• 한국환경과학회지
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• 제16권11호
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• pp.1279-1285
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• 2007

The activated carbon was prepared from waste citrus peels using NaOH. With the increase of NaOH ratio, iodine adsorptivity and specific surface area of the activated carbon prepared were increased, but activation yield was decreased. The optimal condition of activation was at 300% NaOH and $700^{\circ}C$ for 1.5 hr. For the activated carbon produced under optimal condition, iodine adsorptivity was 1,006 mg/g, specific surface area was $1,356 m^2/g$, and average pore diameter was $20{\sim}25{\AA}$. From the adsorption experiment for benzene vapor in fixed bed reactor, it was found that the adsorption capacity of activated carbon prepared from waste citrus peel was higher than that of activated carbon purchased from Calgon company. This result implied that the activated carbon prepared from waste citrus peel could be used for gas phase adsorption.

• 펄프종이기술
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• 제39권1호
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• pp.38-47
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• 2007

This study was carried out to develop a new application field and obtain the basic data of citrus peel as waste in Jeju island and traditional Hanji for producing functional Hanji. The results measuring physical and optical properties, water vapor permeance and antibacterial activity are as follows. It was revealed that apparent density go as down but bulk raise up in the structural view of Hanji with increasing of the addition various Korean citrus peel (citrus unshiu, cheonggyun and hanrabong peel, and citrus unshiu peel powder) percentages, and that the density of Hanji added citrus unshiu peel was higher, but bulk was lower in compared with Hanji added other kinds of peel. Those Hanji added citrus unshiu peel, cheonggyun peel, hanrabong peel and citrus unshiu powder were very great not only in the strength (breaking length, burst index, tear index and folding endurance) but also in water vapor permeant rate in comparison with Hanji. The pHs of Hanji were neutrality (7 to 8). The brightness of the Hanji added various citrus peel percentages was low in compared to Hanji, and the 40% addition of hanrabong peel was the lowest. When 40% hanrabong peel was added to Hanji, it was very yellow in the color degree. When cheonggyun peel was added to Hanji manufacture, water vapor permeant rate was highly effective. It is known that vacant space of intrafiber was reduced by image analysis of Hanji and the additions of peel of citrus unshiu, cheonggyun and hanrabong were distributed equally in the interior of Hanji. The antibacterial activity of Hanji added citrus unshiu peel is more than 98%. After all, it would be able to increase utilization of Hanji, extensively. Namely, production of high quality Hanji added functional materials is expected for new valuable industry of citrus peel and Hanji.

• 한국환경과학회지
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• 제27권6호
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• pp.401-410
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• 2018

Waste citrus peel-based activated carbon (WCAC) was prepared from waste citrus peels by activation with KOH. The removal of Cu and Pb ions from aqueous solution by the prepared WCAC was investigated in batch experiments. The solution pH significantly influenced Cu and Pb adsorption capacity and the optimum pH was 4 to 6. The adsorption of Cu and Pb ions by WCAC followed pseudo-second-order kinetics and the Langmuir isotherm model. The maximum adsorption capacity calculated by Langmuir isotherm model was 31.91 mg/g for Cu and 92.22 mg/g for Pb. As the temperature was increased from 303 K to 323 K, the ${\Delta}G^{\circ}$ value decreased from -7.01 to -8.57 kJ/mol for Cu ions and from -0.87 to -2.06 kJ/mol for Pb ions. These results indicated that the adsorption of Cu and Pb by WCAC is a spontaneous process.

• 공업화학
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• 제35권1호
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• pp.42-47
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• 2024

벤튜리를 이용한 진공건조 공정에 의해 폐 감귤박으로부터 리모넨을 분리하고 건조된 감귤박을 이용하여 바이오 에탄올을 생산하였다. 벤튜리를 이용한 진공건조가 열풍건조 및 자연건조에 비해 수분 및 리모넨의 제거에 매우 효과적이었으며, 벤튜리 진공건조에 의해 건조된 감귤박이 에탄올 발효에 가장 적절하였다. 벤튜리 진공건조에 의해 15시간 동안 건조된 감귤박의 수분 및 리모넨 함량은 각각 17.0% 및 3.2%이었다. 벤튜리 진공건조에 의해 리모넨을 함유한 정유와 플로럴 워터를 각각 얻을 수 있었으며, 벤튜리 진공건조에 의해 분리된 정유의 양은 4.21 mL/kg 감귤박이었고, 분리된 정유의 79.9%는 리모넨이었다.

• 공업화학
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• 제29권4호
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• pp.369-375
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• 2018

폐감귤박 활성탄(WCAC, waste citrus peel based activated carbon)에 의한 항생제 아목시실린(AMX)의 흡착에서 온도, 초기농도, 접촉시간 및 흡착제 투여량과 같은 운전변수의 영향을 조사하기 위해 회분식 실험을 수행하였다. 흡착 속도 및 등온 실험결과는 각각 유사 2차 속도식 및 Langmuir 등온 모델에 의해 잘 설명될 수 있었다. Langmuir 등온 모델로부터 계산된 WCAC에 의한 AMX의 최대 흡착량은 345.49 mg/g이었다. WCAC에 의한 AMX의 흡착은 흡착 과정에서 막 확산(외부 물질 전달)과 입자 내부 확산이 동시에 일어난다는 것을 보여 주었다. 흡착 속도는 WCAC의 입자 크기가 증가함에 따라 외부 물질 전달보다 입자 내부 확산에 의해 더 영향을 받았고, 입자 내부 확산이 율속 단계였다. 열역학적 파라미터는 WCAC에 의한 AMX의 흡착 반응은 흡열반응이고 자발적인 과정임을 나타내었다.

• 한국식품과학회지
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• 제9권4호
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• pp.245-250
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• 1977

밀감 과피의 효율적인 건조방법과 건조특성을 알기 위하여 온도, 표면적의 변화, 종류, 화학적 및 물리적 처리후의 건조등에 대하여 열풍건조 실험을 하였다. (1) 상온하에서 자연건조시는 $3{\sim}6$일에 수분함량을 70%에서 20%까지 떨어뜨릴 수 있었다. (2) 온도에 따른 열풍건조는 $60^{\circ}C$에서 50분가량 소요되는 것을 관찰할 수 있었으며 $60^{\circ}C$이상에서는 별다른 건조속도의 증가를 볼 수없었다. (3) 표면적의 효과를 보기 위하여 256등분으로 하여 표면적을 약 2배로 한결과 건조시간이 50분에서 15분으로 단축되는 것을 볼 수 있었다. (4) 문단(文旦)과 병교을 제외하곤 밀감의 종류에 따른건조속도의 변화는 볼 수 없었다. (5) 소석회 처리와 압착후 건조는 둘다 건조시간을 단축시킬 수 있으나 생과피의 경우는 별다른 잇점이없고 최초수분함량이 $1200{\sim}1300%$인 경우는 유리하다고 보아진다. 결론적으로 온주밀감및 대부분의 감귤과피는 잘게 썰어서 $60^{\circ}C$에서 열풍건조 하면 15분정도에서 수분함량을 10%이하까지 건조할 수 있으며 연중을 통하여 유효성분을 추출할 수있는 원료가 될 수 있다고 판단된다.

• 공업화학
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• 제29권3호
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• pp.270-277
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• 2018

반응 표면법(RSM)과 Box-Behnken 설계(BBD) 통계 방법을 사용하여 폐감귤박으로 만든 활성탄(WCAC)에 의한 염료 Eosin Y의 흡착을 검토하였다. 실험은 Eosin Y의 농도(Conc. : 30~50 mg/L), 용액 온도(Temp. : 293~313 K) 및 흡착제 투여량(Dose : 0.05~0.150 g/L)의 3가지 입력 변수를 가진 BBD에 따라 수행하였다. 염료 Eosin Y 제거에 대해 얻어진 2차 다항식 모델의 회귀분석 결정계수($R^2$) 값이 0.9851이고 적합성 결여(Lack of fit)의 p 값은 0.342로 실험 데이터는 2차 다항식 모델에 잘 부합하였다. 염료 농도 50 mg/L, 온도 333 K 및 흡착제 투여량 0.1056 g에서 최적 염료 흡착량 59.3 mg/g이 얻어졌다. WCAC에 의한 Eosin Y의 흡착공정은 유사 2차 속도식에 의해 잘 기술되었으며, 등온 실험결과는 Langmuir 모델식을 따랐다.

• 공업화학
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• 제28권6호
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• pp.649-654
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• 2017

제주도에서 다량 발생하고 있는 폐감귤박을 활성화제로 KOH를 사용하여 활성탄을 제조하였고, 제조된 활성탄의 특성을 검토하였다. KOH 침적비율(100~300%), 활성화 온도($400{\sim}900^{\circ}C$) 및 활성화 시간(0.5~1.5 h)의 조건에서 각 조건이 증가할수록 요오드 흡착능은 증가하였으나 활성탄의 수율은 감소하였다. 그리고 활성화 시간의 경우 1.5 h 이상에서는 요오드 흡착능 및 활성탄 수율에서 비슷하였다. 또한 KOH 침적비율이 증가할수록 비표면적 및 세공부피는 증가하였으나 세공크기는 감소하였으며, 제조된 평균 세공크기는 $20{\sim}25{\AA}$이었다. KOH의 침적비율 300%, 활성화 온도 $900^{\circ}C$, 활성화 시간 1.5 h에서 제조된 활성탄은 비표면적 및 요오드 흡착능이 각각 $1,527m^2/g$ 및 1,246 mg/g으로 가장 높았다.

• 한국환경과학회지
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• 제27권11호
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• pp.1095-1104
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• 2018

The adsorption characteristics of bisphenol A (BPA) were investigated using activated carbon based on waste citrus peel (which is abandoned in large quantities in Jeju Island), denoted as WCP-AC, and surface-modified with various $P_2O_5$ concentrations (WCP-SM-AC). Moreover, coconut-based activated carbon (which is marketed in large amounts) was surface-modified in an identical manner for comparison. The adsorption equilibrium of BPA using the activated carbons before and after surface modification was obtained at nearly 48 h. The adsorption process of BPA by activated carbons and surface-modified activated carbons was well-described by the pseudo second-order kinetic model. The experimental data in the adsorption isotherm followed the Langmuir isotherm model. With increasing $P_2O_5$ concentration (250-2,000 mg/L), the amounts of BPA adsorbed by WCP-SM-AC increased till 1,000 mg/L of $P_2O_5$; however, above 1,000 mg/L of $P_2O_5$, the same amounts adsorbed at 1,000 mg/L of $P_2O_5$ were obtained. With increasing reaction temperature, the reaction rate increased, but the adsorbed amounts decreased, especially for the activated carbon before surface modification. The amounts of BPA adsorbed by WCP-AC and WCP-SM-AC were similar in the pH range of 5-9, but significantly decreased at pH 11, and increased with increasing ionic strength due to screening and salting-out effects.

• 한국환경과학회지
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• 제31권8호
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• pp.691-706
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• 2022

Magnetic activated carbon was prepared by adding a magnetic material to activated carbon that had been prepared from waste citrus peel in Jeju. The adsorption characteristics of an aqueous solution of the antibiotic trimethoprim (TMP) were investigated using the magnetic activated carbon, as an adsorbent, and response surface methodology (RSM). Batch experiments were carried out according to a four-factor Box-Behnken experimental design affecting TMP adsorption with their input parameters (TMP concentration: 50~150 mg/L; pH: 4~10; temperature: 293~323 K; adsorbent dose: 0.05~0.15 g). The significance of the independent variables and their interaction was assessed by ANOVA and t-test statistical techniques. Statistical results showed that TMP concentration was the most effective parameter, compared with others. The adsorption process can be well described by the pseudo-second-order kinetic model. The experimental isotherm data followed the Langmuir isotherm model. The maximum adsorption capacities of TMP, estimated with the Langmuir isotherm model were 115.9-130.5 mg/g at 293-323 K. Also, both the thermodynamic parameters, ΔH and ΔG, have both positive values, indicating that the adsorption of TMP by the magnetic activated carbon is an endothermic reaction and proceeds via an involuntary process.