• Bulletin of the Korean Chemical Society
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• v.19 no.2
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• pp.218-222
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• 1998

Removal of Cd(Ⅱ), Zn(Ⅱ) and Cu(Ⅱ) from aqueous solutions using the adsorption process on magadiite has been investigated. It was found that the removal percentage of metal cations at equilibrium increases with increasing temperature, and follows the order of Cd(Ⅱ) > Cu(Ⅱ) > Zn(Ⅱ). Equilibrium modeling of adsorption showed that the adsorptions of Cd(Ⅱ), Cu(Ⅱ), and Zn(Ⅱ) were fitted to Langmuir isotherm. Kinetic modeling of the adsorption showed that first order reversible kinetic model fitted to experimental data. From kinetic model and equilibrium data, the overall rate constant (k) and the equilibrium constant (K) for the adsorption process were calculated. The overall rates of adsorption of metal ions follow the order of Cd(Ⅱ) > Cu(Ⅱ) > Zn(Ⅱ). From the results of thermodynamic analysis, standard Gibbs free energy (ΔG°), standard enthalpy (ΔH°), and standard entropy (ΔS°) of adsorption process were calculated.

• KSBB Journal
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• v.14 no.2
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• pp.141-145
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• 1999

The study was conducted for the efficient utilization of biomaterials such as Chestnut shell which was wasted tremendously as an agricultural by-products. This biomaterials were examined for their removal rate of heavy metal ions as adsorbents in wastewater by batch adsorption experiments. In this experiment, the heavy metal ions used were $\Cd^{2+},\;Fe^{2+},\;Cr^{6+},\;Mn^{2+},\;Cu^{2+}$ and $Pb^{2+}$. The range of time for the removal rates of heavy metal ions were observed about 10 min. The range of high pH for the removal rates of $\Cd^{2+},\;Fe^{2+},\;Mn^{2+},\;Cu^{2+}$ and $Pb^{2+}$ ere observed 7.0-9.0. The range of high pH for the removal rate of $Cr_{6+}$ was observed 2. In the case of raw chestnut shell, the removal rates of $\Fe^{2+},\;Mn^{2+},\;Cu^{2+}$ and $Pb^{2+}$ were above 70 percent. The removal rates of heavy metals in formaline pretreated chestnut shells except $Cd_{2+}$ were above 50 percent and in phosphorylating chestnut shells except $Cr_{6+}$ were above 60 percent. Chestnut shells pretreated by formaline and phosphorylating were not so good enough for improvement of removal rates with pH change in mixed heavy metal solution.

• Journal of the Korea Organic Resources Recycling Association
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• v.16 no.2
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• pp.38-46
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• 2008

Many researchers have reported that many biopolymers making up cell walls of the microorganisms display an ion-exchange property and play a major role in the sorption of the metal ions. Such polymers derived from microbial biomass are potentially useful as biosorbent materials for recovery various metal ions in industrial applications. although synthetic polymers such as ion-exchange resins and chelating resins have been widely used as commercial sorbents. In this study, valuable and commercial biopolymers for metal removal will be introduced.

• Environmental Engineering Research
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• v.13 no.2
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• pp.79-84
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• 2008

Adsorption of heavy metals by sawdust was investigated to evaluate the effectiveness of using sawdust to remove heavy metals from aqueous solutions. Kinetic and isotherm studies were carried out by considering the effects of initial concentration and pH. The adsorption isotherms of heavy metals fitted the Langmuir or Freundlich model reasonably well. The adsorption capacity of metal was in the order $Pb^{2+}$ > $Cu^{2+}$ > $Zn^{2+}$. A high concentration of co-existing ions such as $Ca^{2+}$ and $Mg^{2+}$ depressed the adsorption of heavy metal. Adsorption data showed that metal adsorption on sawdust follows a pseudo-second-order reaction. Kinetic studies also indicated that both surface adsorption and intraparticle diffusion were involved in metal adsorption on sawdust. Column studies prove that sawdust could be effective biosorbent for the removal of heavy metals from aqueous phase.

• Journal of environmental and Sanitary engineering
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• v.15 no.1
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• pp.54-61
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• 2000

We studied the adsorption characteristics on the treatment process of heavy metal wastewater by using cuttle fish bones powder. When adding the 0.25% cuttle fish born powder in the heavy metal solution, $Fe^{3+}$ and $Pb^{2+}$ were high removed than other heavy metals as above 95%. In the solution which was adjusted to pH 5, 7 and 9, there was not observed the difference thing on the heavy metal removal rate. At test using plating wastewater treatment, adding 1%, 1.5% and 2% of the cuttle fish born powder, the heavy metal removal rate were as follows; Zn 12.5 - 37.5%, Mn 18.0 - 62.2%, Cd 36.8 -93.0%, Cu 51.4 - 97.4%, Cr 70.8 - 99.1%, Fe 87.2 - 99.3% and Pb 92.8 - 99.9%. When adding the 0.15% cuttle fish born powder and mixing for 20 minutes, the solution was happened the adsorption equability. Applied this results to the Freundlich＇s iso-thermal equation, we found the cuttle fish born＇s probability as a good adsorbent.

• Journal of the East Asian Society of Dietary Life
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• v.9 no.3
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• pp.363-369
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• 1999

The heavy metal removability of four kinds of tea was investigated in the various conditions: particle size of tea(10, 35. 70, 100 mesh), concentration of heavy metal(25, 50, 100ppm) and extraction temperature(30. 50, 70. 10$0^{\circ}C$). The removabilities by the tea solids were increased as the particle size decreased, concentration of heavy metal increased, and extracting temperature increased. Of the four kinds of tea Pb, Cd and Cu removability by Eucommia ulmoides Oliv tea was the highest. In addition, heavy metal removability by Schizandra chinensis Baillon tea was better than that of other tea as extraction temperature was increased.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2002.09a
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• pp.40-43
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• 2002

Electrokinetic remediation was studied for the removal of toxic heavy metals from tailing soils. This study emphasized the dependency of removal efficiency upon heavy metal speciation, as demonstrated by different extraction methods (sequential extraction, total digestion, and 0.1 N HC1 extraction). The tailing soils examined showed different physicochemical characteristics, in view of initial pH, particle size distribution, and major mineral constituents, and contained high concentrations of target metal contaminants in various forms. The electrokinetic removal efficiency of heavy metals was significantly influenced by their partitioning prior to treatment, and by the pHs of the tailing soils. The mobile and weakly bound fractions of heavy metals, such as exchangeable fraction, were easily removed by electrokinetic treatment (more than 90% in removal efficiency), whereas immobile and strongly bound fractions, such as organically bound and residual fractions, were not effectively removed (less than 20% in removal efficiency).

• Journal of Korean Society of Water and Wastewater
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• v.30 no.6
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• pp.683-690
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• 2016

Modified coagulants were investigated for the removal of phosphorus from secondary effluent of wastewater treatment. The modified coagulants were prepared by mixing alkali earth metal ions such as calcium and magnesium. The basicity of a coagulant influenced on the removal of phosphorus, and coagulants with basicity of 5.9% showed a better removal of total phosphorus than that of 38.5%. Also, coagulants with alkali earth metals enhanced the performance of coagulation by 10% and resulted in 67.1% for total phosphorus removal. Moreover, the removal of suspended solids and chemical oxygen demand was improved using coagulants with low basicity and earth metal ions. Results of this study demonstrated that the use of coagulants with low basicity, and calcium and magnesium ions is recommended to improve wastewater effluent quality.

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

• Journal of the Korea Organic Resources Recycling Association
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• v.22 no.2
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• pp.50-56
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• 2014

Conventional coagulation-gravity settling processes in heavy metal removal have a problem in coagulant cost and instability of the settling efficiency. The authors investigated the effects of pH and slow mixing conditions on heavy metal hydroxide precipitation and the particle size distribution of the precipitate for a precipitation-membrane separation process. The optimum pH values for the hydroxide precipitation ranged from 9 to 10. The addition of $FeCl_3$ did not enhance the heavy metal removal. 20 min of slow mixing at 70 rpm showed the maximum heavy metal removal to meet the water quality criteria for effluent discharge. More than 99.9% of the heavy metal precipitate particles were bigger than $2{\mu}m$.