• Korean Journal of Environmental Agriculture
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• v.25 no.4
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• pp.316-322
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• 2006

Objective of this research was to assess the release characteristics of metals from the mine tailing to base the prediction of metal load potential from tailing to soils. Water-soluble concentrations of Cd, Cu, Pb and Zn released from mine tailing after 2 hrs were 2.31, 129.38, 17.17, and 287.53 mg/kg, respectively, as compared to 1.6, 128, 108, and 142 mg/kg that were extractable by 0.1 M HCl. Kinetics of metal releases followed the power function model significantly indicating that more of water soluble fractions of those metals released at the initial short time, followed by a slow increase. Concentrations of metals released from tailing by water and 0.1 M HCl were in the orders of Zn > Cu > Pb > Cd. The breakthrough curve from the column experiment showed that concentrations of Cd, Cu, and Zn reached at highest after one pore volume, but that of Pb reached highest after five pore volumes when 0.1 M HCl was used as eluent. The release rate of Cd from mine tailing was the fastest but Pb was the slowest. The cumulative mass of metal released by 0.1 M HCl was in the order of Zn > Cu > Pb > Cd after nine pore volume elution.

• Economic and Environmental Geology
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• v.41 no.4
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• pp.383-392
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• 2008

This study aims to evaluate the mechanical-chemical stability of used coal ash blocks, for improving fishing grounds. The surface of weathered ash blocks in seawater showed a decrease in the Ca and an increase in the Mg contents, compared to that of fresh blocks. This result reflects the substitution of Ca by Mg in seawater. The compressive strengths of ash blocks submerged into seawater during 12 months ranged from 235.23 to $447.43\;kgf/cm^2$; this is higher than the standard strength of wave-absorbing blocks($180\;kgf/cm^2)$ that are used for harbor construction. In addition, the compressive strength of ash blocks tends to increase with increasing installation time in seawater. The result of leaching experiments on coal ash blocks by Korean Standard Leaching Test(KSLT) method showed that leached concentrations of most metals except Cr(that leached up to 50 ppb, approaching standard concentration) do not exceed the seawater quality standards. A long-term(112 days) heavy metal leaching test to analyze seawater without mixing-dilution also showed that the concentrations of leached heavy metals, except for Cu, under anaerobic conditions do not exceed the seawater quality standards. Accordingly, the use of coal ash blocks in marine environments appears to be safe from chemical and mechanical factors that decrease the efficiency of concrete. Also, leaching concentration of Cu seems to be stable by decrease of leaching concentration due to dilution of seawater.

• Proceedings of the KSEEG Conference
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• 2003.04a
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• pp.76-79
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• 2003

국내의 토양오염 공정시험방법에서는 Zn, Ni 추출시 산분해법에 가까운 방법을 사용하는 반면, Cd, Cu, Pb, $Cr^{6+}$ 추출시 0.1N HCl용액으로 산처리하여 1시간을 진탕한 후 이를 필터로 여과하여 분석용액을 추출하는 용출법을 사용하고 있다(환경부, 2001). 시료내에는 완충 물질이 존재하기 때문에 용출법 사용시 초기 pH 인 1(0.1N HCl)이 유지되지 않아 완충능력이 높은 토양의 경우 현재 국내 공정법상의 용출법이 중금속 오염정도를 추정하는데 적절치 않을 수 있다. (중략)

• Korean Journal of Mineralogy and Petrology
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• v.33 no.4
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• pp.391-405
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• 2020

Leaching chracteristics of Andong-dam sediment was conducted for heavy metal and nutrients. Five mixed sediment samples were prepared and leaching was conducted under aerobic and anaerobic condition for 60 days. Cd, Cu, Pb, Cr, Zn, Hg, As, Fe, Mn, phosphorus, and nitrogen were analyzed at each sampling time. The leaching rate of phosphorus was higher in anaerobic condition comparing with that of under aerobic condition. Some samples showed higher than the water-quality level IV. In case of As and Cd which showed highest contamination level in the sediment, leached concentration were 0.028 mg/L and 0.003 mg/L in maximum, respectively. The leached concentration is below than the lake water quality standard of Korea. Other heavy metals including Cu, Pb, and Cr also showed similar trend. Five step sequential extraction showed that easily extractable 1-2 step portion such as ion-exchangeable and adsorbed one was less than 10% and the most of the portion was residual. For As and Cd, the residual portion were 80% and 95% respectively indicating the risk by the heavy metal leaching into the lake for a short period was not high in comparing with the contamination levels.

• Journal of the Korean Ceramic Society
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• v.38 no.8
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• pp.732-739
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• 2001

산업부산자원으로부터 유입되는 중금속이 시멘트 수화반응에 미치는 영향에 대하여 연구하였다. 출발물질은 순수시약을 사용하여 $C_3$S와 $C_2$S 조성으로 배합하고 여기에 Zn, Cu, Cr의 중금속 산화물을 1000ppm, 2000ppm, 3000ppm 첨가하여 150$0^{\circ}C$에서 1시간 소결하여 중금속의 고용분배, 결정구조, 용출상태 그리고 수화열을 관찰하였다. 중금속중 Zn는 $C_3$S와 간극질에 집중 고용되고 Cu는 간극물질에 집중 고용되며 Cr은 $C_3$S와 $C_2$S에 집중 고용되었다. 광학현미경 및 XRD 관찰결과 중금속 함량별로 $C_3$S와 $C_2$S의 결정상에는 큰 영향이 없는 것으로 나타났다. 그리고 7일간 수화시 Zn는 40~50%, Cu와 Cr은 전량 용출되었다. Conduction calorimeter 분석결과 중금속 함량별 변화에도 $C_3$S와 $C_2$S 수화열에는 차이가 없었다.

• Journal of Korean Society of Environmental Engineers
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• v.38 no.11
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• pp.627-634
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• 2016

We investigated the characteristics of heavy metal desorption and recovery from carbon foam after plating wastewater treatment. The heavy metal desorption depends on solution chemistry because desorption occurred in HCl and $H_2SO_4 $ solution but did not occur in distilled water. Heavy metal desorption efficiency was increased using ultrasonication with desorption solution. The higher ultrasonic power and the longer reaction time improve efficiency. The copper plating rinse solution was treated reliably by carbon foam adsorbent during 200 bed volume. The adsorbed copper was dissolved using desorption solution and recovered by DC power supply. After copper recovery, the reuse efficiency of desorption solution was 84.2%.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2006.04a
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• pp.166-170
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• 2006

본 연구에서는 폐광산 주변에 산재되어 있는 광미/광폐석을 처리하기 위하여 고형화 실증 실험을 수행하였다. 고형화 공정에서 흔히 사용하는 포틀랜드 시멘트와 MSG-E, MSG-N을 고화제로 사용하였으며 현장 광미 및 광폐석을 대상으로 고화체를 양생하고 고화체의 압축강도 및 중금속 용출 정도를 측정하였다. 고화체의 물리/화학적 특성을 비교하기 위해 광미/고화제 비율, 배합수/고화제 비율 그리고 고화체 양생기간을 실험인자로 설정하였다. 실험 결과 광미/고화제의 비율 1:1 만을 고려하더라도 중금속 용출의 급격한 감소가 이루어지는 것을 확인할 수 있었으며 광미/고화제의 비율을 3:1 이하로 유지시키는 경우, 고화체의 압축강도가 현행 폐기물 관리법(20조 관련)에서 규정하고 있는 차단형 매립시설 내부막의 압축강도 기준인 $0.21kgf/mm^2$ 보다 높은 것으로 나타났다. 다양한 pH를 갖는 수용액에 대하여 시간에 따른 고화체의 중금속 용출률을 측정한 결과, 수용액의 pH가 1과 13인 강산/강염기 용액에서 일부 중금속의 용출 농도가 지하수 생활용수 기준치를 초과하였으나, pH와 3 - 11인 경우에는 중금속 용출률이 급격히 감소하여 모두 기준치 이하를 나타내었다. 또한, pH가 1과 13인 수용액의 경우에도 고화체와 반응하는 시간이 증가할수록 고화체의 buffering 효과에 의해 수용액의 pH가 감소하였다. 이러한 결과는 현장에서 접촉수의 pH가 강산이나 강염기라 하여도, 고화체의 buffering 효과에 의해 시간이 지남에 따라 수용액의 pH가 낮아져 고화체로부터의 중금속 용출은 매우 감소할 것임을 의미한다.ss of an active application defined using the model. The technique is developed in a platform- and language-independent way, and it is algorithmic and can be automated by computer program. We give an example dealing with network auction to illustrate the use of the model and the verification technique.품으로 내부 온도분포를 측정하였으며, 유한차분법 프로그램으로 대류열전달계수를 결정하였다. 대류열전달계수는 792에서 2,107 W/m$^2$로 분석되었다. 대류열전달 계수는 액상식품과의 상대속도가 증가함에 따라서 증가하였고, 점도가 증가함에 따라서는 감소하였다.ce of precision/recall of 90.99%/92.52%, and 93.39%/93.41% respectively. 의한 변성에 부분적으로 보호 작용을 나타 낼 것으로 추정된다.경(製麴72時間頃)의 활성(活性)은 보리쌀국(麴), 밀가루국(麴), 찹쌀국(麴), 고구마국(麴)의 순이었다.험 결과 오전용 사료는 관행적인 산란계 배합사료에서 Ca공급제를 제외한 것을 급여하고, 오후용 사료는 Ca공급제를 3배 첨가한 T2처리로 15:00~16:00시에 교체급여를 하면 사료섭취량 감소와 사료비 절감면에서 바람직할 것으로 사료되며, 고에너지-고단백질-저Ca의 분말사료와 저에너지-저단백질-고Ca의 펠렛사료를 혼합급여하면 산란계의 사료

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2006.04a
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• pp.213-215
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• 2006

반응용액의 pH와 반응시간에 따른 용출실험 결과를 PHREEQC를 이용하여 용출된 중금속이 어떠한 화학적 형태가 우세한지 알아보고자 하였다. 용출용액에 용해된 Zn, Cd, Cu, Mn 및 Fe의 주요 존재형태는 free ion 및 sulfate complexes($metal-SO_4$)인 것으로 계산되었다. pH 5와 pH 3의 조건에서 각 원소의 화학적 존재형태는 서로 유사하고, 반응시간이 증가할수록 free ion 상태로 존재하는 비율은 감소하고 sulfate complexes로 존재하는 비율은 증가하는 경향을 보였다. pH 1에서 용출된 용액에 존재하는 각 원소의 화학적 존재형태는 sulfate의 농도가 크게 증가됨에도 불구하고 free ion 상태로 존재하는 금속이온의 함량의 증가비율보다 sulfate complexes로 존재하는 함량의 증가비율이 더 큰 것으로 예측되었다.

• Journal of the Korean earth science society
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• v.29 no.3
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• pp.246-254
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• 2008

This study has been performed to evaluate the possibility of utilizing feldspar porphyry as an adsorbent for heavy metals in natural water. The research sample rock 'Maekbansuk' was altered feldspar porphyry which included chlorite, epidote and calcite formed by a prophylitic alteration process. In extraction tests, the majority of extracted elements were Ca and Na, which were extracted in much greater abundance from the groundmass than from the feldspar phenocryst. In adsorption tests, the adsorption capacities of Pb, Fe and Cu within an hour of reaction time were 99, 98 and 97%, respectively, but that of As remained 25% for a full 24 hours. The high adsorption capacities of altered feldspar porphyry for Pb, Fe and Cu suggest its potential utilization as a heavy metal adsorbent fur water purification.

• Korean Journal of Ecology and Environment
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• v.41 no.2
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• pp.166-173
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• 2008

Chemical forms and release potential of heavy metals were studied in the lime treated sediment of lake Chungcho. Chemical forms of heavy metals were analyzed using a sequential extraction method, and release potential of heavy metals was evaluated by the ratio of the content of labile forms to total metal one. Dominant form of Cd, Cu, Pb, and Zn in the untreated sediments was organic/sulfidic form that is stable in the reducing environment such as the bottom of Lake Chungcho. With liming of the sediment, the chemical forms of studied metals were greatly changed from organic/sulfidic form to adsorbed and reducible form, especially Cd and Cu to adsorbed and reducible form, but Pb and Zn to reducible form. It is believed that increase of unstable form of heavy metals in the sediments by liming was caused by the increase of pH of the pore water at the expense of organic/sulfidic form. Thus, we concluded that the liming approach currently used in the treatment of dredged sediments might cause the increase of labile form which is easily dissolved, and may increase the release of metals from the sediment into overlying water.