• Proceedings of the Korean Radioactive Waste Society Conference
• /
• 한국방사성폐기물학회 2018년도 추계학술논문요약집
• /
• pp.379-379
• /
• 2018

MXenes are a new family of 2D transition metal carbide nanosheets analogous to graphene (Lv et al., 2017; Sun et al., 2018). Due to the easy availability, hydrophilic behavior, and tunable chemistry of MXenes, their use in applications for environmental pollution remediation such as heavy metal adsorption has recently been explored (Li et al., 2017). In this study, three-dimensional (3D) MXene ($Ti_3C_2T_x$) films with high adsorption capacity, good mechanical strength, and high selectivity for specific radionuclide from aquose solution were successfully fabricated by a polymeric precursor method using vacuum-assisted filtration. The highest removal efficiency on the films was 99.54%, 95.61%, and 82.79% for $Sr^{2+}$, $Co^{2+}$, and $Cs^+$, respectively, using a film dosage of 0.06 g/ L in the initial radionuclide solution (each radionuclide concentration = 1 mg/L and pH = 7.0). Especially, the adsorption process reached an equilibrium within 30 min. The expanded interlayer spacing of $Ti_3C_2T_x$ sheets in MXene films showed excellent radionuclide selectivity ($Cs^+$ and/or $Sr^{2+}/Co^{2+}$) (Simon, 2017). Besides, the MXene films was not only able to be easily retrieved from an aqueous solution by filtration after decontamination processes, but also to selectively separate desired target radionuclides in the solutions. Therefore, the newly developed MXene ($Ti_3C_2T_x$) films has a great potential for radionuclide removal from aqueous solution.

• Journal of Microbiology and Biotechnology
• /
• 제30권1호
• /
• pp.118-126
• /
• 2020

Silicon and phosphorus are elements that are beneficial for plant growth. Despite the abundant availability of silicate and phosphate in the Earth's crust, crop nutritional requirements for silicon and phosphorus are normally met through the application of fertilizer. However, fertilizers are one of the major causes of heavy metal pollution. In our study, we aimed to assess silicate and phosphate solubilization by the bacteria Enterobacter ludwigii GAK2, in the presence and absence of phosphate [Ca₃(PO₄)₂] or silicate (Mg₂O₈Si₃), to counteract cadmium stress in rice (Oryza sativa L). Our results showed that the GAK2-treated rice plants, grown in soil amended with phosphate [Ca₃(PO₄)₂] or silicate (Mg₂O₈Si₃), had significantly reduced cadmium content, and enhanced plant growth promoting characteristics including fresh shoot and root weight, plant height, and chlorophyll content. These plants showed significant downregulation of the cadmium transporter gene, OsHMA2, and upregulation of the silicon carrier gene, OsLsi1. Moreover, jasmonic acid levels were significantly reduced in the GAK2-inoculated plants, and this was further supported by the downregulation of the jasmonic acid related gene, OsJAZ1. These results indicate that Enterobacter ludwigii GAK2 can be used as a silicon and phosphorus bio-fertilizer, which solubilizes insoluble silicate and phosphate, and mitigates heavy metal toxicity in crops.

• The Korean Journal of Malacology
• /
• 제9권2호
• /
• pp.85-93
• /
• 1993

Contamination of heavy metals in water and sediments along Mantyeong (river) has reached up to critical level, The object of the study is to dlucidate some macroinvertebrates which inhabit along the river in respect to the modulatory role in reducing the pollution. For the purpose, Scapharca subcrenata(sea shell) which is common in numbers and biomass in the area was collected, and cadmium (Cd) was subjected as a reference metal in the experiment. The seashell was dried and autoclaved, followed by pellet preparation under various concentration of Cd: 50,100,250,500 and 1,500 ug /pellet. Mice were fed for 3 months, althrough last group(5 mice), 1,500 ug/pellet, died within 4 weeksof the administration.MT-Cd in liver and kidney increased in correlation with the amont of Cd concentration in pellet, especially in kidney than in liver. Liver and kidney of the mice showed pathological changes such as cellular infiltration and focal necrosis in liver, and peri-tubular cell infiltration or tubular necrosis etc. The changes were more intensive by amount of the Cd. Overall results in the present study suggest that Cd may eventually combine with soluble-protein forming metalloprotein, then reduce the toxicity of heavy metal, How the formed Mt-Cd is discharged from the kidney and the mechanism shall be the further subject to be clarified.

• Applied Chemistry for Engineering
• /
• 제22권3호
• /
• pp.332-335
• /
• 2011

As our interests in eco-friendly materials have been significantly increased, the utilization of porous zeolite concrete that has structural functionality and permeability has been increased. In this paper, the mixture of porous concrete and zeolite, which can be used as multirole boulders, was investigated for the suitability of an environment-friendly product by evaluating of the water purification ability. The contamination removal rates of BOD, TOC, T-N, and T-P in stagnant water tank were 70.6, 67.0, 57.7, and 50.6%, respectively. Also for the non-point source pollution with the inflow and the outflow, the removal rates of Zn, Pb, BOD, and COD were 99.9, 90.0, 69.2, and 33.5%, respectively. The performance of the heavy metal contamination removal for the porous zeolite showed better than that of stagnant system. Therefore, it is expected that the installation of the porous zeolite concrete can play a role as an eco-friendly products by its high contamination removal.

• Journal of the Korean Home Economics Association
• /
• 제33권1호
• /
• pp.19-32
• /
• 1995

The purpose of this study is to investigate the consumer safety problems appeared in the Korean mass media-the newspaper(the Kong-A Ilbo and the Chosun Ilbo) and the consumer magazines(the Sobija-Sidae and the Sobija) from 1991 to 1993. I use the content analysis of the articles related with consumer safety through the above mass media. The results are (1) the goods-services areas that are severe in the consumer safety problem are food, environment, medicine, electric appliances, services(restaurant, medical service), and etc. (2) the most important problem areas are Toxic ingredients(remaining agricultural chemicals and heavy metal), Food additionals, Sanitary problem, Hygiene products hazard, Safety accident, Environmental pollution, etc. (3) the goods-service area and the consumer safety problem are different according to the publication year and the mass media type.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
• /
• 한국측량학회 2006년도 춘계학술발표회 논문집
• /
• pp.345-351
• /
• 2006

습지나 얕은 바다에 존재하는 중금속의 분포를 모델링하는 것은 그 곳의 생태계를 보존하기 위해 꼭 필요한 일이다. 본 연구에서는 GIS(Geographic Information System) 기법 및 위성영상, 실제 대상지역 측량자료를 이용하여 베트남의 동남쪽에 있는 메콩강 삼각주 지역의 중금속 분포를 예측하는 기법을 제안하였다. 이를 위해 중금속의 분포에 영향을 미치는 공간적 요소(Spatial factor)와 구조적 요소(Structural factor)를 통계적으로 처리함으로써 대상지역에 대한 As(arsenic) 오염도를 예측하였다. 또한 중금속 오염되었다고 평가된 지역을 위성영상을 이용하여 표현함으로써 본 연구의 결과를 시각적으로 제시하였다.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 한국지하수토양환경학회 2000년도 창립총회 및 춘계학술발표회
• /
• pp.41-45
• /
• 2000

Geotube is made of permeable but soil-tight geotextile, hydraulically filled with soil include dredged sand and mud, which has been successfully applied in hydraulic and coastal engineering projects. Ceotube method is getting popular and being used a lot in many countries of the world because of the simplicity of the placement and construction, cost effectiveness and minimum impact on the environment, and enable to store & isolate contaminated materials as obtained by harbor dredging. Laboratory tests and field construction were performed to determine the design methodology and construction procedures. From the results of laboratory and field construction, the retention ratio of solid particle is a minimum 86%. The minimum permeability and the tensile strength of geotextile are $\alpha$ x 10$^{-4}$ cm/sec and 20t/m, respectively Also, based on the environmental test results, it can be concluded that this method does meet the Korean EPA standards.

• Proceedings of the Korea Air Pollution Research Association Conference
• /
• 한국대기환경학회 2003년도 추계학술대회 논문집
• /
• pp.461-462
• /
• 2003

산업의 발달과 함께 자연의 자정능력 한계를 넘어선 오염은 인간의 생존을 위협하는 심각한 사회문제로 대두되기에 이르렀다. 지금까지 대기오염에 대한 관심은 주로 실외대기, 즉 건물의 바깥쪽에 있는 대기오염에 편중되어 있었다. 대도시 및 중ㆍ소 공업 도시 등 대기오염이 문제되는 지역에서의 하루 생활은 하루 24시간 중 80％이상을 실내 공간에서 생활하고 있어 다양한 직업을 가진 현대인은 개인에 따라 다소 차이가 있지만 대기오염의 영향보다는 하루 중 많은 시간을 보내는 실내오염의 영향을 더 많이 받는다. (중략)

• Proceedings of the Korea Air Pollution Research Association Conference
• /
• 한국대기환경학회 2003년도 추계학술대회 논문집
• /
• pp.209-210
• /
• 2003

국제 표준화 연구와 관련하여, 측정 및 분석과 관련된 국제기관들이 참여하여 1993년에 발행된 측정 불확도의 표현지침인 GUM은 데이터의 품질 관리 및 보증의 수단으로서 활발히 연구되고 있다. 특히, 국제적으로도 CCQM, CITAC, Eurachem, NIST 등의 기관을 중심으로 GUM 규격의 적용이 활발히 연구되고 있으나, 미국보다는 유럽에서 데이터 품질의 계량화 기술로서 연구되고 있다. 한편, 유해 대기오염물질인 중금속측정 자료가 국내에 축적되고 있음에도 불구하고 이러한 물질에 대한 측정 불확도가 거의 평가된 적이 없어 분석 값에 대한 보증을 위해 행하는 일련의 과정에 대한 표준 절차서가 시급한 현실이다.(중략)

• Proceedings of the Korea Air Pollution Research Association Conference
• /
• 한국대기환경학회 2002년도 춘계학술대회 논문집
• /
• pp.53-54
• /
• 2002

도시대기중의 분진은 입경 분포에 따라 공기 역학적 직경 2.5$\mu\textrm{m}$를 기준으로 미세 입자(fine particles)와 거대 입자(coarse particles)로 나누어지는 쌍극분포를 보인다. 미세 입자는 주로 화석연료의 연소, 자동차의 배기가스 등과 같은 인위적 발생원에 의한 것이며, 거대입자는 토사의 재 비산, 해염 통과 같은 자연적 발생원에 의한 것이다. 미세 입자는 오염된 도심지역 분진수의 90-99%에 이르는 높은 비율을 보이고 있고, 폐 깊숙히 침투하여 폐 질환을 일으킬 수 있다. (중략)