Initial Copper Ion Concentration Research Articles

Removal of Cu<sup>2+</sup> from Aqueous Solution using Fly Ash

This research aims at investigating the utilization of fly ash as a low-cost adsorbent to remove copper ions from aqueous solutions such as wastewater. Fly ash dosage as well as initial copper ion concentration，temperature and pH value were varied to find the optimum conditions for Cu 2+ adsorption by fly ash. The results from sorption process showed that the maximum adsorption rate was obtained at 50 mg/L when different dosage of fly ash was added into the solution, and it could be concluded that decreasing the initial concentration of copper ion is beneficial to the adsorption ability of fly ash. With the increase of pH value, the removal rate increased. When pH was 6, the removal rate reached the maximum of 99.60%. When initial copper content was 50 mg/L, pH value was 6, the adsorption capacity of fly ash sample reached 0.98 mg/mg. The main removal mechanisms were assumed to be the adsorption at the surface of the fly ash together with the precipitation from the solution.

Removal of Copper (II) Ions from Aqueous Solutions by Adsorption with Low Cost Acid Activated Cynodon Dactylon Carbon

The main purpose of this work was to exploit low cost and efficient sorbents for the removal of copper from aqueous solution using Cynodon dactylon carbon. It was observed from the experimental results that almost 90‐100% copper can be removed from the aqueous solution. Adsorption kinetics and equilibrium have been investigated as a function of initial copper ion concentration. pH, contact time and adsorbent dosage. Kinetics studies suggested that the adsorption allowed first order reaction. Equilibrium data were analyzed using Langmuir and Freundlich isotherm models. On the basis of experimental results and the model parameters, it can be concluded that the carbonaceous Cynodon dactylon is effective for the removal of copper ion from aqueous solution.

Isolation and molecular characterization of some copper biosorped strains

The biosorption of copper (II) from aqueous solution using different bacterial strains was studied. Copper-biosorbing bacteria were isolated from tannery effluent collected from Borg Al-Arab, Alexandria, Egypt. These isolates displayed different degrees of copper biosorption under aerobic conditions. Based on 16S rDNA gene sequence analysis, three of them (S2, S5 and S7) were identified as Chryseobacterium sp., Enterobacter sp. and Stenotrophomonas sp., respectively. Initial copper (II) ion concentrations from 25-250 mg/L at constant temperature 30 oC were studied. The residual copper (II) concentration and its toxicity effect in solution were determined using atomic absorption spectrophotometer and bioluminescent bioreporter. The bioluminescence inhibition of strain (S5) reached to 91.4 % as compared with the strain (S7) reached to 83.3 % at 225 mg/L of copper ion where the maximum biosorption efficiency for S5 and S7 were 71 % and 70.1 % correspondingly using atomic absorption. The biolumi- nescent bioreporter was proved to be fast and accurate technique for measurement the toxicity effect of residual copper (II) in solution.

Removal of copper(II) ions from aqueous solution by adsorption using cashew nut shell

In the present study, cashew nut shell(CNS) was investigated as a biosorbent for the removal of copper ions from aqueous solutions. Batch experiments were carried out to investigate the effect of solution pH, CNS concentration, contact time, initial copper(II) ion concentration and temperature on sorption efficiency. The copper adsorption was favored with maximum adsorption at pH 5.0. The percentage of copper ion removal onto the CNS was decreased with increasing temperature. Biosorption equilibrium time was observed in 30 min. The equilibrium adsorption data were fitted to Langmuir and Freundlich adsorption isotherm models and the model parameters were evaluated. The kinetics of copper(II) ion was discussed using four kinetic models, the pseudo-first-order, the pseudo-second-order, the Elovich kinetic model and the intra-particle diffusion models. It was shown that the adsorption of copper ions could be described by the pseudo-second order kinetic model. Thermodynamic quantities such as Gibbs free energy (∆G o), the enthalpy (∆H o) and the entropy change of sorption (∆S o) have also been evaluated and it has been found that the sorption process was feasible, spontaneous and exothermic in nature. The results showed that CNS could be employed as a low-cost alternative adsorbent for the removal of copper ions from aqueous solutions.

Removal of corper(II) Ions from aqueous solution by a lactic acid bacterium

Enterococcus faecium, a lactic acid bacterium (LAB), was evaluated for its ability to remove copper(II) ions from water. The effects of the pH, contact time, initial concentration of copper(II) ions, and temperature on the biosorption rate and capacity were studied. The initial concentrations of copper(II) ions used to determine the maximum amount of biosorbed copper(II) ions onto lyophilised lactic acid bacterium varied from 25 mg L-1 to 500 mg L-1. Maximum biosorption capacities were attained at pH 5.0 and 6.0. Temperature variation between 20°C and 40°C did not affect the biosorption capacity of the bacterial biomass. The highest copper(II) ion removal capacity was 106.4 mg per g dry biomass. The correlation regression coefficients show that the biosorption process can be well defined by the Freundlich equation. The change in biosorption capacity with time was found to fit a pseudo-second-order equation.

Isolation and molecular characterization of some copper biosorped strains

The biosorption of copper (II) from aqueous solution using different bacterial strains was studied. Copper-biosorbing bacteria were isolated from tannery effluent collected from Borg Al-Arab, Alexandria, Egypt. These isolates displayed different degrees of copper biosorption under aerobic conditions. Based on 16S rDNA gene sequence analysis, three of them (S2, S5 and S7) were identified as Chryseobacterium sp., Enterobacter sp. and Stenotrophomonas sp., respectively. Initial copper (II) ion concentrations from 25-250 mg/L at constant temperature 30 oC were studied. The residual copper (II) concentration and its toxicity effect in solution were determined using atomic absorption spectrophotometer and bioluminescent bioreporter. The bioluminescence inhibition of strain (S5) reached to 91.4 % as compared with the strain (S7) reached to 83.3 % at 225 mg/L of copper ion where the maximum biosorption efficiency for S5 and S7 were 71 % and 70.1 % correspondingly using atomic absorption. The biolumi- nescent bioreporter was proved to be fast and accurate technique for measurement the toxicity effect of residual copper (II) in solution.

Selective leaching of nickel from low-sulfur Ni-Cu matte at atmospheric pressure

A process of the selective leaching of nickel from low-sulfur Ni-Cu matte at atmospheric pressure was described. This matte was obtained from high grade Ni-Cu matte by magnetic separation, which mainly contained Ni-Cu alloy and a small quantity of sulfides. Firstly, the acid-oxygen (CuSO 4-H 2SO 4-O 2) leaching of the matte was conducted at atmospheric pressure. When the solution pH value reached 1.0–2.0, the oxygen flow was ceased. Then, the aqueous copper was rejected by cementation reaction with Ni in the alloy. The mineralogical characteristics of the matte in the process were analyzed by X-ray diffractometry, optical microscopy and scanning electron microscopy. And the effects of variations in temperature, particle size distribution, oxygen flow rate, pulp density, initial acid concentration and initial concentration of copper ion were investigated.

Synthesis of novel mixed matrix scaffolds and adsorption of copper ions of waste water

Mixed matrix scaffolds were synthesized by uniformly distribution of ion exchange resins (H+ form Amberjet, ID 780 μm) into the stereo-structural chitosan matrix and then used for the removal of copper ions from waste water. Specifically, Amberjet particles suspended in a 1 wt% of viscous chitosan solution were filled with cylindrical aluminum containers to prepare chitosan mixed matrix scaffolds through the freeze-gelation process. The internal surface area of mixed matrix scaffolds is 78 m2/g. The adsorption processes were performed by chelate copper ions of waste water onto the amine functional groups (-NH2) exposure on the external and porous stereo-structural surfaces of chitosan matrix as well as the sulfonate functional groups on the outer surface of ion exchange resins, respectively. Results of a low initial copper ion concentration of 5mg Cu2+/L were used to study the adsorption capacities as well as adsorption kinetics experimentally. The kinetic experimental data correlated well with the second...

Intensification of the rate of heavy metal removal from wastewater by cementation in a jet reactor

Removal of copper by cementation on zinc disc from dilute copper sulfate solution in a recirculating batch reactor which consisted of a horizontal zinc disc impinged by an axial turbulent submerged jet was studied. The effect of different parameters such as, initial copper ion concentration, solution flow rate and the axial distance between the zinc disk and submerged jet on the rate of copper ion removal were investigated. The rate of cementation was found to increase with increasing solution flow rate, decreasing the axial distance between jet and zinc disc, and by increasing copper ion concentration. The rate of diffusion controlled cementation of copper ion was expressed in terms of the mass transfer coefficient, the data were correlated with the following dimensionless correlation: Sh = 0.306 S c 0.33 Re 0.997 ( d n / l ) 0.0337 . The high rate of mass transfer of the jet reactor, qualifies the reactor for diffusion controlled heavy metals removal from wastewater.

Synthesis of sol-gel silica chemically bonded with cyanex 272 for the removal of Cu(II), Ni(II), and Zn(II)

This article reported on the synthesis of SSCBB, a new solid-phase, sol-gel silica chemically bonded with [bis (2,4,4-trimethylpentyl) phosphinate], (BTMPP, anion of Cyanex 272) prepared with a sol-gel method, and its application as a reusable solid-phase sorbent for the selective removal of Cu(II), Ni(II), and Zn(II). The synthesized SSCBB was characterized by FTIR, EDX, SEM, BET, TGA, and DSC. To evaluate its extraction performance, various parameters such as equilibration time, pH of the aqueous phase, solid to liquid ratio, initial copper ion concentration and reusability of SSCBB were studied. Equilibrium time was found to be 60 min for all metals and almost 100% extraction occurred at a pH of 4.0, 6.0, and 8.8 for Zn(II), Cu(II), and Ni(II) extraction, respectively. The maximum extraction capacity was found to be 0.2 mmol of Cu(II) per gram of SSCBB. Moreover, it was also regenerated and reused for subsequent recovery in ten cycles. The uptake performance of regenerated SSCBB after ten regeneration cycles was found to be the same as the freshly prepared SSCBB. Finally, based on the results, a proposed flow sheet for the removal of Cu(II), Ni(II), and Zn(II) was provided.

Reduction of copper(II) ions in polyacrylic acid-polyethyleneimine complexes using X-ray radiation

The specifics of X-ray-induced reduction of copper(II) ions in the polyacrylic acid-polyethyleneimine-copper(II) (PAA-PEI-Cu2+) complexes were studied. It was found that the action of radiation led to the effective reduction of Cu2+ in the PAA-PEI-Cu2+ films swollen in an aqueous-alcohol medium. The formation of metal nanoparticles in irradiated samples was revealed by electron microscopy and X-ray diffraction techniques. Analysis of ESR data has demonstrated that the Cu2+ reduction rate increases with an increase in the initial concentration of copper ions in the samples. Formal yields of the radiation-chemical reduction of Cu2+ in the PAA-PEI complex films were found to be quite high (>100 ions per100 eV of energy absorbed by the swollen film), which can be explained by involvement of the radiolysis products of aqueous alcoholic solutions (outer medium) in the reduction processes.

EQUILIBRIUM AND KINETIC STUDIES OF COPPER (II) REMOVAL ON PUROLITE S930 RESIN

The presence of heavy metals in the environment is a major concern due to their non-biodegradability, bioaccumulation tendency, persistence in nature and toxicity to many life forms. Different treatment techniques for wastewater laden with copper have been developed in recent years to decrease the amount of wastewater produced and to improve the quality of the treated effluent. All techniques have their advantages and limitations in application. One of the most used techniques to remove copper from waste water is based on ion exchange process. In this study, the Purolite S930 resin with iminodiacetic acid (IDA) functional groups was used to remove Cu (II) ions from synthetic aqueous solutions. Batch sorption experiments were performed using both forms of the resin (sodium S930-Na and hydrogen S930-H) by varying the initial solution pH (1.0 5.0), initial concentration of copper (10 300 mg/L), temperature (20 40 C) and contact time (10 minutes up to 24 hours). The practical capacity of the resin increases with the initial solution pH, temperature and concentration of copper ions. It was observed that, initially sorption increases rapidly, but after that, the rate becomes slower; the equilibrium can be considered attained after 24 hours. The equilibrium data were analysed using Freundlich, Langmuir and Dubinin Radushkevich sorption isotherm models; sorption was best fitted by the Langmuir model. The values of calculated thermodynamic parameters (.G, .H and .S) indicate that the sorption is an endothermic and spontaneous process. The sorption kinetic data were tested using the pseudo-first order, pseudo-second order and intraparticle diffusion kinetic models; kinetic studies showed that the sorption of copper onto chelating resin followed a pseudo-second order reaction.

Hydroxyapatite modified with silica used for sorption of copper(II)

AbstractThis paper aims to increase the sorption capacity of hydroxyapatite and to find the best apatite-based material for metal ions sorption. The sorption process of copper ions from water solutions by HAP and structurally modified HAP was carried out in this work. Structural modifications of HAP were realized in the preparation phase by an addition of sodium silica into the reaction medium. The prepared materials were characterized by physical-chemical methods: IR, electron-microscopy and X-ray diffraction. The composites characterized were tested in kinetic studies regarding ion exchange and adsorption of Cu2+. It was revealed that the silica content, particle size and initial copper ion concentration influence the process rate.

Adsorption kinetics and equilibrium of copper from aqueous solutions using hazelnut shell activated carbon

Abstract The adsorption of Cu(II) ions from aqueous solutions by hazelnut shell activated carbon (HSAC) was studied in a batch adsorption system. Factors influencing copper adsorption such as initial copper ion concentration (25–200 mg L−1), pH (2–6), adsorbent dosage (0.5–3.0 g L−1) and temperature (293–323 K) were investigated. The adsorption process was relatively fast and equilibrium was established about 90 min. Maximum adsorption of Cu(II) ions occurred at around pH 6. A comparison of the kinetic models on the overall adsorption rate showed that the adsorption system was best described by the pseudo second-order kinetics. Desorption experiments were carried out to test the performance of the carbon and desorption efficiencies in four cycles were found to be in the range 74–79%. The adsorption equilibrium data fitted best with the Langmuir isotherm and the monolayer adsorption capacity of Cu(II) ions was determined as 58.27 mg g−1 at 323 K. Thermodynamic parameters were calculated for the Cu(II) ion–HSAC system and the positive value of ΔH (18.77 kJ mol−1) showed that the adsorption was endothermic and physical in nature.

Biosorption of copper(II) ions on Enteromorpha prolifera: Application of response surface methodology (RSM)

Abstract In this study, the biosorption of copper(II) ions on Enteromorpha prolifera , a green seaweed, was investigated in a batch system. The effects of operating parameters such as initial pH, temperature, initial metal ion concentration and biosorbent concentration on the copper(II) biosorption were analysed using response surface methodology (RSM). The proposed quadratic model for central composite design (CCD) fitted very well to the experimental data that it could be used to navigate the design space according to ANOVA results. The optimum biosorption conditions were determined as initial pH 4.0, temperature 25 °C, biosorbent concentration 1.2 g/L and initial copper(II) ion concentration 200 mg/L. The Langmuir and Freundlich isotherm models were applied to the equilibrium data at different temperatures and initial pH values. The maximum monolayer coverage capacity of E. prolifera for copper(II) ions was found to be 57.14 mg/g at 25 °C and initial pH 4.0 indicating that the optimum biosorption temperature and initial pH. The external and intraparticle diffusion models were also applied to biosorption data of copper(II) ions with E. prolifera and it was found that both the external diffusion as well as intraparticle diffusion contribute to the actual biosorption process. The pseudo-second order kinetic model described the copper(II) biosorption process with a good fitting. The thermodynamics of copper(II) biosorption on E. prolifera indicated its spontaneous and exothermic nature.

Dynamic Measurement of Copper (II) Ion Adsorption in Activated Carbon Fixed Bed Columns

Dynamic experiments were carried out on the adsorption of copper (II) ions in a laboratory packed bed of activated carbon. Both pulse and step change inputs were used. Measurements were reproducible and replicate measurements furnished nearly identical parameters for a heterogeneous model of the activated carbon bed assuming Langmuir adsorption isotherm. The initial concentration of copper (II) ion was 3 ppm and the average particle size of activated carbon was 1.5 mm. The adsorption experiments in the shallow beds of activated carbon, 3 and 5 cm bed height had little effect on the parameters. Hydraulic loading, 25 and 50 ml min-1, affected dispersion and the volumetric mass transfer coefficient, but unexpectedly also changed the effective diffusivity. This apparently comes from the incorporation of errors due to instrumental noise and model approximations in the parameters. A 5 min pulse input has a low residual sum of square (RSS) with all of set of starting point while a 10 min pulse has a low RSS using some set of starting point. A step up input has a high RSS that may arise from a large number of data. These affected the Langmuir adsorption isotherm constant and diffusivity as expected from their concentration dependency. Step change and pulse simulations using the model agreed well with the experiments.

Hevea brasiliensis - A Biosorbent for the Adsorption of Cu(II) from Aqueous Solutions

The activated carbon produced from rubber wood sawdust by chemical activation using phosphoric acid have been utilized as an adsorbent for the removal of Cu(II) from aqueous solution in the concentration range 5-40 mg/l. Adsorption experiments were carried out in a batch process and various experimental parameters such as effect of contact time, initial copper ion concentration, carbon dosage, and pH on percentage removal have been studied. Adsorption results obtained for activated carbon from rubber wood sawdust were compared with the results of commercial activated carbon (CAC). The adsorption on activated carbon samples increased with contact time and attained maximum value at 3 h for CAC and 4 h for PAC. The adsorption results show that the copper uptake increased with increasing pH, the optimum efficiency being attained at pH 6. The precipitation of copper hydroxide occurred when pH of the adsorbate solution was greater than 6. The equilibrium data were fitted using Langmuir and Freundlich adsorption isotherm equation. The kinetics of sorption of the copper ion has been analyzed by two kinetic models, namely, the pseudo first order and pseudo second order kinetic model. The adsorption constants and rate constants for the models have been determined. The process follows pseudo second order kinetics and the results indicated that the Langmuir model gave a better fit to the experimental data than the Freundlich model. It was concluded that activated carbon produced using phosphoric acid has higher adsorption capacity when compared to CAC.

Application of response surface methodology for the biosorption of copper using Rhizopus arrhizus

Response surface methodology was used to study the cumulative effect of the various parameters namely, initial copper ion concentration, pH, temperature, biomass loading and to optimize the process conditions for the maximum removal of copper. For obtaining the mutual interaction between the variables and optimizing these variables, a 2 4 full factorial central composite design using response surface methodology was employed. The analysis of variance (ANOVA) of the quadratic model demonstrates that the model was highly significant. The model was statistically tested and verified by experimentation. A maximum copper removal of 98% was obtained using the biosorption kinetics of copper under optimum conditions.

Removal of copper(II) ions from aqueous medium by biosorption onto powdered waste sludge

Powdered waste sludge (PWS) was used for removal of copper(II) ions from aqueous solution by biosorption. Waste activated sludge obtained from a paint industry wastewater treatment plant was pre-treated with 1% hydrogen peroxide solution dried, ground and sieved to a number of fractions with different particle sizes. Biosorption capacity of pre-treated PWS for Cu(II) ion removal was investigated as function of particle sizes (external surface area), copper(II) and PWS concentrations and also pH using batch biosorption experiments. Biosorbed copper ion concentrations increased with increasing specific external surface area of PWS, initial Cu 2+ concentration and pH, but decreased with increasing PWS concentration. Percent copper removal from the solution also increased with increasing external surface area or decreasing particle size of the adsorbent, PWS concentration and pH, but decreased with increasing initial copper ion concentration. The maximum biosorption capacity was 156 mg Cu 2+ g PWS −1 when PWS concentration was 0.25 g l −1 with an average particle size of 64 μm. The initial volumetric rate of biosorption also increased with increasing specific external surface area of PWS resulting in nearly 70 mg Cu l −1 h −1 at a specific external surface area of 943 cm 2 g −1 with the smallest particle size (53 μm) tested. Optimal pH resulting in maximum biosorption was 5 with a minimum zeta potential (−15.6 mV) on the surface of the PWS particles.

Removal of Copper, Lead, and Cadmium Ions in a Fluidized Bed

In this study, the recovery of copper from synthetic wastewaters prepared from CuSO4 was studied using a fluidized bed containing hydrogen‐based solid Amberlite. The effects of operating parameters including liquid flow rate, initial copper ions concentration, pH of the influent solution, and Amberlite weight on the breakthrough curves were investigated. It was found that the copper uptake increased with the increase in Amberlite weight, the decrease in initial copper concentration, and decrease in liquid flow rate, but there was no affect with solution influent pH. The recovery of cadmium and lead ions prepared from CdSO4 and Pb(NO3)2, respectively, was also investigated. Comparison between the adsorption of Cu2+, Cd2+ and Pb2+ showed that the adsorption capacity followed the following order: Pb2+ > Cd2+ > Cu2+. It was found that the order of adsorption was independent of the flow rate or the initial feed concentration.