• Journal of Korea Foundry Society
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• v.28 no.3
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• pp.105-112
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• 2008

• Journal of Korean Society for Atmospheric Environment
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• v.23 no.5
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• pp.575-584
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• 2007

The adsorption capability of iron phthalocyanine derivatives were investigated by means of X-ray diffractometor (XRD), IR (infrared) spectroscopy, scanning electron microscopy (SEM) and temperature programmed desorption (TPD). According to TPD results, iron phthalocyanine derivatives showed two desorption peaks at low temperature ($100{\sim}150^{\circ}C$) and high temperature ($350{\sim}400^{\circ}C$) indicating that there were two kinds of acidities. Tetracarboxylic iron phthalocyanine (Fe-TCPC) have a stronger desorption peak (chemical adsorption) at the high temperature and a weaker desorption peak (physical adsorption) at the low temperature than iron phthalocyanine (Fe-PC). The specific surface areas of Fe-TCPC and Fe-PC were $26.46\;m^2/g\;and\;11.77\;m^2/g$, respectively. The pore volumes of Fe-TCPC and Fe-PC were $0.14\;cm^3/g\;and\;0.06\;cm^3/g$, respectively. The adsorption capability of triethyl amine calculated by breakthrough curve at 220 ppm of equilibrium concentration was 29.2 mmoL/g for Fe-TCPC and 0.8 mmoL/g for Fe-PC. The removal efficiency of dimethyl sulfide of Fe-TCPC and Fe-PC in batch experiment of 225 ppm of initial concentration were 44.9% and 28.9%, respectively. The removal efficiency of trimethyl amine of Fe-TCPC and Fe-PC in batch experiment of 118 ppm of initial concentration were approximately 100.0% and 33.9%, respectively.

• Microbiology and Biotechnology Letters
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• v.42 no.2
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• pp.131-138
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• 2014

While coupling wastewater treatment with microalgal bioenergy production is very promising, new approaches are needed to enhance microalgal growth and lipid accumulation in wastewater. Therefore, this study investigated the effect of iron on the growth, nutrient removal, and lipid accumulation of Scenedesmus sp. LX1 in both artificial wastewater and domestic secondary effluents. When increasing the iron concentration from 0 to 2 mg/l in the artificial wastewater, the biomass production of Scenedesmus sp. LX1 increased from 0.17 to 0.54 g/l; the nitrogen and phosphorus removal efficiency increased from 15.7% and 80.6% to 97.0% and 99.2%, respectively; and the lipid content was enhanced 84.2%. The relationship between the carrying capacity/maximal population growth rate of Scenedesmus sp. LX1 and the initial iron concentration were also in accordance with the Monod model. Furthermore, when increasing the iron concentration to 2 mg/l in four different domestic secondary effluent samples, the lipid content and lipid production of Scenedesmus sp. LX1 was improved by 17.4-33.7% and 21.5-41.8%, respectively.

• Journal of Soil and Groundwater Environment
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• v.20 no.6
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• pp.117-126
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• 2015

Reductive degradation of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) by nanoscale zero-valent iron (nZVI) was investigated to evaluate the feasibility of using it for in-situ groundwater remediation. Batch experiments were conducted to quantify the kinetics and efficiency of RDX removal by nZVI, and to determine the effects of pH, dissolved oxygen (DO), and ionic strength on this process. Experimental results showed that the reduction of RDX by nZVI followed pseudo-first order kinetics with the observed rate constant (k_obs) in the range of 0.0056-0.0192 min⁻¹. Column tests were conducted to quantify the removal of RDX by nZVI under real groundwater conditions and evaluate the potential efficacy of nZVI for this purpose in real conditions. In column experiment, RDX removal capacity of nZVI was determined to be 82,500 mg/kg nZVI. pH, oxidation-reduction potential (ORP), and DO concentration varied significantly during the column experiments; the occurrence of these changes suggests that monitoring these quantities may be useful in evaluation of the reactivity of nZVI, because the most critical mechanisms for RDX removal are based on the chemical reduction reactions. These results revealed that nZVI can significantly degrade RDX and that use of nZVI could be an effective method for in-situ remediation of RDX-contaminated groundwater.

• Progress in Superconductivity and Cryogenics
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• v.18 no.1
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• pp.28-32
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• 2016

There are a few thousand abandoned metal mines in South Korea. The abandoned mines cause several environmental problems including releasing acid mine drainage (AMD), which contain a very high acidity and heavy metal ions such as Fe, Cu, Cd, Pb, and As. Iron oxides can be formed from the AMD by increasing the solution pH and inducing precipitation. Current study focused on the formation of iron oxide in an AMD and used the oxide for adsorption of heavy metals. The heavy metal adsorbed iron oxide was separated with a superconducting magnet. The duration of iron oxide formation affected on the type of mineral and the degree of magnetization. The removal rate of heavy metal by the adsorption process with the formed iron oxide was highly dependent on the type of iron oxide and the solution pH. A high gradient magnetic separation (HGMS) system successfully separated the iron oxide and harmful heavy metals.

• Journal of Applied Biological Chemistry
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• v.61 no.4
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• pp.383-389
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• 2018

Degradation of the insecticide O,O-diethyl O-3,5,6-trichloro-2-pyridyl phosphorothioate (chlorpyrifos) in aqueous solution was investigated using iron salts and potassium persulfate during ZVI treatment through a series of batch experiments. The degradation rate of chlorpyrifos increased with increases in the concentrations of iron salts and potassium persulfate in the aqueous system. Ferric chloride was found to be the most effective iron salt for the ZVI-mediated degradation of chlorpyrifos in aqueous solution. Further, the iron salts tested could be arranged in the following order in terms of their effectiveness: $FeCl_3$> $Fe_2(SO_4)_3$> $Fe(NO_3)_3$. The persulfate-ZVI system could significantly degrade chlorpyrifos present in the aqueous medium. This revealed that chlorpyrifos degradation by treatment with $Fe^0$ was promoted on adding ferric chloride and potassium persulfate. The kinetics of the degradation of chlorpyrifos by persulfate-amended $Fe^0$ was higher than that for iron-salt-amended $Fe^0$. This suggests that using a sequential $Fe^0$ reduction-ferric chloride or $Fe^0$ reduction-persulfate process may be an effective strategy to enhance the removal of chlorpyrifos in contaminated water.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.09a
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• pp.395-398
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• 2003

Geosynthetic Clay Liners(GCLs) have been widely used as hydraulic barrier in landfills and remediation projects of contaminated sites. The aim of this research is to modify GCLs for effective removal of contaminants. We perform the free swell test, hydraulic conductivity test, and contaminants (TCE, hexavalent chromium, and nitrate) removal test on the bentonite-ZVI mixture with various ZVI content. As the ZVI content increased, contaminants removal efficiencies and swell volume increased, and hydraulic conductivity decreased.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.09a
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• pp.87-90
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• 2003

This research examines the feasibility of using laboratory-synthesized nano scale zero-valent iron particles to remove arsenic from aqueous phase. Batch experiments were performed to determine arsenic sorption rates as a function of the nano scale zero-valent iron solution concentration. Rapid adsorption of arsenic was achieved with the nano scale zero-valent iron. Typically 1 mg $L^{-1}$ arsenic (III) was adsorbed by 5 g $L^{-1}$ nano scale zero-valent iron below the 0.01 g $L^{-1}$ concentration within 7min. The kinetics of the arsenic sorption followed pseudo-first-order reaction kinetics. Observed reaction rate constants ( $K_{obs}$) varied between 11.4 to 129.0 $h^{-1}$ with respect to different concentrations of nano scale zero-valent iron. A variety of analytical techniques were used to study the reaction products including HGAAS (hydride generator atomic adsorption spectrophotometer), SEM (scanning electron microscopy) and TEM (transmission electron microscopy). Our experimental results suggest novel method for efficient removal of arsenic Iron groundwater.r.

• Journal of Korean Society of Water and Wastewater
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• v.20 no.4
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• pp.487-498
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• 2006

The oxidation processes of metal catalysis were practically applied into the flexographic inks wastewater treatment to derive the most effective and economical system among all the processes of iron-salts coagulation, iron-catalyzed air oxidation, and coagulation followed by biological treatment. The iron concentration and pH were optimized as $2.8{\times}10^{-3}mol$ and 5.5~6.0, respectively, for all the oxidation processes. At the optimal reaction conditions, the removal efficiencies of $TCOD_{Mn}$ and Color were as follows for the respective process: i) 75% $TCOD_{Mn}$ and 77% Color removals for iron-salts coagulation, ii) 91% TCODMn and 90% Color removals for iron-catalyzed air oxidation, iii) 74~92% $TCOD_{Mn}$ and 81~90% Color removals for coagulation followed by biological treatment. Based on the economical and technological aspects, iron-catalyzed air oxidation was confirmed as the most effective process in the treatment of industrial wastewater.

• Journal of Korean Society on Water Environment
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• v.31 no.2
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• pp.209-215
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• 2015

The purpose of this study is to evaluate the characteristic of the iron oxide carrier for removing arsenic contained in the groundwater. 4 types of iron oxide carrier used in the study is iron oxide coated sand carrier (IOCSC), iron oxide coated zeolite carrier (IOCZC), iron oxide plasticity carrier (IOPC) and platinum iron oxide plasticity carrier (PIOPC). The results of this study, IOPC is showed high arsenic adsorption strength and the maximum amount of adsorption than the IOCC. Based on the results of the arsenic adsorption characteristic, by using IOCC was conducted to column test. As a result, PIOPC is showed a high arsenic adsorption amount than IOPC, it was found that the time required to reach the breakthrough point is also extended. Therefore it is determined that stably compliance with water quality standards enhanced drinking water when using the PIOPC.