• Title/Summary/Keyword: 중금속이온

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Effect of the Removal Efficiency of Heavy Metals by the EPS Production of Bacillus Microorganisms (환경변화에 따른 바실러스 미생물의 EPS 생성이 중금속 제거 효율에 미치는 영향)

  • Son, Han-Hyung;Kim, Pan-Soo;Lee, Sang-Ho
    • Proceedings of the KAIS Fall Conference
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    • 2006.11a
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    • pp.309-312
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    • 2006
  • 최근에는 산업의 발전에 따라 다종 다양한 형태의 중금속이 이용되고 있지만 처리공정의 효율상의 한계성 때문에 미량의 중금속이 배출되어 생태계의 치명적인 위협요소로 부각되고 있다. 중금속이 포함된 폐수는 일반적으로 여러 가지 방법이 있지만 생체물질을 이용한 생체흡착에 대한 연구 및 공정 개발이 활발히 이루어지고 있다. 생체흡착은 중금속이 생물체 표면이나 내부로 물리 화학 및 생물학적 상호작용에 의한 이온교환, 흡착등 다양한 기작에 의해 수용액으로부터 중금속이 제거되는 것이다. 본 연구에서 바실러스에 의한 EPS 물질을 추출하였으며 포자화 전과 후의 EPS를 이용하여 중금속제거 실험을 하였다. EPS 물질은 Protein이 Carbohydrate보다 많은 함량을 보였으며 중금속 제거는 포자화 전보다 포자화 후의 EPS가 더 많이 제거되는 것으로 나타났다.

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Assessment Techniques of Heavy Metal Bioavailability in Soil - A critical Review (토양 중 중금속 생물유효도 평가방법 - 총설)

  • Kim, Kwon-Rae;Owens, Gary;Naidu, Ravi;Kim, Kye-Hoon
    • Korean Journal of Soil Science and Fertilizer
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    • v.40 no.4
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    • pp.311-325
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    • 2007
  • The concept of metal bioavailability, rather than total metal in soils, is increasingly becoming important for a thorough understanding of risk assessment and remediation. This is because bioavailable metals generally represented by the labile or soluble metal components existing as either free ions or soluble complexed ions are likely to be accessible to receptor organismsrather than heavy metals tightly bound on soil surface. Consequently, many researchers have investigated the bioavailability of metals in both soil and solution phases together with the key soil properties influencing bioavailability. In order to study bioavailability changes various techniques have been developed including chemical based extraction (weak salt solution extraction, chelate extraction, etc.) and speciation of metals using devices such as ion selective electrode (ISE) and diffusive gradient in the thin film (DGT). Changes in soil metal bioavailability typically occur through adsorption/desorption reactions of metal ions exchanged between soil solution and soil binding sites in response to changes in environment factors such as soil pH, organic matter (OM), dissolved organic carbon (DOC), low-molecular weight organic acids (LMWOAs), and index cations. Increasesin soil pH result in decreases in metal bioavailability through adsorption of metal ions on deprotonated binding sites. Organic matter may also decrease metal bioavailability by providing more negatively charged binding sites, and metal bioavailability can also be decreases as concentrations of DOC and LMWOAs increase as these both form strong chelate complexeswith metal ions in soil solution. The interaction of metal ions with these soil properties also varies depending on the soil and metal type.

Surface Complexation of Cationic Metal Adsorption Onto Amorphous Aluminum Oxide (무정형 알루미늄 산화물에 의한 양이온 중금속의 표면착화)

  • Park, Youn-Jong;Yang, Jae-Kyu;Choi, Sang-Il
    • Journal of Soil and Groundwater Environment
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    • v.13 no.1
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    • pp.101-109
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    • 2008
  • The adsorption characteristics of cationic metals such as copper, cadmium, and lead onto the amorphous aluminum oxide, AMA-L, which was mineralized from raw sanding powder at $550^{\circ}C$ were investigated. Additionally, surface complexation reaction of cationic heavy metals onto AMA-L was simulated with MINEQL + software employing a diffuse layer model. From the batch adsorption tests in a single element system, the adsorption affinity of each metal ion onto AMA-L was following order: lead > copper > cadmium. In a binary system composed with copper and cadmium, quite a similar adsorption affinity was observed in each metal ion compared to the single element system. When the surface complexation constants obtained in the single system were used in the prediction of experimental adsorption results, model predictions were well fitted with experimental results of both single and binary systems.

Heavy Metal Removal using Sawdust (톱밥을 이용한 중금속 제거에 관한 연구)

  • Jeon, Choong;Kim, Jung Hwan
    • Journal of the Korea Organic Resources Recycling Association
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    • v.15 no.2
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    • pp.81-88
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    • 2007
  • A study on the removal of heavy metals using sawdust was performed. Among heavy metals such as lead, copper and cadmium ions, uptake capacity of lead ions was the highest as about 0.22 mmol/g-dry mass at pH 4. The surface condition and existence of lead ions onto the sawdust was confirmed by the FT-IR, SEM (Scanning Electron Microscopy), and EDX (Energy Dispersive X-ray) instrumental analyses. When 0.5g of sawdust was added to initial lead solution (100ppm) removal efficiency was approximately 90%. Isothermal adsorption curve for lead ions was described by the Langmuir model equation and experimental data well fitted to model equation. Most adsorption for lead ions was also completed within 60min and pH of lead solution from 5.8 to 4.5 decreased with time.

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Effect of Heavy Metal Ions on the Oocyte Maturation of Frog, Rana dybowskii in vitro (중금속 이온이 산개구리 난자성숙에 미치는 영향에 관한 연구)

  • 고선근;이두표
    • Korean Journal of Environment and Ecology
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    • v.11 no.3
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    • pp.310-315
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    • 1997
  • In oreder to know the effect of the oocyte maturation with several heavy metal ions(Cd$^{2+}$, Hg$^{2+}$, Cu$^{2+}$, Pb$^{2+}$) on frog(Rana dybowskii) by FPH(Frog pituitary homogenate: 0.1 p.e./ml) in vitro, oocytes were cultured for 20 hours and exanimed the maturation rates with exposure of various comcentrations of those ions. The results showed that Cd$^{2+}$ at concentration of 0.1 ppm suppressed the maturation of the oocytes, while Hg$^{2+}$, Cu$^{2+}$ and Pb$^{2+}$ suppressed them significantly at 1 and 5 ppm respectively. To examine the reversibility of the inhibitory effects, the oocutes were exposed to the metal ions only for 3 hours and transferred to plain medium and cultured further for 17 hours. The oocytes were recovered from the toxic effect of the ions when they were exposed to 1 ppm of Cd$^{2+}$ for 3 hours and not available to 2.5 ppm. The effect of 2.5 ppm of Hg$^{2+}$, Cu$^{2+}$, Pb$^{2+}$ were also reversible and not available to 5 ppm for 3 hours exposure. From the abave results, it reveal that heavy metal ions in this study suppressed the maturation of oocytes at relatively low concentration. Therefore the oocyte culture system can be used as a useful tool to evaluate the toxicity of the pollutants in envirment.

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Properties of Heavy Metal Adsorption of Clay Minerals (점토광물에 의한 중금속 흡착 특성)

  • 엄태호;김유택;이기강;김영진;강승구;김정환
    • Journal of the Korean Ceramic Society
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    • v.39 no.7
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    • pp.663-668
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    • 2002
  • Cation exchange capacity of clay, white clay and zeolite was estimated by performing the powder adsorption test for 6 different heavy metal (Cd, Cr, Cu, Fe, Pb and Zn) standard solutions whose concentrations were varied by 5,10,15 and 20 ppm. The adsorption rate of heavy metals decreased with increasing the concentration of standard heavy metal solutions. The adsorption rate of the clay and the white clay showed more than 80% for the all tested heavy metals except Cr and especially above 99% for the Fe and the Pb. The Cr adsorption rate of the mixture of the clay and the white clay increased, however, that of Zn decreased. The adsorption rate of Cr and Zn showed relatively lower values as compared with those of the other heavy metals because the cation exchange H$\^$+/ ions and heavy metal ions of the clay or the white clay were in competition at low pH region.

Removal of Pb2+ Ions from Water by Surfactant-templated Mesoporous Silicates (계면활성제가 담지된 메조포러스 실리케이트에 의한 수중 납이온 제거)

  • Choi, Hyun Suk;Lee, Dong Gue;Cho, Guk Jin;Lee, Chae Young;Chung, Jin Suk;Yoo, Ik-keun;Shin, Eun Woo
    • Korean Chemical Engineering Research
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    • v.44 no.2
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    • pp.172-178
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    • 2006
  • Mesoporous silicate materials have been used as adsorbents for the removal of heavy metals from water by introducing functional groups such as thiol and amine. In this research, it was investigated whether surfactants used as templating agents in synthetic processes can act as adsorption sites for heavy metals. Three mesoporous silicates-SBA-15, MCM-41, and HMS were synthesized using, respectively, block copolymer, hexadecyltrimethylammoniumbromide (HDTMA), and dodecyamine as surfactants. X-ray diffraction and $N_2$ gas adsorption analysis confirmed that the mesoporous silicates were well prepared and FT-IR spectra resulted in the existence of the surfactants in as-synthesized mesoporous silicates and the removal of surfactants after calcination. The interactions between $Pb^{2+}$ ions and the mesoporous silicate materials with/without surfactants were observed. In adsorption kinetic experiments, it revealed that the calcined mesoporous silicates and the surfactant-loaded SBA-15 almost had no adsorption capacity for $Pb^{2+}$ ions. In contrast, the surfactant-loaded MCM-41 and HMS showed, respectively, the adsorption capacities of 26.60 and 115.16 mg/g which were acquired through the fits of adsorption kinetic data to the pseudo second order kinetic model. The adsorption capacities were comparable to those of other mesoporous adsorbents for heavy metals.

Stabilization Behavior of Heavy Metals in the EAF Dust-clay Body Mixtures at Various Sintering Conditions (점토계소지내에서 전기로 더스트 중금속의 소성 온도별 안정화거동)

  • Kwon, Yong-Joon;Kim, Yoo-Taek;Lee, Gi-Gang;Kim, Young-Jin;Kang, Seung-Gu;Kim, Jung-Hwan
    • Journal of the Korean Ceramic Society
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    • v.39 no.8
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    • pp.728-734
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    • 2002
  • Stabilization behavior of Cr, Cd, Cu, Pb, Fe and Zn heavy metals in the EAF dust was investigated by adding EAF dust to clay or white clay, respectively, up to 50 wt% with 10 wt% intervals and sintering at temperatures between 200 and $1200^{\circ}C$ with $200^{\circ}C$ intervals with an aid of ICP-AES followed by TCLP test to evaluate heavy metal cation exchange capacity of the clay or the white clay. The clay or the white clay had a better Cr ion exchange capacity than that of zeolite. The TCLP leaching test for the sintered specimens showed that Cr and Fe were rarely detected for all the specimens and the concentration of Cd and Zn decreased with increasing sintering temperature and decreasing EAF dust contents respectively. When the clay or the white clay were mixed with EAF dust, cation exchange may occur between the clay and the EAF dust so that the first stabilization of the mixtures containing semistabilized heavy metals may happen. Stabilization of heavy metals in the ceramic bodies was further completed probably due to the eutectic reaction caused by the sintering of semi-stabilized mixtures. It was conceivable that the white clay rather than the clay may be a better stabilizer for the EAF dust containing heavy metals.