• Title/Summary/Keyword: Absorption/Adsorption

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Removal of Cu (II) from aqueous solutions using magnetite: A kinetic, equilibrium study

  • Kalpakli, Yasemen
    • Advances in environmental research
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    • v.4 no.2
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    • pp.119-133
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    • 2015
  • Water pollution means that the physical, chemical and biological properties of water are changing. In this study, adsorption was chosen as the treatment method because it is an eco-friendly and low cost approach. Magnetite is a magnetic material that can synthesize chemical precipitation. Magnetite was used for the removal of copper in artificial water samples. For this purpose, metal removal from water dependent on the pH, initial concentration of metal, amount of adsorbent and effect of sorption time were investigated. Magnetite was characterized using XRD, SEM and particle size distribution. The copper ions were determined by atomic absorption spectrometry. The adsorption of copper on the magnetite was studied in a batch process, with different aqueous solutions of Cu (II) at concentrations ranging from 10 to $50mg\;l^{-1}$. Optimum conditions for using magnetite were found to be concentration of $10mg\;L^{-1}$, pH: 4.5, contact time: 40 min. Optimum adsorbent was found to be 0.3 gr. Furthermore, adsorption isotherm data were analyzed using the Langmuir and Freundlich equations. The adsorption data fitted well with the Freundlich ($r^2=0.9701$) and Langmuir isotherm ($r^2=0.9711$) equations. Kinetic and equilibrium aspects of the adsorption process were studied. The time-dependent Cu (II) adsorption data were described well by a pseudo-second-order kinetic model.

Precursor and Substituent Effects on the Alternate Adsorption of Polycation and Anionic Dyes as Studied by Second Harmonic Generation and Absorption Spectroscopies

  • Yamada, Sunao;Niidome, Yasuro;Hinoguchi, Takeshi
    • Journal of Photoscience
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    • v.7 no.1
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    • pp.9-13
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    • 2000
  • An alternately assembled polycation-anionic dye film was prepared on a precursor assembly of poly(allylamine)hydrochloride (PAH) and poly(sodium styrenesulfonate) (PSS) or of poly (djallyldimethyl)ammonium chloride (PDDA) and PSS. The (PAH/PSS) precursor assembly gave better adsorptivity to the anionic dye than the (PDDA/PSS) one. Four kinds of anionic dyes (EB-T, AR-17 AR-18, AR-27) with different numbers of sulfonate substituents were compared. The extent of dye assembling was higher for the dye with a smaller number of sufonate substituents. Second harmonic generation (SHG) was clearly observed from the films. The SHG signal and the absorption intensity correlated well up to four polycation/dye bilayers, while further assembly did not increase the SHG signal appreciably. Second order nonlinear coefficients for ten bilayer assemblies were the order of pm/V.

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An Investigation on the Tetrahydropyrimidine Derivatives as Acid Corrosion Inhibitors for Mild Steel

  • Chitra, S.;Gayathri, N.;Parameswari, K.
    • Corrosion Science and Technology
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    • v.8 no.2
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    • pp.45-52
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    • 2009
  • The corrosive behavior of mild steel in 0.05 M to 10 M $H_2SO_4$ solutions containing different concentrations of tetrahydropyrimidine derivatives (THPM) was investigated using weight loss method, gasometric technique, electrochemical studies which include AC - impedance and potentiodynamic polarization method, atomic absorption studies and synergistic effect. The results obtained reveal that THPM derivatives is an efficient mixed type inhibitor but slightly anodic and it is more effective in reducing corrosion of mild steel in $H_2SO_4$ media. The adsorption of the inhibitor on the mild steel surface obeys the Langmuir adsorption isotherm. The thermodynamic parameters of adsorption reveal a strong interaction and spontaneous adsorption of THPM on the mild steel surface. The influence of temperature and inhibitor concentration on the corrosion of mild steel has also been investigated.

Adsorption and Desorption Characteristics of Toluene in Modified Activated Carbon Using Microwave Irradiation (마이크로파를 이용한 탈착시스템에서 개질화 된 활성탄의 흡.탈착 특성)

  • Kim, Beom-Jun;Choi, Sung-Woo
    • Journal of Environmental Science International
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    • v.17 no.5
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    • pp.493-500
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    • 2008
  • This paper describes the adsorption/desorpton efficiency of a modified activated carbon by irradiated microwave to treat toluene. By employing microwave energy, the regeneration time was considerably shortened compared with conventional thermal heating regeneration. New adsorbent called ACB (Activated Carbon-Bentonite) was prepared from powder activated carbon with mixing bentonite as a binder. Specific surface area, average pore size and total pore volume of ACB were calculated from the nitrogen adsorption/desorption isotherm. The surface of ACB was characterized with scanning electron microscope(SEM). The results showed that the specific surface area, total pore volume, average pore size of ABC was not influenced by regenerating cycle with microwave irradiation. Toluene was adsorbed onto ACB which desorbed by MW irradiation. Absorption capacity of ACB was 0.117 $g_{toluene}/g_{ACB}$. Desorption efficiency of toluene increased as higher microwave output was applied.

Mercury Adsorption Behaviors of Copper/Activated Carbons by Electroless Plating

  • Bae, Kyong-Min;Kim, Byung-Joo;Park, Soo-Jin
    • 한국신재생에너지학회:학술대회논문집
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    • 2009.11a
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    • pp.304-304
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    • 2009
  • In this study, the adsorption behaviors of mercury ions on the electroless Cu-plated activated carbons have been investigated. The amount of copper on activated carbons have been confirmed by atomic absorption spectrophotometer (AAS). The surface properties of the ACs studied have been characterized by using Boehm's titration method and scanning electron microscopy (SEM).Experimental results showed the adsorption capacity of mercury ions was increased as the electroless Cu plating. This was probably due to the introduction of copper on ACs leaded to an increase in the surface basicity.

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A Study on the Absorptive Removal of Magnesium ion and Calcium ion for Corrosion Prevent (부식방지를 위한 마그네슘 및 칼슘 이온의 흡착 제거에 관한 연구)

  • Hong Sung-Uk;An Hyung-Hwan
    • Journal of the Korean Society of Safety
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    • v.19 no.3 s.67
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    • pp.40-44
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    • 2004
  • To the removal of hardness materials, we've test the absorptive capacity of main material $Mg^{2+},\;Ca^{2+}$ on the using the activated carbon powder saturated in 0.1M Nitrilotriacetic acid by experimental methods. The absorptive properties of $Ca^{2+}\;and\;Mg^{2+}$ were measured with absorbent quantity and contact time., and investigated the physical properties of overall rate constant and adsorption constant adsorption isotherm, and Langmuir and Freundlich constant. In case of k' adsorption rate constants of $Ca^{2+},\;Mg^{2+}$, was 0.00299, 0.00529 by Bhattahary and Venkobachar equation. $k_{aa}$ was 0.00373, 0.00640 according with adsorption rate constants of Lagergren.

How Does the 2-Thiophenecarboxaldehyde Behaves on the Ge(100) Surface

  • Lee, Myungjin;Shin, Minjeong;Lee, Hangil
    • Proceedings of the Korean Vacuum Society Conference
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    • 2013.08a
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    • pp.136-136
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    • 2013
  • High-resolution photoemission spectroscopy (HRPES) measurements were collected and density functional theory (DFT) calculations were conducted to track the coverage dependent variation of the absorption structure of 2-thiophenecarboxaldehyde (C4H3SCHO: TPCA) on the Ge(100) surface at room temperature. In an effort to identify the most probably adsorption structures on the Ge(100) surface, we deposited TPCA molecules at a low coverage and at a high coverage and compared the differences between the electronic features measured using HRPES. The HRPES data provided three possible adsorption structures of TPCA on the Ge(100) surfaces, and DFT calculations were used to determine the plausibility of the structures. HRPES analysis, corroborated by DFT calculations, indicated that an S-dative bonded structure was the most probable adsorption structure at relatively lower coverage levels, the [4+2] cycloaddition structure was the second most probable structure, and the [2+2]-C=O cycloaddition structure was the last probable structure on the Ge(100) surfaces at relatively higher coverage levels.

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Effects of the Changes in Handsheet Structure on the Water Absorption and Moisture Absorption (수초지 구조변화에 따른 흡수·흡습 특성 변화 연구)

  • Sung, Yong Joo;Kim, Dong Sung;Lee, Ji Young
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.48 no.3
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    • pp.30-36
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    • 2016
  • This study was conducted to investigate the influence of the changes in handsheet structure by beating, wet pressing and the addition of wood flour spacer on the water absorption and the moisture absorption properties. The higher beating treatment of BKP resulted in the denser structure of handsheet samples, which leaded to the lower water and moisture absorption. The wet pressing showed the similar effects by reducing the bulk of handsheets. In case of the handsheet samples with similar bulk structure made of different beaten pulps, the severer beating treatment increased the water absorption and the moisture absorption. The addition of the wood flour spacer resulted in the higher bulk following the higher water and moisture adsorption. Since the water and the moisture absorption properties of paper products could greatly affect on not only the product quality but also the process runnability, the control of the water response of paper product has been considered as very important technology. The results of this study might be useful for control of water and moisture absorption properties of paper products.

The Study on the Precursor Adsorption using in-situ Nanoparticle-assisted Attenuated Total Reflectance Infrared Spectroscopy

  • Shin, Jae-Soo;Park, Myung-Su;Jung, Won-Jun;Park, Hee-Jung;Yun, Ju-Young;Kim, TaeWan;Kang, Sang-Woo
    • Applied Science and Convergence Technology
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    • v.24 no.4
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    • pp.90-95
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    • 2015
  • The adsorption behavior of tris (dimethylamino)-cyclopentadienyl-zirconium (Cp-Zr) precursor using an in-situ attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FT-IR) was studied. In attempt to improve the detection intensity of an adsorbed precursor, nanoparticles were uniformly distributed on the Ge ATR crystal surface employing the spray method. The absorption characteristics studies were carried out over the Ge crystal temperature in the range of $30{\sim}50^{\circ}C$. Upon increasing the temperature, a reduction of absorption was observed. Based on the peak intensities of ATR-FT-IR spectroscopy, higher-$ZrO_2$ absorption efficiency occurs when the nano-particles are utilized compared to pure Ge crystal.

Spatial Distribution of CO2 Absorption Derived from Land-Cover and Stock Maps for Jecheon, Chungbuk Province (토지피복도와 임상도를 이용한 제천시의 이산화탄소 분포 추정)

  • Jeon, Jeong-Bae;Na, Sang-Il;Yoon, Seong-Soo;Park, Jong-Hwa
    • Journal of Korean Society of Rural Planning
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    • v.19 no.2
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    • pp.121-128
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    • 2013
  • The greenhouse gas emission according to the energy consumption is the cause of global warming. With various climates, it is occurs the direct problems to ecosystem. The various studies are being to reduce the carbon dioxide, which accounts for more than 80% of the total greenhouse gas emissions. In this study, estimate the carbon usage using potential biomass extracted from forest type map according to land-use by satellite image, and estimate the amount of carbon dioxide, according to the energy consumption of urban area. The $CO_2$ adsorption is extracted by the amount of forest based on the direct absorption of tree, the other used investigated value. The $CO_2$ emission in Jecheon was 3,985,900 $TCO_2$ by energy consumption. At the land cover classification, the forest is analyzed as 624,085ha and the farmland is 148,700ha. The carbon dioxide absorption was estimated at 1,834,850 Tons from analyzed forest. In case of farmland, it was also estimated at 706,658 Tons.