• International Journal of Concrete Structures and Materials
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• 제9권3호
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• pp.283-294
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• 2015

In the present study, a porous concrete with alkali activated slag (AAS) and coal bottom ash was developed and the effect of carbonation on the physical property, microstructural characteristic, and heavy metal leaching behavior of the porous concrete were investigated. Independent variables, such as the type of the alkali activator and binder, the amount of paste, and $CO_2$ concentration, were considered. The experimental test results showed that the measured void ratio and compressive strength of the carbonated porous concrete exceeded minimum level stated in ACI 522 for general porous concrete. A new quantitative TG analysis for evaluating $CO_2$ uptake in AAS was proposed, and the result showed that the $CO_2$ uptake in AAS paste was approximately twice as high as that in OPC paste. The leached concentrations of heavy metals from carbonated porous concrete were below the relevant environmental criteria.

• 한국지하수토양환경학회지:지하수토양환경
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• 제18권4호
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• pp.8-18
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• 2013

Biocarrier beads with dead biomass, Bacillus drentensis, immobilized in polymer polysulfone were synthesized to remove heavy metals from wastewater. To identify the sorption mechanisms and theoretical nature of underlying processes, a series of batch experiments were carried out and a mathematical model was developed to quantify the biosorption of Pb(II) by the biocarrier beads. A series of mass balance equations for representing mass transfer of metal sorbents in biocarrier beads and surrounding solution were established. Major model parameters such as external mass transfer coefficient and maximum sorption capacity, etc. were determined from pseudo-first-order kinetic models and Langmuir isotherm model based on kinetic and equilibrium experimental measurements. The model simulation displays reasonable representations of experimental data and implied that the proposed model can be applied to quantitative analysis on biosorption mechanisms by porous granular beads. The simulation results also confirms that the biosorption of heavy metal by the biocarrier beads largely depended on surface adsorption.

• 한국기계가공학회지
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• 제17권4호
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• pp.137-142
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• 2018

Recycled synthetic resin materials produced from waste vinyl and waste plastic contain many foreign substances. Plastic products made from this recycled resin materials containing foreign substances are of poor quality, with reduced the strength and rigidity. Foreign substances include heavy metals, cement, foil, dyed paper and dust. In this study, the scratch-Dies process; which remove foreign sbustances, with precision and automation, through a three-stage mesh filter, is designed. The process is evaluated with finite element analysis according to vibration loading and make. After installing the manufactured equipment, recycled resin was producde, and its heavy metal content was evaluated. Recycled synthetic resin materials were also used plastic products and evaluate their strength. In addition, the change in production was assessed.

• 한국지하수토양환경학회지:지하수토양환경
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• 제18권7호
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• pp.63-72
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• 2013

This study estimated stabilization efficiency of As and heavy metal contaminated agricultural soil in abandoned mine through pot experiment. Also contaminants uptake of plant (lettuce) was compared as function of amendment (limestone, steelmaking slag and the mixture of these) addition. In soil solution analysis, concentration of contaminants in soil solutions which added limestone or steelmaking slag were lower than that of the mixture. Especially in As analysis, concentration with 5% (wt) addition of steelmaking slag showed the lowest value among those with other amendments. This seems that As stabilization happens through Fe adsorption during precipitation of Fe by pH increasing. Leachability of As in stabilized soil by TCLP was represented similar result with soil solution analysis. However leachability of heavy metals in stabilized soil was similar with that of non-stabilized soil due to dissolution of alkali precipitant by weak acid. Contaminants uptake rate by plant was also lower when limestone or steelmaking slag was used. However this study revealed that concentration of contaminants in soil solution didn't affect to the uptake rate of plant directly. Because lower $R^2$ (coefficient of determination) was represented in linear regression analysis between soil solution and plant.

• 에너지공학
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• 제13권1호
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• pp.82-91
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• 2004

석탄 및 하수슬러지 내에 함유된 무기물질을 환경적 측면에서 안정적인 물질로 재활용하기 위해서는 회재의 형태가 아닌 슬랙의 형태로 발생시키는 것이 한 방법이다. 가스화 반응에서 생성된 석탄 슬랙과 소각ㆍ용융과정에서 생성된 하수슬러지 슬랙의 특성을 분석하여, 재활용 측면에서 살펴보았다. 급냉을 시킨 슬랙들은 잘게 쪼개진 수 mm크기로 발생되었고, 함유된 미연탄소분은 모두 0.15% 이하였으며 슬랙의 구조는 대부분 무결정형인 특징을 보여주고 있었다. 분석 결과를 보면, 석탄 슬랙과 하수슬러지 슬랙 모두 중금속 성분이 용출되는 양은 국내기준치의 10배나 엄격한 일본기준보다도 훨씬 낮아서 재활용 물질로 활용하는 데에 문제가 없음을 알 수 있었다. 슬랙 내에 함유된 중금속 농도에서는 큰 차이가 있었는데, 향후 중금속 함량규제가 도입될 경우에는 두 슬랙 원료의 혼합 활용을 통해 중금속 함량 조절도 가능할 것이다.

• 유기물자원화
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• 제22권3호
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• pp.53-59
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• 2014

본 연구에서는 A 지역의 하수슬러지 건조장치가 설치되기 전과 후 탈수슬러지의 조성 및 성상, 중금속함유량 등을 측정 및 조사 분석을 하였다. 분석결과 건조로 설치전보다 약 95.7%의 제거효율을 보였으며, 설계값으로 1차건조로 35%, 2차건조로 10% 함수율을 제거하지만, 측정해본결과 1차건조로 20.8%, 리본 3.3%로 실제 운전효과가 더 좋은 것으로 나타났다. 중금속 함유량은 건조장치 설치 전 Cu : 352~614ppm, Hg : 1.3~1.44ppm, Cd : 1.1~1.86ppm, Pb : 17.25~ 28.93 ppm, As : 1ppm 이고 설치 후 Cu : 340~350 ppm, Hg : 0 ppm, Cd : 0~0.021 ppm, Pb : 0 ppm, As : 0~0.043 ppm으로 건조장치설치 전과 후 모두 법정 기준치에 초과하지 않음을 확인하였다. 또한 건조장치를 통과한 하수슬러지는 평균적으로 ${\frac{1}{4}}$의 건조슬러지가 발생하였다.

• 분석과학
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• 제14권6호
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• pp.530-534
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• 2001

Effect of stripping solutions on the Duolite GT-73 chelating resin for ten elements, Ag(I), Al(III), Ca(II), Cd(II), Cu(II), Fe(II), Hg(II), Mn(II), Pb(II), and Zn(II), was investigated. Relation between affinities of the metal ions and solubility products of metal sulfides was studied. The smaller the solubility product of metal sulfideis, the larger the affinitie with the ionsis. The ions which have the solubility products larger than $10^{-23}$ could be effectively desorbed with nitric acid. Complexation with chloride ion enhanced the desorption efficiencies of the ions having moderately strong affinity with the resin. The ions which have very strong affinity by the chelating resin can be desorbed by complextion with thiourea and hydrochloric acid.

• 한국어병학회지
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• 제24권3호
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• pp.269-278
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• 2011

Gene expression of two glyceraldehyde-3-phosphate dehydrogenase (GAPDH) paralogs was examined during Edwardsiella tarda challenge and heavy metal exposures in mud loach (Misgurnus mizolepis; Cypriniformes) kidney and spleen. Transcription of the two mud loach GAPDH paralogs (mlGAPDH-1 and mlGAPDH-2) was significantly modulated by these stimulatory challenges in an isoform-dependent manner. Based on the real-time RT-PCR analysis, the mlGAPDH-2 transcripts were more preferentially induced by E. tarda challenge, whereas the mlGAPDH-1 transcripts were proven to show more inducibility in response to heavy metal exposure using Cd, Cu, Mn and Zn at $5{\mu}M$. Their isoform-specific response patterns were closely in accordance with the TF binding profiles in promoter and intron-1 of the two mlGAPDH isoforms, in which the mlGAPDH-2 has more binding sites for immune-related transcription factors than mlGAPDH-1 while the mlGAPDH-1 possesses exclusively metal responsive elements in its intron. Collectively, the mlGAPDHs are potentially involved in cellular pathways independent of glycolysis and the two GAPDH paralogs might undergo functional diversification or subfunctionalization at least at the transcription level.

• 한국막학회:학술대회논문집
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• 한국막학회 2005년도 추계 총회 및 학술발표회
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• pp.96-101
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• 2005

A theory for the material transports through ion exchange membrane has been developed on the basis of nonequilibrium thermodynamics by removing the assumption of solvent flow in the previous paper and applied to a detailed study of the ionic transport properties of new charged mosaic membrane(CMM) system. The CMM having two different fixed charges in the polymer membrane indicated unique selective transport behavior then ion-exchange membrane. The separation behavior of ion transport across the CMM with a parallel array of positive and negative functional charges were investigated. It was well-known the analysis of the volume flux and solute flux based on nonequilibrium thermodynamics. Our suggests preferential salt transport across the charged mosaic membranes. Transport properties of heavy metal ions, $Mg^{2+}$, $Mn^{2+}$and sucrose system across the charged mosaic membrane were estimated. As a result, we were known metal salts transport depended largely on the CMM. The reflection coefficient indicated the negative value that suggested preferential material transport and was independent of charged mosaic membrane thickness.

• 대한환경공학회지
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• 제31권4호
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• pp.241-248
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• 2009

거풍광산 주변 밭의 오염된 중금속을 토양오염공정시험법과 TCLP를 이용하여 분석한 결과 비소, 납, 카드뮴, 구리, 아연과 같은 중금속의 농도가 전국 토양 평균치를 초과하는 것으로 나타났다. 본 연구에서는 중금속 오염된 토양의 안정화를 위해서 구연산칼슘인산염 용액을 이용하는 방안에 대한 기초연구를 실험실 조건과 현장 조건에서 수행하였다. 실험실 조건에서 구연산칼슘인산염 용액을 투여한 실험 결과, 고압멸균처리한 반응조에 비해 토착미생물 군집이 존재하는 반응조에서 용존 인산염의 농도가 현격히 감소하였으며, 중금속 안정화율도 높다는 것을 확인하였다. 현장 실험에서도 구연산칼슘인산염 용액 투여가 용존 인산염 감소와 중금속 안정화 결과를 가져왔다. 이는 미생물의 인산염 사용이 중금속 안정화 향상에 도움이 되었음을 의미한다. 현장 실험에서 미생물군집을 분석한 결과, 구연산칼슘인산염 용액 투여로 다양성이 증대되었으며, Anaerofilum과 Treponema 같은 혐기성 미생물 개체가 우점종으로 발현되는 결과를 얻었다. 이러한 결과들을 살펴볼 때, 구연산칼슘인산염의 투여로 인한 토착미생물 신진대사 활성화를 통해서 토양 내 혐기성 환원 조건을 제공하거나 토양미생물이 인산염을 중금속 안정화에 이용되기 쉽게 도와주는 미지의 기작을 통해서 해당 현장의 중금속 안정화에 기여한 것으로 해석된다.