• Analytical Science and Technology
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• v.15 no.2
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• pp.163-171
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• 2002

The adsorption characteristics of Cd(II) and Pb(II) ions has been studied by using chitin as an adsorbent. The pure chitin was obtained from the extraction of red-crab shell dumped by fish factory. Adsorption kinetics of Cd(II) and Pb(II) ions on the chitin reached at the maximum adsorption within two minutes. Adsorbed amounts of heavy metals were pH 7.0>10.5>3.5 in the following order. Adsorption ratio by chitin was 21${\sim}$99% for Cd(II) ion and 24${\sim}$95% for Pb(II) ion. Recovery ratio of Cd(II) ion on the chitin was 22${\sim}$53%, and that of Pb(II) ion was 22${\sim}$73%. The adsorption behavior of these heavy metals was explained well by Freundlich adsorption isotherm.

• Journal of Environmental Science International
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• v.5 no.2
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• pp.195-201
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• 1996

This study was conducted for the efficient utilization of a scoria, which is abundantly found in Cheju island, as adsorbent and the scoria was examined for its performance in clarification of adsorption of heavy metal ions. The order in heavy metal ions adsorbed on scoria was; Pb+>Cd^{2+}$>Cu^{2+}$>Ag^+$>Co^{2+}$>Zn^{2+}$>Cr^{3+}$>Cr^{6+}$. This tendency was relatively consistent with the decreasing order of radius of hydrated metal ion. Also, the smaller scoria size and the larger amounts of scoria showed higher removal efficiency for heavy metal ions. The same scoria size showed more effective removal efficiency for heavy metal ions at lower initial concentration than at higher initial concentration. The adsorption abilities of original scoria and chemically treated scoria were compared. Adsorption isotherm of scoria was generally obeyed to Freundlich formula than langmuir formula and Freundlich constant, than was obtained in the range of 0.2~0.4.

• Journal of Environmental Health Sciences
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• v.45 no.6
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• pp.561-568
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• 2019

Objectives: The most commonly detected heavy metals in rocks and soils, including Pb, Cd, Cu, Fe, Mn and As, are representative pollutants discharged from abandoned mines and have been listed as potential sources of contamination in drinking water. This study focused on increasing the removal efficiency of heavy metals from drinking water resources by surface modification of natural adsorbents to reduce potential health risks. Methods: Iron oxide coating and graft polymerization with zeolites and talc was conducted for bipolar surface modification to increase the combining capacity of heavy metals for their removal from water. The removal efficiency of heavy metals was measured before and after the surface modification. Results: The removal efficiency of Pb, Cu, and Cd by surface modified zeolite showed 100, 92, and 61.5%, respectively, increases compared to 64, 64, and 38% for non-modified zeolite. This implies that bipolar surface modified natural adsorbents have a good potential use in heavy metal removal. The more interesting finding is the removal increase for As, which has both cation and anion characteristics showing 27% removal efficiency where as non-modified zeolite showed only 2% removal. Conclusions: Zeolite is one of the most widely used adsorptive materials in water treatment processes and bipolar surface modification of zeolite increases its applicability in the removal of heavy metals, especially As.

• Korean Journal of Environmental Agriculture
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• v.33 no.3
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• pp.220-230
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• 2014

BACKGROUND: Excessive metals in the soil have become one of the most significant environmental problems. Phytoremediation has received considerable attention as a method for restoring the contaminated soils. The microbes having remarkable metal tolerance and plant growth-promoting abilities could also play a significant role in remediation of metal-contaminated soils, because bioaugmentation with such microbes could promote phytoextraction of metals. Therefore, the present study was focused on evaluating the phytoextraction of heavy metals (Co, Pb and Zn) in Helianthus annuus (sunflower) induced by bioaugmentation of a phosphate solubilizing bacterium. METHODS AND RESULTS: A phosphate solubilizing bacterium was isolated from metal-contaminated soils based on the greater halo size (>3 mm) with solid NBRIP agar medium containing 10 g glucose, 5 g $Ca_3(PO_4)_2$, 5 g $MgCl_2{\cdot}6H_2O$, 0.25 g $MgSO_4.7H_2O$, 0.2 g KCl, 0.1 g $(NH_4)_2SO_4$ in 1 L distilled water. Isolated bacterial strain was assessed for their resistance to heavy metals; $CoCl_2.6H_2O$, $2PbCO_3.Pb(OH)_2$, and $ZnCl_2$ at various concentrations ranging from $100-400{\mu}g/mL$ (Co, Pb and Zn) using the agar dilution method. A pot experiment was conducted with aqueous solutions of different heavy metals (Co, Pb and Zn) to assess the effect of bacterial strain on growth and metal uptake by Helianthus annuus (sunflower). The impact of bacterial inoculation on the mobility of metals in soil was investigated under laboratory conditions with 50 mL scaled polypropylene centrifuge tubes. The metal contents in the filtrate of plant extracts were determined using an atomic absorption spectrophotometer (Perkinelmer, Aanalyst 800, USA). CONCLUSION: Inoculation with Enterobacter ludwigii PSB 28 resulted in increased shoot and root biomass and enhanced accumulation of Co, Pb and Zn in Helianthus annuus plants. The strain was found to be capable of promoting metal translocation from the roots to the shoots of H. annuus. Therefore, Enterobacter ludwigii PSB 28 could be identified as an effective promoter of phytoextraction of Co, Pb and Zn from metal-contaminated soils.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.38 no.3
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• pp.153-157
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• 2005

The biosorption of Pb and Cr by Sargassum thunbergii was investigated in a batch conditions. The Pb and Cr uptake capacity of Sargassum thunbergii was 232.5 mg Pb/g biomass and 91.6 mg Cr/g biomass, respectively. An adsorption equilibria was reached within about 0.5 hr for both the Pb and the Cr. The adsorption parameters for both the Pb and the Cr were determined according to the Langmuir and Freundlich model. With increasing pH values, more negative sites are becoming available for the adsorption of Pb and Cr. The selectivity of mixture solution showed an uptake order of Pb>Cu>Cr>Cd. Pb and Cr adsorbed by S. thunbergii could be recovered ken 0.1 M HCl, 0.1 M $HNO_3$ and 0.1M EDTA by a desorption process, and the efficiency of Pb desorption was above $95.8\%$, whereas the efficiency of the Cr desorption was below $50.7\%$.

• Journal of the Korea Organic Resources Recycling Association
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• v.17 no.4
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• pp.74-80
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• 2009

Effect of dye wastewater on heavy metal removal using carboxylated alginic acid bead was performed. When carboxylated alginic acid bead was used as support, effect of dye wastewater on adsorption of $Pb^{2+}$ and $Cu^{2+}$ ions was very small. Also, when $Pb^{2+}$ was coexisted with dye wastewater, adsorption process was almost completed within 2-3 hrs and $Pb^{2+}$ ions (50 ppm) was almost removed with 0.3g of bead. This result means that carboxylated alginic acid bead has effective adsorbent for heavy metal removal in dye wastewater.

• Journal of the Korean Ceramic Society
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• v.39 no.7
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• pp.680-686
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• 2002

The solidification/stabilization mechanism of each cementious material was investigated. It was found that when $C_3$S was hydrated , the Pb element could be transferred to the insoluble Ca[Pb(OH)$_3$.$H_2O$]$_2$and the Cr element to the CaCr $O_4$$H_2O$. The addition of heavy metal tends to delay the hydration until initial 7 days. The Pb element as also delayed the hydration and the Cr element was substituted for the ettringite. On the occasion of the hydration of $C_4$ $A_3$ $S^{S}$, the Pb and Cr ions were solidified/stabilized by the substitution into the ettringite and/or monosulfate. Leaching of the Pb, Cr and Zn elements in the solidified material was extremely little, indicating that heavy metals were effectively solidified/stabilized in the hydrated cementious materials. Solidification/stabilization of heavy metal ions in the industrial wastes such as the STS, BF and COREX sludge was investigated. In case of the mixing ratio of cement and slag was 3 : 7, leaching of hazardous heavy metal ions was very little, indications that the solidification and stabilization was very successful.l.

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

• The Korea Journal of Herbology
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• v.23 no.4
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• pp.51-58
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• 2008

Objectives: To compare the contents of heavy metals, residual pesticides and sulfur dioxide before/after a decoction. Methods: The heavy metal contents before/after a decoction were measured by Inductively Coupled Plasma Atomic Emission Spectrometer(ICP-AES) and mercury analyzer. In order to analyze pesticides in 5 samples we used simultaneous multi-residue analysis of pesticides by GC/ECD, which was followed by GC/MSD analysis to confirm the identity of the detected pesticide in each sample. In addition, the contents of sulfur dioxide($SO_2$) were performed by Monier-Williams distillation method. Results: 1. The mean values of heavy metal contents(mg/kg) for the samples were as follows: Galgeun-tang(before decoction-Pb; 0.793, Cd; 0.133, As; 0.016 and Hg; 0.005, after decoction-Pb; 0.033, Cd; 0.004, As; 0.002 and Hg; not detected), Gumiganghwal-tang(before decoction-Pb; 0.934, Cd; 0.197, As; 0.046 and Hg; 0.006, after decoction-Pb; 0.062, Cd; 0.007, As; 0.004 and Hg; 0.0001), Sosiho-tang(before decoction-Pb; 0.891, Cd; 0.134, As; 0.091 and Hg; 0.014, after decoction-Pb; 0.036, Cd; 0.002, As; 0.004 and Hg; not detected), Ojuck-san(before decoction-Pb; 0.907, Cd; 0.136, As; 0.084 and Hg; 0.007, after decoction-Pb; 0.074, Cd; 0.007, As; 0.011 and Hg; 0.0005) and Samsoeum(before decoction-Pb; 1.234, Cd; 0.154, As; 0.016 and Hg; 0.007, after decoction-Pb; 0.094, Cd; 0.006, As; 0.002 and Hg; 0.001). 2. Contents(mg/kg) of residual pesticides before/after a decoction in all samples were not detected. 3. Contents(mg/kg) of sulfur dioxide($SO_2$) before a decoction in Galgeun-tang, Gumiganghwal-tang, Sosiho-tang, Ojuck-san and Samsoeum exhibited 1.2, 3.4, 11.1, 12.0 and 5.7, respectively. However, contents of sulfur dioxide after a decoction in all samples were not detected. Conclusions: These results will be used to establish a criterion of heavy metals, residual pesticides and sulfur dioxide.

• Applied Chemistry for Engineering
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• v.9 no.4
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• pp.504-508
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• 1998

Experimental investigation on the adsorption of heavy metal confounds as $Fe^{2+}$, $Cu^{2+}$, $Mn^{2+}$, $Zn^{2+}$, $Ni^{2+}$, $Pb^{2+}$, $Cd^{2+}$, $Cr^{6+}$ using chitosan was carried out. The adsorption of each component of heavy metal compounds was measured by Atomic Absorption apparatus. The range of optimum pH for the removal rates of heavy metal compounds was found pH 7.0~9.0. The maximum time for the removal rate of $Fe^{2+}$ was observed about 15 min. The maximum time for the removal raters of $Cu^{2+}$, $Mn^{2+}$, $Zn^{2+}$, $Ni^{2+}$, $Pb^{2+}$, $Cd^{2+}$, and $Cr^{6+}$ was observed about 25 min. The adsorption rates of heavy metal compounds by chitosan have been found in the order of $Fe^{2+}>Cu^{2+}>Mn^{2+}>Zn^{2+}>Ni^{2+}>Pb^{2+}>Cd^{2+}>Cr^{6+}$.