• Carbon letters
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• v.4 no.1
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• pp.1-9
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• 2003

Recently, the control of pore-characteristics of nano-porous materials has been studied extensively because of their unique applications, which includes size-selective separation, gas adsorption/storage, heterogeneous catalysis, etc. The most widely adopted techniques for controlling pore characteristics include the utilization of pillar effect by metal oxide and of templates such as zeolites. More recently, coordination polymers constructed by transition metal ions and bridging organic ligands have afforded new types of nano-porous materials, porous metal-organic framework(porous MOF), with high degree and uniformity of porosity. The pore characteristics of these porous MOFs can be designed by controlling the coordination number and geometry of selected metal, e.g transition metal and rare-earth metal, and the size, rigidity, and coordination site of ligand. The synthesis of porous MOF by the assembly of metal ions with di-, tri-, and poly-topic N-bound organic linkers such as 4,4'-bipyridine(BPY) or multidentate linkers such as carboxylates, which allow for the formation of more rigid frameworks due to their ability to aggregate metal ions into M-O-C cluster, have been reported. Other porous MOF from co-ligand system or the ligand with both C-O and C-N type linkage can afford to control the shape and size of pores. Furthermore, for the rigidity and thermal stability of porous MOF, ring-type ligand such as porphyrin derivatives and ligands with ability of secondary bonding such as hydrogen and ionic bonding have been studied.

• Applied Chemistry for Engineering
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• v.26 no.6
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• pp.666-673
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• 2015

In this paper the selective reduction catalyst (SCR) for controlling the NOx at high temperature range was studied. XRD and FT-IR BET analysis was also performed to determine the structural properties and adsorption/desorption characteristics of the catalyst. In the case of anatase $TiO_2$ support, a negligible NOx conversion was observed, but the $W/TiO_2$ catalyst made using W as a active metal showed an excellent ability to remove NOx. In particular, the $W/TiO_2$ exhibited a rapid increase in the catalytic activity due to the presence of W for the NOx conversion compared to that of using the pure $TiO_2$ at a high temperature range over $400^{\circ}C$. In addition, the phenomenon of reduced reaction activity due to the heat shock for a long time was found to be suppressed.

• Journal of Soil and Groundwater Environment
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• v.20 no.4
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• pp.113-121
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• 2015

The contaminated soil at abandoned smelter areas present challenge for remediation, as the degraded materials are typically deficient in nutrients, and rich in toxic heavy metals and metalloids. Bioremediation technique is to isolate new strains of microorganisms and develop successful protocols for reducing metal toxicity with heavy metal tolerant species. The present study collected metal contaminated soil and characterized for pH and EC values, and heavy metal contents. The pH value was 5.80, representing slightly acidic soil, and EC value was 13.47 mS/m. ICP-AES analytical results showed that the collected soil samples were highly contaminated with various heavy metals and metalloids such as lead (183.0 mg/kg), copper (98.6 mg/kg), zinc (91.6 mg/kg), and arsenic (48.1 mg/kg), respectively. In this study, a bacterial strain, Bacillus cereus KM-15, capable of adsorbing the heavy metals was isolated from the contaminated soils by selective enrichment and characterized to apply for the bioremediation. The effects of heavy metal on the growth of the Bacillus cereus KM-15 was determined in liquid cultures. The results showed that 100 mg/L arsenic, lead, and zinc did not affect the growth of KM-15, while the bacterial growth was strongly inhibited by copper at the same concentration. Further, the ability of the bacteria to adsorb heavy metals was evaluated.

• Korean Journal of Environmental Agriculture
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• v.16 no.2
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• pp.142-148
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• 1997

This study was performed to develop the biological treatment technology of wastewater polluted with heavy metals. Heavy metal-tolerant microorganisms, such as Pseudomonas putida, P. aeruginosa, P. chlororaphis and P. stutzeri possessing the ability to accumulate cadmium, lead, zinc and copper, respectively, were isolated from industrial wastewaters and mine wastewaters polluted with various heavy metals. The effect of competing ions and metabolic inhibitors on heavy metal accumulation in the cells was investigated. Heavy metal accumulation into cells was drastically decreased in the presence of competing cation, $Al^{3+}$, and also decreased, at a lesser extent, in the presence of competing anions, $CO_3\;^{2-}$ and $PO_4\;^{2-}$. But heavy metal accumulation was not influenced generally in the presence of the other rations and anions. The accumulation of Cd, Zn or Cu by Cd-, Zn- or Cu-tolerant microorganism was remarkably decreased in the presence of metabolic inhibitors, but the accumulation of Pb by Pb-tolerant microorganism was little affected in the presence of metabolic inhibitors. These results suggested that the accumulation of Cd, Zn or Cu by Cd-, Zn- or Cu-tolerant microorganism was concerned with the biological activity depending on energy, and the accumulation of Pb by Pb-tolerant microorganism depended on not the biological activity but the physical adsorption on the cell surface. Each heavy metal-tolerant microorganism also exhibited some ability to accumulate the other heavy metals in solution containing equal concentrations of cadmium, lead, zinc and copper, when measured at 48 hours after inoculation of the microorganisms, but the accumulation rates were somewhat low as compared to the accumulation rates of heavy metal fitting to each tolerance. These results suggested that the accumulation of each heavy metal by each heavy metal-tolerant microorganism was a selective accumulation process.

• Journal of Life Science
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• v.25 no.2
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• pp.164-173
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• 2015

To investigate the effect of lactic acid bacteria on the heavy metal adsorption from internal organs and blood, lactic acid bacteria were isolated from human feces. Some strains resistant to heavy metals were selected by incubation in agar media containing each of chrome and cadmium salts. Among them, a strain named KP-3 was ultimately chosen due to its higher growth rate in selective broth medium containing the heavy metals at the concentration of 0.01%. The strain was identified as Lactobacillus sp. based on its morphological, cultural and physiological characteristics. For evaluating the ability to prevent accumulation of heavy metals by selected Lactobacillus sp. strain in vivo, Sprague Dawley rats were fed with heavy metal salts (cadmium, chrome and lead) with or without cultured whole cells for 7 days. The amounts of heavy metals accumulated in liver, kidney and blood were analyzed. As a result, chrome was accumulated to kidney mostly, and lead was frequently found in liver and kidney. Experimental group (rats fed with lactic acid bacteria) showed less accumulation of heavy metal than control group (rats fed with saline solution). The inhibition rates of heavy metal accumulation were calculated to 41.8% (Cd), 33.4% (Cr) and 44.2% (Pb). Especially, feeding lactic acid bacteria strongly reduced accumulation of cadmium in blood. The results showed that feeding Lactobacillus sp. KP-3 could prevent the bioaccumulation of heavy metals in the living body.