Using of waste sorbent from food industry for the removal of copper ions from water

In recent years, spent kieselguhr and activated carbon are considered not as waste, but as secondary raw materials. The purpose of the work is to investigate the effectiveness of using a previously regenerated spent food industry sorbent modified with sulphide and hydrosulphide ions for adsorption removal of copper (II) ions from water. A comparative analysis of the degree of removal and adsorption of copper (II) ions by the regenerated sorbent (RS) and its modified form (MS) was carried out. Insignificant adsorption of Cu2+ on the surface of the regenerated sorbent (RS) is explained both by the nature of the adsorbate and the morphology of the adsorbent after its acid-alkaline activation. Sorption of Сu2+ ions is mainly carried out by carboxyl groups. Modification of the regenerated sorbent surface with more active sulphide and hydrosulphide ions leads to a significant increase in its selective adsorption in relation to copper (II) ions. It was established that topochemical reactions of formation of copper (II) sulphide CuS and elemental sulphur take place on the surface of the modified sorbent (MS). The possibility of topochemical transformations has been established by IR-spectral and XRD studies. The use of a sorbent modified with sulphide and hydrosulphide ions increases the removal of copper (II) cations from the studied solutions by 65.5 times. The obtained results allow us to recommend the use of a regenerated sorbent (RS) of the food industry, modified with sulphide and hydrosulphide ions, to remove copper (II) ions from water.

Copper(II) and lead(II) removal from aqueous solution in fixed-bed columns by manganese oxide coated zeolite

The discharge of wastewater containing heavy metals into waterbodies is a major environmental issue that can influence the quality of the water supply; therefore, it is important to remove the pollutants dangerous to living organisms. The adsorption of copper (II) ions on modified wheat bran was investigated with respect to initial solution pH (2.0-7.0), contact time (5–120 min), adsorbent mass (0.5 g and 1.0 g), and initial metal ion concentration (2.0–20 mg/L). The optimum adsorption conditions were found to be at pH 5.0 and a contact time of 60 min with an adsorbent mass of 1.0 g where the maximum efficiency was recorded as 84.5 %. The adsorption uptake (in mg/g) of copper (II) ions slowly reached equilibrium in around 30 min and this amount was 0.30 mg/g using an adsorbent mass of 0.5 g. The adsorption uptake of copper (II) ions decreased with increasing mass of adsorbent and the adsorption efficiency (in %) increased with increasing mass of adsorbent. The experimental results were described using the Langmuir and Freundlich models, with the Langmuir model fitting better than the Freundlich model. The maximum modelled adsorption capacity was 4.24 mg/g and the modelled specific surface area of modified wheat bran was 6.36 m2. It was observed that the adsorption of copper (II) ions on modified wheat bran is efficient and suitable, therefore modified wheat bran is a relatively good adsorbent for the removal of copper (II) ions from polluted water compared to other agricultural adsorbents.

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

The removal of copper(II) ion from aqueous solution by the granular activated carbon, obtained from hazelnut shells (ACHS) (Corylus avellana L. var. lunga istriana), was investigated. The ACHS was prepared from ground dried hazelnut shells by specific method carbonisation and water steam activation at 950oC for 2 h. The granular activated carbon produced from hazelnut shells has a high specific surface area (1 452 m2∙g-1) and highly developed microporous structure (micropore volume: 0.615 cm3∙g-1). In batch tests, the influences of solution pH, contact time, initial metal ion concentration and temperature on the sorption of copper(II) ion on ACHS were studied. The results indicate that sorption of copper(II) ion on ACHS strongly depends on pH values. The adsorption data can be well described by the Langmuir isotherm and Redlich-Peterson model. The monolayer adsorption capacity of the ACHS-copper(II) ion, calculated from the Langmuir isotherms, is 3.07 mmol∙g-1. The time-dependent adsorption of copper(II) ion could be described by the pseudo second-order and Elovich kinetics, indicating that the rate-limiting step might be a chemical reaction. The intra-particle diffusion model indicates that adsorption of copper(II) ions on ACHS was diffusion controlled.Keywords: Activated carbon, lunga istriana, copper, equilibrium, kinetics

The present work reports an effective method for the removal of inorganic and organic pollutants using membranes based on different carbonaceous materials. The membranes were prepared based on cellulose acetate (18 wt. %), polyvinylpyrrolidone as a pore-generating agent (2 wt. %) and activated carbon (1 wt. %). Activated carbons were developed from residues after extraction of the mushroom Inonotus obliguus using microwave radiation. It has been demonstrated that the addition of activated carbon to the membranes resulted in alterations to their physical properties, including porosity, equilibrium water content and permeability. Furthermore, the chemical properties of the membranes were also affected, with changes observed in the content of the surface oxygen group. The addition of carbon material had a positive effect on the removal of copper ions from their aqueous solutions by the cellulose-carbon composites obtained. Moreover, the membranes proved to be more effective in the removal of copper ions than iron ones and phenol. The membranes were found to show higher effectiveness in copper removal from a solution of the initial concentration of 800 mg/L. The most efficient in copper ions removal was the membrane containing urea-enriched activated carbon.

High concentration of heavy metals in the environment can be detrimental to a variety of living species. The purpose of this research was to explore the use of baobab (Adsononsia digitata) fruit shells in the removal of lead(II) and copper(II) ions from aqueous solutions. Batch experiments were conducted to determine the effect of varying adsorption parameters on the removal of aqueous lead and copper ions. The adsorption of Pb(II) was found to be maximum at pH 5.5 using adsorbent dose of 0.7 g. The adsorption of Cu(II) was found to be optimum at pH 6 using adsorbent dosage of 0.9 g. The adsorption data conformed to Langmuir, Freundlich and Temkin isotherms. However the Temkin isotherm showed the best fitting model with highest R 2 values for both lead and copper (0.9977 and 0.9967) respectively. Baobab fruit shells can be used as a cost effective adsorbent for the removal of lead(II) and copper(II) ions from aqueous solutions in the treatment of industrial effluent.

Removal of Copper ions from aqueous solutions using polymer derivations of poly (styrene-alt-maleic anhydride)

Magnetic flocculation technology was investigated for the removal of copper and zinc ions from simulated tin smelting wastewater, and the effects of magnetic powder dosage, flocculant dosage, and pH on the removal of copper and zinc ions were estimated. The results show that the effluent quality is poor with magnetic powder, PAC and PAM separately dosed, but when magnetic powder is combined with PAC or PAM, the excellent effluent quality is obtained with the removal rate of the copper and zinc ions of more than 90% and 70% respectively. In addition, under the condition of magnetic powder dosage of 30g/L and PAC dosage of 60mg/L, pH show more significant effect on zinc ions than copper ions with pH increased from 5 to 10, and the removal rate of zinc ions increase by about 24%, while the removal rate of copper ions only increase by about 2.5%. Compared with the system with single metal ion, the coexistent ion system has excellent heavy metal removal efficiency, namely the copper ions removal rate increase by 3.42%, and the zinc ions removal rate increase by 0.46%. Moreover, magnetic flocculation technology presents the characteristics of shorter time of flocculation and sedimentation, smaller volume of the flocs and faster separation velocity.

The adsorption capacities of mesoporous silica modified with N‐(3‐(trimethoxysilyl)propyl)ethylenediamine (MCM‐41‐NH2) and its 4‐hydroxysalicylidene Schiff‐base, MCM‐41‐N‐Hdhba, as sorbents for removal and recovery of copper(II) ions from aqueous media have been investigated. The sorption uptake is highly dependent on the pH, contact time, temperature, diverse ions, mass of sorbent as well as initial Cu(II) ions concentration. At pH 6, the two sorbents, MCM‐41‐NH2 and MCM‐41‐N‐Hdhba, show 96.4% and 99.9% Cu(II) ions removal, respectively. Langmuir isotherm gave the best fit of the experimental data with maximum adsorption capacities 138.8 and 222.2 mg g−1 for MCM‐41‐NH2 and MCM‐41‐N‐Hdhba, respectively. The uptake kinetics were modeled using a pseudo‐second‐order rate equation and the thermodynamic parameters (ΔH°, ΔG° and ΔS°) verified favorable, spontaneous, and exothermic for MCM‐41‐NH2 and endothermic for MCM‐41‐N‐Hdhba adsorption processes. Successive adsorption–desorption studies indicated that MCM‐41‐NH2 and MCM‐41‐N‐Hdhba maintain their adsorption and desorption efficiencies constant over five cycles. Of particular importance is the fact that MCM‐41‐NH2 and MCM‐41‐N‐Hdhba were able to remove 95% of Cu(II) ions from polluted river and tap water. The structures and physicochemical properties of the sorbents before and after adsorption of Cu(II) ions were characterized by using spectroscopic (FTIR and XRD), morphological (TEM‐EDX), thermal, elemental analysis, and magnetic susceptibility measurements. © 2017 American Institute of Chemical Engineers Environ Prog, 37: 746–760, 2018

This study was conducted to characterize the industrial wastewater containing Copper (II) ion and to evaluate the effect of different thickness of polysulfone as the support membrane in the fabrication of thin film composite membrane (TFC), on the removal of Copper (II) ion. From the wastewater analysis, it showed that the concentration of copper (II) ion are out of the acceptable range of Environmental Quality (Industrial Effluent) Regulations 2009. For the TFC, the polysulfone support membrane was prepared at two thicknesses, 60μm and 90μm. For each thickness, two formulations of thin layer were coated on it; i) A polymer blend of Polyvinyl Alcohol and Chitosan, and ii) Hybrid membrane as thin layer. Before undergo the treatment process, the pH of the wastewater sample was altered to 7 as the pre-treatment. The final result shows that composite membrane with hybrid membrane as thin layer with 90μm thickness of polysulfone membrane was the best membrane because it could remove 99.67% of copper (II) ion. Finally, the treated water can be discharged to the groundwater because the concentration of copper ion is less than 1 ppm, which it has fulfilled the Environmental Quality regulations. Keywords— Chitosan, Copper ion, composite membrane, hybrid membrane, industrial wastewater

The batch removal of copper(II) ions from aqueous solution under different experimental conditions using alkali-leached silica and activated charcoal was investigated in this study. The copper(II) uptake was dependent on varying time, pH, copper concentration and temperature. Copper sorption was found fast reaching equilibrium within 1 h with better performance for alkali-leached silica than charcoal. Copper sorption was low at low pH values and increased with rise in initial pH-value until 6.7. Sorption fits well the Langmuir and Freundlich equations with higher uptake by increasing temperature. According to Langmuir equation, the maximum uptake of Cu(II) ions by alkali-leached SiO2 and charcoal was found to be 242.5 and 94.4 mmol/g at temperature 60 °C and pH 6. Thermodynamic studies confirm that the process was spontaneous and endothermic nature. Kinetic data for Cu(II) sorption was found to follow pseudo-second-order model.

Removal of copper ions from a waste mine water by a liquid emulsion membrane method

Polypyrrole conducting polymer and its application in removal of copper ions from aqueous solution

The removal of copper (II) ion by using ultrasound pre-treatment to increase the pores structure and surface area on peanut husk powder via direct sonication (ultrasound probe) and indirect ultrasound (ultrasound bath) at powder level 3.5 W. In previous studies, researchers had applied ultrasound simultaneous with adsorption process. This method is not suitable to treat huge amount of heavy metal in wastewater effluent. In this study, the percentage removal of copper (II) ion and adsorption capacity of direct and indirect ultrasound pre-treated peanut husk powder were compared with untreated peanut husk powder and simultaneous ultrasound adsorption process. The peanut husk powder was characterized by scanning electron microscope (SEM). The effect of variables such as different initial concentration (10-50 mg/L), contact time (0.5–3 h), pH (2–8), and dosage (0.1–0.3 g) were evaluated. 3 h adsorption equilibrium time was required for adsorption of copper (II) ion onto peanut husk surface. The indirect ultrasound pre-treated peanut husk powder has achieved the highest copper (II) ion percentage removal of 99.79% at pH 6 and 0.3 g dosage. It was 57.07% and 19.63% higher than untreated peanut husk powder and simultaneous ultrasound respectively. Both ultrasound pre-treated peanut husk powder shown significant improvement on copper (II) ion removal compared to untreated peanut husk powder and simultaneous ultrasound.