• Journal of Soil and Groundwater Environment
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• v.12 no.2
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• pp.27-36
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• 2007

A recent study showed that MTBE can be degraded by Fenton's Reagent (FR). The treatment of MTBE with FR, however, has a definite limitation of extremely low pH requirement (optimum pH $3{\sim}4$) that makes the process impracticable under neutral pH condition on which the ferrous ion precipitate forming salt with hydroxyl anion, which result in the diminishment of the Fenton reaction and incompatible with biological treatment. Consequently, this process using only FR is not suitable for in-situ remediation of MTBE. In order to overcome this limitation, modified Fenton process using NTA, oxalate, and acetate as chelating reagents was introduced into this study. Modified Fenton reaction, available at near neutral pH, has been researched for the purpose of obtaining high performance of oxidation efficiency with stabilized ferrous or ferric ion by chelating agent. In the MTBE degradation experiment with modified Fenton reaction, it was observed that this reaction was influenced by some factors such as concentrations of ferric ion, hydrogen peroxide, and each chelating agent and pH. Six potential chelators including oxalate, succinate, acetate, citrate, NTA, and EDTA were tested to identify an appropriate chelator. Among them, oxalate, acetate, and NTA were selected based on their remediation efficiency and biodegradability of each chelator. Using NTA, the best result was obtained, showing more than 99.9% of MTBE degradation after 30 min at pH 7; the initial concentration of hydrogen peroxide, NTA, and ferric ion were 1470 mM, 6 mM, and 2 mM, respectively. Under the same experimental condition, the removal of MTBE using oxalate and acetate were 91.3% and 75.8%, respectively. Optimum concentration of iron ion were 3 mM using oxalate which showed the greatest removal efficiency. In case of acetate, $[MTBE]_0$ decreased gradually when concentration of iron ion increased above 5 mM. In this research, it was showed that modified Fenton reaction is proper for in-situ remediation of MTBE with great efficiency and the application of chelatimg agents, such as NTA, was able to make the ferric ion stable even at near neutral pH. In consequence, the outcomes of this study clearly showed that the modified Fenton process successfully coped with the limitation of the low pH requirement. Furthermore, the introduction of low molecular weight organic acids makes the process more available since these compounds have distinguishable biodegradability and it may be able to use natural iron mineral as catalyst for in situ remediation, so as to produce hydroxyl radical without the additional injection of ferric ion.

• Journal of Technology Innovation
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• v.24 no.1
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• pp.113-142
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• 2016

T-50 exportation to Indonesia embodied an objective of governmental policy and became a catalyst accelerating the exportation of domestic defense industries. Defense industry exportation is recognized as a new growth engine creating economic interests and it became an important policy of the government. This study will suggest an effective direction for the support policy of the defense industry exportation through analysis on factors behind the success of the T-50 exportation to indonesia in the view of policy network. Policy network theory has its efficacy and workability in analyzing what kind of results are yielded from each policy actor's attributes and their interaction during the execution and establishment of the support policy for the defense exportation. The type of policy network of the T-50 exportation to Indonesia was a policy community. Many governmental ministries, defense industry which is the group of interest, and experts from the research institutes have established the Korea Defense Trade Support Center(KODITS) for accomplishing common policy goal with mutually shared sentiment, and sought for a strategy for the success of the defense industry exportation having official and unofficial meeting centering around the KODITS. Although there were oppositions and conflicts among major actors, though forming a cooperative relationship among majority of the actors, policy-wise decision making for the exportation of the T-50 to Indonesia was efficiently carried out. The cooperative relationship was the key in the success of the T-50 exportation. Considering that the policy community from cooperative mutual interaction is efficient in reaching the goal of the defense industry exportation support policy, this study suggests operating government-wise temporary Task Force(TF) to succeed in big exportation projects such as the T-X exportation to the U.S. In addition, institutional and procedural supplementation such as regular meetings among the head of related governmental ministries and etc. are required in order to enhance the mutually cooperative relationship withing the TF.