• Polymer(Korea)
• /
• v.26 no.5
• /
• pp.551-558
• /
• 2002

It was observed that adsorption characteristics of sulfonated fabric ion-exchanger for separating nickel ion from electroplating rinse water. Swelling ratio was increased by increasing degree of sulfonation and polarity of solvent. Ion-exchange capacity was also increased by increasing degree of sulfonation and showed 3.38 meq/g at 16% sulfonated ion-exchanger. There was little effects of pH. Adsorption equilibrium was attained within 10 min, and adsorption rate was 7.5 mg/min. Adsorption capacity was not changed after 7 cycles of regeneration process. Regeneration adsorption capacity was slightly decreased to 2.01 meq/g. It confirmed that durability of sulfonated fabric ion-exchanger was suitable for adsorption process. Adsorption equilibrium time was linearly increased by increasing L/D and adsorption capacity showed the ion exchange capacity within the range of 2.71 ∼ 3.01 meq/g in continuous process. Design of adsorption column could be possible for L/D<2. Under constant L/D condition, there is no little pH effect when rinse water is acidic solution, and operation condition of adsorption process was optimized under pH 5.

• Journal of the Korean GEO-environmental Society
• /
• v.15 no.8
• /
• pp.39-44
• /
• 2014

Effects of operating parameters on the breakthrough properties of Pb(II) by $Mn_3O_4$ coated activated carbon prepared by supercritical technique were investigated through fixed-bed column experiments. The mass transfer zone and equilibrium adsorption capacity were enhanced about 2.8 times for Pb(II) by $Mn_3O_4$ coating onto activated carbon. Increase of bed height enhanced the residence time of Pb(II) in adsorption zone, giving the higher breakthrough time, mass transfer zone and equilibrium adsorption capacity. Increase of flow rate reduced the residence time and diffusion of Pb(II) in adsorption zone, therefore decreased the equilibrium adsorption capacity. The higher inlet concentration of Pb(II) decreased the breakthrough time and mass transfer zone through the promotion of Pb(II) transfer onto adsorbent.

• Journal of the Korean Wood Science and Technology
• /
• v.31 no.6
• /
• pp.73-82
• /
• 2003

Various forest humic substances were collected at different climate regions with different forest types, and adsorption of heavy metals such as Cu(II), Zn(II), Cd(II) and Cr(III) were characteristically conducted to obtain optimal adsorption conditions and to evaluate the removal efficiency of heavy metals by each forest humic substance. The adsorption isotherms for Cu(II), Zn(II), Cd(II) and Cr(III) conformed to Langmuir's equation. In the stirred reactor, the removal efficiencies of Cu(II), Zn(II) and Cd(II) by forest humic substances were more than 90% but that of Cr(III) was less than 60%. The adsorption capacities of heavy metals in the stirred reactor were considerably varied depending on the type of forest humic substances. Among humic substances, the one from deciduous forest at subtropical region showed the highest removal efficiency for Cu(II). There was no significant difference in removal efficiency by each heavy metal depending on reaction temperature ranged from 20 to 50oC except for Cr(III), and the adsorptions of Cu(II), Zn(II) and Cd(II) were occurred rapidly in the incipient stage within 10 min, while Cr(III) needed more reaction time to be adsorbed. The stirred and packed bed column reactors showed similar adsorption characteristics of heavy metals by humic substances, but the removal efficiency was considerably higher in the packed bed column reactor than in the stirred reactor. Therefore, in actual operation process, a continuous packed bed column reactor was more economical.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.4 no.2
• /
• pp.25-33
• /
• 1984

The effect of particle size on adsorption of trihalomethane have been studied. Using mean particle sizes ranging from 0.73 to 2.03 mm, physical properties of carbon and trihalomethane adsorption characteristics have been investigated experimentally. With increasing particle size specific surface area and pore volume decreased, and the mean pore radius increased significantly. Large pores were dominant in large particles, while small particles were composed of small pores. Isotherm studies were conducted using static bottle point technique and the results were well described by the Freundlich isotherm equations. The adsorption capacity increased significantly with decreased particle size. Additionally micro-column tests were carried out, and the results were compared with the model simulation. From the micro-column studies it was found out that the film transfer coefficient were almost constant, and the differences in the trihalomethane removal efficiency was mainly due to the differences in the adsorption capacity of the particles of different size.

• Journal of Korean Society of Water and Wastewater
• /
• v.30 no.1
• /
• pp.87-97
• /
• 2016

First of all, Fe or/and Mn immobilized granular activated carbons (Fe-GAC, Mn-GAC, (Fe, Mn)-GAC) were synthesized and tested to remove arsenate (As(V)). The results in batch test indicated that Fe-GAC removed As(V) effectively, even though the surface area of Fe-GAC was reduced largely. Moreover, adsorption isotherm test indicated that the experimental data fit well with Langmuir model and the maximum adsorption capacity ($q_{max}$) of Fe-GAC for As(V) was $3.49mg\;g^{-1}$, which was higher than GAC ($2.24mg\;g^{-1}$). In column test, the simulated water, which consisted of As(V), Fe(III), Mn(II) and Ca(II) in tap water, was used. Fe-GAC column with 1 hr of pre-washing time treated As(V) effectively while GAC column removed Fe(III) better than Fe-GAC column. Moreover, the increasing pre-washing time from 1 to 9 hour in Fe-GAC column enhanced Fe(III) removal with little negative impact of As(V) removal. Mostly, the column filled with Fe-GAC and GAC (i.e. the mass ratio of Fe-GAC:GAC = 2:8) showed the higher treatability of both As(V) and Fe(III), even it operated with 1 hr pre-washing time.

• Journal of Korean Society for Atmospheric Environment
• /
• v.9 no.1
• /
• pp.101-106
• /
• 1993

In order to separate the Freon-12 and air mixture$(CF_2Cl_2/Air=0.1/99.9 vol.%)$ by pressure swing adsorption (PSA), the breakthrough curve was experimentally observed in a fixed bed adsorption column. A single adsorber was packed with various adsorbents such as, the activated carbon(S-AC, W-AC) and the molecular sieve(MS-5A, MS-13X). The order of appearance of breakthrough curve is MS-5A > MS-13X > W-AC > S-AC. The activated carbon was found to be more effective adsorbent for separating Freon-12 from the mixture than the molecular sieve was. From the experimental data obtained by the separation of Freon-12 gas out of the air stream in the steady-state PSA process cycle, whose size is the same one of column used for the breakthrough curve observation, it has been confirmed that Freon-rich gas could be obtained from the purge step of PSA and Freon-free air could be obtained from the adsorption step of PSA cycle.

• Elastomers and Composites
• /
• v.24 no.2
• /
• pp.105-109
• /
• 1989

Liquid phase adsorption of organic compounds solution on the activated carbon fiber was measured by chromatographic method in a packed column. Adsorption equilibrium constant Ka of dextrose solution was found to be $72.5cm^3/g$ on ACF without bacteria growth, while in the bacterial ACF packed column Ka was $87.9cm^3/g$. It is suggested that for biological ACF there is a large contribution of bacterial activity to the adsorption equilibrium constant. Axial dispersion coefficient Ez was determined to be in proportional to flow rate and Pe=dpu/Ez independent or existence or bacteria.

• Journal of Korean Society of Water and Wastewater
• /
• v.31 no.4
• /
• pp.281-287
• /
• 2017

Mill scale, an iron waste, was used to separate magnetite particles for the adsorption of phosphate from aqueous solution. Mill scale has a layered structure composed of wustite (FeO), magnetite ($Fe_3O_4$), and hematite ($Fe_2O_3$). Because magnetite shows the highest magnetic property among these iron oxides, it can be easily separated from the crushed mill scale particles. Several techniques were employed to characterize the separated particles. Mill scale-derived magnetite particles exhibited a strong uptake affinity to phosphate in a wide pH range of 3-7, with the maximum adsorptive removal of 100%, at the dosage of 1 g/L, pH 3-5. Langmuir isotherm model well described the equilibrium data, exhibiting maximum adsorption capacities for phosphate up to 4.95 and 8.79 mg/g at 298 and 308 K, respectively. From continuous operation of the packed-bed column reactor operated with different EBCT (empty bed contact time) and adsorbent particle size, the breakthrough of phosphate started after 8-22 days of operation. After regeneration of the column reactor with 0.1N NaOH solution, 95-98% of adsorbed phosphate could be detached from the column reactor.

• Applied Chemistry for Engineering
• /
• v.32 no.1
• /
• pp.97-101
• /
• 2021

Adsorption properties of heavy metals and organics in the mixed packed column of scoria and activated carbon, as well as physicochemical properties and functional groups of scoria were investigated. As the mixing ratio of scoria increased, the average removal ratios of cadmium, nickel, chromium, and lead ions increased, but that of benzene and toluene decreased. The mixed packed column of scoria and activated carbon could be effectively used for the simultaneous removal of heavy metals and organics. Scoria has Si-H and Si-O functional groups, and it was confirmed that Si-O functional groups greatly contributed to the adsorption of heavy metals.

• Environmental Engineering Research
• /
• v.14 no.3
• /
• pp.153-157
• /
• 2009

Arsenic at abandoned mine sites has adversely affected human health in Korea. In this study, the feasibility of using cationic surfactant-modified activated carbon (MAC) to remove As(V) was evaluated in terms of adsorption kinetics, adsorption isotherms, and column experiments. The adsorption of As(V) onto MAC was satisfactorily simulated by the pseudo-second-order kinetics model and Langmuir isotherm model. In column experiments, the breakthrough point of AC was 28 bed volumes (BV), while that of MAC increased to 300 BV. The modification of AC using cationic surfactant increased the sorption rate and sorption capacity with regard to As(V). As a result, MAC is a promising adsorbent for treating As(V) in aqueous streams.