본 연구는 해조류인 괭생이 모자반을 탄화하여 만든 바이오차의 중금속 흡착 및 제거 효과를 확인하고 중금속 흡착제로 이용 가능성을 확인하고자 연구가 수행되었다. 모자반 바이오차(SBC)는 500℃조건에서 2시간 열분해를 통해 생산하였다. 중금속 흡착실험은 Pb, Cd, Cu 및 Zn의 각 농도별 흡착량을 확인하였으며, Freundlich 및 Langmuir 등온흡착모델을 통해 중금속 흡착 효율성을 확인하였다. 모자반 바이오차의 중금속 제거효율은 Pb, Cd, Cu 및 Zn에서 각각 97.3, 85.2, 76.4 및 42.0%로 Pb＞Cd＞Cu＞Zn 순의 제거효율을 보였다. 등온흡착결과로 Freundlich 등온흡착패턴은 L형이었으며, 흡착강도(1/n)는 0.49 ~ 0.80 범위로 조사되었다. Langmuir 등온흡착식에서 최대흡착량은 Pb, Cd, Cu 및 Zn에서 각각 200, 92.6, 47.8 및 70.4 mg g-1이었으며, 흡착강도는 각각 0.4950, 0.1004, 0.0245 및 0.0188로 조사되었다. 본 실험 결과로 볼 때 모자반 바이오차는 중금속 흡착제로써 활용이 가능할 것으로 보여지며, 이를 활용하기 위한 추가 연구가 필요하다고 보여진다.

2019년부터 2023년까지 서울지역에 유통되는 식약공용 농·임산물 60품목 1,340건을 대상으로 ICP-MS와 수은분 석기, 모니어-월리엄스 변법을 사용하여 중금속(납, 카드 뮴, 비소, 수은) 및 이산화황의 함량을 조사하고 위해성 평 가를 수행하였다. 중금속의 평균 검출량 및 범위는 납 0.327 mg/kg (ND-36.933), 카드뮴 0.083 mg/kg (ND-1.700), 비소 0.075 mg/kg (ND-2.200), 수은 0.004 mg/kg (ND- 0.047)으로 나타났다. 품목별은 2023년에 복령 1건에서 납 이 36.933 mg/kg으로 기준을 초과하였고 카드뮴은 2022년 에 구절초 2건이 각각 1.700 mg/kg, 0.650 mg/kg으로 기준 를 초과하였다. 나머지 품목은 모두 허용기준 이내였다. 이 산화황의 평균 검출량 및 범위는 0.75 mg/kg (ND-192.00)이 였으며, 2019년에 천마 2건에서 각각 192.00 mg/kg과 42.00 mg/kg으로 기준치을 초과하였다. 약용부위별 중금속 평균 검출량은 납은 버섯류(1.377 mg/kg), 카드뮴은 수·근피 류(0.156 mg/kg)와 등목류(0.144 mg/kg), 비소는 엽류 (0.149 mg/kg), 수은은 전초류(0.009 mg/kg), 엽류(0.009 mg/ kg)에서 높게 검출되었다. 이산화황 평균 검출량은 근경류 (4.12 mg/kg)에서 높게 검출되었다. 원산지별로 중금속 및 이산화황 함량을 비교한 결과, 납, 카드뮴 및 수은은 국내 산, 중국산, 중국 외 수입산 간에 차이는 없었으나, 비소 와 이산화황은 중국산이 국내산과 중국 외 수입산보다 높 게 검출되었다. 위해성 평가 결과, 납은 대부분의 품목에 서 노출안전역(MOE)값이 1보다 커서 인체 위해성이 낮았 지만, 복령에서 MOE 값이0.66으로 1보다 낮아 위해성이 있는 것으로 나타났다. 카드뮴, 비소 및 수은의 위해도(HI) 는 각각 0.2740-1.0702%, 0.0049-0.0335% 및 0.0041- 0.0287%로 매우 낮은 수준으로 평가되었다. 이산화황의 위해도(HI)는 모든 품목에서1을 초과하지 않아 안전한 수 준이었다. 앞으로도, 식약공용 농·임산물의 안전성에 대한 지속적인 관심과 모니터링이 필요하다.

Copper, silver, and gold-reduced graphene oxide nanocomposite (Cu-rGO, Ag-rGO, and Au-rGO) were fabricated via the hydrothermal method, which shows unique physiochemical properties. Environment friendly electromagnetic radiation was employed to synthesize rGO from GO. The nonlinear optical phenomenon of noble metal decorated rGO is predominantly due to excited state absorption, which arises from surface plasmon resonance and increases in defects at the surface due to Cu, Ag, and Au incorporation. It is found that the third-order nonlinear absorption coefficient was in the order of 10− 10 m/W, with notable enhancements in the third-order properties of Au-rGO compared to other nanocomposites and their respective counterparts. Functionalizing rGO induces defect states ( sp3), increasing NLO response. Cu, Ag, and Au exhibit higher Surface-Enhanced Raman Scattering (SERS) activity due to rGO-induced structural modifications. SERS signals are influenced by dominant signals from Au nanorods. The electronic structures for pure and doped rGO were investigated through Density Functional Theory (DFT). The computed partial density of states (PDOS) confirms the enhancement of the state in Au-doped rGO is due to the charge transference from Au to C 2p orbital. The optical absorption spectra and PDOS reveal the possibility of free carrier absorption enhancement in Au which validates experimentally observed higher two-photon absorption (β) value of Au-doped rGO. The tuning of nonlinear optical and SERS behaviour with variation in the noble metal upon rGO provides an easy way to attain tuneable properties which are exceedingly required in both optoelectronics and photonics applications.

발효주의 잔류물질 실태조사를 위해 울산지역에서 유통 되는 발효주 150건을 수거하여 잔류농약 400종과 중금속 납, 카드뮴, 수은을 분석하였다. 잔류농약 분석 결과, 102 건(68%)의 검출을 나타냈으며 검출된 농약 종류는 35종 으로 그 중 원료 농산물의 기준이 없는 농약은 4종이 검 출되었다. 발효주 종류별로 비교하면 와인이 60건의 검사 중 54건(90%)으로 가장 많은 잔류농약이 검출되었고 맥 주는 60건 중 37건(61.7%), 막걸리는 30건 중 11건(36.7%) 이 검출되었다. 발효주에 대한 중금속 분석 결과는 납 73 건(48.7%), 카드뮴은 9건(6.0%), 수은은 36건(24.0%)을 나 타내었다. 납은 73건의 검출 중 와인이 57건(78.1%)을 차 지해 가장 높은 검출을 나타내었고 카드뮴과 수은은 검출 된 9건, 36건 중 막걸리가 7건(77.8%), 13건(36.1%)으로 가장 많이 검출되었다. 각 품목에서 검출된 잔류농약 및 중금속 항목에 대해 인체노출량 평가결과는 모두 1% 미 만으로 안전한 것으로 나타났다.

환경오염을 제어하기 위한 청정에너지에 대한 수요 증가는 빠르게 증가하고 있습니다. 리튬 이온 배터리와 같은 충전식 배터리는 청정에너지의 우수한 원천이지만 높은 수요와 공급 불일치로 인해 리튬 금속이 빠르게 고갈되고 있습니다. 배터리 폐기물에서 귀금속을 회수하는 것은 환경오염 제어와 함께 가능한 해결책 중 하나입니다. 멤브레인 기반 분리 방법은 폐기물에서 리튬을 회수할 수 있는 매우 성공적인 상업적 공정입니다. 이 작업은 최근에 보고된 다양한 방법을 다룰 것이며 검토 형식으로 작성될 것입니다.

We selected literature from the core collection of the Web of Science (WOS) database as the research object and used visualization bibliometric software to analyse the 1313 collected studies. We found that the research on the graphene-based adsorption of heavy metals from wastewater has received widespread attention in various countries around the world, especially developing countries, since 2015, and Chinese researchers have made significant contributions. The adsorption mechanisms, adsorbent materials, and advanced adsorption techniques for the removal of heavy metals from wastewater by graphene have been the focus and hotspots in the research in this field in recent years. Heavy metal removal from wastewater with graphene has strong application potential. In the future, researchers in this area can focus on exploring issues such as “new materials,” “recyclability,” and “interdisciplinarity” to break through existing technological bottlenecks, supplement the technical research and development of graphene materials, and promote advances in this field.

Chelating agents, such as ethylenediaminetetraacetic acid (EDTA), diethylenetriaminepentaacetic acid (DTPA), and nitrilotriacetic acid (NTA) are widely used in industry and agriculture as water softeners, detergents, and metal chelating agents. In wastewater treatment plants, a significant amount of chelating agents can be discharged into natural waters because they are difficult to degrade. Since those compounds affect the mobility of radionuclides or heavy metals in decontamination operations at nuclear facilities and radioactive waste disposal, quantification of the amount of ligand is very important for safe nuclear waste management. To predict the behavior of the main complexation in sample matrices of radioactive wastes, it is essential to evaluate the distribution of the metal-chelating species and their stabilities in order to develop analytical techniques for quantifying chelating agents. We have investigated to collect information on the pH speciation of metal chelation and the stability constants of metal complexes depending on three chelating agents (EDTA, DTPA, and NTA). For example, Zhang’s group recently reported that the initial coordination pH of Cu(II) and EDTA4− is delayed with the addition of Fe(III), and the pH range for the stable existence of [Cu(EDTA)]2− is narrowed compared to when it is alone in the sample matrix. The addition of Fe(III) clearly impacts the chemical states of the Cu(II)-EDTA solution. Additionally, Eivazihollagh’s group demonstrated differences in the speciation and stability of Cu(II) species between Cu(II) and three chelating ligands (EDTA, DTPA, and NTA). This study will be greatly helpful in identifying the sample matrix for binding major chelating agents and metals as well as developing chemically sample pretreatment and separation methods based on the sample matrix. Finally, these advancements will enable reliable quantitative analysis of chelating agents in decommissioning radioactive wastes.

Рrecipitation of platinum group metals (Rh, Ru, Pd, so-called MPG) from the melt essentially affects the reliability of installations for vitrification of high-level liquid radioactive waste (HLW). To date, it is difficult to find an approach which allows simultaneous recovery of all three metals. The aim of our work was to select a sorbent that would provide simultaneous up to complete recovery of given metals. The following inorganic materials were tested as sorbents – yellow blood salt (YBS).and hexacyanoferrates of iron, aluminum, copper and nickel. The degree of metal recovery was studied is influenced by the temperature and concentration of nitric acid. Only palladium was completely recovered using YBS. At the same time, specially prepared iron hexacyanoferrate (HCF-Fe) under optimal experimental conditions recovers almost all Pd and more than 95% and 90% of Rh and Ru, respectively. The behavior of fission products, including the main dose-forming components of HLW (Cs, Sr) and Mo, U, Ag, REE) in the course of MPG recovery was studied. The experiments were carried using both multicomponent model solutions and real raffinates. Options for further management of the recovered metals have been worked out. Thus, the proposed method of metal recovery seems promising for the development of a technology for the removal of MPG from nitric HLW during the reprocessing of the spent nuclear fuel (SNF) before vitrification. The recovered metals can be probably used in various technological processes. Also, this method can provide the MPG recovery from low-concentration tail solutions.

The semiconductor industry faces physical limitations due to its top-down manufacturing processes. High cost of EUV equipment, time loss during tens or hundreds of photolithography steps, overlay, etch process errors, and contamination issues owing to photolithography still exist and may become more serious with the miniaturization of semiconductor devices. Therefore, a bottom-up approach is required to overcome these issues. The key technology that enables bottom-up semiconductor manufacturing is area-selective atomic layer deposition (ASALD). Here, various ASALD processes for elemental metals, such as Co, Cu, Ir, Ni, Pt, and Ru, are reviewed. Surface treatments using chemical species, such as self-assembled monolayers and small-molecule inhibitors, to control the hydrophilicity of the surface have been introduced. Finally, we discuss the future applications of metal ASALD processes.

To raise the physical strength of alginate beads, this study manufactured alginate-cellulose bead by adding cellulose to alginate, and wanted to identify whether falginate-cellulose beads were sufficiently efficient in removing heavy metals. To find out optimal amounts of alginate and cellulose injection, this study conducted a pilot study, and repeated experiments proved that alginate 2 w/v% + cellulose 1 w/v% were the optimal amounts in manufacturing beads. Using micro materials tester, this study compared strengths of alginate beads and alginate-cellulose beads. Choosing Cd2+, Pb2+, and Ni2+ as materials to be removed, this study analyzed concentrations of them before and after the treatment. Experiments showed that, compared with alginate beads, the strength of alginate-cellulose beads was 2.26 times stronger, and that the latter could remove 98.22%, 99.99%, and 92.57% of Cd2+, Pb2+, Ni2+, respectively. While addition of cellulose to alginate made the absorption rate drop by about 1%, the beads were still highly efficient in removing heavy metals. Accordingly, it seems that alginate-cellulose beads can be used in removing heavy metals.

Combination of liquid-phase exfoliation and hydrothermal method has progressed in recent years mainly on production of 2D materials. In this study, graphene was successfully synthesized via combinatorial of liquid-phase exfoliation and hydrothermal method with the aid of various conductive surfactants perylene-3, 4, 9, 10-tetracarboxylate (PTCA), lithium perylene-3, 4, 9, 10-tetracarboxylate (LiPTCA) and sodium perylene-3, 4, 9, 10-tetracarboxylate (NaPTCA). The effect of the lithium ( Li+) and sodium ( Na+) cations toward the efficiency of the graphene exfoliation process and its electrical properties was thoroughly investigated. Based on the characterization techniques, it is revealed that NaPTCA is the ideal conductive surfactant to exfoliate graphene sheets. X-ray diffraction spectra verified that the Na+ cation certainly can enhance the exfoliation process by expanding the interlayer spacing. The lateral size of the graphene sheets with Na-PTCA surfactant was the smallest (4.17 μm) as observed from SEM micrograph. The maximum concentration of the graphene yield was achieved up to 0.151 mgmL− 1 in NaPTCA surfactant alongside with excellent electrical conductivity of 746.27 Sm− 1 and relevant specific capacitance of 129 Fg− 1.

This study was conducted to determine the concentration of heavy metals and their characteristics in the bodies of 2,446 residents living near industrial areas from 2007 to 2015. The concentration of heavy metals showed diverse characteristics according to gender, food types consumed and period of residence. Especially, levels of cadmium and mercury were high in the urine samples of the group that had lived in the local area for a long time. In order to obtain more accurate results, it will be necessary to comprehensively study the influence and effects from such matters related to lifestyle, eating habits and levels of environmental pollutants.

국내 유통 중인 콜라겐 제품 120건을 대상으로 중금속 4종(납, 카드뮴, 비소, 수은) 함량에 대해 조사하였다. 수 은은 금아말감화법을 이용한 수은분석기로 분석하였고 납, 카드뮴, 비소는 ICP-OES를 이용하여 분석하였다. 검사 결 과 납의 평균 함량은 0.097±0.055 mg/kg이었고 건강기능 식품, 기타가공품, 음료류, 과·채가공품에서 각각 평균 0.108±0.052mg/kg, 0.084±0.053 mg/kg, 0.131±0.047 mg/ kg, 0.149 mg/kg 농도로 검출되었다. 카드뮴의 평균 함량 은 0.026±0.011 mg/kg이었으며 검출된 제품은 모두 건강 기능식품이었다. 비소의 평균 함량은 0.097±0.048 mg/kg 이었고 건강기능식품, 기타가공품, 과·채가공품에서 각각 평균 0.091±0.055 mg/kg, 0.133 mg/kg, 0.086 mg/kg 농도 로 검출되었다. 수은의 평균 함량은 0.0025±0.0016 mg/kg 으로 건강기능식품, 기타가공품, 과·채가공품, 캔디류에서 각각 평균 0.0012 mg/kg, 0.0028±0.0018 mg/kg, 0.0013 mg/kg, 0.0031 mg/kg 농도로 검출되었다. 중금속 기준·규 격이 있는 음료류(납 0.3 mg/kg, 카드뮴 0.1 mg/kg) 및 캔 디류(납 0.2 mg/kg)는 모두 기준 이하로 검출되어 적합하 였다. 기준·규격이 없는 제품도 국내외 식품의 중금속 기 준과 보고된 식품 중금속 함량과 비교하였을 때 비교적 안전한 수준이라고 판단되었다.

Plasma Arc Melter (MSO) system has been developed for the treatment and the stabilization of various kinds of hazardous and radioactive waste into the readily disposable solidification products. Molten salt oxidation system has been developed for the for the treatment of halogen- and sulfurbearing hazardous and radioactive waste without emissions of PCDD/Fs and acid gases. However, PAM system has showed some difficulty in the off-gas treatment system due to the volatilization of radionuclides and toxic metals at extremely high-temperature plasma arc melter and the emissions of acid gases. MSO system has also showed the difficulty in the treatment of spent molten salt into the disposable waste form. Present study discussed the results of organics destruction performance tests for the PAM-MSO combination system, which is proposed and developed to compensate the drawbacks of each system. The worst-case condition tests for the organics destruction were conducted at lowest temperatures and the worst-case condition tests for the retention of metals and radionuclides were conducted at highested temperatures under the range of normal operating condition. For the worst-case organic destruction test, C6H5Cl was selected as a POHCs (Principal Organic Hazardous Constituents) because of its high incinerability ranking and the property of generation of chlorine gases and PCDD/Fs when incompletely destroyed. Simulated concrete waste spiked with 1 L of C6H5Cl was treated and the emissions of 17 kinds of PCDD/Fs and other hazardous gases such as CO, THCs, NOx, SO2 and HCl/Cl2 were measured. For the worst-case condition tests for the retention of metals and radionuclides, Pb and Cs were selected because of its high volatility characteristics. The emissions of PCDD/Fs was extremely lowered than the emission limit and those of other hazardous constituents were below their emission limit. The results of performance tests on the organics destruction suggested that tested PAM-MSO combination system could readily treat PCBs-bearing spent insulation liquid, spent ion-exchange resins used for the treatment of spent decontamination liquid in the decommission process and the concreted debris bearing hazardous organic coating materials. The decontamination factor of Cs and Co were 1.4×105, 1.4×105, respectively. The emisison of Pb was 0.562 ppm. These results suggested that tested PAM-MSO system treated low-level radioactive and pb-bearing mixed waste.

Safe storage of spent nuclear fuel in deep underground repositories needs an understanding of the long-term alteration (corrosion) of metal canisters and buffer materials. We conducted a small-scale laboratory alteration tests on some metal (Cu and Fe) chips by embedding them into the compacted bentonite blocks, which were placed in anaerobic water for 1 year. Some additives like lactate, sulfate, and bacteria were separately loaded into the water to promote biochemical reactions. The bentonite blocks immersed in the water were finally dismantled after 1 year, and they showed that their alteration was insignificant. However, the Cu chip exhibited some microscopic etch pits on its surface, wherein sulfur component was slightly detected. Overall, the Fe chip was more corroded than the Cu chip under the same condition. The secondary phase of the Fe chip was locally found as carbonate materials, such as siderite (FeCO3) and calcite ((Ca, Fe)CO3). These secondary products could imply that the local carbonate production around the Fe chip may be initiated by an evolution (alteration) of bentonite and a diffusive provision of biogenic CO2 gas. These laboratory scale test results suggest that the long-term alteration (corrosion) of metal canister/bentonite blocks in the engineered barrier could be possible and may be promoted by microbial activities.

This study evaluated the migrant and residue tests of lead (Pb), cadmium (Cd), nickel (Ni), arsenic (As), and antimony (Sb) in 70 tumbler samples. The migration levels of hazardous metals in all the samples were within the migration limits outlined in the Korean standards and specifications for utensils, containers, and packages. Moreover, in all the tumbler samples, only Ni was detected in 0.5% citric acid solution of a food stimulant. The maximum level of Ni 0.0144 mg/L was 14.4% of the migrant specification (not more than 0.1 mg/L), which was relatively safe. The 0.5% citric acid solution was eluted at 4oC, 70oC, and 100oC for 30 min, and only Ni was detected while testing for migration levels according to the temperature variations; all temperature conditions conformed to the standards. The level of Ni migration increased significantly with increasing migration temperature. Regarding the residue level outside the paint-coated tumbler samples, the Pb level was found to range from N.D. to 20638.1323 mg/kg. The risk of Ni was further estimated to be at a safe level of 0.00 to 0.01% compared to the %TDI as a result.

The official analytical method for the analysis of harmful heavy metals in Meju, distributed in Korea, employs a strong acid to decompose the organic components. This analysis is time consuming and harmful to the users and/or the environment. This study aimed to develop a new pre-treatment technology using laser ablation, to rapidly analyze harmful heavy metals without using strong acids. The results obtained from this method were validated by the National Institute of Food and Drug Safety Evaluation guideline (NIFDS, 2016). Moreover, a comparison of the two methods showed that the analytical time for 55 Meju samples was shortened by 96% or more in the new method. The results showed no significant difference in the recovery ranging from 90–120%. The proposed method proved suitable for detecting harmful heavy metals in Meju.

Activated corrosion products deposited on the reactor coolant system in a nuclear power plant should be removed to reduce the radiation exposure to workers. Chemical decontamination processes using organic acids have been widely applied to remove the activated corrosion products. However, they are highly corrosive to the base metal and generate a considerable amount of ion exchange resin waste, which is hard to be treated. In order to resolve this problem, KAERI has been developed a chemical decontamination process using chelate-free inorganic acid, HyBRID (Hydrazine Based Reductive metal Ion Decontamination) process. Especially, the Cyclic SP (Sulfuric acid/Permanganate)- HyBRID process was suggested as the decontamination process for applying to the remove the double oxide layer generated on the reactor coolant system in the pressurized water reactor (PWR). During the Cyclic SP-HyBRID process, the process is continuously applied without discharging or recharging of the decontamination process solution from the primary circuit. Thus, it is necessary to include the removal processes of the decontamination reagents middle of the Cyclic SP-HyBRID process, e.g., ‘Mn removal step’ for removing the permanganate ions and ‘hydrazine decomposition step’ for decomposition of the remaining hydrazine. During these removal processes, the metal ions can also be removed from the process solution. In this study, the behaviors of metals were investigated during the Cyclic SP-HyBRID process. The concentration changes of metal ions in the process solution were analyzed using atomic absorption (AA) spectroscopy. The metal precipitates generated during the process were characterized using X-ray diffraction (XRD) and Fourier Transform Infrared (FT-IR) spectroscopy. From the results of the analysis, it was observed that the metal ions dissolved in the process solution were converted into metal hydroxides and precipitated at the Mn removal process. It was confirmed by equilibrium calculation result that the OH− ions generated at the Mn removal can react with the metal ions and form the metal hydroxides. It is considered that this removal behaviors of the metals can contribute the decontamination performance.