• 한국광물학회지
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• 제20권4호
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• pp.327-337
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• 2007

흰색, 노란색, 정제된 노란색 등 3 가지 종류의 영동 일라이트에 대하여 정량 X선 회절분석법에 의하여 광물조성을 구하였으며, 레이저 입도분석기를 이용하여 입자 크기 및 입도 분포를 측정하였다. 영동 일라이트의 인산염 흡착 특성을 규명하기 위하여 배치(batch) 흡착 실험을 실시하였다. 흰색 일라이트는 노란색 일라이트에 비하여 적은 양의 일라이트를 포함하고 있지만, 입자 크기는 더 작다. 정제된 노란색 일라이트는 정제하지 않은 시료에 비하여 월등히 많은 일라이트를 포함하며, 입자 크기도 훨씬 미세하다. 일라이트의 양이 많아짐에 따라 인산염의 흡착률은 대체로 증가하는 경향을 보이는데 반하여, pH가 증가하면 인산염의 흡착량은 감소하는 경향을 나타낸다. 일반적으로 일라이트의 함량이 많고, 입자 크기가 미세할수록 인산염의 흡착량이 증가하지만, 일라이트의 함량이 적은 흰색일라이트가 노란색 일라이트보다 더 많은 인산염을 흡착하는 이유는 작은 입자 크기, 높은 층간 전하, 낮은 사면체 자리의 치환에 기인한 것으로 여겨진다. 흰색 일라이트는 랑미어 흡착등온선, 노란색 일라이트는 프로인드리히 흡착등온선에 더욱 잘 부합하는 경향을 보여주고 있다.

• 상하수도학회지
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• 제28권4호
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• pp.453-459
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• 2014

The excessive concentration of phosphorus in the river and reservoir is a deteriorating factor for the eutrophication. The converter slag was used to remove the phosphate from the synthetic wastewater. Influencing factors were studied to remove soluble orthophosphate with the different particle sizes through the batch and the column experiments by continuous flow. Freundlich and Langmuir adsorption isotherm constants were obtained from batch experiments with $PS_A$ and $PS_B$. Freundlich isotherm was fitted better than Langmuir isotherm. Regression coefficient of Freundlich isotherm was 0.95 for $PS_A$ and 0.92 for $PS_B$, respectively. The adsorption kinetics from the batch experiment were revealed that bigger size of convert slag, $PS_A$ can be applied for the higher than 3.5 mg/L of phosphate concentration. The pilot plant of continuous flow was applied in order to evaluate the pH variation, breakthrough points and breakthrough adsorption capacity of phosphate. The variation of pH was decreased through the experimental hours. The breakthrough time was 1,432 and 312 hours to 10 mg/L and 50 mg/L for the influent concentration, respectively. The breakthrough adsorption capacity was 3.54 g/kg for 10 mg/L, and 1.72 g/kg for 50 mg/L as influent phosphate concentration.

• 상하수도학회지
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• 제31권6호
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• pp.521-527
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• 2017

Phosphorus is one of the limiting nutrients for the growth of phytoplankton and algae and is therefore one of leading causes of eutrophication. Most phosphorous in water is present in the form of phosphates. Different technologies have been applied for phosphate removal from wastewater, such as physical, chemical precipitation by using ferric, calcium or aluminum salts, biological, and adsorption. Adsorption is one of efficient method to remove phosphates in wastewater. To find the optimal media for phosphate removal, physical characteristics of media was analysed, and the phosphate removal efficiency of media (silica sand, slag, zeolite, activated carbon) was also investigated in this study. Silica sand showed highest relative density and wear rate, and phosphate removal efficiency. Silica sand removed about 36% of phosphate. To improve the phosphate removal efficiency of silica sand, Fe coating was conducted. Fe coated silica sand showed 3 times higher removal efficiency than non-coated one.

• Bulletin of the Korean Chemical Society
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• 제35권6호
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• pp.1817-1824
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• 2014

The adsorption characteristics of chromium (VI) and phosphate on calcined Mg-Al-$CO_3$ layered double hydroxides (CLDH) were investigated in single and binary systems. A series of batch experiments were performed to study the influence of various experimental parameters. In this study, CLDH exhibited a high adsorption capacity for Cr (VI) and P in a single system. The experimental data were close to the theoretical adsorption capacity given by the Langmuir isotherm, the calculating adsorption capacities of Cr (VI) and P were up to 70.42 mg/g and 97.09 mg/g, respectively. It was found that the initial pH was approximately 6 and it took 24 h to reach equilibrium when P and Cr (VI) were added simultaneously. The experimental data were best fitted by a pseudo-second-order kinetics model. Competitive adsorption between Cr (VI) and P existed in the binary system. The presence of Cr (VI) had no significant influence on P adsorption. However, the suppression of Cr (VI) adsorption was obvious when the initial concentration of P was up to 10 mg/L with a concentration of 0.5 g/L of CLDH.

• 상하수도학회지
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• 제23권1호
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• pp.113-119
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• 2009

The feasibility of using cork oak bark for phosphorus removal from wastewater was evaluated in this study. Recently, development of more cost-effective media while maintaining high efficiency in pollutants removal has received concern. Barks have a negative surface charge and, hence, tend to show a high affinity to bind cations, and they need to undergo chemical modification to increase their adsorption capacity of anions. Bark was hydrolyzed by HCl solution and it received modification using an aqueous solution of high molecular weight polyethylenimine(PEI). Surface modification with HCl and PEI resulted in a decrease of specific surface area of the bark from $1.932 m^2/g$ to $1.094 m^2/g$. The adsorption experiments were carried out in batch tests and the data were fitted to the Langmuir isotherm and Freundlich isotherm equations. Phosphate removal rate was higher at the lower solution pH possibly due to the form of phosphate ion in solution. For the initial phosphate concentration of 10 mg/L, maximum adsorption was 20.88 mg P/g at pH 3 and 12.02 mg P/g at pH 5. Mechanism of phosphorus sorption onto the HCl-PEI bark was examined through FT-IR spectrometer. Ion exchange between $NH^+$ and $H_2PO_4{^-}$ appeared to be a key mechanism of phosphate adsorption onto the HCl-PEI bark surface.

• 상하수도학회지
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• 제31권4호
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• pp.281-287
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• 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.

• Advances in environmental research
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• 제3권2호
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• pp.163-172
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• 2014

Magnetite was chosen as a typical adsorbent to study its phosphate adsorption capacity in water body with low concentration of phosphorus (below $2mg\;PL^{-1}$). Magnetite was collected from Luoyang City, Henan Province, China. In this research, three factors have been studied to describe the adsorption of phosphate on magnetite, which was solution concentration (concentration ranging from 0.1 to $2.5mg\;PL^{-1}$), suspension pH (1 to 13) and temperature (ranging from $10^{\circ}C$ to $40^{\circ}C$). In addition, the modified samples had been characterized with XRD and FE-SEM image. The results show that iron ions contains in magnetite were the main factors of phosphorus removal. The behavior of phosphorus adsorption to substrates could be fitted to both Langmuir and Freundlich isothermal adsorption equations in the low concentration phosphorus water. The theoretical saturated adsorption quantity of magnetite is 0.158 mg/g. pH has great influence on the phosphorus removal of magnetite ore by adsorption. And pH of 3 can receive the best results. While temperature has little effect on it. Magnetite was greatly effective for phosphorus removal in the column experiments, which is a more practical reflection of phosphorous removal combing the adsorption isotherm model and the breakthrough curves. According to the analysis of heavy metals release, the release of heavy metals was very low, they didn't produce the secondary pollution. The mechanism of uptake phosphate is in virtue of chemisorption between phosphate and ferric ion released by magnetite oxidation. The combined investigation of the magnetite showed that it was better substrate for water body with low concentration of phosphorus.

• 상하수도학회지
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• 제27권5호
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• pp.631-639
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• 2013

국내 하수처리장 인 방류기준이 강화되어 다양한 방법의 인 제거기술이 적용되고 있다. 흡착은 비교적 간단하면서 효과적으로 인을 제거할 수 있다. 본 연구에서는 흡착제인 Fe-Mn-Si oxide와 Fe-Mn oxide을 개발하여, 인 제거효율을 검토하였으며 이 흡착제에 대하여 Kinetic과 Isotherm모델을 비교하였다. 두 흡착제의 최대흡착양은 각각 47.8, 35.5 mg-$PO{_4}^{3-}/g$이었고, 이들은 낮은 pH에서 효과적으로 흡착하였다. Freundlish isotherm 모델이 Langmuir 모델보다 Fe-Mn-Si oxide의 흡착에 더 적합했다. 이온성 용액은 인이 흡착되는 과정에서 음이온들과 경쟁관계로 흡착능이 감소되었다. 비록 음이온과 humic물질들로부터 흡착에 영향을 받지만 Fe-Mn-Si oxide는 Fe-Mn oxide보다 흡착능이 크게 나타났다.

• 한국광물학회지
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• 제21권2호
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• pp.117-127
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• 2008

카올리나이트 KGa-2 (표준 점토)의 인산염 흡착-탈착 특성을 규명하기 위하여 벳치(batch) 흡착 실험을 실시하였으며, 흡착 상태를 알아보기 위하여 ATR-FTIR (Attenuated Total Reflectance-Fourier Transform Infrared) 분광분석을 실시하였다. 인의 함량은 UV-VIS-IR 분광분석 기를 사용하여 측정하였으며, 이 때 파장은 820 nm를 이용하였다. pH 4에서 pH 9 범위 내에서 카올리나이트 KGa-2의 인산염 흡착량은 pH가 증가하면 대체적으로 증가하는 경향을 나타내지만, 인산염 농도에 따라 매우 다른 형태를 보여준다. 카올리나이트 KGa-2의 인산염 흡착 특성은 랑미어 흡착등온선, 템킨 흡착등온선, 프로인드리히 흡착등온선 순으로 잘 부합하며, 랑미어 최대 흡착능은 $204.1{\sim}256.5\;mg/kg$, 평균간은 232.5 mg/kg으로서, 카올리나이트 KGa-1b에 비하여 높은 인산염 흡착능을 가진다. 카올리나이트에 흡착된 대부분의 인산염이 탈착되기보다, 광물 내에 고착되는 경향을 나타내지만 이에 대해서는 후속적인 실험이 필요한 것으로 판단된다. ATR${\sim}$FTIR 스펙트럼에서 카올리나이트에 의한 흡수피크의 위치가 인 피크와 거의 중첩되고, 카올리나이트에 의한 흡수 피크의 강도가 인 피크에 비하여 월등히 크기 때문에 카올리나이트에 흡착된 인에 의한 피크를 카올리나이트 자체에 의한 피크로부터 분리하는 것이 거의 불가능하였다.

• 대한환경공학회지
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• 제32권8호
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• pp.761-766
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• 2010

본 연구에서는 인 및 암모니아 흡착에 효과적인 La(III) 및 제올라이트를 적절히 결합하여 호소수 및 연못 등의 질소 및 인을 동시에 효과적으로 제거할 수 있는 La(III)-zeolite 복합체 개발을 목적으로 하였다. 연구 결과 La(III)-zeolite 복합체 제조 시 최적 결합 비는 0.0048 La(III) g:1 zeolite g 인 것으로 나타났다. 복합체 제조 시 건조 온도는 인 흡착에 결정적인 영향을 주는 것으로 나타났는데 상온 건조가 가장 적합한 것으로 관찰되었다. La(III)-zeolite 복합체 최적 주입량은 4.052 g/L로 나타났다. La(III)-zeolite 복합체 주입 시 최적 흡착 시간은 90 분으로 나타났다. 수용액상에서 알칼리도의 존재는 암모니아 및 인흡착에 긍정적인 영향을 주는 것으로 관찰되었다. 상온에서 건조시킨 La(III)-zeolite 복합체는 용액 내에서 La(III)의 탈리 현상이 관찰되지 않았으며, 이는 La(III)-zeolite 복합체가 인을 흡착하여 바닥에 가라앉은 후 바닥으로부터 용출되는 인을 효과적으로 차단 할 수 있음을 의미한다.