• Resources Recycling
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• v.8 no.3
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• pp.26-30
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• 1999

The removal of phosphorus was investigated from sewage waste water (SWW) using the used foundry sand (UFS). The optimal pH occurred at pH 2 for adsorption of phosphorus species in batch test. Phosphorus could be recovered with 99.9% from SWW in two hours at pH 2 using 100 g of UFS per liler of SWW. The adsorption of phosphorus species on UFS obeyed Langmuir isotherm, whose equation could be expressed by 1= 0.00059/(1+2.49878). Continuous column test for adsorption showed that breakthrough point appeared In 25 hours on the condition of breakthrough concentration of 8 mg/l

• Resources Recycling
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• v.7 no.2
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• pp.9-15
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• 1998

Recovery af molybdenum in spent desulfuriring catalyst of petrochemical industries was studied from MfGnatc solulion which is a resultant of firstly remvercd vanadium by wet processes. In order to separate and recover molybdenum from upper mentioned rafinatz solution containing several mctal ions, such as molybdenum (1,100 ppm), vanadium (150 ppm), aluminium (19 ppm), and nickel (33 ppm), either adsorption technique by chelate resin or solvent extr~ction by tertiary amine as extractant was applied. In case of adsorption method, palyamine type chelate resin showed the highest selectivily far molybdenum ion up lo 60 ddm' of ancentration aftcr eluting with 3.0 rnolld~n' of NH,OH. On the othcr hand. molybdenum ion wa cffectlvely cxtractcd in Ule whole ranges of equilibrilrm pR by solvent extraction method with 10 ~01%-alamine 336 which was pretreated with 2N-HCI

• Applied Chemistry for Engineering
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• v.10 no.6
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• pp.929-933
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• 1999

Under the condition of water electrolysis in aqueous hydrochloric acid as the electrolyte, the lead removal from the lead-loaded activated carbon packed on the anode was investigated. The adequate flow condition is a total flow rate of 10 mL/min in the same flow rate ratio to both electrodes. The increase of current decreases pH values at the anode and the decrease of pH leads to the lead removal. This work shows that the water electrolysis is an efficient method for the lead removal from the lead-loaded activated carbon with a reduction in quantity of the chemical used in comparison with the acid rinse.

• Journal of Korea Soil Environment Society
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• v.4 no.2
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• pp.103-111
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• 1999

This study is on the mathematical modeling and its verification of the retardation phenomenon of gas migration in an unsaturated zone of very little moisture content The adsorption of VOCs onto the surface of the dry medium was taken into account, which has not been usually considered in the conventional models. The trichloroethylene(TCE) gas migration predicted from the mathematical model developed in this study fits the experimental results obtained from a dry glass-bead column and a dry silica sand column very well The model developed in this study gave much better prediction than did a coventional model.

• Journal of the Korean Chemical Society
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• v.50 no.4
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• pp.321-327
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• 2006

red 1 and acid blue 92, anionic dyes, were removed from synthetic wastewater by the surfactant-modified clay minerals. Two different clays, such as Korean clay(M78) and Japanese clay(KJ) were treated with three different sulfactants, CTMA, DSDMA and TMSA. The surfactant-modified clay minerals such as M-1(CTMA), M-3(TMSA), KJ-1(CTMA) and KJ-3(TMSA), showed high removal efficiencies with dyes, while M-2(DSDMA) and KJ-2(DSDMA) could adsorb both dyes with relatively low efficiencies. Furthermore, almost 100% absorption of both dyes onto M-1(CTMA) and KJ-3(TMSA) revealed the possibility that these materials can be used for the removal of hazardous organic dyes from wastewater.

• Journal of Wetlands Research
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• v.26 no.3
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• pp.272-278
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• 2024

Due to industrialization, a trace amount of residues of pharmaceuticals and personal hygiene products (PPCPs) flows into the ecosystem, polluting the ecosystem. In particular, it was intended to remove trace pollutants flowing into the effluent due to the increase in the amount of acetaminophen detected after COVID 19. To conduct this experiment, selected 6 media which are suitable for construcgted wetland and isothermal adsorption experiments. Langmuir equation and the Freundlich equation were used to calculate the maximum removal rate of acetaminophen. Among them, the Freundlich equation showed a higher result value of 0.9823. It was applied when forming constructed wetlands in urban areas to model the reduction rate of acetaminophen in wetlands.

• Journal of the Korean Magnetics Society
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• v.5 no.6
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• pp.956-962
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• 1995

본 연구에서는 포화지방산으로 피복된 초미립 마그네타이트(Magnetite, Fe$_{3}$ $O_{4}$) 중에 nonanoic acid가 용해되어 있는 알칼리 수용액을 첨가한 후, 이들 슬러리(slurry)를 건조하여 kerosene에 분산시켜 유상자성유체를 제조하였다. Stearic acid 첨가량에 따른 분산율의 변화를 조사한 결과 stearic acid 첨가량이 증가함에 따라 분사율은 증가하였으나, 2.6 * $10^{-2}$ mol 이상에서는 분산율이 78%로 감소하 였다. Stearic acid로 피복된 마그네타이트에 의해 유상자성유체제조시 분산안정제로서 사용된 nonanoic acid 첨가량에 따른 분산율의 변화를 조사한 결과 nonanoic acid 를 첨가하지 않은 경우 분산이 일어나지 않았으나, nonanoic acid를 첨가함에 따라 분산율은 급격히 증가하였다. 포화지방산을 계면활성제로 사용하여 흡착-유기상 분산 법에 의해 유상자성유체를 제조한 결과, $C_{12}$ ~ $C_{16}$ 지방산을 사용하여 유상자성유체를 제조할 경우 20% 내외의 분산율을 나타내었다. 분산제로서 Nonanoic acid를 사용하여 유상자성유체를 제조할 경우 $C_{10}$ 지방산으로 제조한 유상자성 유체는 분산이 일어나지 않았으나, C 사슬의 길이가 증가함에 따라서 분산율은 급격히 증가하였으며 $C_{15}$ 지방산 부터는 90% 이상의 분산율을 나타내었다.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.7
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• pp.738-745
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• 2006

In this research, the decolorization mechanisms of dye wastewater were divided into two pathways, one was physicochemical sorption to biomass flocs and the other was biological removal by microbial metabolisms. Batch tests were conducted to examine the reaction conditions, anaerobic and aerobic conditions, types and dose of cosubstrates, and to confirm the mechanisms of decolorization through the biosorption tests using the activated sludge and the autoclaved deactivated sludge. From the tests, the decolorization efficiencies of dye wastewater were 102 ${\Delta}$unit/g MLSS under the aerobic condition and 123 ${\Delta}$unit/g MLSS under the anaerobic condition, and organic removals were 82 $mg{\Delta}$COD/gMLSS and 75 $mg{\Delta}$COD/gMLSS respectively. Acetate was the more efficient cosubstrate than the domestic wastewater in the decolorization step. In addition the removal of colors and organics was increased with cosubstrates dosage. And $20.3{\sim}37.3$ ${\Delta}$unit/g MLSS was removed by the autoclaved sludge and $102.0{\sim}159.0$ ${\Delta}$unit/g MLSS by the activated sludge. The physicochemical sorption was dominant in the beginning of biosorption tests, and the biological decolorization was increased with a cosubstrate in the course of time.

• Korean Journal of Food Science and Technology
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• v.30 no.3
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• pp.574-580
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• 1998

The technical feasibility of removing cholesterol from milk fat by supercritical carbon dioxide $(SC-CO_2)$ extraction followed by adsorption on different adsorbents and of fractionating milk fat into different fatty acid composition at $40^{\circ}C/276$ bar was investigated. Cholesterol could be selectively removed from milk fat by adsorption on a typical commercial florisil with $SC-CO_2$ extraction. Lower weight ratio of milk fat feed to florisil showed higher reduction of cholesterol, but gave lower yield in the milk fat fractions. The effective capacity of florisil for removing cholesterol from milk fat was 2.0g/g, which is the ratio of the fat feed to the adsorbent for 89% cholesterol reduction with a fat yield of 57.5%. Fatty acid composition showed higher short-chain and lower unsaturated long-chain fatty acids in the extracted fractions. Milk fat fractionation method by supercritical fluid extraction in coupled with adsorption would appear suitable for removing undesirable ingredients such as cholesterol and for enriching short-chain fatty acids in the fractions.

• Korean Chemical Engineering Research
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• v.43 no.2
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• pp.249-258
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• 2005

A two-column six-step pressure swing adsorption(PSA) process was to study separation of hydrogen from hydrogen and methane($60_{vol}%/40_{vol}%$) binary system onto activated carbon adsorbent. The effects of the feed gas pressure, the feed flowrate and the P/F(purge to feed) ratio on the process performance were evaluated. The cyclic steady-states of PSA process were reached to after 15 cycles. $H_2$ purity increases according as the P/F ratio and pressure increase and the feed flow rate decreases; however, $H_2$ recovery shows an opposite phenomena to the purity. PSA process simulation studied to find optimum operation condition. In the results, 22 LPM feed flowrate, 11 atm adsorption pressure and 0.10 P/F ratio might be optimal values to obtain more than 75% recovery and 99% purity hydrogen. In this study was non-isothermal and non-adiabatic model considering linear driving force(LDF) model and Langmuir-Freundlich adsorption isotherm considered to compare between prediction and experimental data.