• Journal of the Korean Chemical Society
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• v.26 no.5
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• pp.340-348
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• 1982

The presence of 10 mole percent triphenyl borate accelerated dramatically the rate of reduction of structurally different sulfoxides with borane in tetrahydrofuran at room temperature, compared to the slow reduction with borane itself. Tetramethylene sulfoxide underwent complete reduction in 5 min and diethyl sulfoxide, dibenzyl sulfoxide and benzylphenyl sulfoxide were reduced quantitatively within 1h, whereas the reduction of diphenyl sulfoxide was rather slow, giving diphenyl sulfide in 90% yield in 24h. Boron trifluoride etherate and triethyl borate were less effective than triphenyl borate. A possible mechanism is presented.

• Journal of the Korean Chemical Society
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• v.18 no.5
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• pp.363-367
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• 1974

Approximate rate and stoichiometry of the reaction of ten compounds which contain functional group such as nitrile, nitro, halogen and one of these functional group together with a carbonyl group by the two phase reduction were tested at room temperature. Nitrile, nitro and halogen were all inert under these condition. Therefore selective reduction of carbonyl group in the presence of these group were examined. Thus m-nitrobenzaldehyde, m-nitroacetophenone, p-bromoacetophenone and p-cyanobenzaldehyde were reduced to corresponding alcohols in excellent yields, 95∼100 %.

• Journal of the Korean Chemical Society
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• v.30 no.1
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• pp.105-108
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• 1986

Ultrasound(50KHz) accelerated the reduction reaction of aromatic nitro group to aromatic amino group in high yield with mild condition using iron, hydrazine hydrate and activated carbon under room temperature and atmospheric pressure. The activated carbon has been used as a mixing material to highly active metals. However, aromatic nitro group does not reduce at all only with iron-hydrazine witliout adding activated carbon even under ultrasonic irradiation. We also discovered that the conversion yield from nitro group to amino group is directly proportional to the amount of activated carbon.

• Journal of Soil and Groundwater Environment
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• v.9 no.2
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• pp.11-19
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• 2004

Chlorinated and nitroaromatic compounds are non-degradable substances that are extremely toxic and are known to be carcinogens and mutation causing agents. Moreover, the half-lives of substances such as carbon tetrachloride, hexachloroethane and nitroaromatic compounds are several decades. In this study, the optimal conditions to detoxify chlorinated compounds by the reductive degradation were investigated. The following results were obtained in the reductive degradation of CCl$_4$, C$_2$Cl$\_$6/, C$_2$HCl$\_$5/, C$_2$Cl$_4$, and C$_2$HCl$\_$5/ by using Fe, FeS and FeS$_2$ as mediators. CCl$_4$ was reduced to CH$_2$Cl$_3$ and CH$_2$Cl$_2$in anaerobic conditions when FeS was used as a mediator. While the reduction of CCl$_4$ to CHCl$_3$ was rapidly proceeded, the reduction of CHCl$_3$ to CH$_2$Cl$_2$ was occurred slowly. Further reduction to CH$_3$Cl was not observed. Unlike CCl$_4$, C$_2$Cl$\_$6/ was degraded to C$_2$HCl$\_$5/, C$_2$Cl$_4$. C$_2$HCl$_3$ and cis-1,2-C$_2$H$_2$Cl$_2$ by complicated pathways such as hydrogenolysis, dehalo-elimination and dehydrohalogenation. A small amount of C$_2$HCl$\_$5/ was detected only in the early stages of the reduction. However, majority of the C$_2$Cl$\_$6/ was reduced to C$_2$Cl$_4$. cis-1,2-C$_2$H$_2$C1$_2$ was the only product among other possible isomers.

• Journal of the Korean Ceramic Society
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• v.39 no.7
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• pp.657-662
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• 2002

The reduced ferrites, reduced NiF $e_2$ $O_4$ and CuF $e_2$ $O_4$, by C $H_4$ were applied to $CO_2$ decomposition to avoid the greenhouse effects. At the reduction reaction above $700^{\circ}C$, $H_2$ and CO were generated by partial oxidation of C $H_4$ After the reduction reaction up to 80$0^{\circ}C$, the spinel structure ferrites changed to mixture of the oxygen deficient iron oxide (Fe $O_{(1-{\delta})}$(0$\leq$$\delta$$\leq$1)) and the metallic Ni or Cu. The rate and quantity of $CO_2$ decomposition with reduced CuF $e_2$ $O_4$ were larger than those with reduced NiFe $O_4$. The $CO_2$ gas was decomposed by oxidation of the oxygen deficient iron oxide. The metallic Cu and Ni were not oxidized and remained in a metallic state up to 80$0^{\circ}C$. The $CO_2$ decomposition reaction with the reduced ferrite by C $H_4$ gas is excellent process preparing useful gas such as $H_2$and CO and decomposing $CO_2$ gas.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.11
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• pp.1146-1153
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• 2008

Numerical simulation was carried out to study the trichloroethylene (TCE) degradation by permeable reactive barrier (PRB), and revealed the effect of concentration of TCE, iron medium mass, and concentration of iron-reducing bacteria (IRB). Newly developed model was based on axial dispersion reactor model with chemical and biological reaction terms and was implemented using MATLAB ver R2006A for the numerical solutions of dispersion, convection, and reactions over column length and elapsed time. The reaction terms include reactions of TCE degradation by zero-valent iron (ZVI, Fe$^0$) and ferrous iron (Fe$^{2+}$). TCE concentration in the column inlet was maintained as 10 mg/L. Equation for Fe$^0$ degradation includes only TCE reaction term, while one for Fe$^{2+}$ has chemical and biological reaction terms with TCE and IRB, respectively. Two coupled equations eventually modeled the change of TCE concentration in a column. At Fe$^0$ column, TCE degradation rate was found to be more than 99% from 60 hours to 235 hours, and declined to less than 1% in 1,365 hours. At the Fe$^{2+}$ and IRB mixed column, TCE degradation rate was equilibrated at 85.3% after 210 hours and kept it constant. These results imply that the ferrous iron produced by IRB has lowered the TCE degradation efficiency than ZVI but it can have higher longevity.http://kci.go.kr/kciportal/ci/contents/ciConnReprerSearchPopup.kci#

• Resources Recycling
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• v.7 no.3
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• pp.27-35
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• 1998

EAF dust generated from electric arc steelmaking process is classified as "hazardous" materials by tbe environmental regulation because of the existence of water leachable heavy metals such as Fe, Zn, Pb, and Cd. However, Fe and Zn among t the elements in the dust can be recovered to high valuable materials by applying a proper process. Therefore, in order to study t the possibility of recovery of iron from EAF dust, the effect oE carbon content and basicity, of synthesized EAF dust on the reduction rate of iron oxide was studied. Experimental results are as follows: TIle softening and melting temperature of the slag w was illcreased with increasing carbon addition amount [or carbon reduction eqUIvalent. At the carbon addition amount of 100% for carbon reduction equivalent and basicity of 1.7, reduction rate of $Fe_2O$ in the slag was the highest. The reaction order fur reduction of $Fe_2O$ by carbon was nearly first order.

• Resources Recycling
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• v.15 no.4 s.72
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• pp.44-51
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• 2006

Most electric arc furnace dust (EAFD) treatment processes to recover zinc from EAFD employ carbon as a reducing agent for the zinc oxide in the EAFD. In the present work, the reduction reaction of zinc oxide with carbon in the present of iron oxide was kinetically studied. The experiments were carried out at temperatures between 1173 K and 1373 K under nitrogen atmosphere using a weight-loss technique. From the experimental results, it was concluded that adding the proper amount of iron oxide to the reactant accelerates the reaction rate of zinc oxide with carbon. This is because iron oxide in the reduction reaction of zinc oxide with carbon promotes the carbon gasification reaction. The spherical shrinking core model for a surface chemical reaction control was found to be useful in describing kinetics of the reaction over the entire temperature range. The reaction has an activation energy of 53 kcal/mol (224 kJ/mol) for ZnO-C reaction system, an activation energy of 42 kcal/mol (175 kJ/mol) for $ZnO-Fe_{2}O_{3}-C$ reaction system, and an activation energy of 44 kcal/mol (184 kJ/mol) for ZnO-mill scale-C reaction system.

• Economic and Environmental Geology
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• v.42 no.5
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• pp.487-494
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• 2009

The purpose of this study was to investigate the feasibility of As(V) reduction by aqueous Fe(II), and subsequent As(III) immobilization by the precipitation of As(III) incorporated magnetite-like material [i.e., co-precipitation of As(III) with Fe(II) and Fe(III)]. Experimental results showed that homogeneous As(V) reduction did not occur by dissolved Fe(II) at various pH values although the thermodynamic calculation was in favor of the redox reaction between As(V) and Fe(II) under the given chemical conditions. Similarly, no heterogeneous reduction of sorbed As(V) by sorbed Fe(II) was observed using synthetic iron (oxy)hydroxide (Goethite, ${\alpha}$-FeOOH) at pH 7. Experimental results for the effect of As(V) on the oxidation of Fe(II) by dissolved oxygen showed that As(V) inhibited the oxidation of Fe(II). These results indicate that As(V) could be stable in the presence of Fe(II) under the anoxic or subsurface environments.

• Proceedings of the Korea Association of Crystal Growth Conference
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• 1997.10a
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• pp.63-67
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• 1997

환원확산법은 저렴한 Nd 산화물을 환원제를 이용하여 환원시키고 환원된 Nd가 Fe, FeB와 확산하여 주상인 Nd$_2$Fe14B가 만들어지는 공정으로 환원제로 사용된 CaO나 미반응 Ca 및 잔존 산소함량을 조절하는데 어려움이 있어 아직까지는 상업되지 못하고 있는 실정이다. 본 연구에서는 환원확산법을 이용하여 Nd-Fe-B계 영구자석에 사용될 미세분말을 제조하고 그 자기적 특성을 관찰하였다.