• Title/Summary/Keyword: Aluminum ions

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Preparation of PVC-Al(OH)3 Beads Immobilized Al(OH)3 with PVC and their Adsorption Characteristics for Fluoride Ions from Aqueous Solution (Al(OH)3를 PVC로 고정화한 PVC-Al(OH)3 비드의 제조와 수중의 불소 이온의 흡착 특성)

  • You, Hae-Na;Kam, Sang-Kyu;Lee, Min-Gyu
    • Journal of Environmental Science International
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    • v.23 no.5
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    • pp.887-893
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    • 2014
  • In order to remove fluoride ions from aqueous solution, PVC-$Al(OH)_3$ beads were prepared by immobilizing $Al(OH)_3$ with polyvinyl chloride (PVC). The prepared PVC-$Al(OH)_3$ bead was characterized by using SEM, EDS and Zeta potential. Dependences of pH, contact time and initial fluoride concentration on the adsorption of fluoride ions were studied. The optimal pH was in the range of 4~10. The adsorption was rapid during the initial 12 hr, and equilibrium was attained within 72 hr. The adsorption rate of fluoride ions by PVC-$Al(OH)_3$ beads obeyed the pseudo-second-order kinetic model. The maximum adsorption capacity obtained from Langmuir isotherm model was found to be 62.68 mg/g.

Effect of pH and Initial Phosphorus Concentration on Phosphorus Removal by Aluminum Salts (알루미늄염에 의한 인 제거 시 pH와 초기 인 농도의 영향)

  • Park, Jeongwon;Kwak, Hyoeun;Min, Sojin;Chung, Hyung-Keun;Park, Pyung-Kyu
    • Journal of Korean Society of Water and Wastewater
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    • v.30 no.2
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    • pp.123-130
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    • 2016
  • Phosphorus (P) removal by aluminum sulfate solution was investigated with varying pH and initial P concentrations. P removal was the highest at around pH 6. The pH range where P removal occurred was slightly wider at higher initial P concentrations. Compared to theoretical calculations, it was confirmed that $AlPO_4$ precipitation was the main reason for P removal at low pH. At high pH, where there should be no $AlPO_4$ precipitates, the P removal by adsorption of amorphous $Al(OH)_3$ precipitates was experimentally observed. The P removal by adding amorphous $Al(OH)_3$ precipitates prepared before the adsorption experiments, however, was lower than that by injecting aluminum sulfate solution because the prepared precipitates became larger, leading to less specific surface area available for adsorption. Ions other than sulfate had little influence on P removal.

A Experimental Study on Improvement of Marine Clay through the Electrolytic Leaching Effect in Aluminum Electrode (알루미늄 전극의 용출에 따른 해성점토의 개량에 관한 실험적 연구)

  • Kim, Jong-Yun;Yun, Myung-Suk;Jung, Seung-Yong;Kim, Soo-Sam
    • Proceedings of the Korean Geotechical Society Conference
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    • 2006.03a
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    • pp.1173-1180
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    • 2006
  • In this study, aluminum electrodes were put in marine clay which was taken from the south coast in Korea to increase the undrained shear strength by inducing the densification and cementation between clay particles and precipitates which were developed by electric decomposition in an electrode. To raise the cementation rate and reduce treatment time, high electric current (2.5A) was applied in each electrode at a semi-pilot scale soil box with marine clay. After the tests, the undrained shear strength was measured at designated points using a static cone penetration test device and sampling was conducted simultaneously in order to measure water content, pH and electric conductivity which would be the key for configuring the cementation effects indirectly. In the results of electric decomposition in aluminum electrode, the measured shear strength was increased considerably compared to the initial shear strength because of the cementation effect between iron ions and soil particles.

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Formation of Amorphous Oxide Layer on the Crystalline Al-Ni-Y Alloy

  • Kim, Kang Cheol;Kim, Won Tae;Kim, Do Hyang
    • Applied Microscopy
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    • v.43 no.4
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    • pp.173-176
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    • 2013
  • The oxidation behavior of the crystallized $Al_{87}Ni_3Y_{10}$ alloy has been investigated with an aim to compare with that of the amorphous $Al_{87}Ni_3Y_{10}$ alloy. The oxidation at 873 K occurs as follows: (1) growth of an amorphous aluminum-yttrium oxide layer (~10 nm) after heating up to 873 K; and (2) formation of $YAlO_3$ crystalline oxide (~220 nm) after annealing for 30 hours at 873 K. Such an overall oxidation step indicates that the oxidation behavior in the crystallized $Al_{87}Ni_3Y_{10}$ alloy occurs in the same way as in the amorphous $Al_{87}Ni_3Y_{10}$ alloy. The simultaneous presence of aluminum and yttrium in the oxide layer significantly enhances the thermal stability of the amorphous structure in the oxide phase. Since the structure of aluminum-yttrium oxide is dense due to the large difference in ionic radius between aluminum and yttrium ions, the diffusion of oxygen ion through the amorphous oxide layer is limited thus stabilizing the amorphous structure of the oxide phase.

Electrochemical Damage Characteristics of Anodized 5083 Aluminum Alloy with Flow Rate in Seawater (양극산화 처리된 5083 알루미늄 합금의 해수 내 유속변화에 따른 전기화학적 손상 특성)

  • Park, Il-Cho;Kim, Seong-Jong
    • Journal of the Korean institute of surface engineering
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    • v.49 no.4
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    • pp.349-356
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    • 2016
  • In this study, electrochemical damage behaviors with flow rate were investigated for anodized 5083 aluminum alloy in seawater. As the results of anodic polarization experiments and potentiostatic experiments at +1.0 V (vs. SSCE), the non-flow condition presented largely damaged surface resulting from a tendency of local pitting damage. Under various flow rate conditions, however, less surface damages under the application of anodic potential was obtained which is attributed to no accumulation of $H^+$ and $Cl^-$ ions on the surface. On the other hand, the results of the potentiostatic experiments at -1.0 V (vs. SSCE) with flow rate showed that anodized 5083 aluminum alloys could achieve the effective cathodic protection by low cathodic protection current density less than $2.61{\times}10^{-7}A/cm^2$ even under high flow rate of 1 m/s.

The Effect of Seawater Temperature on the Electrochemical Corrosion Behaviour of Stainless Steels and Anodized Aluminum Alloys (스테인리스강과 양극산화된 알루미늄 합금의 전기화학적 부식특성에 미치는 해수온도의 영향)

  • Chong, Sang-Ok;Kim, Seong-Jong
    • Corrosion Science and Technology
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    • v.20 no.2
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    • pp.85-93
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    • 2021
  • The corrosion damage of materials in marine environment mainly occurs by Cl- ions due to the breakdown of passive films. Additionally, various characteristics in seawater such as salinity, temperature, immersion time, flow rate, and biological activity also affect corrosion characteristics. In this study, the corrosion characteristics of stainless steels (STS 304 and STS 316L) and anodized aluminum alloys (AA 3003 and AA 6063) were evaluated with seawater temperature parameters. A potentiodynamic polarization experiment was conducted in a potential range of -0.25 V to 2.0 V at open circuit potential (OCP). Corrosion current density and corrosion potential were obtained through the Tafel extrapolation method to analyze changes in corrosion rate due to temperature. Corrosion behavior was evaluated by measuring weight loss before/after the experiment and also observing surface morphology through a scanning electronic microscope (SEM) and 3D microscopy. Weight loss, maximum damage depth and pitting damage increased as seawater temperature increased, and furthermore, the tendency of higher corrosion current density with an increase of temperature attributed to an increase in corrosion rate. There was lower pitting damage and lower corrosion current density for anodized aluminum alloys than for stainless steels as the temperature increased.

Microfluidic Fabrication of Conjugated Polymer Sensor Fibers (미세유동을 이용한 공액 고분자 센서 섬유 제작)

  • Yoo, Imsung;Song, Simon
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.38 no.10
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    • pp.853-858
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    • 2014
  • We propose a fabrication method for polydiacetylene (PDA)-embedded hydrogel microfibers on a microfluidic chip. These fibers can be applied to the detection of cyclodextrines (CDs), which are a family of sugar and aluminum ions. PDA, a family of conjugated polymers, has unique characteristics when used for a sensor, because it undergoes a blue-to-red color transition and nonfluorescence-to-fluorescence transition in response to environmental stimulation. PDAs have different sensing characteristics depending on the head group of PCDA. By taking advantage of ionic crosslinking-induced hydrogel formation and the 3D hydrodynamic focusing effect on a microfluidic chip, PCDA-EDEA-derived diacetylene (DA) monomer-embedded microfibers were successfully fabricated. UV irradiation of the fibers afforded blue-colored PDA, and the resulting blue PDA fibers underwent a phase transition to red and emitted red fluorescence upon exposure to CDs and aluminum ions. Their fluorescence intensity varied depending on the CDs and aluminum ion concentrations. This phase transition was also observed when the fibers were dried.

Mode of Cell Death and Molecular Change of Oral Squamous Carcinoma Cells Exposed to Metal Ions

  • Kim, Hyung-Il;Baek, Chang-Jun;Kim, In-Ryoung;Kim, Hyung-Keun;Park, Hae-Ryoun
    • International Journal of Oral Biology
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    • v.31 no.1
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    • pp.15-20
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    • 2006
  • Concerns remain regarding the biocompatibility and adverse effects of dental casting alloys. The aim of this study was to understand the cytopathogenic effect of metal ions, which might be released from dental alloys, on oral squamous carcinoma(OSC) cells. The cellular morphology, viability, the type of cell death and molecular change in response to metal ion salt solutions including aluminum(Al), cobalt(Co), copper(Cu) and nickel(Ni) were examined. The $TC_{50}$ values for the metal ions with the exception of AI were estimated to be between 400 and $600{\mu}M$. The cells treated with the metal ions showed apoptotic change with the exception of Al ions. Metal ion-induced apoptosis was further confirmed using flow cytometric analysis. This study showed that the cytotoxicity and the mode of cell death by metal ions clearly depend on the cell type, the type of metal ion and the duration of exposure. The protein level of Rb, a tumor suppressor that affects apoptosis para-doxically, was higher in the cells treated with Co, Cu and Ni. It is believed that apoptosis and cell damage in the OSC cells treated with Co, Cu or Ni can be evoked by the regulation of Rb.

Effect of Aluminum Potassium Sulfate Addition on the Color Change in Caesalpinia Sappan Dyeing by Rice Straw Ash Solution (볏짚 잿물 매염에 의한 소목 염색에서 명반 첨가가 색상변화에 미치는 영향)

  • Seo Hee-Sung;Jeon Dong-Won;Kim Jeon-Jun
    • Journal of the Korean Society of Clothing and Textiles
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    • v.29 no.11
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    • pp.1465-1474
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    • 2005
  • The primary purpose of this study is to investigate the differences in the characteristics of the mordants, synthetic aluminum mordants and ash solutions as natural mordants, used in Caesalpinia sappan dyeing. By introducing aluminum potassium sulfate in the ash solutions, the behavior of the aluminum in the ash solutions were observed. In the rice straw ash solutions, adjusted to the levels of pH6 and pH10, the aluminum potassium sulfate was introduced to achieve various concentration levels. From the analysis of the ash solution of pull, $K^+$ and $Na^+$ ion concentrations were found to be extremely high, while $Al^+$ ion concentration was 0. The color development in the Caesalpinia sappan dyeing by ash solution mordanting was found to be mainly governed not by the mordanting actions of the metallic ions but by those of alkali components. In the case of cotton, the application of pH10 ash solution promoted reddish color development compared to the case of non-mordanting, regardless of the aluminum potassium sulfate addition. In the case of silk, the application of pH10 ash solution increased a* value and decreased b* value compared to the case of non-mordanting.

Optimizing of Coagulation and Solid-Liquid Separation Conditions Using Aluminum Sulfate and Poly-Aluminum Chloride Coagulants from Brine Wastewater Discharged by the Epoxy-resin Process (에폭시수지 공정에서 발생되는 고염 폐수로부터 황산알루미늄과 PAC 응집제를 이용한 응집/고액분리 조건 최적화)

  • Lee, Chang-Han;Kim, Yu-Jin;Moon, Sung-Hyun;Kwon, Sung-Hun;Ahn, Kab-Hwan
    • Journal of Environmental Science International
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    • v.31 no.1
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    • pp.1-8
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    • 2022
  • In this study, solid-liquid separation conditions for coagulation and sedimentation experiments using inorganic coagulant (aluminum sulfate and Poly-Aluminum Chloride (PAC)) were optimized with brine wastewater discharged by the epoxy-resin process. When the turbidity and suspended solid (SS) concentration in raw wastewater were 74 NTU and 4.1 mg/L, respectively, their values decreased the lowest in a coagulant dosage of 135.0 - 270.0 mg Al3+/L. The epoxy resin was re-dispersed in the upper part of wastewater treated above 405.0 mg Al3+/L. The removal efficiencies of turbidity and SS via dosing with aluminum sulfate and PAC were evaluated at initial turbidity and SS of 74 - 630 NTU and 4.1 - 38.5 mg/L, respectively. They increased most in the range from 135.0 - 270.0 mg Al3+/L. The solid-liquid separation condition was quantitatively compared to the correlation of SS removal efficiency between the coagulant dosage and SS concentration based on the concentration of aluminum ions. The empirical formula, R = beaD, shows the relationship between SS removal efficiency (R) and coagulant dosage (D) at 38.5 mg/L; it produced high correlation coefficients (r2) of 0.9871 for aluminum sulfate and 0.9751 for PAC.