팔라디움과 인디움을 담지한 Al 층간가교 몬모릴로나이트 촉매의 수중 질산성질소 환원 특성

정상조 ( Sangjo Jeong ) 한국물환경학회(구 한국수질보전학회) 2018 한국물환경학회지 Vol.34 No.6

In this study, catalyst was made through incipient wetness method using palladium (Pd) as noble metal, indium (In) as secondary metal, and montmorillonite (MK10) and Al pillared montmorillonite (Al-MK10) as supporters. The nitrate reduction rate of the catalysts was measured by batch experiments where H2 gas was used as reducing agent and formic acid as pH controller. Transmission electron microscopy (TEM) equipped with energy dispersive spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS) were all used to determine the elemental distribution of Pd, In, Al, and Si on catalysts. It was observed that Al pillaring increased the Al/Si elemental composition ratio and point of zero charge of MK10, but decreased its BET specific surface area and pore volume. The nitrate reduction rate of Al-MK10 Pd/In was 2.0 ~ 2.5 times higher than that of MK10 Pd/In using artificial groundwater (GW) in ambient temperature and pressure. Nitrate reduction rates in GW were 1.2 ~ 1.7 times lower than those in distilled deionized water (DDW). Nitrate reduction rates in acidic conditions were higher than those in neutral condition in both GW and DDW. The amount of produced NH3-N over degraded NO3- at acid conditions was lower than that of neutral condition. Even though the leaching of Pd after reaction was measured in DDW it was not detected when both Al-MK10 Pd/In and MK10 Pd/In were used in GW. The modification of montmorillonite as a supporter significantly increased the reductive catalytic activities of nitrates. However, the ratio of producing ammonia by-products to degraded nitrates in ambient temperature and pressure was similar.

Palladium 촉매와 포름산을 활용한 액상 trinitrotoluene 분해 특성 연구

정상조 ( Sangjo Jeong ),최형진 ( Hyungjin Choi ),박상진 ( Sangjin Park ),이준일 ( Juneil Lee ) 한국물환경학회 2015 한국물환경학회지 Vol.31 No.5

Various methods to degrade explosives efficiently in natural soil and water that include trinitrotoluene (TNT) have been studied. In this study, TNT in water was degraded by reduction with palladium (Pd) catalyst impregnated onto alumina (henceforth Pd-Al catalyst) and formic acid. The degradation of TNT was faster when the temperature of water was high, and the initial TNT concentration, pH, and ion concentration in water were low. The amounts of Pd-Al catalyst and formic acid were also important for TNT degradation in water. According to the experimental results, the degradation constant of TNT with unit mass of Pd-Al catalyst was 8.37 min-1g-1. The degradation constant of TNT was higher than the results of previous studies which used zero valent iron. 2,6-diamino-4-nitrotoluene and 2-amino-4,6-dinitrotoluene were detected as by-products of TNT degradation showing that TNT was reduced. The by-products of TNT were also completely degraded after reaction when both Pd-Al catalyst and formic acid existed. Even though there are several challenges of Pd-Al catalyst (e.g., deactivation, poisoning, leaching, etc.), the results of this study show that TNT degradation by Pd-Al catalyst and formic acid is a promising technique to remediate explosive contaminated water and soil.

The properties of carbonaceous materials that control sorption capacities of hydrophobic organic contaminants

정상조(Sangjo Jeong),챨리 월스(Charles J. Werth),조원희(Won hee Jo),한욱(Uk Han) 대한지질학회 2005 지질학회지 Vol.41 No.3

아세트산을 조절인자로 제작한 크롬 기반 금속유기골격체의 diisopropyl methyl phosphonate 흡착 특성 연구

정상조 ( Sangjo Jeong ) 한국공업화학회 2023 공업화학 Vol.34 No.6

크롬 기반 금속유기골격체(MIL-101(Cr))를 제조하고 이들을 활용한 유사화학작용제 diisopropyl methyl phosphonate(DIMP) 흡착 실험을 통해 방독면 정화통이나 보호의 충진물질로서 활용 가능성을 평가하였다. MIL-101(Cr)은 조절인자로 아세트산(MIL-101(Cr)-A)과 수산화나트륨(MIL-101(Cr)-N)을 활용하여 각각 제작하였는데, 아세트산을 조절인자로 사용하였을 때 보다 넓은 비표면적과 높은 DIMP 흡착량을 보였다. MIL-101(Cr)-A는 상대습도 90% 환경에서 10일동안 노출 시 흡착제 무게 대비 약 160%의 수분을 흡수하여 활성탄 등 다른 흡착제와 비교할 때 흡수율이 높았다. MIL-101(Cr)-A를 상대습도 90% 환경에서 일정기간 노출한 시료에 대한 DIMP 흡착량 실험 결과 24시간 이후에는 노출되지 않았을 때 흡착량의 약 40% 수준으로 감소하였으나, 이 흡착량은 상용 방독면 정화통 충진 활성탄과 비교하였을 때 여전히 높은 흡착량으로 추후 방독면 정화통이나 보호의 충진물질로서 활용가능성이 높은 것으로 판단된다. Chromium-based metal-organic frameworks (MIL-101(Cr)) were synthesized, and their potential use as a filling material for gas masks or protective clothing was assessed through adsorption experiments using diisopropyl methyl phosphate (DIMP) as a simulant for chemical warfare agents. MIL-101(Cr) was prepared using acetic acid (MIL-101(Cr)-A) and sodium hydroxide (MIL-101(Cr)-N) as modulators. The use of acetic acid as a modulator resulted in a larger specific surface area and a higher DIMP adsorption capacity. MIL-101(Cr)-A absorbed approximately 160% of its own weight of moisture when exposed to an environment with a relative humidity of 90% for 10 days, surpassing other adsorbents such as activated carbon. The DIMP adsorption capacity of MIL-101(Cr)-A decreased to about 40% of its initial adsorption capacity after 24 hours of exposure to an environment with a relative humidity of 90%. However, this capacity is still higher compared to that of activated carbon used in commercial gas masks, suggesting a high potential for future use as a filling material for gas masks or protective clothing.

오대호 퇴적물에 포함된 크롬의 시공간적 변화에 관한 연구

정상조,한욱,Jeong, Sangjo,Han, Uk 대한자원환경지질학회 1996 자원환경지질 Vol.29 No.1

The vertical concentration profiles of chromium in sediment cores were measured from Lakes Superior, Michigan, and Ontario in an attempt to determine spatial and historical variations. Pre-industrial concentrations of chromium are typical for soils in the Great Lakes region. Only Lakes Ontario and Michigan exhibit anthropogenic enrichments of chromium in the sediments. Sediment profiles in Lakes Ontario and Michigan indicate that the rates of anthropogenic chromium loading to the Great Lakes region are decreasing. Focusing corrected inventories are similar within each lake and those are higher in Lake Ontario than Lake Michigan. The results are interpreted to indicate that there is a small atmospheric component to chromium inputs to the Great Lakes and that the relative importance of this input decreases from Lake Superior to Lake Ontario.

극초단파(마이크로파)와 첨가제를 이용한 오염토양 내 준휘발성 유기오염물질 제거

정상조,최형진,Jeong, Sangjo,Choi, Hyungjin 한국지하수토양환경학회 2013 지하수토양환경 Vol.18 No.1

To improve the energy efficiency of conventional thermal treatment, soil remediation with microwave has been studied. In this study, the remediation efficiency of contaminated soil with semi-volatile organic contaminants were evaluated with microwave oven and several additives such as water, formic acid, iron powder, sodium hydroxide (NaOH) solution, and activated carbon. For the experiment, loamy sand and sandy loam collected from Imjin river flood plain were intentionally contaminated with hexachlorobenzene and phenanthrene, respectively. The contaminated soils were treated with microwave facility and the mass removals of organic contaminants from soils were evaluated. Among additives that were added to increase the remediation efficiency, activated carbon and NaOH solution were more effective than water, iron powder, and formic acid. When 10 g of hexachlorobenzene (142.4 mg/kg-soil) or phenanthrene (2,138.8 mg/kg-soil) contaminated soil that mixed with 0.5 g iron powder, 0.5 g activated carbon and 1 ml 6.25 M NaOH solution were treated with microwave for 3 minutes, more than 95% of contaminants were removed. The degradation of hexachlorobenzene during microwave treatments with additives was confirmed by the detection of pentachlorobenzene and tetrachlorobenzene. Naphthalene and phenol were also detected as degradation products of phenanthrene during microwave treatment with additives. The results showed that adding a suitable amount of additives for microwave treatments fairly increased the efficiency of removing semi-volatile soil organic contaminants.

실험실 규모 칼럼에서의 팔라디움-인디움-알루미나 촉매를 이용한 지하수 내 질산성질소 제거

김홍현 ( Hong-hyun Kim ),정상조 ( Sangjo Jeong ) 한국수처리학회(구 한국수처리기술연구회) 2018 한국수처리학회지 Vol.26 No.5

In order to develop optimal operation conditions for nitrate removal in a continuous flow system which has a 5% palladium-0.65% indium on alumina catalyst, the effects of initial concentration of nitrate, flow rate, and temperature were evaluated. First, the rates of nitrate removal decreased from 100% to 69% when the initial concentration of nitrate increased from 150 mg/L to 300 mg/L. Second, as the flow rate of nitrate decreased from 2 ml/min to 0.5 ml/min, the nitrate removal efficiency increased from 40% to 80% when the initial concentration of nitrate was 300 mg/L. Third, when increasing the column temperature from 0℃ to 80℃, the removal rate of nitrate increased from 20% to 96%. In addition, the production of N₂, NO₂^-, NH₄ ⁺, and changes of pH due to the reduction of nitrate were analyzed. In order to reactivate the catalyst, treatment using 56 mM NaOCl solution was more efficient than that using 56 mM H₂O₂ or 1 M HCOOH. The characteristics of the various parameters derived from the laboratory scale column experiments are thought to be of great help in the operation of nitrate removal system in the field.

The studies on the temperature and thermal properties of the active layer soil at the Sejong Station, Antarctica

한욱(Uk Han),이춘기(Choon-Ki Lee),정상조(Sangjo Jeong),이방용(Bang Yong Lee),남상헌(Sang Heon Nam) 대한지질학회 2006 지질학회지 Vol.42 No.4

서로 다른 산을 조절인자로 활용하여 제조한 지르코늄 기반 금속유기골격체의 Diisopropyl Methylphosphonate 흡착 특성

장원형 ( Wonhyeong Jang ),김홍현 ( Honghyun Kim ),정상조 ( Sangjo Jeong ) 한국공업화학회 2021 공업화학 Vol.32 No.5

UiO-66은 높은 흡착능력과 구조적 및 열적 안정성 등으로 여러 현장에 적용 가능한 금속유기골격체(MOF)이다. UiO-66은 제조과정에서 조절인자로 사용되는 산의 종류와 양에 따라 구조적 특성이 변형되고, 화학작용제 흡착 능력을 높일 수 있다고 알려져 있다. 이에 본 연구에서는 다양한 산을 조절인자로 첨가하여 UiO-66을 합성하고, 그 특성을 FT-IR, XRD, 적정장치, 그리고 유사화학작용제 diisopropyl methylphosphonate (DIMP)를 활용한 흡착실험을 통해 분석하였다. 연구 결과 UiO-66의 제조과정에서 염산을 첨가할 시 UiO-66의 Zr-OH 결합과 UiO-66의 유기연결체인 테레프탈산 구조에 일부 손상이 있었다. 특히 이러한 구조 손상은 염산의 농도가 일정 수준 이상으로 높을 때, 그리고 합성시간이 일정 시간 이상으로 길어질 때 발생하였다. 하지만 아세트산과 포름산을 조절인자로 활용하여 제조한 UiO-66은 구조적 손상이 발견되지 않았으며, 염산을 활용하여 제조한 UiO-66에 비하여 결정도, 비표면적, 공극의 부피, 그리고 DIMP 흡착 능력이 모두 높게 나타나 향후 화학작용제 흡착제로서 활용 가능성이 높을 것으로 판단되었다. Depending on the type and amount of acid used as a modulator in the manufacturing process, the structural properties of UiO-66 can be modified and the adsorbability of chemical warfare agents can be enhanced. In this study, several acids as a modulator were used to synthesize UiO-66. Their properties were analyzed with FT-IR, XRD, titrator, and adsorption isotherms using chemical warfare agent simulant, DIMP. The UiO-66, structurally damaged by hydrochloric acid as a modulator, showed lower crystallinity and DIMP adsorption capacity and also smaller specific surface area and volume of voids compared to those of UiO-66, which was manufactured using acetic acid, and formic acid as a modulator. Additionally, UiO-66 which was synthesized by adding formic acid and hydrochloric acid as a modulator, showed the highest DIMP adsorption capacity and is likely to be used as an adsorbent for chemical warfare agent in the future.

방음벽 높이에 따른 헬기 비행장 소음 저감효과 연구

박정태(Jungtae Park),김홍현(Hong-Hyun Kim),정상조(Sangjo Jeong),최형진(Hyung-Jin Choi) 한국소음진동공학회 2021 한국소음진동공학회 논문집 Vol.31 No.4