프러시안 블루를 담지한 커피박 바이오차의 세슘 흡착 제거

임영수,김동우,장지선,김보람,이대성 대한환경공학회 2021 대한환경공학회지 Vol.43 No.5

Objectives: Among various radioactive contaminants, radioactive cesium is one of the most harmful radionuclides that causes human health issues due to its high emission of gamma-ray, high solubility, high mobility, high fission yield, and long half-life. Different kinds of adsorbents have been developed for the removal of cesium from radioactive wastewater. Especially, biochar has attracted great attention as a potential adsorbent in the treatment of pollutants and for water purification. In addition, Prussian blue is a cubic lattice structure that contains a cage size similar to the hydrated cesium ionic radius, indicating it can selectively remove cesium ions. Therefore, the aim of this study is to investigate the cesium adsorption performance of synthesized Prussian blue-immobilized coffee ground biochar (PB-CGBC) under various experimental conditions for cesium removal from radioactive wastewater. Methods: After wasted coffee ground was washed and dried, it was heated at 400℃ with 10℃/min of heating rate and 5 h of retention time in a furnace with little or no available air. The PB-CGBC was synthesized using a facile co-precipitation method. Fourier transform-infrared spectroscopy, X-ray diffractometer, field emission-transmission electron microscope, Brunauer-Emmett-Teller, and zeta potential analyzer were used to analyze physico-chemical characteristics and surface structure of the synthesized adsorbents. The kinetic and equilibrium experiments of cesium adsorption on PB-CGBC were carried out and the effect of pH, temperature, initial cesium concentration, and contact time were also investigated in a batch system. Results and Discussion: The characteristic analysis clearly confirmed the successful synthesis of PB-CGBC, indicating its abundant functional groups and special surface structure. In the batch study, it was found that the cesium adsorption onto the PB-CGBC was exothermic nature. The Elovich kinetic model and Temkin isotherm also provided a good correlation with the cesium adsorption reaction onto the PB-CGBC. The maximum adsorption capacity of PB-CGBC for cesium was 129.57 mg/g at 15℃ and pH 8 at 40 mM of an initial cesium concentration, which was one of the highest values among those of previously reported adsorbents. Conclusions: In this study, the PB-CGBC was synthesized by immobilizing Prussian blue to the surface of coffee ground biochar and successfully applied for the adsorptive removal of cesium ions. Based on the experimental results, the synthesized PB-CGBC can be served as a great adsorbent for treatment of wastewater polluted with radioactive cesium. 목적: 방사성 세슘은 높은 감마선 방출량, 높은 용해성, 높은 이동성, 높은 핵분열율과 긴 반감기 때문에 인체에 가장 큰 악영향을 주는 방사성핵종 가운데 하나로 분류된다. 현재까지 다양한 흡착제가 액체 방사성폐기물 내 세슘을 제거하기 위해 개발되었다. 특히, 바이오차는 오염물질 처리와 수질 정화에 탁월한 흡착제로서 많은 주목을 받고 있다. 또한, 프러시안 블루는 면심입방구조체로서 수화된 세슘이온과 비슷한 크기의 격자구조를 가지고 있어 선택적인 세슘 제거가 가능하다. 따라서, 본 연구에서는 액체 방사성 폐기물 내 세슘 제거를 위해 다양한 실험 조건에서 프러시안 블루로 담지된 커피박 바이오차(PB-CGBC)의 세슘 흡착 성능을 조사하고자 한다. 방법: 폐기된 커피박을 세척하고 건조시킨 후 10℃/min의 열분해 속도와 5시간의 체류시간, 공기가 없는 400℃ 조건에서 열분해하였다. PB-CGBC는 간단한 공침법을 이용하여 합성하였다. 적외선/근적외선 분광광도계, X선 회절분석기, 전계방사형 투과전자현미경, 비표면적 및 기공도 측정기, 제타전위 분석기를 사용하여 흡착제의 물리・화학적 특성과 표면 구조를 분석하였다. 회분식 실험을 바탕으로 PB-CGBC의 세슘 흡착에 대한 흡착속도와 평형실험을 수행하였고 pH, 온도, 초기 세슘 농도 및 반응시간에 대한 영향인자 실험도 함께 진행하였다. 결과 및 토의: PB-CGBC의 특성 분석 결과로부터, PB-CGBC 표면에 풍부한 기능기 그룹이 존재하고 독특한 표면구조를 가지고 있음을 확인할 수 있었다. 회분식 흡착 실험에서 PB-CGBC의 세슘 흡착이 발열반응이며 Elovich 속도식과 Temkin 등온식이 PB-CGBC에 대한 세슘 흡착반응을 잘 나타냄을 확인할 수 있었다. PB-CGBC의 최대흡착량은 15℃, 초기 세슘 농도 40 mM, pH 8에서 129.57 mg/g으로 나타났는데 이는 선행 연구된 흡착제들과 비교했을 때, 가장 큰 값이었다. 결론: 커피박 바이오차 표면에 프러시안 블루을 담지하여 PB-CGBC를 합성하였으며, 이를 세슘 흡착제거에 성공적으로 적용할 수 있었다. 실험결과로부터 PB-CGBC는 방사성 세슘으로 오염된 폐수를 처리하기 위한 훌륭한 흡착제로서 사용할 수 있을 것이다.

Desorption of cesium from montmorillonite and vermiculite interlayers by surfactant intercalation

김보현,박찬우,서범경,문제권,이근우,박소진 한국공업화학회 2016 한국공업화학회 연구논문 초록집 Vol.2016 No.0

The importance of efficient cesium desorption from clay minerals has been increasingly recognized due to specific adsorption of radioactive cesium on clays, which inhibits successful remediation of cesium contaminated soils. Cesium ions are irreversibly adsorbed on clays by stable inner-sphere complex, thus it is difficult to remove cesium. Among clay minerals, a montmorillonite has the highest cesium adsorption capacity and cesium ions are adsorbed on interlayer. Vermiculite is expansible and has high cesium adsorption selectivity through frayed edge site. Hence, We studied cesium desorption from contaminated clay by intercalation of cationic surfactant in montmorillonite and vermiculite interlayer. The cationic surfactant, dodecyltrimethylammonium bromide (DTAB), showed adsorption on two clay and efficient desorption of cesium ion by exchange with trimethyl ammonium head group of DTAB. The intercalated surfactants were removed by decomposition reaction with hydrogen peroxide.

Dendropanax morbifera Léveille extract ameliorates cesium-induced inflammation in the kidney and decreases antioxidant enzyme levels in the hippocampus

Hyo Young Jung,권현정,한규리,Daeyoung Yoon,Woosuk Kim,Jong Whi Kim,김용재,Yeo Sung Yoon,Dae Won Kim,In Koo Hwang 대한독성 유전단백체 학회 2018 Molecular & cellular toxicology Vol.14 No.2

Backgrounds: In this study, we investigated the effects of Dendropanax morbifera Léveille leaf extract (DML) on cesium-exposed kidneys and hippocampi of rats. Methods: Seven-week-old Sprague-Dawley rats received a daily oral dose of 500 mg/kg cesium chloride and/or DML (30, 100, and 300 mg/kg) for 4 weeks. Animals were killed 2 h after the last cesium chloride and/or DML treatment. Blood, liver, and kidney cesium levels were assessed by inductively coupled plasma mass spectrometry. In addition, inflammatory parameters of the kidney such as inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, and IL-6 levels were measured by western blot analysis, and activity of antioxidant enzymes such as Cu, Zn-superoxide dismutase (SOD1), catalase (CAT), and glutathione peroxidase (GPx) was assessed in the hippocampus. Results: Cesium chloride treatment significantly increased the levels of cesium in blood, and in the kidney and liver by 200 times or more, but the administration of DML did not show any significant effect on the levels of cesium in any tissue. Nevertheless, the administration of DML significantly ameliorated the cesium-induced increase in iNOS, COX-2, TNF-α, IL-1β, and IL-6 levels in the kidney in a dose-dependent manner. In addition, the administration of DML reversed the cesium-induced decrease in the levels of antioxidant enzymes such as SOD1 and GPx, but not of CAT, in the hippocampus. Conclusion: These results suggest that DML reduces the cesium-induced inflammatory response in the kidney and the hippocampal decrease in antioxidant enzymes levels, although it could not decrease the accumulation of cesium in the blood, kidney, and liver.

MCNP Simulation Based Optimization of Prussian Blue for Cesium Removal

So On Park,Byung Sik Lee,Su Jung Min,Bum Kyoung Seo,Chang hyun Roh,Sang Bum Hong 한국방사성폐기물학회 2023 한국방사성폐기물학회 학술논문요약집 Vol.21 No.2

The nuclear fuel that melted during the Fukushima nuclear accident in 2011 is still being cooled by water. In this process, contaminated water containing radioactive substances such as cesium and strontium is generated. The total amount of radioactive pollutants released by the natural environment due to the nuclear accident in Fukushima in 2011 is estimated to be 900 PBq, of which 10 to 37 PBq for cesium. Radioactive cesium (137Cs) is a potassium analog that exists in the water in the form of cations with similar daytime behavior and a small hydration radius and is recognized as a radioactive nuclide that has the greatest impact on the environment due to its long half-life (about 30 years), high solubility and diffusion coefficient, and gamma-ray emission. In this study, alginate beads were designed using Prussian blue, known as a material that selectively adsorbs cesium for removal and detection of cesium. To confirm the adsorption performance of the produced Prussian blue, immersion experiments were conducted using Cs standard solution, and MCNP simulations were performed by modeling 1L reservoir to conduct experiments using radioactive Cs in the future. An adsorption experiment was conducted with water containing standard cesium solution using alginate beads impregnated with Prussian blue. The adsorption experiment tested how much cesium of the same concentration was adsorbed over time. As a result, it was found that Prussian blue beads removed about 80% of cesium within 10-15 minutes. In addition, MCNP simulation was performed using a 1 L reservoir and a 3inch NaI detector to optimize the amount of Prussian blue. The results of comparing the efficiency according to the Prussian volume was shown. It showed that our designed system holds great promise for the cleanup and detection of radioactive cesium contaminated seawater around nuclear plants and/or after nuclear accidents. Thus, this work is expected to provide insights into the fundamental MCNP simulation based optimization of Prussian blue for cesium removal and this work based MCNP simulation will pave the way for various practical applications.

Cesium-induced inhibition of bacterial growth of Pseudomonas aeruginosa PAO1 and their possible potential applications for bioremediation of wastewater

Kang, S.M.,Jang, S.C.,Heo, N.S.,Oh, S.Y.,Cho, H.J.,Rethinasabapathy, M.,Vilian, A.T.E.,Han, Y.K.,Roh, C.,Huh, Y.S. Elsevier Scientific Pub. Co 2017 Journal of hazardous materials Vol.338 No.-

Radioactive isotopes and fission products have attracted considerable attention because of their long lasting serious damage to the health of humans and other organisms. This study examined the toxicity and accumulation behavior of cesium towards P. aeruginosa PAO1 and its capacity to remove cesium from waste water. Interestingly, the programmed bacterial growth inhibition occurred according to the cesium environment. The influence of cesium was analyzed using several optical methods for quantitative evaluation. Cesium plays vital role in the growth of microorganisms and functions as an anti-microbial agent. The toxicity of Cs to P. aeruginosa PAO1 increases as the concentration of cesium is increased in concentration-dependent manner. P. aeruginosa PAO1 shows excellent Cs removal efficiency of 76.1% from the contaminated water. The toxicity of cesium on the cell wall and in the cytoplasm were studied by transmission electron microscopy and electron dispersive X-ray analysis. Finally, the removal of cesium from wastewater using P. aeruginosa PAO1 as a potential biosorbent and the blocking of competitive interactions of other monovalent cation, such as potassium, were assessed. Overall, P. aeruginosa PAO1 can be used as a high efficient biomaterial in the field of radioactive waste disposal and management.

A feasibility study of cesium removal using Rhodococcus erythropolis

( Seong-sik Kim ),( Chang-hyun Jeon ),( Yun-hui Jeon ),( Woong Kim ) 한국폐기물자원순환학회(구 한국폐기물학회) 2019 한국폐기물자원순환학회 심포지움 Vol.2019 No.1

The half-lives of ¹³⁴C₃, ¹³⁵C₃, and ¹³⁷C₃ which are radioactive waste fission-producing nuclear species, have a long half-life of 2.1 years, 2.3 million years, and 30 years, respectively. (Avery. 1995; Dekker et al. 2014) In addition, high solubility and bioavailability of monovalent cesium ions make it an important nuclear waste. Above all, cesium is easily absorbed into the organism because it is similar to the absorption system of potassium (K), which is a vital element, causing environmental pollution and destruction in the soil and seawater. Finally, It exposes humans for a long time and causes serious diseases. (the food chain), (Avery 1995; Mosquera et al. 2006; Charkraborty et al. 2007) Recently, cesium removal studies using various strains have been carried out using the biological characteristics of cesium. This study was aimed to biologically remove cesium with Rhodococcus erythropolis. These bacteria were cultured in BS (Base selective) medium at pH 7.5 for 24 h at 28 °C. The maximum uptake of Cs⁺ on Rhodococcus erythropolis was 1564.221 and 727.196 mg/g, when the concentrations were 75 and 10 mg/L, respectively, proposing the strategy for effective and efficient way to treat radioactive waste materials using cesium-resistant bacterial as potential biosorbent.

수중의 세슘처리를 위한 수처리 기술 동향 및 개선방안

정우창 ( Woochang Jeong ),여우석 ( Wooseok Yeo ),이병락 ( Beong Rak Lee ),김종규 ( Jong Kyu Kim ) 한국수처리학회(구 한국수처리기술연구회) 2017 한국수처리학회지 Vol.25 No.5

Cesium-137 is one of the most dangerous and ubiquitous radionuclides that has been released to the eco system and human being. Many treatment methods have been used to remove cesium particles, such as adsorption, ion exchange, filtration, coagulation and precipitation. Recently, various studies have been carried out using Prussian blue which has a high adsorption effect not only in the eco system but also on the removal of cesium absorbed in the human body. However, despite the excellent effect of removing cesium, Prussian blue has a disadvantage in separation and reuse due to its difficulty in recovering from water because of its high water-solubility characteristics. In order to overcome this disadvantage, a post-treatment process such as a separate filtration process or a secondary adsorption process is required, which is not efficient in terms of environmental and economic aspects. Recently, a research study combining a magnetic materials and Prussian blue showed that cesium particles in water were effectively removed. However, when the external magnetic field is present, the recovery rate is kept high, but the recovery rate is decreased due to the inability to magnetize itself. Therefore, if a super magnetic material having a magnetic force higher than that of a conventional magnetic material and a ferromagnetic material magnetizing itself after application of an external magnetic field are actively studied, it will be possible to effectively remove cesium from the water in an environmentally friendly and economical way.

2P-761 Cesium-induced Inhibition of Bacterial Growth of Pseudomonas aeruginosa PAO1 and Their Possible Potential Applications for Bioremediation of Wastewater

허윤석,강성민,허남수,오서영,( Muruganantham Rethinasabapathy ),( A. T. Ezhil Vilian ),한영규 한국공업화학회 2017 한국공업화학회 연구논문 초록집 Vol.2017 No.1

This study examined the toxicity and accumulation behavior of cesium towards P. aeruginosa PAO1 and its capacity to remove cesium from waste water. The toxicity of P. aeruginosa PAO1 increases as the concentration of cesium is increased in concentration-dependent manner. P. aeruginosa PAO1 shows excellent Cs removal efficiency of 76.1% from the contaminated water. The toxicity of cesium on the cell wall and in the cytoplasm were studied by transmission electron microscopy and electron dispersive X-ray analysis. Finally, the removal of cesium from wastewater using P. aeruginosa PAO1 as a potential biosorbent and the blocking of competitive interactions of other monovalent cation, such as potassium, were assessed. Overall, P. aeruginosa PAO1 can be used as a high efficient biomaterial in the field of radioactive waste disposal and management.

A Study on the Decontamination Performance of Cesium by Soil Washing Process With Flocculating Agent

Jong Soon Song,Sun Il Kim 한국방사성폐기물학회 2018 방사성폐기물학회지 Vol.16 No.1

원전사고 및 시설보수 과정에서 방출되는 방사성물질 중 137Cs은 토양의 주 오염원 중 하나이다. 세슘으로 인한 토양오염은 주민의 거주 및 공업용지로의 재사용을 위해 제염이 불가피하다. 본 연구에서는 다양한 토양복원 기술 중 국내·외에서 실 제 방사성물질로 오염된 토양에 적용한 사례가 있는 토양세척 기술을 선정하였다. 토양세척 공정은 세척제를 사용하여 토양 과 세슘의 표면장력을 약화시켜 토양과 세슘을 분리하는 원리이다. 이러한 토양세척 공정의 세척수 재사용을 통해 공정효율 을 높이고자 세척수에 응집제를 적용하여 미세토양 및 세슘의 제거 성능 실험을 수행하였다. ICP-OES를 통해 세슘 수용액 에 토양을 첨가하여 세슘을 흡착시킨 후 응집제를 첨가하여 세슘의 농도를 측정하였으며 응집제 적용시 최대 세슘 제거율은 약 88%, 최소는 67%였다. Visual MINTEQ Code를 통한 세슘과 토양과의 종결합을 예측하였으며 탁도 측정을 통해 응집제 투여 후 탁도를 측정하여 세척수의 재사용 여부 및 미세토양 제거율을 분석하였다. Radioactive substances, especially 137Cs discharged in the course of Nuclear Power Plant Accident or maintenance of power plants, cause contamination of the soil. For habitation of residents and reuse of industrial land, it is inevitably necessary to decontaminate the soil. This study examines a soil washing process that has actually been used for washing of radioactivecontaminated soil. The soil washing process uses a washing agent to weaken surface tension of the soil and cesium, separating cesium from the soil. In this study, in order to raise the efficiency of the process, a flocculating agent was added to the washing water to remove fine soil and cesium. The cesium concentrations before and after applying the flocculating agent to cesium solution were measured through ICP-OES. When using 0.1 g of J-AF flocculating agent in the experiment, the maximum Cs removal performance was approximately 88%; the minimum value was 67%. Species combinations between cesium and soil were predicted using Visual MINTEQ Code; the ability to reuse the washing water or not, and the removal rate of the fine soil, determined via measurement of the turbidity after applying the flocculating agent, were determined.

Optimization of Sorbents for Radiocesium Removal and Risk Assessment of Secondary Contamination

( Jaehyun Lee ),( Weon Shik Han ),( Jong Gil Park ),( Sungwook Choung ),( Jeonghwan Hwang ) 대한지질공학회 2019 대한지질공학회 학술발표회논문집 Vol.2019 No.2

There are many safety measures to prevent accidents at a nuclear power plant, but unexpected situations can occur that cause severe radiation accidents. Leakage of cesium-137 causes widespread contamination in water resources due to the high water solubility. In this situation, sorbents can be used to remove cesium, and it is important to calculate the effect of the factors involved in the sedimentation of the sorbents and determine the optimum conditions. In addition, transport modeling of desorbed cesium-137 from settled sorbents was performed to analyze the risk of secondary contamination. The study was carried out with 3 kinds of sorbents: illite, zeolite and activated carbon. First, the database of settling time was constructed by the influence of diameter, shape, and roughness that confirmed by Dietrich's method. And the adsorption time was calculated with regression analysis of the equilibrium adsorption experiments of illite and black carbon. After that, the particle size and depth of water conditions for the maximum efficiency were derived. The secondary contamination of cesium-137 can be affected by the desorption rate of the sorbent, the amount of cesium, and hydraulic properties. Therefore, by using EOS7R module of TOUGH2, 2D model which can consider the half-life and sorption at the aquifer are predicted. As a result, the risk of the actual secondary contamination is not large due to the high distribution coefficient which cesium-137 has. However, in order to predict more precisely, it is necessary to consider the situation where mobility of cesium increases such as colloid-facilitated transport.