• 유기물자원화
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• 제31권2호
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• pp.63-71
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• 2023

수계 내 질소의 증가는 부영양화나 녹조 및 적조현상을 유발하여 수계의 파괴 및 물의 자정능력을 저하시켜 전세계적으로 중요한 환경문제가 되었다. 수계 내 질소의 가장 일반적인 형태는 암모늄(NH₄⁺)이온의 형태로 폐수로부터 유입되는 가장 많은 부분을 차지하고 있으며 부영양화의 주요 원인이 되고 있어 암모늄 제거에 있어 적절한 처리 및 방안이 필요하다. 본 연구에서는 생장력이 좋은 바이오매스 중 하나인 수단그라스를 적용하여 바이오차를 생산하였으며, 200℃-400℃ 탄화 온도 조건 변화에 따른 과정에서 생성된 수단그라스 바이오차를 활용하여 암모늄 이온, 10~100ppm 농도 변화에 따른 흡착능력 분석하였으며, 이 결과를 통해 흡착제로써 활용 가능성을 평가하고자 하였다. 탄화반응으로 인해 수단그라스의 화학구조가 분해되면서 바이오차의 탄소 및 고정 탄소함량이 증가하였다. 바이오차의 pH는 탄화 온도가 높을수록 pH와 전기전도도가 높아지면서 전기전도도로 인해 양이온에 대해 높은 흡착 가능성을 보였다. 흡착실험 결과를 바탕으로 NH₄-N의 농도가 높아지면서 최대 54.5%, 최저 17.4%의 제거효율을 보였으며, 탄화 온도가 높을수록 바이오차의 기공 및 비표면적 증가로 인해 오염물질의 흡착이 용이해져 NH₄-N의 제거효율이 높아졌다. FT-IR 분석 결과, 탄화반응의 고온으로 인해 전체적인 표면 작용기의 감소가 나타났다.

• 한국산학기술학회논문지
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• 제21권7호
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• pp.667-674
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• 2020

활성탄에 의한 reactive orange 16 (RO 16) 염료의 흡착은 흡착제의 양, pH, 초기 농도, 접촉시간과 온도를 흡착변수로 사용하여 실험하였으며, 분리계수, 속도상수, 율속단계, 활성화 에너지, 엔탈피, 엔트로피, 자유에너지와 같은 공정 파라미터에 대해 조사하였다. RO 16의 흡착은 활성탄 표면의 양이온 (H⁺)과 RO 16이 가지고 있는 설포네이트 이온 및 수산 이온사이의 정전기적 인력으로 인해 pH 3에서 흡착율이 가장 높았다. 등온자료는 Langmuir, Freundlich 및 Temkin 등온식을 적용하였다. Freundlich 상수(1/n=0.398~0.441)와 Langmuir 분리계수(R_L=0.459~0.491)에 의해 활성탄에 의한 RO 16의 흡착조작은 적절한 제거방법임을 확인하였다. Temkin 식의 흡착에너지 (B_T=0.293~0.576 kJ/mol) 값으로부터 이 흡착공정이 물리흡착공정이라는 것을 알았다. 흡착 동력학 실험은 RO 16의 흡착이 유사이차반응속도식에 잘 맞는 것으로 나타났다. 흡착공정의 율속단계는 입자 내 확산 단계인 것이 확인되었다. 양수값의 엔탈피 변화는 물리흡착임을 나타냈다. 음수값의 깁스 자유에너지 변화는 온도가 올라갈수록 -3.16<-11.60<-14.01 kJ/mol 순으로 작아졌다. 따라서 RO 16의 흡착공정의 자발성이 온도가 증가할수록 높아진다는 것을 보여주었다.

• 공업화학
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• 제21권4호
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• pp.396-400
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• 2010

본 연구에서는 킬레이트 관능기가 도입된 활성탄소의 이산화탄소 흡착거동에 관하여 고찰하였다. 활성탄소에 peroxide의 열분해를 통해 glycidyl methacrylate를 그래프트 중합한 후 에폭사이드기에 킬레이트 관능기로서 diethylene triamine을 도입하였다. 킬레이트 관능기가 처리된 활성탄소의 표면특성은 scanning electron microscope와 X-ray photoelectron spectroscopy를 사용하여 측정하였으며, 흡착표면적과 기공도는 BET법을 이용한 $N_2$ 기체 흡착을 통해 알아보았다. 또한 킬레이트 관능기 처리된 활성탄소의 흡착특성을 비교하기 위해 이산화탄소의 흡착실험을 수행하였다. 실험 결과, 활성탄소 표면에 도입된 킬레이트 관능기는 비표면적 감소에 따른 물리적 흡착량이 감소하더라도 이산화탄소에 대한 선택적, 화학적 흡착량을 향상시킴을 알 수 있었다.

• 대한화학회지
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• 제36권1호
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• pp.137-146
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• 1992

양이온 교환된 천연 제올라이트 $K_{111}$의 CO 기체 흡착특성과 양이온효과를 연구하였다. $Na^+-,\;Cu^{2+}-\;및\;Ba^{2+}-\;K_{111}$ 의 경우 우수한 CO 흡착능을 가졌으며, 0.4N $BaCl_2$ 수용액으로 처리된 것이 가장 큰 CO 흡착능을 나타내었고, 합성 제올라이트 4A, 5A보다 뛰어난 흡착능을 가짐을 알 수 있었다. 양이온의 종류에 따른 흡착경향은 $Ba^{2+}>Cu^{2+}>Na^+>K^+>Mg^{2+}>Ca^{2+}$ 의 순서로 나타났으며 단위격자당 교환된 양이온의 수와 종류 그리고 세공의 크기 등이 CO 기체의 흡착에 있어 주요 인자로 작용함을 알 수 있었다. 그리고 K111의 양이온에 따른 흡착경향을 비교하기 위해서 CNDO/2 계산을 행하였다. 계산된 결과 8원환 모델 내의 양이온과 CO 기체와의 상호작용 에너지는 실험결과와 비슷한 경향임을 알 수 있었다.

• 한국산업보건학회지
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• 제5권2호
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• pp.119-127
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• 1995

The purpose of this study was to determine the effects of surface-treatment by zinc salts on break-through and adsorption capacity of toluene. Firstly, the coconut activated carbon treated the surface with zinc salts, were exposed by the spike sample(toluene, 69.02ppm, $260.1mg/m^3$), and then the effects of zinc salts were examined by using the gas adsorption kinetics. The results obtained were as follows : 1) BET(Brumaure Emmett Teller) surface area were $954.4m^3/g$ in coconut activated carbon treated with 0.0001 N $Zn(NO_3)_3$ $6H_2O$, and $830.3m^2/g$ in coconut activated carbon treated with 0.0001 N $ZnCl_2$. 2) Migration was decreased in coconut activated carbon treated with the thin level of zinc salts. 3) Breakthrough volume were 73.07 L in coconut activated carbon treated with 0.0001 N $Zn(NO_3)_3$ $6H_2O$, and 72.76 L in charcoal treated with 0.0001 N $ZnCl_2$. 4) ${\tau}$ values(the time required for 50% breakthrough) were 1046.1 min in coconut activated carbon treated with 0.0001 N $ZnCl_2$ and 921.2 min in coconut activated carbon treated with 0.0001 N $Zn(NO_3)_3$ $6H_2O$. 5) Maximum adsorption capacity was 53.9 mg/tube in coconut activated carbon treated with 0.0001 N $ZnCl_2$ and 47.4 mg/tube in coconut activated carbon treated with 0.0001 N $Zn(NO_3)_3$ $6H_2O$. In conclusion, the coconut activated carbon treated the surface with the thin concentration of zinc salts, decreased the breakthrough and increased the BET surface area and the adsorption capacity in case of sampling airborne toluene.

• Carbon letters
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• 제19권
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• pp.99-103
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• 2016

Porous carbons have attracted much attention for their novel application in gas storage. In this study, porous graphite nano-fiber (PGNFs)-based graphite nano fibers (GNFs) were prepared by KOH activation to act as adsorbents. The GNFs were activated with KOH by changing the GNF/KOH weight ratio from 0 through 5 at 900℃. The effects of the GNF/KOH weight ratios on the pore structures were also addressed with scanning electron microscope and N₂ adsorption/desorption measurements. We found that the activated GNFs exhibited a gradual increase of CO₂ adsorption capacity at CK-3 and then decreased to CK-5, as determined by CO₂ adsorption isotherms. CK-3 had the narrowest micropore size distribution (0.6–0.78 nm) among the treated GNFs. Therefore, KOH activation was not only a significant method for developing a suitable pore-size distribution for gas adsorption, but also increased CO₂ adsorption capacity as well. The study indicated that the sample prepared with a weight ratio of ‘3’ showed the best CO₂ adsorption capacity (70.8 mg/g) as determined by CO₂ adsorption isotherms at 298 K and 1 bar.

• 한국물환경학회지
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• 제28권2호
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• pp.197-201
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• 2012

The objective of this study was to evaluate the removal efficiency of arsenite and arsenate using composite adsorbents with various mixing ratio of recycled aluminum oxides and $TiO_2$. From batch adsorption experiments, while the removal of As(III) was almost same with 4 different composite samples in the entire pH range, the removal of As(V) was substantially increased as the weight ratio of $TiO_2$ in composite samples reduced and showed anionic adsorption characteristics. Both adsorption of As (III) and As(V) on composite samples followed pseudo-second-order adsorption equation and C-3 showed faster reaction rate for the removal of arsenic. From the adsorption isotherm experiments, Langmuir isotherm explained well and the maximum adsorption capacities of arsenic were obtained with C-1.

• Bulletin of the Korean Chemical Society
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• 제34권12호
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• pp.3570-3576
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• 2013

Poly(methacrylic acid)-functionalized SBA-15 silicas (denoted as P-x-PMA/SBA-15 where x is molar ratio of TSPM/(TEOS+TSPM) in percentage in the initial mixture) were synthesized by co-condensation of tetraethoxysilane and varying contents of 3-(trimethoxysilyl)propyl methacrylate in acidic medium with the block copolymer Pluronic 123 as a structure directing agent and then polymerization by methacrylic acid in the presence of ammonium persulfate as an initiator. The functionalized materials were characterized by PXRD, TEM, SEM, IR, and $N_2$ adsorption-desorption at 77 K. The investigation of phenol adsorption in aqueous solution on the materials showed that the poly(methacrylic acid)-functionalized mesoporous silicas possess strong adsorption ability for phenol with interaction of various kinds of hydrogen bonds. The adsorption data were fitted to Langmuir isotherms and the maximum adsorption capacity of the three functionalized materials P-5-PMA/SBA-15, P-10-PMA/SBA-15, and P-15-PMA/SBA-15 to be 129.37 mg/g, 187.97 mg/g, and 78.43 mg/g, respectively, were obtained. The effect of the pH on phenol adsorption was studied.

• 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.

• 환경위생공학
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• 제17권3호
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• pp.7-13
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• 2002

The removal efficiency of heavy metals by chitosan complex isolated from biological industrial waste was investigated through laboratory experiments. The results of the study are as follows. The adsorption kinetics of heavy metals were reached the equilibrium adsorption in approximately 30 minutes and the removal efficiency were showed 70.7～97.4%. The effect of temperature on heavy metals adsorption by chitosan complex shows that as the temperature increased, the amount of heavy metals adsorption per unit weight of chitosan complex increased. The correlation between amount of heavy metals adsorption per unit weight of chitosan complex and temperature were obtained through the coefficient of determination($R^2$). $R^2$ values were 0.75(p<0.05), 0.99(p<0.05) and 0.98(p<0.05) in Hg, Mn, and Zn, respectively. The injected chitosan complex in which 0.1 g was adsorpted highly and the removal of heavy metals was found to have the best removal efficiency A linearized Freundlich equation was used to fit the acquired experimental data. As a result, Freundlich constants, the adsorption intensity(I/n) was 0.5564, 0.4074, 0.5244 on the Hg, Mn, Zn, respectively And the measure of adsorption(k) was 2.2144, 1.6963, 2.0792 on the Hg, Mn, Zn, respectively. So, it was concluded that adsorption of heavy metals by chitosan complex is effective.