reaction. A dimensionless correlation in the form that: Sh = 6.9 Re0.55Sc0.33(Pd/Bh)0.49was deduced. Industrial application of the results obtained was discussed.

Biosorption of copper (II) on Sargassum angostifolium C.Agardh phaeophyceae biomass

Biosorption of copper (II) ions on Sargassum angostifolium C.Agardh as brown alga was investigated. The effects of operating parameters such as initial metal ion concentration, temperature, pH, and biomass dose on the copper (II) biosorption were studied. The Langmuir and Freundlich isotherm models were applied to the equilibrium data. The experimental data for copper (II) ions are in good agreement with those calculated using the pseudo-second-order kinetics for the studied parameters. The experiment is designed to predict the role of cooperating parameters on biosorption by using the response surface methodology. The Box Behnken model in the response surface methodology is used for optimal conditions. The maximum uptake conditions were determined as initial pH 6.0, temperature 45°C, biosorbent concentration 0.4 g L-1 and initial copper (II) ion concentration 150 mg L-1.