• Journal of Korean Society on Water Environment
• /
• v.22 no.6
• /
• pp.996-1003
• /
• 2006

The absorption characteristics of powdered activated carbon doped by transition-metal nanoparticles were investigated to enhance the remove efficiencies of $TCOD_{Mn}$ and Color from the flexo-inks wastewater. According to the adsorption dynamics of PAC and MPAC, the optimal dosage of activated-carbon adsorbents was 3 g/L under the reaction conditions of pH6.0, 30 mill of reaction time, 240 rpm of mixing intensity. The removal efficiencies by the optimal dosages were maximized as 19% $TCOD_{Mn}$, 57% Color for PAC and 88% $TCOD_{Mn}$, 95% Color for MPAC. Freundlich indexes of isotherm absorption were estimated as follows: i) For PAC, k=-8.11, 1/n=2.98, r=0.91 in the raw water, and k=0.14, b/n=0.75, r=0.96 in the biological treatment water, ii) For MPAC, k=2.69, 1/n=0.21, r=0.80 in the raw water, and k=0.74, 1/n=1.17, r=0.95 in the biological treatment water. MPAC (Powdered activated carbon doped by transition-metal nanoaprticles) was very effective in the removal of organics from the raw water and biological treatment water, as Freundlich indexes of 1/n for both types of water were estimated less than 2.0.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.6 no.4
• /
• pp.29-42
• /
• 1986

This study is an experimental research on the adsorption capacity and the adsorption system utilizing Discarded Automotive Tires(DAT) and Powdered or Granular Activated Carbon(PAC or GAC) for the removal of heavy metals, Ag(I), Cd(II), Cu(II), Zn(II). Batch shaking test was conducted to determine the adsorption capacity of DA T and PAC in removing the heavy metals from aqueous wastes; and laboratory-scale column experiment was performed to present design factors affecting the optimum design of adsorption column with DAT and GAC, through the concept of Bed Deph/Service Time(BDST). As results, DAT has been proven to be a good adsorbent will its adsorption capacity not falling behind PAC or GAC. Factors affecting heavy metals removals were amount of adsorbents, initial concentrations, pH and so on. BDST equations were compared with values presented by the breakthrough data from adsorption system.

• Journal of the Korean GEO-environmental Society
• /
• v.13 no.4
• /
• pp.37-44
• /
• 2012

This study investigated on the adsorption of nonpoint pollution source using the Sand, hydroxyapatite(HAP), Zeolite and mixed culture. The adsorption of nonpoint pollution source on Sand, hydroxyapatite(HAP), Zeolite and mixed culture was investigated during a series of batch adsorption experiments. After the batch absorption experiments analysed COD, T-N, T-P on adsorption water. The experimental data was analysed using the pseudo-first-order adsorption kinetic models. Langmuir and Freundlich isotherm models were tested for their applicability. The maximum adsorbed amount $(Q_{max})$ of COD were found to be sand 0.0511mg/g, HAP 0.1905mg/g, Zeolite 1.0366mg/g and Mixed media 0.7444mg/g. The maximum adsorbed amount $(Q_{max})$ of T-N were found to be sand 0.0159mg/g, HAP 0.0537mg/g, Zeolite 0.5496mg/g and Mixed media 0.1374mg/g. The maximum adsorbed amount $(Q_{max})$ of T-P were found to be sand 0.0202mg/g, HAP 0.1342mg/g, Zeolite 0.0462mg/g and Mixed media 0.1180mg/g. As a result, the mixed media was effective to remove nonpoint pollution source.

• Journal of Biosystems Engineering
• /
• v.26 no.5
• /
• pp.469-474
• /
• 2001

Milling the rice with low moisture requires more energy, produces more cracked rice, and results in reducing taste of cooked rice. Accordingly, it is necessary to add moisture to the rice with low moisture to obtain optimum moisture level for milling and taste of rice. This study was performed to evaluate the influence of initial moisture content and absorption rate on rice crack, milling energy and whiteness of milled rice and to obtain the information for design of rewetting system mounted on stirring device in grain bin. The tests were conducted for the four levels of initial moisture content in the range of 11.4 to 14.5%(w.b.) and six levels of absorption rate in the range of 0.04 to 1.0%, w.b./hr. In the case of lower moisture content below 12%(w.b.), crack ratios of brown rice were remarkably high regardless of initial moisture contents. Therefore, it was found that rough rice below 12%(w.b.) in initial moisture content could not rewetted by spraying water without crack generation of low level. Absorption rate must be below 0.3%, w.b./hr to maintain crack ratio increase of less than 1% regardless of initial moisture contents. In the case of allowable crack ratio increase of 2% and 5%, it was found that the maximum absorprion rate was respectively 0.6%, w.b./hr and 1.0%, w.b./hr in the initial moisture content of above 13.5%(w.b.). Rewetting the rough rice in moisture content of 11.4 to 14.5%(w.b.) to 14.3 to 16.9%(w.b.) decreased milling energy consumption by 15.9 to 22.3%. The effect of energy saving was higher in the samples of higher initial moisture content. Whiteness of milled rice was decreased by 0.5 to 1.5.

• Applied Chemistry for Engineering
• /
• v.28 no.3
• /
• pp.332-338
• /
• 2017

The objective of this work was to study the low temperature vacuum adsorption technology applicable to small and medium scale painting plants, which is the main emission source of volatile organic compounds. The low-temperature vacuum swing adsorption (VSA) technology is the way that the adsorbates are removed by reducing pressure at low temperature ($60{\sim}90^{\circ}C$) to compensate disadvantages of the existing thermal swing adsorption (TSA) technology. Commercial activated carbon was used and the absorption and desorption characteristics of toluene, a representative VOCs, were tested on a lab scale. Also based on the lab scale experimental results, a $30m^3min^{-1}$ VSA system was designed and applied to the actual painting factory to assess the applicability of the VSA system in the field. As a result of lab scale experiments, a 2 mm pellet type activated carbon showed higher toluene adsorption capacity than that of using 4 mm pellet type, and was used in a practical scale VSA system. Optimum conditions for desorption experiments were $80{\sim}90^{\circ}C$ and 100 torr. In the practical scale system, the adsorption/desorption cycles were repeated 95 times. As a result, VOCs discharged from the painting factory can be effectively removed upto 98% or more even after repeated adsorption/desorption cycles when using VSA technology indicating potential field applicabilities.

• Archives of Pharmacal Research
• /
• v.17 no.5
• /
• pp.287-293
• /
• 1994

The effect of several adsorbents on paraquat poisohing was investigated (1) by measuring the saturatd amount of the poison adhered on the adsorbents in vitro and (2) by assaying the blood level of paraquat in the rat in in situ intestinal absorption experiments. Activated charcoal powder, natural aluminum silifonate) were used as adorbents. The steady-state blood level of paraquat in its absorption experiment with the cationic exchange resins was markedly lower than those without the resins or with other adsorbents. A good relationship was achieved between the calculated AUC or adsorptioin rate (in situ) and the saturated adsorption amount (in vitro). The rank order of the effect was sodium polystyene sulfonate > calcium polystyene sulfonate>natural aluminum silicate>activated charcoal powder. The effect of sodium polystyrene sulfonate after intestinal washing with physiological saline ws also measured, and a synergistic effect (marked decrease in blood paraquat level0 was found as compared with the intestinal washing alone. The simultaneous use of G.I. weshing and powerful adsorbent was scientifically proven to be most benefical.

• Journal of the Architectural Institute of Korea Structure & Construction
• /
• v.34 no.3
• /
• pp.43-52
• /
• 2018

This study is conducted to evaluate the performance of ceramic panels and painting materials for humidity control which are developed in non-plastic room temperature hardening structure as part of a project to improve a residential environment for the low-income class, rather than the performance of high-priced humidity control materials that are produced with the existing plasticity processing. The testing methods included the measurements of absorption & desoprtion of humidity per material; Mock-up Testing; an evaluation method of comparing the absorption & desoprtion performances of Ecocarat, ceramic panels and painting materials through Living Lab. According to the measurements of absorption & desoprtion per material, ceramic panels, E panel, and ceramic painting material showed 73.3g/m2, 96.6g/m2, and 111.1g/m2, respectively. That is, the performance of humidity control of each material was found to be good in the order of: Ceramic Paint > E panel > Ceramic Panel. According to performance evaluation testing with Mock-up test and Living Lab, Ceramic Paint, Ecocarat, and Ceramic Panels showed better absorption & desoprtion performances in the order.

• Journal of the Mineralogical Society of Korea
• /
• v.22 no.1
• /
• pp.23-34
• /
• 2009

The adsorption of iodide on untreated bentonite and bentonites modified with organic cation (i.e., hexadecylpyridinium chloride monohydrate ($HDP^+$)) was investigated, and the organobentonites were characterized using uptake measurements, ${\mu}$-XRD, and electrophoretic mobilities measurement. Uptake measurements indicate that bentonite has a high affinity for $HDP^+$. Our ${\mu}$-XRD study indicates that organobentonites significantly expanded in basal spacing and organic cations were substantially intercalated into the interlayer spaces of bentonite. The electrophoretic mobility indicates that organobentonite tht is modified with organic cations in excess of the CEC of bentonite is completely different from untreated bentonite in the surface charge distribution. We found significant differences in adsorption capacities of iodide depending on the bentonite properties as follows: iodide adsorption capacities were 439 mmol/kg for the bentonite modified with $HDP^+$ at an equivalent amount corresponding to 200% of the CEC of bentonite whereas no adsorption of iodide was observed for the untreated bentonite. The molecular environments of iodine adsorbed on organobentonites were further studied using I K-edge and $L_{III}$-edge x-ray absorption spectroscopy (XAS). The X-ray absorption near-edge structure (XANES) of iodine spectra from organobentonites was similar to that of KI reference solution. Linear combination fitting of EXAFS data suggests the fraction of iodine reacted with the organic compound increased with increasing loading of the organic compound on organobentonites. In this study, we observed significant differences in the adsorption environments of iodide depending on the modified property of bentonite and suggest that an organobentonite has potential as reactive barrier material around a nuclear waste repository containing anionic radioactive iodide.

• Asian Journal of Atmospheric Environment
• /
• v.10 no.2
• /
• pp.99-113
• /
• 2016

In order to improve the portability of basic absorbents monoethanolamine (MEA) and glycine (Gly), both were supported on microporous activated carbon (AC). Chemical modification by alkali-metal ion exchange (of Li, Na, K) was carried out on Gly-based absorbents. All supported absorbents were subjected to $CO_2$ absorption capacity (pure $CO_2$) and selectivity (indoor level) tests. Textural and chemical characterizations were carried out on test sorbents. All impregnation brought about significant reduction of specific surface area and microporosity of the adsorbent Depreciation in the textural properties was found to result to reduction in pure $CO_2$ sorption. Contrarily, low-level $CO_2$ removal capacity was enhanced as the absorbent dosage increases, resulting in supported 5 molar MEA in methanol solution. Adsorption capacities were improved from 0.016 and 0.8 in raw ACs to 1.065 mmol/g for MEA's. Surface chemistry via X-ray photoelectron spectroscopy (XPS) of the supported sorbents showed the presence of amine, pyrrole and quaternary-N. In reducing sequence of potency, pyridine, amine and pyrrolic-N were noticed to contribute significantly to $CO_2$ selective adsorption. Furthermore, the adsorption isotherm study confirms the presence of various SNGs heterogeneously distributed on AC. The adsorption mechanism of the present AC adsorbents favored Freundlich and Langmuir isotherm at lower and higher $CO_2$ concentrations respectively.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.26 no.2
• /
• pp.349-354
• /
• 2002

In order to decolorize the reactive dye wastewater, we investigated the dye-adsorption ability of chitin, which was natural polymer obtained from shrimp shell. Chitin particle(less than 250 ${\mu}{\textrm}{m}$n) was prepared from shrimp shells in the processes of decalcification in aqueous hydrochloric acid solution and deproteination in aqueous sodium hydroxide solution. The particle size of chitin was controlled to less than 250 ${\mu}{\textrm}{m}$. Three tripes of the reactive dyes-C.I. Reactive Red 120, C.I. Reactive red 241 and C.I. Reactive Black 5-were used. Dye adsorption ability of chitin was investigated by dipping the particle in the dyebaths of concentration of 0.0l%, 0.03% and 0.05% for various periods of time(1,3,5, 10,20,40,80,160minutes). The influence of addition of salt(Na$_2$SO$_4$) and alkali to the dyebaths on dye-absorption was also investigated. We obtained the following results fur the dye-absolution ability of chitin in the dyebaths of three types of reactive dyes. 1) The amount of dye uptake by chitin was increased by addition of salt to the dyebaths. 2) As the concentration of alkali became higher than 3g/I, the amount of dye uptake by chitin was increased. Chitin showed good dye-adsorption ability, when the alkali concentration was high. 3) Chitin showed equal dye uptake in the three types of dyebaths when the dye concentration was 0.0l%. Over 90% of dyestuffs was adsorbed from the dyebaths in ten minutes. When the dye concentration was higher, better adsorption ability was showed in a dye bath of Reactive black 5 than in the others. When the dye concentration was 0.03%, 90% of Reactive red 120 and Reactive red 241 was adsorbed in 40 minutes and the same of Reactive black 5 in 10 minutes. When the dye concentration was 0.05%, 9()% of Reactive red 120 was adsorbed in 80 minutes, and Reactive black 5 in to minutes.