• The Korean Journal of Food And Nutrition
• /
• v.9 no.3
• /
• pp.299-306
• /
• 1996

The study was performed under the various conditions, such as the edible parts and particle sizes of Allium. The concentrations, the temperartures, and the pH of heavy metal solutions to investigated their adsorption capacity of heavy metals by genus Allium. The adsorption amount of Pb by Allium in the aqueous soluton was apparently higher than that of Ni and Cu by them. The larger the particle sloe of welsh onion and shallot was, the higher the adsorption of Cu was. The adsorptlons of Cu, Ni and sorption ratio was not different. As the temperature increased, the amount of heavy metal adsorption increased in general, but the adsorption of Ni by welsh onion and wild garlic and leek, Cu by shallot, wild garlic and leek decreased. Adsorption of Pb to Allium was not affected by the different values of pH, and adsorptions of Ni and Cu were greatly affected by those of pH. Especially, the higher the pH was, the greater the Ni adsorption to Allium was, and the lower the pH was, the higher the Cu adsorption was. The correlation between the amount of components in edible parts of Allium and that of adsorption of heavy metals was significantly high In amino acids containing sulfhydryl group(-SH) and vitamin B2.

• Carbon letters
• /
• v.10 no.4
• /
• pp.305-313
• /
• 2009

In this study, the adsorption of toxic pollutants onto cetyltrimethylammonium kaolin (CTAB-Kaolin) is investigated. The organo-kaolin is synthesized by exchanging cetyltrimethylammonium cations (CTAB) with inorganic ions on the surface of kaolin. The chemical analysis, the structural and textural properties of kaolin and CTAB-kaolin were investigated using elemental analysis, FTIR, SEM and adsorption of nitrogen at $-196^{\circ}C$. The kinetic adsorption and adsorption capacity of the organo-kaolin towards o-xylene, phenol and Cu(II) ion from aqueous solution was investigated. The kinetic adsorption data of o-xylene, phenol and Cu(II) are in agreement with a second order model. The equilibrium adsorption data were found to fit Langmuir equation. The uptake of o-xylene and phenol from their aqueous solution by kaolin, CTAB-kaolin and activated carbon proceed via physisorption. The removal of Cu(II) ion from water depends on the surface properties of the adsorbent. Onto kaolin, the Cu(II) ions are adsorbed through cation exchange with $Na^+$. For CTAB-kaolin, Cu(II) ions are mainly adsorbed via electrostatic attraction with the counter ions in the electric double layer ($Br^-$), via ion pairing, Cu(II) ions removal by the activated carbon is probably related to the carbon-oxygen groups particularly those of acid type. The adsorption capacities of CTAB-kaolin for the investigated adsorbates are considerably higher compared with those of unmodified kaolin. However, the adsorption capacities of the activated carbons are by far higher than those determined for CTAB-kaolin.

• Journal of environmental and Sanitary engineering
• /
• v.12 no.1
• /
• pp.97-100
• /
• 1997

The adsorption of the Chchory particles on Cu(II), Pb(II) and Cd(II) ions were examined by measurements of the adsorption percentage under various condition of temperature, pH, times, heavy metal concentration. Each of 100ml sample solution of Cu(II), Pb(II) and Cd(II) ions mixed with 2g of the Cichory under stirring in shaking water bath for minutes. The solutions were then filtered and pretreatmented according to water pollution official test methods. The concentrations of Cu(II), Pb(II) and Cd(II) ions in the solution were determined by the atomic adsorption spectrophotometer. As a results, the most effective pH of the adsorption of Cu(II), Pb(II) and Cd(II) was 9. With increasing the concentration of heavy metals the amount of adsorption on Cichory was increased. The adsorption equilibrium of Pb(II) and Cd(II) ions were reached to equilibrium by shaking for about 40 minutes. The absorptivities were 85%, 75% respectively.

• Journal of the Korean Wood Science and Technology
• /
• v.14 no.4
• /
• pp.1-7
• /
• 1986

This investigation involves a study of the physical and chemical factors of Pinus densiflora SIEB. et ZUCC. and Quercus mongolica Fisher barks affecting on the adsorption of heavy mteal ions. The results obtained can be summarized as follows. 1. The capacity of the untreated bark to remove the Cu and Cd from solution was similar to or 5% higher than that of formaldehyde treated bark in both species. Considering that untreated bark lead to color-leaching problem, bark treated with formaldehyde are economical. 2. With decreasing particle size of bark(20-80), the adsorption ratio of the Cu and Cd from solution was increased. Quercus bark adsorbed more Cu and Cd at smaller particle size compared to Pinus bark. 3. The heavy metal eqilibrium adsorption of the bark from Cu and Cd solution was attained within 10 min. Pinus bark removed about 48% of the Cu and 41% of the Cd from solution in 10 min while Quercus bark removed about 50% during that period. 4. As the initial metal concentration increased. the absolute metal uptake was increased while percentage removal was decreased. At the lower metal concentration (10 ppm). Pinus and Quercus barks removed 77-94% of the Cu and 72-84% of the Cd. At high metal concentration (200 ppm), the adsorption ratio was 40% Cu and 25% Cd, respectivelty. 5. The maximum adsorption of the Cu and Cd from solution was obtained at pH 5-6 in filtrate. 6. With increased bark weight per given metal concentration, absolute removal of metal ion from solution was increased, but the percentage removal was decreased. The amount of adsorption was 4.2 mg Cu and 4.2 mg Cd per gr. Pinus, bark and 5.4 mg Cu and 4.3 mg Cd per gr. Quercus bark, respectively.

• Bulletin of the Korean Chemical Society
• /
• v.23 no.12
• /
• pp.1765-1768
• /
• 2002

The isotherms of CO adsorption on the Cu/ZnO sample treated with with hydrogen and methanol are investigated. The heats of adsorption of CO on the Cu/ZnO treated with hydrogen at 723K for 3 h are in the range from 25.7 kJ/mol at $\theta=0.8$ to 59.8 at $\theta=0.1$, while those on the Cu/ZnO sample treated with methanol at 523 K for 3 h are in the range 30.3 kJ/mol at $\theta=0.8$ to 99.8kJ/mol at $\theta=0.1.$ The Cu/ZnO samples treated with hydrogen do. The heats of adsorption at q=0.1 increase with the methanol treatment time within 30 min and leveled off afterwards.

• Journal of the Korean Chemical Society
• /
• v.62 no.2
• /
• pp.79-86
• /
• 2018

This study reported the adsorption of Cu(II) ions onto activated carbon prepared from Myristica Fragrans shell (MFS AC) over independent variables of contact time, activating chemical (NaOH) concentration, initial adsorbate concentration, initial pH of adsorbate solution and adsorption temperature. The MFS AC structure, morphology and total surface area were characterized by FTIR, SEM and BET techniques, respectively. The Cu(II) ions adsorption on the MFS AC (activated using 0.5 M NaOH) fitted best to Freundlich adsorption isotherm (FAI), and the FAI constant obtained was 0.845 L/g at $30^{\circ}C$ and pH 4.5. It followed the pseudo first order of adsorption kinetic (PFOAK) model, and the PFOAK based adsorption capacity was 107.65 mg/g. Thermodynamic study confirmed the Cu(II) ions adsorption should be exothermic and non-spontaneous process, physical adsorption should be taken place. The total surface area and pore volume based on BET analysis was $99.85m^2/g$ and 0.086 cc/g, respectively.

• Korean Journal of Environmental Agriculture
• /
• v.34 no.1
• /
• pp.21-29
• /
• 2015

BACKGROUND: Heavy metal adsorptionnot only depends on biochar characteristics but also on the nature of the metals involved and on their competitive behavior for biochar adsorption sites. The goal of this study was to investigate the competitive absorption characteristics of Cu and Cd in mono-metal and binary-metal forms by biochar derived from Phragmites communis. METHODS AND RESULTS: Batch and column experiments were conducted to evaluate the competitive adsorption characteristics of the biocharfor Cu and Cd. In the batch experiments, the maximum adsorption capacity of Cd(63 mg/g) by biochar was higher than that for Cu (55 mg/g) in the mono-metal adsorption isotherm. On the other hand, the maximum Cu adsorption capacity (40 mg/g) by biochar was higher than that for Cd(25 mg/g) in the binary-metal adsorption isotherm. Cu was the most retained cations. Cd could be easily exchanged and substituted by Cu. The amounts of adsorbed metals in the column experiments were in the order of Cd (121 mg/g) > Cu (96 mg/g) in mono-metal conditions, and Cu (72 mg/g) > Cd (29 mg/g) in binary-metal conditions. CONCLUSION: Overall, the results demonstrated that competitive adsorption among metals increased the mobility of these metals. Particularly, Cd in binary-metal conditions lost its adsorption capacity most significantly.

• Journal of Environmental Science International
• /
• v.27 no.5
• /
• pp.299-308
• /
• 2018

The adsorption characteristics of Cu ions were studied using the zeolite Na-A synthesized from Jeju volcanic rocks. The effects of various operating parameters such as initial concentration of Cu ions, contact time, solution pH, and solution temperature were investigated in batch experiments. The adsorption of Cu ions by Na-A zeolite was fitted well by pseudo-second-order kinetics and the Langmuir isotherm model. The maximum adsorption capacity determined using the Langmuir isotherm model was 152.95 mg/g. In addition, the adsorption of Cu ions by zeolite Na-A was primarily controlled by particle diffusion model in comparison with the film diffusion model. As the temperature increased from 303 K to 323 K, ${\Delta}G^o$ decreased from -2.22 kJ/mol to -3.41 kJ/mol, indicating that the adsorption of Cu ions by Na-A zeolite is spontaneous process.

• Applied Chemistry for Engineering
• /
• v.30 no.1
• /
• pp.54-61
• /
• 2019

In this study, a magnetic adsorbent was synthesized by growing ferrite nanoparticles substituted with metals (Me = Co, Mn, Ni) on zeolite 4A for the efficient separation of waste adsorbents present in the solution after the adsorption of Cu(II). The metal ferrite grown on the surface of zeolite was prepared by solvothermal synthesis. Characteristics of the magnetic adsorbent were analyzed by X-ray diffractometer (XRD), scanning electron microscopy (SEM) and physical property measurement system (PPMS). The saturation magnetization of the A type zeolite coated with Co-ferrite (CFZC) was the highest at 5 emu/g and the Cu(II) adsorption performance was also excellent. The adsorption results of Cu(II) on CFZC were well fitted by the Langmuir model at 298 K. Also, the adsorption of Cu(II) on CFZC follows a pseudo-second order kinetic. The Gibbs free energy values (${\Delta}G^0$) ranging from -4.63 to -5.21 kJ/mol indicates that the Cu(II) adsorption is spontaneous in the temeprature range between 298 and 313 K.

• Journal of Environmental Science International
• /
• v.11 no.4
• /
• pp.333-338
• /
• 2002

In this work, the characterization of adsorption of Cu, Zn and Cd on granular activated carbon in water has been studied. The factors that affect adsorption in boundary between activated carbon and wastewater are concentration, temperature, contact time, pH and so on. As the result of this study, the maximum adsorption amount of Cu occurred near pH 7, while that of Zn and Cd was near pH 9.6 and 10, respectively. As contact time and temperature are transformed, such factors as optimum contact time and temperature are taken into consideration in an adsorptive process of heavy metal because an adsorption and a reducing process occur. In isotherm of Freundlich, 1/n values of Cu, Cd capacity were between 0.16 and 0.5.