Fe-Mn 입자의 안정화를 통한 인산염 효율 향상

강서연,신정우,안병렬 대한상하수도학회 2023 상하수도학회지 Vol.37 No.6

The binary oxide adsorbent using Fe and Mn (Fe-Mn) has been prepared by precipitation method to enhance the removal of phosphate. Different amounts of chitosan, a natural organic polymer, were used during preparation of Fe-Mn as a stabilizer to protect an aggregation of Fe-Mn particles. The optimal amount of chitosan has been determined considering the separation of the Fe-Mn particles by gravity from solution and highest removal efficiency of phosphate (Fe-Mn10). The application of Fe-Mn10 increased removal efficiency at least 15% compared to bare Fe-Mn. According to the Langmuir isotherm model, the maximum uptake (q m ) and affinity coefficient (b) were calculated to be 184 and 240 mg/g, and 4.28 and 7.30 L/mg for Fe-Mn and Fe-Mn10, respectively, indicating 30% and 70% increase. The effect of pH showed that the removal efficiency of phosphate was decrease with increase of pH regardless of type of adsorbent. The enhanced removal efficiency for Fe-Mn10 was maintained in entire range of pH. In the kinetics, both adsorbents obtained 70% removal efficiency within 5 min and 90% removal efficiency was achieved at 1 h. Pseudo second order (PSO) kinetic model showed higher correlation of determination (R 2 ), suggesting chemisorption was the primary phosphate adsorption for both Fe-Mn and Fe-Mn10.

Ni-Mn-Co-Fe 산화물 후막 NTC 서미스터의 제조 및 전기적 특성

박경순,방대영,윤성진,최병현,Park, Kyeong-Soon,Bang, Dae-Young,Yun, Sung-Jin,Choi, Byung-Hyun 한국세라믹학회 2002 한국세라믹학회지 Vol.39 No.10

스크린 인쇄법을 이용하여 알루미나 기판위에 Ni-Mn-Co-Fe 산화물 후막을 코팅하였다. 후막의 조성과 소성온도를 변화시키며 미세구조와 전기적 특성을 연구하였다. 1150${\circ}C$에서 소성한 시편의 경우 모든 구성 원소가 후막에 균일하게 분포되어 있었다. 그러나, 1200${\circ}C$와 1225${\circ}C$에서 소성한 시편의 경우 Co 원소는 후막에 균일하게 분포되어 있으나 Mn, Ni 및 Fe 원소는 불균일하게 분포되어 있어 Mn 원소의 농도가 큰 영역과 Ni과 Fe 원소의 농도가 큰 영역이 존재하였다. 제조한 모든 후막 NTC 서미스터는 NTC 서미스터의 특성인 로그 저항(log R)과 온도의 역수(1/T) 사이에서 직선적인 관계를 보였다. $(Ni_{1.0}Mn_{1.0}Co_{1-x}Fe_x)O_4$ (0.25${\le}$x${\le}$1.0)와 $(Ni_{0.75}Mn_{1.25}Co_{1-x}Fe_x)O_4$ (0.25${\le}$x${\le}$0.75) 서미스터의 저항, B 정수 및 활성화 에너지는 Fe2O3 함량이 증가함에 따라 증가하였다. Ni-Mn-Co-Fe oxide thick films were coated on an alumina substrate by screening printing technique. The microstructure and electrical properties of the thick films, as a function of composition and sintering temperature, were investigated. The components of the NTC thick films sintered at 1150${\circ}C$ were distributed homogeneously. On the other hand, in the case of the NTC thick films sintered at 1200 and 1250${\circ}C$, Co element was distributed homogeneously, but Ni, Mn and Fe elements were distributed heterogeneously, resulting in the formation of Ni rich and Mn-Fe rich regions. All the thick film NTC thermistors prepared showed a linear relationship between log resistance (log R) and the reciprocal of absolute temperature (1/T), indicative of NTC characteristics. At a given NiO and $Mn_3O_4$ content, the resistance, B constant and activation energy of $(Ni_{1.0}Mn_{1.0}Co_{1-x}Fe_x)O_4$ (0.25${\le}$x${\le}$0.75) and $(Ni_{0.75}Mn_{1.25}Co_{1-x}Fe_x)O_4$ (0.25${\le}$x${\le}$0.75) thermistors increased with increasing $Fe_2O_3$ content.

토양조건에 따른 고추와 토마토의 철 및 망간 흡수특성

이주영(Ju-Young Lee),성좌경(Jwa-Kyung Sung),박재홍(Jae-Hong Park),이수연(Su-Yeon Lee),박성용(Seong-Yong Park),이예진(Ye-Jin Lee),김태완(Tae-Wan Kim),송범헌(Beom-Heon Song),장병춘(Byoung-Choon Jang) 한국토양비료학회 2009 한국토양비료학회지 Vol.42 No.3

토양을 침지한 후 배수, 통기 및 침지를 조합한 처리에서 토양의 Eh와 수분함량을 조사함과 아울러 고추에 대하여 토양단독, 토양+상토+바로크의 혼용처리와 토마토에 대하여 토양단독, 토양+볏짚, 토양+퇴비, 토양+Aeration의 혼용처리를 하여 식물체 엽 중Fe과 Mn흡수 특성을 구명하기 위하여 포트조건에서시험을 수행하였다. 토양 환원처리 후 Eh와 토양 수분함량을 조사한 결과, 배수와 Aeration을 처리한 후 72시간부터 토양을 산화상태로 변화시켰으며, 토양 수분함량은 처리와동시에 감소하기 시작하였다. 정식 후 30일에 채취한고추 식물체의 엽 중 Fe와 Mn을 분석한 결과, 토양단독처리구의 식물체 엽 중 Mn은 토양 산성에 의해 과잉 흡수(1,324 mg kg<SUP>-1</SUP>) 되었으며, 길항작용에 의해 Fe 흡수장애가 나타났다. 혼합 토양 처리구에서의 식물체 엽 중 Mn 함량(947 mg kg<SUP>-1</SUP>)은 토양 단독 처리 구에 비해 적었으나 Fe 흡수장애를 야기하였다. 정식후 60일에 채취한 토마토 식물체의 엽 중 Fe와 Mn을 분석한 결과에서 Fe 함량은 토양(50%) + 퇴비 (50%)처리에서 가장 높았고, Mn 함량은 토양 단독처리에서 가장 높게 나타났다. 본 시험의 결과로 볼때 작물의 생육은 Eh 및 공극률이 토양 수분함량과 밀접한 관계가 있으며, 토양이 산성상태일 때 식물체는 토양으로부터 Mn을 우선적으로 흡수하며, 이는Fe 결핍을 야기하는 것으로 판단되었다. This experiment was performed to understand the relationship between uptake of Fe and Mn by plants, red pepper and tomato, and soil physico-chemical properties under different soil conditions at an environmentally controlled chamber in NAAS(National Academy of Agricultural Science) in 2008. After the dipping for 3 days, four treatments, dipping, dipping+aeration, drainage, drainage+aeration, were set up to investigate the changes in soil redox potential and moisture content. Drainage+aeration changed soil to the oxidation condition from 72 hrs of treatment, and soil moisture content was immediately reduced after treatment. Uptake of Fe and Mn of red pepper was investigated with two treatments, soil only and the mixed[soil(50%) : bed soil(35%) : bark(15%)]. Red pepper leaves taken at 30 days after treatment absorbed excessively Mn from the treatment of soil only and the mixed, and thus uptake of iron was strongly reduced. Also, uptake pattern of Fe and Mn of tomato was examined with four treatment, soil only, soil(50%) + rice straw(50%), soil(50%) + compost(50%) and soil + aeration. Contents of Fe and Mn in tomato leaves was measured at 60 days after treatment. Fe content was the greatest in soil(50%) + compost(50%) whereas Mn content was the highest in soil only. As a result of this experiment, plant growth was stronger influenced by soil moisture content than redox potential or porosity, and the oxidation status of soil was likely to promote that plant predominantly absorbed Mn from soil and thus resulted in Fe deficiency.

활성화된(Fe_1-xMn_x)₃O_4-_δ과 (Fe_1-xCo_x)₃O_4-_δ의 이산화탄소 분해 특성

박원식,오경환,이상인,서동수,Park, Won-Shik,Oh, Kyoung-Hwan,Rhee, Sang-In,Suhr, Dong-Soo 한국재료학회 2013 한국재료학회지 Vol.23 No.4

Activated magnetite ($Fe_3O_{4-{\delta}}$) has the capability of decomposing $CO_2$ proportional to the ${\delta}$-value at comparatively low temperature of $300^{\circ}C$. To enhance the $CO_2$ decomposition capability of $Fe_3O_{4-{\delta}}$, $(Fe_{1-x}Co_x)_3O_{4-{\delta}}$ and $(Fe_{1-x}Mn_x)_3O_{4-{\delta}}$ were synthesized and then reacted with $CO_2$. $Fe_{1-x}Co_xC_2O_4{\cdot}2H_2O$ powders having Fe to Co mixing ratios of 9:1, 8:2, 7:3, 6:4, and 5:5 were synthesized by co-precipitation of $FeSO_4{\cdot}7H_2O$ and $CoSO_4{\cdot}7H_2O$ solutions with a $(NH_4)_2C_2O_4{\cdot}H_2O$ solution. The same method was used to synthesize $Fe_{1-x}Mn_xC_2O_4{\cdot}2H_2O$ powders having Fe to Mn mixing ratios of 9:1, 8:2, 7:3, 6:4, 5:5 with a $MnSO_4{\cdot}4H_2O$ solution. The thermal decomposition of synthesized $Fe_{1-x}Co_xC_2O_4{\cdot}2H_2O$ and $Fe_{1-x}Mn_xC_2O_4{\cdot}2H_2O$ was analyzed in an Ar atmosphere with TG/DTA. The synthesized powders were heat-treated for 3 hours in an Ar atmosphere at $450^{\circ}C$ to produce activated powders of $(Fe_{1-x}Co_x)_3O_{4-{\delta}}$ and $(Fe_{1-x}Mn_x)_3O_{4-{\delta}}$. The activated powders were reacted with a mixed gas (Ar : 85 %, $CO_2$ : 15 %) at $300^{\circ}C$ for 12 hours. The exhaust gas was analyzed for $CO_2$ with a $CO_2$ gas analyzer. The decomposition of $CO_2$ was estimated by measuring $CO_2$ content in the exhaust gas after the reaction with $CO_2$. For $(Fe_{1-x}Mn_x)_3O_{4-{\delta}}$, the amount of $Mn^{2+}$ oxidized to $Mn^{3+}$ increased as x increased. The ${\delta}$ value and $CO_2$ decomposition efficiency decreased as x increased. When the ${\delta}$ value was below 0.641, $CO_2$ was not decomposed. For $(Fe_{1-x}Co_x)_3O_{4-{\delta}}$, the ${\delta}$ value and $CO_2$ decomposition efficiency increased as x increased. At a ${\delta}$ value of 0.857, an active state was maintained even after 12 hours of reaction and the amount of decomposed $CO_2$ was $52.844cm^3$ per 1 g of $(Fe_{0.5}Co_{0.5})_3O_{4-{\delta}}$.

Effect of Fe and Mn Content on the Microstructures and Tensile Behaviour of AlSi7Cu3 Alloy: Thermal Analysis and Tensile Tests

Zaidao Li,Nathalie Limodin,Amina Tandjaoui,Philippe Quaegebeur,Xiangzhen Zhu,David Balloy 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.9

The present study was performed on two AlSi7Cu3 alloys with different Fe and Mn contents (standard alloy and high-Fe/Mnalloy). The evolution of microstructures during solidification of the standard AlSi7Cu3 alloy was investigated by thermalanalysis and interrupted quenching test. The effect of Fe and Mn content on the solidification reaction and sequence werestudied. The results show that increasing the Fe and Mn content changes the precipitation sequence of the iron-intermetallicα-Al15 (Fe,Mn)3Si2 and β-Al5FeSi, leading to the precipitation of α + β phases at a higher temperature. Microstructural characterizationswere also performed on the fully solidified alloys to study the effect of Fe and Mn content on the microstructureof AlSi7Cu3 alloy. Fe and Mn were found to promote the formation of Fe-intermetallics. With the increase of Fe/Mn content,Fe-intermetallics increased in both size and amount, while more small pores (Feret diameter < 200 μm) were also introduced. 3D networks of α-Al15(Fe,Mn)3Si2 and β-Al5FeSi phases were revealed by Lab X-ray Computed Tomography, however, it isdifficult to perform a quantitative analysis of the respective volume fraction of α-Al15(Fe,Mn)3Si2 and β-Al5FeSi phase fromtheir 3D morphology. Monotonic tensile tests on both alloys show the mechanical properties of the studied alloys were notsensitive to the Fe/Mn content, while the fractography analysis reveals that cracks growth and final fracture under monotonicload are more prone to occur through the eutectic Si, Al2Cuphases and iron-intermetallics than through aluminium matrix.

F344 rats를 이용 망간 및 철 화합물의 체내 흡수와 생식기 및 운동성에 미치는 영향

김현영 ( Hyeon Yeong Kim ),이성배 ( Sung Bae Lee ),한정희 ( Jeong Hee Han ),최성봉 ( Sung Bong Choi ),강민구 ( Min Gu Kang ),이채관 ( Chae Kwan Lee ) 한국산업위생학회 2007 한국산업보건학회지 Vol.17 No.3

This study aimed to examine the harmful effects of Mn and Fe, which may be generated as dust or fume in the industrial sites, on the body and genital organs by their inhalation. It is intended to find the characteristics and differences of the hazardousness by inhaling a single and the mixed materials of Mn and Fe. Male F344 rats were divided into the control group and 3 exposed groups on the basis of the test material compound (Mn 1.5 mg/㎥ Mn 1.5 and Fe 3.0 mg/㎥, Fe 3.0 mg/㎥). The 4 groups were divided into 4 subgroups again on the basis of the exposure period (4 and 13 weeks) and the recovery period (4 and 13 weeks). The exposure condition was 6 hours a day, 5 days a week for the whole body. Clinical tests including changes in weight and feed rate, blood biochemical test, motility change, changes in the number and the amount of spermatozoon (sperm count), daily sperm production (DSP), deformity test of spermatozoon and changes in the accumulation of Mn and Fe in blood and internal organs were performed. Motility was reduced by Mn exposure. Especially, the effect of Mn was exposure period responsible. By mixing with Fe, no significant change in motility Mn and Fe accumulation in organs was observed. Sperm count and daily sperm production (DSP) were decreased by Mn. Additional effect like the reduction of sperm count and DSP, and delayed restoration of sperm count and DSP during the recovery period were observed in the mixed exposure group. These results indicate that Mn and Fe may affect the motility reduced and has male reproductive toxicity. Mixed exposure of Mn and Fe lead to synergic effects on the male reproductive toxicity.

Bi(Fe_{0.9}Mn_{0.1})O_{3} 박막의 강유전 및 자기 특성

도달현 한국물리학회 2014 새물리 Vol.64 No.6

Bi(Fe_{0.9}Mn_{0.1})O_{3} (BFMO) thin films were prepared on Pt(111)/Ti/SiO_{2}/Si substrates by using a pulsed laser deposition method. The crystal structure, the oxidation states of the Mn and the Fe ions, and the ferroelectric and the magnetic properties were investigated. There was no changes in the crystal structure of the BFMO thin films compared to the BiFeO_{3} (BFO) thin films. According to the X-ray photoelectron spectroscopy results, Mn²+, Mn³+, Mn⁴+ ions coexisted in the BFMO thin films. Also, the reduced volume fraction of Fe²+ ions, compared to that in BFO thin films, was confirmed. Although ferroelectric hysteresis loops were not observed in the BFMO thin films at low frequencies hysteresis loops were observed at high frequencies. The remnant polarization (2P_{r}) of the BFMO thin film was 156 μC/cm² measured under a 10 kHz voltage pulse. The saturation magnetization (M_{s}) of the BFMO thin film was 4.7 emu/cm³. The magnetic hysteresis loops of the BFMO thin films were similar to these of the BFO thin films. 펄스 레이저 증착법을 이용하여 Pt(111)/Ti/SiO_{2}/Si 기판 위에 Bi(Fe_{0.9}Mn_{0.1})O_{3} (BFMO) 박막을 제작하여 Mn 치환에 따른 결정구조, Mn 및 Fe의 산화수, 강유전 및 자기 특성을 연구하였다. X-선 회절 측정 결과에 의하면, BiFeO_{3} (BFO) 박막과 비교해서, Mn의 치환으로 인한 결정구조에서의 큰 변화는 확인할 수 없었다. BFMO 박막에는 Mn²+, Mn³+, Mn⁴+가 동시에 존재하는 것을 확인하였으며, 순수한 BFO 박막과 비교해서 Fe²+의 양이 줄어들었음을 확인하였다. 순수한 BFO 박막과 비교해서, BFMO 박막의 강유전 특성은 낮은 주파수 영역에서는 도체의 특성을 보인 반면, 높은 주파수 영역에서는 BFO 박막과 유사한 강유전 이력곡선을 얻을 수 있었다. 10 kHz에서 측정된 BFMO 박막의 잔류분극(P_{r})은 2P_{r} = 156 μC/cm² 이었다. 포화 자화값(M_{s})은 4.7 emu/cm³로 Mn의 치환에 따른 자기 특성에서의 변화는 관찰할 수 없었으며, BFO 박막에서 관찰되는 자기 이력곡선과 유사한 특성을 보였다.

고압 금형 주조용 Al-4 wt%Mg-0.9 wt%Si계 합금의 인장특성에 미치는 Fe, Mn함량의 영향

김헌주 ( Heon Joo Kim ) 한국주조공학회 2013 한국주조공학회지 Vol.33 No.3

Effect of Fe and Mn contents on the tensile properties of Al-4 wt%Mg-0.9 wt%Si alloy system has been studied. Common phases of Al-4 wt%Mg-0.9 wt%Si alloy system were α-Al, Mg2Si, α-Al12(Fe,Mn)3Si and β-Al5FeSi. As Fe content of Al-4 wt%Mg-0.9 wt%Si alloy system increased from 0.15 wt% to above 0.3 wt%, β-Al5FeSi compound appeared. When Mn content of the alloy increased from 0.3 wt% to 0.5 wt%, morphology of plate shaped β-Al5FeSi compound changed to chinese script α-Al12(Fe,Mn)3Si. As Fe content of Al-4 wt%Mg-0.9 wt%Si-0.3 wt%Mn alloy increased from 0.15 wt% to 0.4 wt%, tensile strength of the as-cast alloy decreased from 191 MPa to 183 MPa and, elongation of the alloy also decreased from 8.0% to 6.2%. Decrease of these properties can be explained as the formation of plate shape, β-Al5FeSi phase with low Mn/Fe ratio of the alloy. However, when Mn content of Al-4 wt%Mg-0.9 wt%Si-0.3 wt%Fe alloy increased from 0.3 wt% to 0.5 wt%, tensile strength of as-cast alloy increased from 181 MPa to 194 MPa and, elongation of the alloy increased from 6.8% to 7.0%. These improvements attribute to the morphology change from β-Al5FeSi phase to chinese script, α-Al15(Mn,Fe)3Si2 phase shape-modified from with high Mn/Fe ratio of the alloy.

As³⁺ removal by Ca-Mn-Fe₃O₄ with and without H₂O₂: Effects of calcium oxide in Ca-Mn-Fe₃O₄

Do, S.H.,Jo, Y.H.,Park, J.Y.,Hong, S.H. Elsevier Scientific Pub. Co 2014 Journal of hazardous materials Vol.280 No.-

<P>As3+ removal by Ca-Mn-Fe3O4 composites, which contained various wt% of Ca, are investigated. Immobilization of Ca (i.e. as crystalline forms including CaO2) and Mn (i.e. as an amorphous hydrous manganese oxide) on Fe3O4 were identified, and it was revealed that the co-immobilization of Ca and Mn (i.e. especially the wt% ratio of Ca:Mn:Fe = 2:3:1) provided higher Ca wt% with greater surface area. The increasing Ca wt% (i.e. 6, 14, 17, and 19%) gradually increased the reactivity of H2O2 to oxidize As3+ to Ass. Moreover, it is suggested that superoxide anion produced from the catalytic decomposition of H2O2 reduces Mn4+ to Mn2+, which is further released into solution. On the other hand, As3+ adsorption was decreased with the highest Ca wt% in Ca-Mri-Fe3O4. It was concluded that the increasing Ca wt% positively affected As3+ oxidation but an excess Ca wt% negatively affected As3+ adsorption. The higher As3+ adsorption was observed when Ca wt% was 17 (i.e. the wt% ratios of Ca:Mn:Fe = 2:3:1). Without H2O2, As3+ was adsorbed and oxidized by Ca-Mn-Fe3O4 itself. It is suspected that As3+ oxidation is due to H2O2 produced from CaO2. Mechanisms for As3+ removal by Ca-Mn-Fe3O4 with and without H2O2 are proposed. (C) 2014 Elsevier B.V. All rights reserved.</P>

고신율 금형주조용 Al-9wt%Si-Mg계 합금의 주조특성에 미치는 Fe, Mn함량의 영향

김헌주 ( Heon Joo Kim ),정창열 ( Chang Yeol Jeong ) 한국주조공학회 2013 한국주조공학회지 Vol.33 No.6

Effect of Fe and Mn contents on the castability of Al-9wt%Si-xMg-yFe-zMn alloy has been studied. The alloy was composed of α-Al phase, Al+eutectic Si phase, β-Al5FeSi compound and chinese script α-Al15(Mn,Fe)3Si2 compound. β-Al5FeSi and α-Al15(Mn,Fe)3Si2 compounds assumed to effect the fluidity and shrinkage behaviors of the alloy during solidification due to the crystallization of α-Al15(Fe,Mn)3Si2 and β-Al5FeSi compounds above eutectic temperature. As Fe and Mn contents of Al-9wt%Si- 0.3wt%Mg system alloy increased from 0.15wt% to 0.6wt% and from 0.3wt% to 0.7wt%, fluidity of the alloy decreased by 5.7% and 3.3%, respectively. And as Mg content of Al-9wt%Si-0.45wt%Fe-0.5wt%Mn system alloy increased from 0.3wt% to 0.4wt%, fluidity of the alloy decreased by 8.6%. When Fe content of the alloy increased from 0.15wt% to 0.6wt%, macro shrinkage ratio decreased from 6.1% to 4.1%, and micro shrinkage ratio increased from 0.04% to 0.24%. Similarly, Mn content of the alloy increased from 0.3wt% to 0.7wt%, macro shrinkage ratio decreased from 6.0% to 4.5% and micro shrinkage ratio increased from 0.12% to 0.18%. Judging from the castability of the alloy, Al-9wt%Si-0.3wt%Mg alloy with low content of Fe and Mn, 0.1wt% Feand 0.3wt% Mn, is recommendable.