• 한국안전학회지
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• 제19권3호
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• pp.57-64
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• 2004

This is the study for the removal of a toxic heavy metal ions and the recycling of expanded polystyrene wastes. Thus expanded polystyrene wastes collected from the packing materials of TV or chemicals and dissolved by $80wt.\%$ solvent(N, N-Dimethylacrylamide), electrospun in DC 20kV by power supply. Generally, the electrospinning is a process of manufacture to the fibers of nanosize from polymer solution. Manufactured nanofiber mats by electrospinning were sulfonated by cone.-sulphuric acid with $Ag_2S_O_4$ catalysts for the exchange capacity of heavy metal ions and the properties of structure with sulfonated time investigated by FESEM(Feild Emission Scaning Electron Microscope). The ion exchange capacity of light metal$(Na^+)$, Cd(II) and Ni(II), and by a nanofiber mats were 1.94[mmo1/g-dry-mat), 1.72(mmol/g-dry-mat), 1.24(mmol/g-dry-mat), respectively., and water uptake content showed a similar trend with IEC. and The selectivity coefficients $K^M_H$ of Cd(II), Ni((II) ions showed 0.324, 0.228. respectively.

• 유기물자원화
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• 제15권4호
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• pp.107-114
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• 2007

다당류의 일종인 알긴산을 이용한 중금속 제거에 관한 연구가 수행되어졌다. 알긴산은 pH 4에서 480mg/g의 납 이온을 흡착하였으며 이것은 다른 생물흡착제에 비해서 약 2배 정도의 높은 흡착능이다. 납 이온에 대한 등온흡착선을 묘사하기 위하여 Langmuir model 식을 이용하였으며 실험결괴는 모델식에서 얻어진 결과와 잘 부합되었다. 온도가 증가함에 따라서 흡착능은 증가하였으며 이는 알긴산과 납 이온의 흡착은 흡열반응임을 보여준다. 납 이온의 흡착에 대한 알칼리 금속(칼슘, 마그네슘 이온)의 영향은 거의 없었으며 대부분의 흡착은 30분 내에 이루어졌다. 구리, 수은, 스트론튬, 세슘 과 같은 다른 금속 이온에 대한 흡착능도 조사되었다.

• Journal of Applied Biological Chemistry
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• 제64권2호
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• pp.159-164
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• 2021

토양 중 중금속은 자유이온, 유기산-중금속 복합체를 포함한 다양한 화학종으로 존재한다. 이 중 중금속 자유이온 비율은 식물체의 중금속 흡수와 밀접한 관련이 있는 것으로 알려져 있다. 본 연구는 중금속 자유이온과 유기산-중금속 복합체 존재 비율이 식물의 납, 카드뮴 흡수에 어떤 영향을 미치는지 알아보기 위하여 수행되었다. 이를 위해 순환식 양액재배 장치에서 28일간 키운 상추를 48시간 동안 납과 카드뮴 용액에 침지시키는 실험을 진행하였다. 침지 전 시트르산, 옥살산, 아세트산, 휴믹산을 이용해 납과 카드뮴 용액의 중금속 자유이온과 유기산-중금속 복합체의 비율이 100:0, 90:10, 70:30, 60:40이 되도록 조절하였다. 침지 후 상추 뿌리와 잎의 납, 카드뮴 농도를 분석한 결과, 용액 중 중금속 자유이온의 비율과 식물이 흡수한 납, 카드뮴 농도는 상관관계를 보이지 않았다. 반면에 처리한 유기산의 종류와 중금속 종류에 따른 차이가 더 큰 것으로 나타났다. 시트르산은 납 흡수는 증가시켰지만 카드뮴 흡수는 감소시켰다. 시트르산은 다른 유기산보다 상추의 납 흡수율을 높였는데 이는 시트르산이 분자량이 크기 때문에 중금속 이온과 복합체를 형성할 수 있는 용량이 더 크기 때문인 것으로 보인다. 그러므로 본 연구 결과는 식물에 의한 중금속 흡수가 단순히 자유이온의 양에 따라 달라지기 보다는 존재하는 유기산의 분자량에 의한 결합용량 차이가 중금속 종류에 따라 달리 작용하여 결정된다는 것을 보여준다.

• 대한약학회:학술대회논문집
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• 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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• pp.293.3-294
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• 2002

In the brain, glial cells serve in the role to sequester metal from the neural microenvironment and therefore play an important role as a cellular deposition site. The central nervous system is highly vulnerable to oxidative stress, and free iron can stimulate oxidative stress by the Fenton reaction. Aluminum may upregulates the transferrin-independent iron uptake system and stimulate oxidative stress. Nramp2. also known as DMT 1. is a 12-transmembrane(TM) domain protein responsible for dietary iron uptake as well as metal ions such as iron. lead, mangamese. zinc. copper, and cobait. (omitted)

• Nuclear Engineering and Technology
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• 제41권8호
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• pp.1101-1108
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• 2009

The ocean contains around eighty elements of the periodic table and uranium is also one among them, with a uniform concentration of 3.3 ppb and a relative abundance factor of 23. With a large coastline, India has a large stake in exploiting the 4 billion tonnes of uranium locked in seawater. The development of radiation grafting techniques, which are useful in incorporating the required functional groups, has led to more efficient adsorbent preparations in various geometrical configurations. Separation based on a polymeric adsorbent is becoming an increasingly popular technique for the extraction of trace heavy metals from seawater. Radiation grafting has provided definite advantages over chemical grafting. Studies related to thermally bonded non woven porous polypropylene fiber sheet substrate characterization and parameters to incorporate specific groups such as acrylonitrile (AN) into polymer back bones have been investigated. The grafted polyacrylonitrile chains were chemically modified to convert acrylonitrile group into an amidoxime group, a chelating group responsible for heavy metal uptake from seawater/brine. The present work has been undertaken to concentrate heavy metal ions from lean solutions from constant potential sources only. A scheme was designed and developed for investigation of the recovery of heavy metal ions such as uranium and vanadium from seawater.

• 한국환경과학회지
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• 제7권1호
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• pp.57-61
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• 1998

중금속 폐수를 처리하는 활성슬러지로 부터 Arthrobactor sp.를 부터 분리하여 생체흡착 실험에 사용하였다. Aythrobactor sp.의 납 흡착량은 초기농도 500 mg/L에서 146.9 mg Pb/g dry biomass로 Sacchuomyces ceieuslae와 Sacchuomyces uvuum보다 약 4배 더 많은 흡착량을 보여주었다. pH가 1.8, 3.0 및 4.0으로 골아 질수록 납의 홉착량은 증가하였고, biomass의 양이 많아질수록 단위 미생물당 납 흡착량은 감소하였다. Biomass에 0.1M KOH, $CaCl_2$및 NaOH로 4시간 동안 전 처리하여 흡착실험을 수행한 결과 KOH로 전 처리된 biomass의 납 흡착량은 1.26배 증가하였으나 NaOH로 처리한 것은 납의 흡착량이 감소하였다. Polyacrylamide에 고정화된 biomass를 반응기에 충진한 연속실험에서, 유속 2.12 $m^3/m^2/$day 에서 15시간 동안 납 제거효율이 99%이상 되었다.

• Journal of Microbiology and Biotechnology
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• 제31권8호
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• pp.1045-1059
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• 2021

Various abiotic stressors like drought, salinity, temperature, and heavy metals are major environmental stresses that affect agricultural productivity and crop yields all over the world. Continuous changes in climatic conditions put selective pressure on the microbial ecosystem to produce exopolysaccharides. Apart from soil aggregation, exopolysaccharide (EPS) production also helps in increasing water permeability, nutrient uptake by roots, soil stability, soil fertility, plant biomass, chlorophyll content, root and shoot length, and surface area of leaves while also helping maintain metabolic and physiological activities during drought stress. EPS-producing microbes can impart salt tolerance to plants by binding to sodium ions in the soil and preventing these ions from reaching the stem, thereby decreasing sodium absorption from the soil and increasing nutrient uptake by the roots. Biofilm formation in high-salinity soils increases cell viability, enhances soil fertility, and promotes plant growth and development. The third environmental stressor is presence of heavy metals in the soil due to improper industrial waste disposal practices that are toxic for plants. EPS production by soil bacteria can result in the biomineralization of metal ions, thereby imparting metal stress tolerance to plants. Finally, high temperatures can also affect agricultural productivity by decreasing plant metabolism, seedling growth, and seed germination. The present review discusses the role of exopolysaccharide-producing plant growth-promoting bacteria in modulating plant growth and development in plants and alleviating extreme abiotic stress condition. The review suggests exploring the potential of EPS-producing bacteria for multiple abiotic stress management strategies.

• 한국염색가공학회지
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• 제8권6호
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• pp.40-46
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• 1996

In order to investigate a practical application of fibrous absorbents to transition metals such as copper, nickel, cobalt, chrome, and iron, amidoximated fiber as a particular class of solid chelate agents were prepared from acrylic fibers treatment with hydroxylamine. The adsorption mechanisms of metal ions onto amidoximated acrylic fibers and their complexes were studied. Amidoximation of acrylic fiber with hydroxylamine is found to be first-order reaction, followed by the disappearance of infrared adsorption peaks due to nitrile groups of acrylic fibers. The uptake of metal ions onto amidoximated acrylic fiber is increased with temperature raising and the adsorption is also depended on pH of the soiutions. About 70% of metal ions can be recovered from aqueous solutions of Ni(II), Co(II), Cr(III), and Fe(II) on the concentration below 5x 10$^$^{-4}$ in the range of pH 2.1~10.0. Transition metals are adsorbed to form complex with amidoxime group by the ligand sites such as C=N, NH, NO, NHOH.OH.

• 한국환경과학회지
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• 제6권1호
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• pp.61-67
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• 1997

미생물에 의한 흡착법으로 중금속을 효과적으로 제거, 회수할 수 있다. 알콜 발효 후 부산물로 생성되는 폐 Saccharomyces cerevisiae는 비교적 가격이 저렴하고, 중금속 생체흡착에 유용한 자원으로 이용될 수 있다. 생체흡착 실험에 사용된 미생물은 부유 및 alginate에 고정화된 S. cerevisiae로 수행하였다. 회분식 실험에서 생체흡착량은 Pb > Cu > Cd의 순으로 이루어졌다. Pb 이온의 흡착 평형은 Freundlich와 Langinuir 모델로 설명하였고, Freundlich 모델이 실험자 료와 잘 부합되었다 고정화된 S. cerevisiae를 이용한 혼합용액( Pb, Cu, Cr 및 Cd )흡착 실험에서 각 중금속들은 선택적 흡착 특성을 나타내었다. 고정화 미생물을 고정층 반응기에 충진하여 혼합 중금속 용액의 생체흡착 실험을 수행한 결과 Pb 이온이 가장 많이 흡착을 하였다. 고정화된 미생물에 흡착된 Pb의 탈착실험에서 0.1M의 HCI 및 $H_2SO_4$가 효과적이었다.

• Journal of the Korean Wood Science and Technology
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• 제14권4호
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• pp.1-7
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• 1986

This investigation involves a study of the physical and chemical factors of Pinus densiflora SIEB. et ZUCC. and Quercus mongolica Fisher barks affecting on the adsorption of heavy mteal ions. The results obtained can be summarized as follows. 1. The capacity of the untreated bark to remove the Cu and Cd from solution was similar to or 5% higher than that of formaldehyde treated bark in both species. Considering that untreated bark lead to color-leaching problem, bark treated with formaldehyde are economical. 2. With decreasing particle size of bark(20-80), the adsorption ratio of the Cu and Cd from solution was increased. Quercus bark adsorbed more Cu and Cd at smaller particle size compared to Pinus bark. 3. The heavy metal eqilibrium adsorption of the bark from Cu and Cd solution was attained within 10 min. Pinus bark removed about 48% of the Cu and 41% of the Cd from solution in 10 min while Quercus bark removed about 50% during that period. 4. As the initial metal concentration increased. the absolute metal uptake was increased while percentage removal was decreased. At the lower metal concentration (10 ppm). Pinus and Quercus barks removed 77-94% of the Cu and 72-84% of the Cd. At high metal concentration (200 ppm), the adsorption ratio was 40% Cu and 25% Cd, respectivelty. 5. The maximum adsorption of the Cu and Cd from solution was obtained at pH 5-6 in filtrate. 6. With increased bark weight per given metal concentration, absolute removal of metal ion from solution was increased, but the percentage removal was decreased. The amount of adsorption was 4.2 mg Cu and 4.2 mg Cd per gr. Pinus, bark and 5.4 mg Cu and 4.3 mg Cd per gr. Quercus bark, respectively.