• 한국건축시공학회지
• /
• 제13권3호
• /
• pp.253-262
• /
• 2013

The test on the mix of PVA fiber of low carbon inorganic composite as a cement substitute found it to be satisfactory in terms of flexibility and stiffness. The result of the evaluation of the properties of low carbon inorganic panel revealed that the absorptivity was low at 8 to 9%, which is lower than the KS value of 25%. Also, the test on non-combustibility and gas toxicity found that these factors satisfied the decision criteria. In the test on heavy metals discharges, Pb, Cd, Cr6+, Hg, and As were not detected. Regarding far-Infrared emissivity and formaldehyde emission, the substitute was found to be harmless to the human body. Therefore, if the issue of shrinkage, which is a disadvantage of inorganic composites, is addressed, it is judged that it is possible to develop a low carbon inorganic composite panel with better performance.

• Bulletin of the Korean Chemical Society
• /
• 제32권5호
• /
• pp.1599-1603
• /
• 2011

Novel chemosensors based on 2-(2'-hydroxyphenyl)quinoline were prepared and evaluated for sensing metal cations. The photophysical properties of chemosensors 1-3 were examined and their ion-selectivity was evaluated by measuring their fluorescent emission responses to alkali, alkaline earth, and transition metal ions. Chemosensors 1, 2 and 3 show ratiometric and enhanced fluorescence changes with transitional metals that are efficient fluorescence quenchers, especially 3 has a high binding constant with $Hg^{+2}$ in $CH_3CN$.

• Bulletin of the Korean Chemical Society
• /
• 제35권9호
• /
• pp.2723-2725
• /
• 2014

Recently we have reported a novel class of anion receptors which are based on 2n-crown-n topology. Trioxane derivatives are capable of anion sensing through pure aliphatic C-H hydrogen bonding. In this work, we highlight another interesting property, i.e., they can also recognize cations as normal crown ethers (3n-crown-n topology). Since the same functional moiety can recognize anions and cations, these coronands are predicted to be amphi-ionophores. However, we could not detect cations even in the gas phase. Considering trioxane is analogous to [$1_6$]starand, this was rather counter-intuitive. The calculation results show that these coronands can detect alkali metals with very low affinity. The low affinity toward cations should be responsible for this failure of experimental detection. With careful theoretical study, we found that this low affinity toward cations could be explained by the unfavorable charge-dipolar moiety orientations as proposed by Cui et al. As in the case of [$1_6$]starand, this is an example that underscores the importance of charge-dipolar moiety orientation in supramolecular interactions.

• 대한화학회지
• /
• 제24권6호
• /
• pp.434-443
• /
• 1980

이번 실험에서 1차 분리된 희토류 산화물로부터 column chromatography에 의하여 희토류 금속들을 분리해 내고 정량하였다. 희토류 산화물을 Amberlite IR-120 수지에 흡착시킨 다음 EDTA 암모니아 알칼리용액을 사용하여 용출시켰다. 각 분획물중의 희토류금속의 함량을 측정한 결과 Ce가 가장 효과적으로 분리되었고 Nd와 Sm도 부분적으로 분리되었으나 Pr은 전혀 분리되지 않았다.

• 한국지하수토양환경학회:학술대회논문집
• /
• 한국지하수토양환경학회 2005년도 총회 및 춘계학술발표회
• /
• pp.242-246
• /
• 2005

The heavy metal analysis (Cd, Pb, Cu, Cr, Zn, Ni) with various extraction methods was performed using the certified sample and real soil sample. In case of the certified samples, $10.5{\sim}118%$ of recovery was showed with various ranges depend on the metal kinds and extraction methods. Also, the alkali-digestion method was showed the proper results by applying in hexavalent chromium. In case of real sample, compared to amounts of heavy metals extracted using 0.1N-HCl, those extracted using acid digestion are higher by $3{\sim}24$ times in Cu, $1.1{\sim}1.5$ times in Cd, $2{\sim}23$ times in Pb, $3{\sim}104$ times in Zn, $12{\sim}101$ times in Ni, $30{\sim}202$ times in Cr. There is no considerable difference between four acid digestion methods.

• Journal of Electrochemical Science and Technology
• /
• 제10권2호
• /
• pp.123-130
• /
• 2019

We investigated the electrochemical behavior of an electrode coated with a nickel hexacyanoferrate/graphene oxide (NiPB/GO) composite to evaluate its potential use for the electrochemical separation of radioactive Cs as a promising approach for reducing secondary Cs waste after decontamination. The NiPB/GO-modified electrode showed electrochemically switched ion exchange capability with excellent selectivity for Cs over other alkali metals. Furthermore, the repetitive ion insertion and desertion test for assessing the electrode stability showed that the electrochemical ion exchange capacity of the NiPB/GO-modified electrode increased further with potential cycling in 1 M of $NaNO_3$. In particular, this electrochemical treatment enhanced Cs uptake by nearly two times compared to that of NiPB/GO and still retained the ion selectivity of NiPB, suggesting that the electrochemically treated NiPB/GO composite shows promise for nuclear wastewater treatment.

• 방사성폐기물학회지
• /
• 제19권2호
• /
• pp.255-266
• /
• 2021

Solid-state mechanochemical reduction combined with subsequent melting consolidation was suggested as a technical option for the oxide reduction in pyroprocessing. Ni ingot was produced from NiO as a starting material through this technique while Li metal was used as a reducing agent. To determine the technical feasibility of this approach for pyroprocessing, which handles spent nuclear fuels, thermodynamic calculations of the phase stabilities of various metal oxides of U and other fission elements were made when several alkaline and alkali-earth metals were used as reducing agents. This technique is expected to be beneficial, not only for oxide reduction but also for other unit processes involved in pyroprocessing.

• Nuclear Engineering and Technology
• /
• 제54권7호
• /
• pp.2339-2358
• /
• 2022

The review discusses various alternative approaches for spent nuclear fuel (SNF) reprocessing in aqueous carbonate media. The main stages, schemes, and methods of the most well-known and well-described processes for reprocessing SNF and some high-level radioactive waste using carbonate systems developed by research groups in Japan, the United States of America, the Republic of Korea, and the Russian Federation described and compared. The main advantages of such methods are outlined compared to the SNF reprocessing in nitric acid media. The levels of development and proximity of the designed processes to the industrial implementation are shown. The main principle achievements, prospects, and routes for the refinement of such methods for the technology of SNF reprocessing and handling of high-level radioactive waste formulated.

• 한국지반환경공학회 논문집
• /
• 제8권2호
• /
• pp.5-9
• /
• 2007

본 연구는 반변천 상류에 위치한 현동, 산성, 금촌 그리고 금학 지역의 토양을 이용하여 물속에 존재하는 Cu(II), Zn(II) 및 Cd(II)과 같은 중금속 이온의 제거능을 조사하였다. 조사 지역에서 채취한 토양의 pH는 8.8~9.2로서 약알칼리성을 나타냈으며, 토양의 화학적 구성 성분 중 $SiO_2$, $Al_2O_3$ 및 $K_2O$는 양적으로 비슷한 분포를 보였으나, $Na_2O$, $TiO_2$ $Fe_2O_3$ CaO 및 MgO는 토양마다 약간의 차이를 나타냈다. 이 지역의 토양을 XRD로 측정 결과, 석영과 장석은 공통된 광물질로 확인되었으나, 카올린, 일라이트, 몬모릴로나이트, 버뮤큘라이트 및 칼사이트는 토양에 따라 다소의 정성적 차이를 나타냈다. 또한 이들 지역의 토양을 사용하여 중금속 제거 실험을 한 결과 Cu(II), Zn(II) 및 Cd(II)의 제거 효율은 98% 이상으로 나타났으며, 특히 다른 중금속에 비하여 Cu(II)의 제거율이 가장 높게 나타났다. 이러한 결과로 보아 본 조사지역의 토양을 폐광과 같은 중금속 상시 유출 지역의 제방 및 복토재로 활용할 경우 폐광 유출수내 중금속을 보다 효율적으로 제거할 수 있을 것으로 사료된다.

• 한국환경농학회지
• /
• 제33권2호
• /
• pp.78-85
• /
• 2014

BACKGROUND: Recent studies using various industrial wastes for heavy metal stabilization in soil were conducted in order to find out new alternative amendments. The acid mine drainage sludge(AMDS) contains lots of metal oxides(hydroxides) that may be useful for heavy metal stabilization not only waste water treatment but also soil remediation. The aim of this study was to investigate the applicability of acid mine drainage sludge for heavy metals stabilization in soils METHODS AND RESULTS: Alkali soil contaminated with heavy metals was collected from the agricultural soils affected by the abandoned mine sites nearby. Three different amounts(1%, 3%, 5%) of AMDS were applied into control soil and contaminated soil. For determining the changes in the extractable heavy metals, $CaCl_2$ and Mehlich-3 were applied as chemical assessments for metal stabilization. For biological assessments, lettuce(Lactuca sativa L.) and chinese cabbage(Brassica rapa var. glabra) were cultivated and accumulation of heavy metals on each plant were determined. It was revealed that AMDS reduced heavy metal mobility and bioavailability in soil, which resulted in the decreases in the accumulation of As, Cd, Cu, Pb, and Zn in each plant. CONCLUSION: Though the high level of heavy metal concentrations in AMDS, any considerable increase in the heavy metal availability was not observed with control and contaminated soil. In conclusion, these results indicated that AMDS could be applied to heavy metal contaminated soil as an alternative amendments for reducing heavy metal mobility and bioavailability.