• 한국토양비료학회지
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• 제35권6호
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• pp.344-351
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• 2002

부식산(humic acid)은 토양 환경내에서 중금속의 용액내 이온종(chemical speciation) 분포 및 이동성(transport)에 커다란 영향을 미친다. 부식산에 대한 카드뮴과 구리의 경쟁흡착을 파악하기 위하여, 상이한 농도의 배경 전해질 조건에서 피트에서 추출한 부식산의 전하발현 양상을 조사하고, 수소이온흡착모델을 통하여 부식산 표변에서의 양성자결합 상수(proton binding constant) 금속이온 흡착모델의 기본상수로 하여 부식산 표면에 대한 카드뮴, 구리흡착과 두 이온의 경쟁흡착을 해석하고자 하였다. 구리는 카드뮴에 비하여 카르복실기에 더 강한 흡착력이 있음을 보여 주었으며 페놀성 수산기에 대한 흡착력은 카드뮴에 비하여 약함을 보여 주었다. 여러 금속이온이 복합적으로 존재하는 환경에서 이온 간의 경쟁을 고려하였을 때 단일 이온만이 존재할 경우를 대상으로 구한 상수를 직접 적용시켜 경쟁효과를 예측하는 데는 어려움이 있음을 알 수 있었지만, 금속이온 각각을 통해 얻은 상수값은 부식산의 표면에 흡착할 수 있는 금속이온의 양을 제시 할 수 있으므로 금속이온간의 상대적인 흡착능의 비교는 가능하다고 생각된다.

• 한국근적외분광분석학회:학술대회논문집
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• 한국근적외분광분석학회 2001년도 NIR-2001
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• pp.1246-1246
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• 2001

The quality of meat is highly variable in many properties. This variability originates from both animal production and meat processing. At the pre-slaughter stage, animal factors such as breed, sex, age contribute to this variability. Environmental factors include feeding, rearing, transport and conditions just before slaughter (Hildrum et al., 1995). Meat can be presented in a variety of forms, each offering different opportunities for adulteration and contamination. This has imposed great pressure on the food manufacturing industry to guarantee the safety of meat. Tissue and muscle speciation of flesh foods, as well as speciation of animal derived by-products fed to all classes of domestic animals, are now perhaps the most important uncertainty which the food industry must resolve to allay consumer concern. Recently, there is a demand for rapid and low cost methods of direct quality measurements in both food and food ingredients (including high performance liquid chromatography (HPLC), thin layer chromatography (TLC), enzymatic and inmunological tests (e.g. ELISA test) and physical tests) to establish their authenticity and hence guarantee the quality of products manufactured for consumers (Holland et al., 1998). The use of Near Infrared Reflectance Spectroscopy (NIRS) for the rapid, precise and non-destructive analysis of a wide range of organic materials has been comprehensively documented (Osborne et at., 1993). Most of the established methods have involved the development of NIRS calibrations for the quantitative prediction of composition in meat (Ben-Gera and Norris, 1968; Lanza, 1983; Clark and Short, 1994). This was a rational strategy to pursue during the initial stages of its application, given the type of equipment available, the state of development of the emerging discipline of chemometrics and the overwhelming commercial interest in solving such problems (Downey, 1994). One of the advantages of NIRS technology is not only to assess chemical structures through the analysis of the molecular bonds in the near infrared spectrum, but also to build an optical model characteristic of the sample which behaves like the “finger print” of the sample. This opens the possibility of using spectra to determine complex attributes of organic structures, which are related to molecular chromophores, organoleptic scores and sensory characteristics (Hildrum et al., 1994, 1995; Park et al., 1998). In addition, the application of statistical packages like principal component or discriminant analysis provides the possibility to understand the optical properties of the sample and make a classification without the chemical information. The objectives of this present work were: (1) to examine two methods of sample presentation to the instrument (intact and minced) and (2) to explore the use of principal component analysis (PCA) and Soft Independent Modelling of class Analogy (SIMCA) to classify muscles by quality attributes. Seventy-eight (n: 78) beef muscles (m. longissimus dorsi) from Hereford breed of cattle were used. The samples were scanned in a NIRS monochromator instrument (NIR Systems 6500, Silver Spring, MD, USA) in reflectance mode (log 1/R). Both intact and minced presentation to the instrument were explored. Qualitative analysis of optical information through PCA and SIMCA analysis showed differences in muscles resulting from two different feeding systems.

• Journal of Microbiology and Biotechnology
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• 제28권10호
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• pp.1760-1768
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• 2018

The type strain Bacillus subtilis subsp. subtilis KCTC $3135^T$ was deeply sequenced and annotated, replacing a previous draft genome in this study. The tar and tag genes were involved in synthesizing wall teichoic acids (WTAs), and these genes and their products were previously regarded as the distinguishing difference between B. s. subtilis and B. s. spizizenii. However, a comparative genomic analysis of B. subtilis spp. revealed that both B. s. subtilis and B. s. spizizenii had various types of cell walls. These tar and tag operons were mutually exclusive and the tar genes from B. s. spizizenii were very similar to the genes from non-Bacillus bacteria, unlike the tag genes from B. s. subtilis. The results and previous studies suggest that the tar genes and the tag genes are not inherited after subspecies speciation. The phylogenetic tree based on whole genome sequences showed that each subspecies clearly formed a monophyletic group, while the tree based on tar genes showed that monophyletic groups were formed according to the cell wall type rather than the subspecies. These findings indicate that the tar genes and the presence of ribitol as a cell-wall constituent were not the distinguishing difference between the subspecies of B. subtilis and that the description of subspecies B. s. spizizenii should be updated.

• 한국산업보건학회지
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• 제26권2호
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• pp.170-177
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• 2016

Objectives: This study was conducted to evaluate the total heavy metals contents and chemical forms in the animal manure compost. Materials and methods: A total of 109 compost samples were collected throughout the country and classified into three groups in accordance with the raw materials; pig manure, poultry manure and mixed(pig+poultry+cattle) manure. The compost samples were analyzed for total metal content and sequential chemical extraction to estimate the quantities of metals. Results: Concentrations of Zn and Cu in several compost samples were higher than the maximum acceptable limits by the Korea Compost Quality Standards. Concentrations of Zn, Cu, and Cd in compost samples were 257~5,102, 68~1,243, and 0.02~2.54 mg/kg respectively, while Cr, Ni, As, and Pb were < 20 mg/kg. The concentrations of heavy metals in pig manure compost were higher than those of both the poultry and the mixed manure compost. The predominant forms for extracted metals were Cr, Ni, Zn, As, and Pb, residual; Cu, organic; and Cd, carbonate. Conclusions: Results indicate that the Zn and Cu contents in compost were higher than other heavy metals and the heavy metal contents were greater in pig manure compost followed by mixed and poultry manure compost. To prevent the accumulation of heavy metals in soil where animal manure compost is applied, strategy for reducing heavy metal concentrations in animal manure and compost must be considered.

• 한국토양비료학회지
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• 제48권2호
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• pp.73-80
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• 2015

Arsenic which is found in several different chemical forms and oxidation states and causes acute and chronic adverse health effects is a toxic trace element widely distributed in soils and aquifers from both geologic and anthropogenic sources. Arsenic which has a mysterious ability to change color, behavior, reactivity, and toxicity has diverse chemical behavior in the natural environment. Arsenic which has stronger ability to readily change oxidation state than nitrogen and phosphorus due to a consequence of the electronic configuration of its valence orbitals with partially filled states capable of both electron donation and acceptance although the electronegativity of arsenic is greater than that of nitrogen and similar to that of phosphorus. Arsenate (V) is the thermodynamically stable form of As under aerobic condition and interacts strongly with solid matrix. However, it has been known that adsorption and oxidation reactions of arsenite (III) which is more soluble and mobile than As(V) in soils are two important factors affecting the fate and transport of arsenic in the environment. That is, the movement of As in soils and aquifers is highly dependent on the adsorption-desorption reactions in the solid phase. This article, however, focuses primarily on understanding the fate and speciation of As in soils and what fate arsenic will have after it is incorporated into soils.

• 대기
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• 제33권3호
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• pp.319-330
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• 2023

As the need for PM type observation increases, Surface Particulate Matter Network (SPARTAN), PM samplers analyzes aerosol samples for PM mass concentration and chemical composition, were recently installed at two sites: Yonsei University at Seoul and Ulsan Institute of Science and Technology (UNIST) at Ulsan. These SPARTAN filter samplers and nephelometers provide the PM_2.5 mass concentration and chemical speciation data with aerosol type information. We introduced the overall information and installation of SPARTAN at the field site in this study. After installation and observation, both Seoul and Ulsan sites showed a similar time series pattern with the daily PM_2.5 mass concentration of SPARTAN and the data of Airkorea. In particular, in the case of high concentrations of fine particles, daily average value of PM_2.5 was relatively well-matched. During the Yonsei University observation period, high concentrations were displayed in the order of sulfate, black carbon (BC), ammonium, and calcium ions on most measurement days. The case in which the concentration of nitrate ions showed significant value was confirmed as the period during which the fine dust alert was issued. From the data analysis, SPARTAN data can be analyzed in conjunction with the existing urban monitoring network, and it is expected to have a synergetic effect in the research field. Additionally, the possibility of being analyzed with optical data such as AERONET is presented. In addition, the method of installing and operating SPARTAN has been described in detail, which is expected to help set the stage for the observation system in the future.

• 자원환경지질
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• 제36권6호
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• pp.481-490
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• 2003

본 연구는 국내 폐금은광산 지역에서의 광산활동의 의한 (1)계의 물시료 및 퇴적물 내의 As의 오염 수준, (2)오염된 자연수 중에 존재하는 As의 화학종의 조사, (3)수계내 As의 건/우기에 따른 계절적 변화, (4)연속추출분석법을 이용한 퇴적물내의 As의 화학적 형태연구를 목적으로 한다. 본 연구를 위하여 국ㆍ내 6개의 폐금은광산 지역에 대하여 갱내수, 하천수 및 지하수 등의 자연수와 하강퇴적물을 채취하였다. 동일광산 갱내수의 As의 함량이 524${\mu}m$/L로 국내 광산폐수내 기준치(500 ${\mu}m$/L)를 초과하였으며, 하천수 역시 동일(63.7∼l17.6${\mu}m$/L) 구봉(56.1∼62.9${\mu}m$/L) 광산지역에서 부화되어 있었다. 연구지역내에서 음용수로 사용하고 있는 지하수내 비소의 함량은 동일, 옥동과 구봉광산에서 각각 11.3∼63.5${\mu}m$/L, 0.2∼68.9 ${\mu}m$/L과 2.0∼101.0${\mu}m$/L으로 일부 시료에서 국내 먹는 샘물 기준치(50${\mu}m$/L)를 초과하였다. 대부분의 수계에서 arsenate(As(V), $H_2AsO_4^-$)가 arsenite[As(III), $H_3AsO_3$]에 비해 우세한 존재형태이나 총As함량에 대한 arsenite(III)의 함량 비가 옥동광산지역의 하천수 시료에서 최고 95%까지 존재하고 있었으며 옥동과 동정광산 지역의 지하수에서는 70∼82%를 나타내었다. 수계내의 A저 계절적 변화의 관찰 결과, 동일광산지역의 수계에서 우기(9월 채취시료)에 비해 건기(4월 채취시료)에 상대적으로 부화된 양상을 명확히 보였다. 퇴적물에 대한 연속추출분석결과 As는 동정과 구봉광산의 시료에서 주로 비결정질 철수산화물과 공침전한 형태로 존재하고 있었으며(35.9∼40.5%) 이는 환원환경 하에서의 As의 재 용출에 의한 오염의 진행을 야기할 수 있다. 그러나, 동일 및 옥동 광산지역의 하강퇴적물은 주로 황화물 형태로 존재했다 (55.2∼83.4%).

• 자원환경지질
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• 제37권1호
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• pp.87-98
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• 2004

청양광산과 서보광산의 광미와 오염된 토양은 5단계 연속추출법을 실시한 후 추출된 중금속 함량을 ICP-AES로 각 단계별로 분석하였다. 청양광산과 서보광산의 광미와 오염된 토양 내 비소와 코발트는 대부분 잔류형태 단계에서 우세하였다. 카드뮴, 구리 및 아연의 경우, 청양광산의 광미는 산화성 형태가 우세한 반면에, 서보광산의 광미는 잔류형태로 안정하였다. 서보광산의 오염된 토양에 함유된 이들 원소는 산화철망간과 수반되었다. 청양광산과 서보광산의 광미 내 함유된 납은 다른 금속에 비해 이온교환형태로 존재하는 함량이 높아 오염 확산의 우려가 있다. 그러나 서보광산의 오염된 토양은 잔류형태로 존재하여 안정하였다.

• Journal of Microbiology and Biotechnology
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• 제17권9호
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• pp.1527-1532
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• 2007

Lysine produced during microbial fermentation is usually recovered by an ion-exchange process, in which lysine is first converted to the cationic form (by lowering the pH to less than 2.0 with sulfuric acid) and then fed to a cationexchange column containing an exchanger that has a sulfone group with a weak counterion such as NH;. Ammonia water with a pH above 11 is then supplied to the column to displace the purified lysine from the column and allow its recovery. To enhance the adsorption capacity and for a possible reduction in chemical consumption, monovalent lysine fed at pH 4 was investigated in comparison with conventional divalent lysine fed at pH 1.5. The adsorption capacity increased by more than 70% on a mass basis using pH 4 feeding compared with pH 1.5 feeding. Lysine adsorbed at pH 4 started to elute earlier than that adsorbed at pH 1.5 when ammonia water was used as the eluant solution, and the extent of early elution became more notable at lower concentrations of ammonia. Moreover, the elution of monovalent lysine fed at pH 4 displayed a stiffer front boundary and higher peak concentration. However, when the ammonium concentration was greater than 2.0 N, complete saturation of the bed was delayed during adsorption and the percent recovery yield from elution was lowered., both drawbacks that were considered inevitable features originating from the increased adsorption of monovalent lysine.

• 한국해양학회지:바다
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• 제4권1호
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• pp.25-32
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• 1999

발전소 가동에 따른 퇴적물내 중금속원소의 오염 가능성을 알아보기 위하여 삼천포화력발전소와 영광원자력 발전소 주변해역의 표층퇴적물을 대상으로 중금속 함량 분석을 실시하였으며 선정된 일부 퇴적물에 대해서는 화학적 존재형태를 파악하기 위해 연속추출분석을 실시하였다. 퇴적불 중의 금속원소 함량 분포는 대체적으로 평균입도에 의해 조절되고 있으며 탄산염 함량 및 유기불 함량에 의해서도 영향을 받고 있는 것으로 나타났다. 또한 화학적 존재형태별 분석에서도 Mn을 제외한 대부분의 중금속이 잔류상으로 존재하고 있어 인위적인 오염에 의해서라기 보다는 자연적인 분산에 의해 존재하고 있는 것으로 나타났다.