• 한국환경과학회지
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• 제17권5호
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• pp.565-571
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• 2008

The surface properties of activated carbon modified by acids and base were studied. The influence of the surface chemistry on the adsorption of benzene and acetone vapor on modified activated carbons has been investigated The modified activated carbons were obtained by treatment with acetic acid ($CH_3COOH$), nitric acid ($HNO_3$) and sodium hydroxide (NaOH). The modified activated carbons had similar porosity but different surface chemistry and adsorption characteristics. The total surface acidity (sum of functional groups) of activated carbon (AC-AN) treated by nitric acid was 2.6 times larger than that of activated carbon (AC) before the acid treatment. Especially, carboxyl group was much developed by nitric acid treatment. The benzene equilibrium adsorption capacity of AC-AN decreased 20% more than that of AC. However, the acetone equilibrium adsorption capacity of AC-AN increased 20% more than that of AC because of the large increase of carboxyl group and acidity.

• Membrane and Water Treatment
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• 제11권4호
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• pp.275-282
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• 2020

Hranfa's marl, a local natural mineral, is selected for the decontamination by adsorption of aqueous effluents in textile industry. Its physicochemical characterization is first performed. It is composed mainly of Calcite, Quartz, Ankerite and Muscovite. Its specific surface area is 40 ㎡ g^-1. Its adsorption performance is then tested in batch conditions using an industrial organic dye, Bemacid Red E-TL, as a model pollutant. The measured adsorption capacity of Hranfa's marl is 16 mg g^-1 which is comparable to that of other types of natural adsorbents. A hybrid process is tested coupling adsorption of the dye on marl in suspension and microfiltration. An adsorption reactor is inserted into the circulation loop of a microfiltration pilot using ceramic membranes. This makes possible a continuous extraction of the treated water provided that a periodic replacement of the saturated adsorbent is done. The breakthrough curve obtained by analyzing the dye concentration in the permeate is close to the ideal one considering that no dye will cross the membrane as long as the adsorbent load is not saturated. These first experimental data provide proof of concept for such a hybrid process.

• Membrane and Water Treatment
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• 제15권3호
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• pp.107-115
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• 2024

This study proposes the recycling of MVS as a value-added product for the removal of phosphate from aqueous solutions. By comparing the phosphate adsorption capacity of each calcined adsorbent at each temperature of MVS, it was determined that the optimal heat treatment temperature of MVS to improve the phosphate adsorption capacity was 800 ℃. MVS-800 suggests an adsorption mechanism through calcium phosphate precipitation. Subsequent kinetic studies with MVS-800 showed that the PFO model was more appropriate than the PSO model. In the equilibrium adsorption experiment, through the analysis of Langmuir and Freundlich models, Langmuir can provide a more appropriate explanation for the phosphate adsorption of MVS-800. This means that the adsorption of phosphate by MVS-800 is uniform over all surfaces and the adsorption consists of a single layer. Thermodynamic analysis of thermally activated MVS-800 shows that phosphate adsorption is an endothermic and involuntary reaction. MVS-800 has the highest phosphate adsorption capacity under low pH conditions. The presence of anions in phosphate adsorption reduces the phosphate adsorption capacity of MVS-800 in the order of CO 3 2-, SO 4 2-, NO 3- and Cl-. Based on experimental data to date, MVS-800 is an environmentally friendly adsorbent for recycling waste resources and is considered to be an adsorbent with high adsorption capacity for removing phosphates from aqueous solutions. This paper combines the advantages of gray predictor and AI fuzzy. The gray predictor can be used to predict whether the bear point exceeds the allowable deviation range, and then perform appropriate control corrections to accelerate the bear point to return to the boundary layer and achieve.

• Membrane and Water Treatment
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• 제7권5호
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• pp.403-416
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• 2016

The possibility of using carica papaya leaf powder for removal of copper from wastewater as a low cost adsorbent was explored. Different parameters that affect the adsorption process like initial concentration of metal ion, time of contact, adsorbent quantity and pH were evaluated and the outcome of the study was tested using adsorption isotherm models. A maximum of 90%-94.1% copper removal was possible from wastewater having low concentration of the metal using papaya leaf powder under optimum conditions by conducting experimental studies. The biosorption of copper ion was influenced by pH and outcome of experimental results indicate the optimum pH as 7.0 for maximum copper removal. Copper distribution between the solid and liquid phases in batch studies was described by isotherms like Langmuir adsorption and Freundlich models. The adsorption process was better represented by the Freundlich isotherm model. The maximum adsorption capacity of copper was measured to be 24.51 mg/g through the Langmuir model. Pseudo-second order rate equation was better suited for the adsorption process. A dynamic mode study was also conducted to analyse the ability of papaya leaf powder to remove copper (II) ions from aqueous solution and the breakthrough curve was described by an S profile. Present study revealed that papaya leaf powder can be used for the removal of copper from the wastewater and low cost water treatment techniques can be developed using this adsorbent.

• 한국물환경학회지
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• 제21권1호
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• pp.14-20
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• 2005

A feasibility study has been conducted regarding the application of waste coffee grounds as an adsorbent for the treatment of nickel ion containing wastewater. The major variables which considered to influence the adsorbability of nickel ion were its initial concentration, reaction temperature, pH, and coexisting ion. The specific surface area of coffee grounds used in the experiment was found to be ca. $39.67m^2/g$, which suggesting its potential applicability as an adsorbent due to its relatively high surface area. In the experimental conditions, more than 90% of the initial amount of nickel ion was shown to adsorb within 15 minutes and equilibrium in adsorption was attained after 3 hours. The adsorption behavior of nickel ion was well explained by Freundlich model and kinetics study showed that the adsorption reaction was second-order. Adsorption was reduced with temperature and its change of enthalpy in standard state was estimated to be -807.05 kJ/mol. Arrhenius equation was employed for the calculation of the activation energy of adsorption and nickel ion was observed to adsorb on coffee grounds exoentropically based on thermodynamic estimations. As pH rose, the adsorption of nickel ion was diminished presumably due to the formation of cuboidal complex with hydroxide ion and the coexistence of cadmium ion was found to decrease the amount of nickel ion adsorption, which was proportional to the concentration of cadmium ion.

• 한국토양환경학회지
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• 제1권2호
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• pp.43-50
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• 1996

The adsorption charateristics of lead(II) ions on Aspergillus niger and Rhizopus arrhizus were investigated. Adsorption amount of A. niger and R. arrhizus was about 95 mg/g and 25 mg/g, respectively. These biomass was approached to adsorption equilibrium within reaction time of 1hr because of their high reactivity. The uptake of lead ion by A. niger was less sensitivity than it by R. arrhizus on the inhibition effect of alkali metals and the decreasing ratio of uptake of lead ion of A. niger and R. arrhizus by inhibition effect of alkali metals was 37% and 50%, respectively. In pre-treatment on these biomass, NaOH treatment was contributed high adsorption capacity to these biomass. Then, adsorption amount of A. niger and R. allhizus was increased about 25 mg/g and 10 mg/g, respectively. In isotherm for the adsorption of lead ion based on Freundlich equation, 1/n value of A. niger and R. ar고izus was calculated the range of 0.28-0.56 and 0.44-0.67, respectively.

• 한국연초학회지
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• 제25권2호
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• pp.111-119
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• 2003

In this work, Rayon-based activated carbon fiber(KF-1500) was treated by HN $O_3$ and $H_2$S $O_4$ with different conditions. Specific surface areas(SSA, $S_{BET}$) of the treated activated carbon fibers were decreased by acidic treatment but, total surface acidities and surface functional groups were increased. In spite of the decrease of SSA, propylamin(PPA) adsorption and removal ability by activated carbon fiber(ACF) were increased by nitric acid treatment compared with the raw-ACF(KF-1500) and coconut based activated carbon. However, acidic treated activated carbon fibers were available to removal for various amines and contaminants by adsorption.n.

• 분석과학
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• 제5권1호
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• pp.1-5
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• 1992

Amberlite XAD 고분자수지 및 고분자수지 대체흡착제인 rice bran, rice straw 그리고 sawdust에 대한 petroleum oil의 흡착량을 최저 흡착조건에서 뱃치법으로 측정하여 조사하였다. Rice bran과 rice straw에 대한 petroleum oil의 흡착량은 XAD계열수지의 흡착량의 약 50% 정도로 흡착성이 우수하였다. 또한 이들 대체흡착제의 흡착능을 증대시키기 위한 탄화시간은 $200^{\circ}C$, 30분이 최적 조건이었다. Sawdust의 경우에는 30% MeOH 매질에서는 흡착성이 매우 약한 반면 0.5M NaCl 매질에서는 XAD수지 흡착능이 약 1/2에 도달하였다. Rice bran과 rice straw는 외관상의 구조차이와는 관계없이 비슷한 흡착능력을 보였다. 따라서 rice bran과 rice straw들은 XAD계열 수지에 대한 대체흡착제로 충분한 흡착능력을 가지고 있는 것으로 보인다.

• 토지주택연구
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• 제15권1호
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• pp.167-177
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• 2024

본 연구에서는 하이드로사이클론, 응결/응집, 용존공기부상 단일 공정이 결합한 실 규모 물순환 조합공정(HCFD)의 오염 지표수 처리 성능을 평가하였다. 실 규모 물순환 공정은 수질 변동이 큰 유입 원수를 대상으로 안정적인 수처리 효율을 보였으며, 유입수의 주요 수질 지표가 매우 나쁨(BOD, TP, COD) 혹은 약간 나쁨(SS)이었으나, 방류수는 매우 좋음(BOD, SS, TP) 혹은 좋음(COD) 수준으로 향상되었다. 물순환 시스템 방류수의 후속 고도 처리를 위해 활성탄 기반 흡착 공정의 용존성 유기물 및 미량오염물질(잔류의약물질 APAP 및 산업 화학물질 AO7) 처리 잠재성을 평가하였다. 오염원 흡착 특성은 흡착동역학 및 등온 흡착실험과 관련된 모델링 기법을 이용하여 관찰하였다. 실험 결과, 후처리 활성탄 흡착은 잔류 유기물, APAP, AO7 유기물에 대한 높은 오염원 제거 잠재성이 있음이 확인되었으며, 오염원 흡착속도 및 최대 흡착량 값은 유사 2차 반응속도 모델과 Langmuir 등온흡착 모델에 의해 결정되었다. 본 연구 결과, 활성탄 기반 흡착 공정은 기존의 물순환 조합공정과 연계시 수처리 효율을 상호 보완적으로 높이고, 흡착 공정은 전단의 입자 분리 공정으로 제거가 어려운 용존성 오염원의 후속 처리에 대한 높은 잠재성이 있음을 시사한다.

• 공업화학
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• 제25권2호
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• pp.167-173
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• 2014

정수 슬러지를 재활용하여 제조한 펠렛형 흡착제의 트리메틸아민과 암모니아의 흡착 특성을 연구하였다. 펠렛형 흡착제를 $110^{\circ}C$에서 건조 처리 했을 때보다 $500^{\circ}C$에서 소성했을 때 BET 표면적과 기공 부피가 증가하는 것을 알 수 있었다. 정수 슬러지를 재활용하여 제조한 펠렛형 흡착제는 브뢴스테드 산점과 루이스 산점을 보유하는 것을 확인하였다. 흡착질 가스인 트리메틸아민과 암모니아가 일정한 농도로 흡착제 층으로 유입되고, 흡착제의 중량과 흡착질의 선속도를 변화시키면서 흡착질 가스의 파과시간을 측정하였다. Wheeler의 흡착속도식을 사용하여 트리메틸아민과 암모니아의 동적흡착용량과 흡착속도상수를 결정하였다. 동적흡착용량과 흡착속도상수가 흡착질 가스의 선속도에 따라 변화함을 알 수 있었다. 정수 슬러지를 재활용하여 제조한 펠렛형 흡착제 상에서, 다양한 흡착조건에서 트리메틸아민과 암모니아의 파과시간을 예측하기 위한 실험식을 도출하였다.