• Resources Recycling
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• v.21 no.1
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• pp.75-81
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• 2012

Porous pellets for immobilizing heavy metals were manufactured from coal tailings and iron oxide powder. Coal tailings was pulverized and mixed with iron oxide powder. The mixed powder was granulated into spherical pellets and roasted. Over $1100^{\circ}C$, residual coal in coal tailings reduced iron oxide to ZVI(Zero-Valent Iron). The pellets have 34.63% of porosity, 1.31 g/mL of bulk density, and 9.82.urn median pore diameter. The pellets were reacted with synthetic solutions containing each heavy metals: arsenic(V), copper(II), chrome(VI), and cadmium(II), respectively. On the test of immobilizing heavy metal, the pellets made at $1100^{\circ}C$ were superior to the other pellets made under $1000^{\circ}C$. Immobilizing over 99.9% of 10ppm heavy metal solutions required I hour for arsenic, 2 hours for chrome, and 4 hours for copper. However, immobilizing capacity of cadmium was inferior to that of the other metals and it was decreased in reversely proportion to initial concentration of the solutions.

• Advances in materials Research
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• v.6 no.2
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• pp.129-153
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• 2017

Platinum is a transition metal that is very resistant to corrosion. It is used as catalyst for converting methyl alcohol to formaldehyde, as catalytic converter in cars, for hydrocracking of heavy oils, in Fuel Cell devices etc. Moreover, Platinum compounds are important ingredient for cancer chemotherapy drugs. The nano forms of Platinum due to its unique physico-chemical properties that are not found in its bulk counterpart, has been found to be of great importance in electronics, optoelectronics, enzyme immobilization etc. The stability of Platinum nanoparticles has supported its use for the development of efficient and durable proton exchange membrane Fuel Cells. The present review concentrates on the use of Platinum conjugated with various metal or compounds, to fabricate nanocomposites, to enhance the efficiency of Platinum nanoparticles. The recent advances in the synthesis methods of different Platinum-based nanocomposites and their applications in Fuel Cell, sensors, bioimaging, light emitting diode, dye sensitized solar cell, hydrogen generation and in biosystems has also been discussed.

• Journal of Environmental Science International
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• v.7 no.1
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• pp.57-61
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• 1998

The biosorption of heavy metals has received a lot of attraction for application of metal ions treatment. In this work, we studied with Arthrobactor sp., screening from a wastewater containing heavy metals. The Pb uptake capacity of Arthrobactor sp. was nearly 146.9 mg Pb/g dry biomass(initial concentration, 500 may L), whereas the Pb uptake capacity of Sacchuomyces cerevisiae and Sacchuomyces uvuum were only around 39.40 and 35.65 mg Pb yg dry biomass, respectively. The Pb and Cr were removed from metal solution much more effeciently than were the other metals(Cd and Cu). The Pb uptake capacity of Aythrobactor sp. increased with increasing in pH(1.8, 3.0 and 4.0) and decreased with Increaslng of biomass concentration. At pH 4.0, the Pb uptake capacity reached 244 mg Pb/g dry biomass in Pb initial concentration of 1000 mg/L. The Pb uptake capacity of Ayhol)actor sp. treated by KOH and $CaCl_2$ were increased above values obtained with untreated Ayurobactor sp. However, the Pb uptake capacity fore the breakthrough points were reached.

• Journal of Microbiology and Biotechnology
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• v.27 no.6
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• pp.1138-1149
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• 2017

The use of microalgal biomass is an interesting technology for the removal of heavy metals from aqueous solutions owing to its high metal-binding capacity, but the interactions with bacteria as a strategy for the removal of toxic metals have been poorly studied. The goal of the current research was to investigate the potential of Burkholderia tropica co-immobilized with Chlorella sp. in polyurethane discs for the biosorption of Hg(II) from aqueous solutions and to evaluate the influence of different Hg(II) concentrations (0.041, 1.0, and 10 mg/l) and their exposure to different contact times corresponding to intervals of 1, 2, 4, 8, 16, and 32 h. As expected, microalgal bacterial biomass adhered and grew to form a biofilm on the support. The biosorption data followed pseudo-second-order kinetics, and the adsorption equilibrium was well described by either Langmuir or Freundlich adsorption isotherm, reaching equilibrium from 1 h. In both bacterial and microalgal immobilization systems in the co-immobilization of Chlorella sp. and B. tropica to different concentrations of Hg(II), the kinetics of biosorption of Hg(II) was significantly higher before 60 min of contact time. The highest percentage of biosorption of Hg(II) achieved in the co-immobilization system was 95% at pH 6.4, at 3.6 g of biosorbent, $30{\pm}1^{\circ}C$, and a mercury concentration of 1 mg/l before 60 min of contact time. This study showed that co-immobilization with B. tropica has synergistic effects on biosorption of Hg(II) ions and merits consideration in the design of future strategies for the removal of toxic metals.

• Analytical Science and Technology
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• v.13 no.3
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• pp.368-377
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• 2000

Si-immobilized Sargassum horneri was used to study the adsorption characteristics along with maximum adsorption conditions of heavy metal ions, Cd(II) and Ph(II) on the Si-immobilized Sargassum horneri. More amount of Cd(II) and Pb(II) ions on the Si-immobilized Sargassum horneri than Sargassum horneri were adsorbed. And Pb(II) ions were more adsorbed in all algae than Cd(II) ions more effectively in alkaline than in acidity. Recovery ratios of Cd(II) and Pb(II) ions on the Sargassum horneri were 58.0-62.6%, 61.2-64.4% respectively, Si-immobilized Sargassum horneri 56.8-92.7%, 37.8-47.9%. Recovery ratio of Cd(II) ion was higher on the Si-immobilized Sargassum horneri but it of Pb(II) ion was lower on the Si-immobilized Sargassum horneri.

• Korean Journal of Environmental Agriculture
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• v.33 no.4
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• pp.245-253
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• 2014

BACKGROUND: Oyster shell(OS) is alkaline with pH 9.8, porous, and has high concentration of $CaCO_3$. It could be used as an alternative of lime fertilizer to immobilize cadmium(Cd) in heavy metal contaminated arable soil. Therefore, this study has been conducted to compare effects of calcium(Ca) materials [OS and $Ca(OH)_2$] on Cd extractability in contaminated soil and determined mechanisms of Cd immobilization with OS. METHODS AND RESULTS: Both Ca materials were added at the rates of 0, 0.1, 0.2, 0.4, and 0.8% (wt Ca wt-1) in Cd contaminated soil and the mixtures were incubated at $25^{\circ}C$ for 4 weeks. Both Ca materials increased pH and negative charge of soil with increasing Ca addition and decreased 1N $NH_4OAc$ extractable Cd concentration. 0.1 N HCl extractable Cd concentration markedly decreased with addition of OS. 1 N $NH_4OAc$ extractable Cd concentration was related with pH and net negative charge of soil, but not with 0.1 N HCl extractable Cd concentration. We assumed that Cd immobilization with $Ca(OH)_2$ was mainly attributed to Cd adsorption resulted from increase in pH-induced negative charge of soil. Scanning electron microscope (SEM) images and energy dispersive spectroscopy(EDS) analyses were conducted to determine mechanism of Cd immobilization with OS. There was no visible precipitation on surface of both Ca materials. However, Cd was detected in innerlayer of OS by EDS analyses but not in that of $Ca(OH)_2$. CONCLUSION: We concluded that Cd immobilization with OS was different from that with $Ca(OH)_2$. OS might adsorbed interlayer of oyster shell or have other chemical reactions.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.5
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• pp.417-426
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• 2010

In this study, ten different bio-adsorbents were prepared by immobilization of vegetable tannins such as mimosa(Catechol Tannin) and chestnut(Pyrogallol Tannin) on the collagen matrix which was derived from during leather manufacturing processing. Removal efficiency of Cu(II), Cd(II), Zn(II), Pb(II), Cr(III) by each bio-adsorbent in synthetic wastewater was evaluated by a laboratory-scale batch reactor at different reaction conditions. When mimosa was used as a vegetable tannin, the penetration efficiency of mimosa into the inner bundle of fiber depended on the dose of the naphthalene condensated penetrant; 3% ${\geq}$ 1.5% > 0%. For all bio-adsorbents, removal of heavy metal ions was not observed below pH 3.0 but was rapidly increased between pH 3.0 and 6.0, showing near complete removal of all heavy metal ions except Zn(II) above pH 6.0. Removal of Cr(III) was quite similar for all bio-adsorbents while removal of Cu(II), Zn(II) and Pb(II) was higher by bio-adsorbents immobilized with chestnut than that by mimosa. Adsorption of Pb(II) and Cu(II) by S10 bio-adsorbent was little affected by the presence of monovalent and divalent electrolytes as well as variation of 1000 times ionic concentration with $NaNO_3$.

• Journal of Applied Biological Chemistry
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• v.58 no.1
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• pp.65-74
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• 2015

X-ray absorption fine structure (XAFS) analysis using X-ray absorption spectroscopy is being applied as a state-of-the-art method in a wide range of disciplines. This review article summarizes the overall procedure of XAFS analysis from the preparation of soil samples to the analysis of data in X-ray absorption near edge structure (XANES) region and extended Xray absorption fine structure (EXAFS) region. The previous studies on application of XANES and EXAFS techniques in environmental soil science field are discussed and classified them according to metal(loid)s (As, Cd, Cu, Ni, Pb, and Zn). A significant number of previous studies of XAFS application in the environmental soil science field have focused on the identification of Pb chemical species in soil. Moreover, XANES and EXAFS techniques have been widely used to investigate the contamination source via identification of metal species. Similarly, these techniques were applied to identify the mechanisms of metal stabilization in soil after application of various amendments, phytoremediation, etc.

• Korean Journal of Environmental Biology
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• v.27 no.4
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• pp.353-362
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• 2009

This study attempted to compare the litter decomposition rate of Arundinella hirta and Miscanthus sinensis var. purpurascens which collected from serpentine soil acting potentially toxic concentration of heavy metals and non-serpentine soil by using the microcosm method for 192 days under constant humidity and $23^{\circ}C$. The contents of Ni, Fe, Mg and Cr in the serpentine and nonserpentine soil originated litter showed high differences between them. The litter samples from serpentine site have lower C/N than non-serpentine litter, but the soluble carbohydrate content was shown almost similar between two plant litter. The mass loss rates of leaf litter from serpentine area were slower than those from non-serpentine site. During the experimental period, the remained dry weight of A. hirta and M. sinensis var. purpurascens litter collected from serpentine site were 64.7%, 65.0% of initial dry weight and litter samples from non-serpentine site showed 54.2%, 50.7%, respectively. K and Na were leached rapidly at the initial decomposition periods, but Ca showed immobilization and other metal elements reserved at the decomposing litter for a long time. The decomposing A. hirta litter from non-serpentine soil showed higher values of $CO_2$ evolution, microbial biomass-C, and microbial biomass-N than those in serpentine soil originated litter acting nutrient stresses and exhibited rapid decay rate. The microbial biomass and microbial respiration of decaying litter were positively correlated with litter decomposition rate, and these relationships showed more rapid slope in non-serpentine soil originated litter than that in serpentine soil.

• Analytical Science and Technology
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• v.12 no.2
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• pp.116-124
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• 1999

Adsorption characteristics of heavy metal ions, Cd(II) and Pb(II), on eastcoast-living algae, ulva pertusa, has been studied in our experiment. The Maximum adsorption amount of Cd(II) and Pb(II) ions on 1 g of the ulva pertusa were 2.3 mg, 3.1 mg in alkaline and 2.0 mg, 2.8 mg in acidic solution. However 3.4 mg, 7.3 mg in alkaline and 3.1 mg, 6.5 mg in acidic solution were shown on the Si-immobilized ulva pertusa in the same condition. Thus, Si-immobilized ulva pertusa adsorbs more amount of heavy metals, Cd(II), Pb(II), than the ulva pertusa, and more effective absorbent in alkaline. Furthermore, more amounts of Pb(II) ion were absorbed compare to Cd(II) ion in our work. Recovery ratio of Cd(II) and Pb(II) ions on the ulva pertusa were 55.0~61.0%, 59.7~66.8% respectively and 87.6~97.5%, 83.5~99.3% on the Si-immobilized ulva pertusa.