• 한국환경과학회지
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• 제5권6호
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• pp.757-762
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• 1996

The removal effectiveness of various heavy metal ions in boron-rich containing plants has been studied by means of spectroscopic and pH methods. Treatment of the boron-rich containing sample which was collected from cherry and root of cabbage to heavy metal ions is resulted in that an excellent removal effect shows in the case of large ionic size of heavy metal. Stability constants are depended on the variation of pH.

• Elastomers and Composites
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• 제30권3호
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• pp.229-234
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• 1995

Membrane process has been applied widely to petroleum chemistry, fine chemistry, polymer, electronics, food, bioprocessing, and wastewater treatment process. Membrane process has advantage that there's no phase change through separation, energy consumption is smaller than other separation processes. And equipment investment and operation cost are inxpensive too. We prepared the silicone rubber membrane and then separated the heavy metal ion from wastewater. Silicone rubber membrane was prepared using a superitical fluid process and heavy metal ions were separated from the chromium nitrate, ferric sulfate, cupric sulfate, nickel sulfate aqueous solution. The pressure difference between top and bottom of separation apparatus was preserved by vacuum pump, and the removal amount of heavy metal at each separation step were analyzed by instrumental analysis, AAS. The surface and pore of silicone rubber membrane was investigated using SEM, and the capability of wastewater treatment using a silicone rubber membrane was proposed as calculated removal rate of heavy metal after comparing removal amount of heavy metal to amount of heavy metal in mother solution by AAS analysis.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 The 6th International Symposium of East Asian Resources Recycling Technology
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• pp.494-499
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• 2001

The present work investigates the possible use of fly ash for the removal of heavy metal ions from aqueous solutions. Batch experiments were conducted and the influences of metal concentration, pH, and fly ash concentration were investigated. Heavy metals used in these studies were zinc, lead and cadmium. Adsorption studies were done over a range of pH values (3-10) at $25^{\circ}C$ and heavy metal concentrations of 10-400 mg/L using fly ash concentrations of 10, 20 and 40 g/L. Experiments were also conducted without fly ash to determine the extent of heavy metal removal by precipitation. Kinetic and equilibrium experiments were performed and adsorption data were correlated with both Langmuir and Freundlich adsorption models. The results indicate that fly ash can be used as an adsorbent for heavy metals in the aqueous solutions, yet the degree of removal depends on the pH.

• 한국지하수토양환경학회지:지하수토양환경
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• 제16권5호
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• pp.90-96
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• 2011

Simultaneous removal of heavy metals (Cd, Pb) and diesel-fuel from a soil column was evaluated by respectively flushing with sodium dodecyl sulfate (SDS) solution, mixture of SDS and sodium iodide (SDS + NaI), and surfactant foam (SDS + NaI foam). First, this study evaluated these flushing methods to the heavy metals only-contaminated soil for removal of heavy metals from the heavy-metal only contaminated soil column. After 7 pore volume flushing of the soil column, Cd removal efficiencies from the soil were 40% by SDS solution, 50% by SDS + NaI mixture, and 60% by surfactant foam. The flushing results implied that anionic surfactant and ligand can be efficiently applied to extraction of Cd from the heavy metal contaminated soil. Furthermore, surfactant foam flushing showed an increased flushing efficiency with enhancing the contact between surfactant solution and soil. However, Pb removal efficiency by these flushing methods did not show any difference unlike those of Cd. Second, this study eventually evaluated flushing methods for simultaneous removal of heavy metals and diesel-fuel from the soil column with 7 pore volume flushing. Diesel-fuel removal efficiencies were 50% by SDS + NaI flushing and 90% by SDS + NaI foam flushing. Cd removal efficiency by the foam flushing reached to 80% which was higher than the result of the previous heavy metals onlycontaminated soil experiment. This result implied that diesel-fuel could act as a metal-solvent while it contacted to heavy metals present in the soil. This study clearly showed that surfactant foam flushing simultaneously removed heavy metals and diesel fuel from the soil column.

• 환경위생공학
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• 제13권1호
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• pp.174-184
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• 1998

Biosorption characteristics were investigated to discuss the use of agar entrapped Spirulina to remove of heavy metal ions from polluted waters. Agar immobilized algae were used as bioadsorbent in continuous reactor for heavy metal ions removal. The process solution contains Pb, Cu, and Cd as single ion and binary ions. In the adsorption of single heavy metal ions by agar immobilized Spirulina, the adsorption reached within 1hr and observed diffusion limitation differed from the free algal cell adsorption. The optimum pH for the adsorption of heavy metals was 4.5 but the influence of pH decreased less than that of free algal cell. Also, the adsorption characteristics of single heavy metal ions with agar immobilized Spirulina fitted the BET isotherm. Both of experiments of free algal cell and agar immobilized algae showed higher removal efficiency in the single ion solutions than binary ions solutions. The experimental results in the packed column with agar immobilized algae were over 90% of removal efficiency for the Pb, Cu, and Cd in single ion solutions.

• 자원리싸이클링
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• 제29권6호
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• pp.41-47
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• 2020

본 연구는 유동층 석탄보일러에서 발생하는 석탄 바닥회를 중금속 처리제로 활용하기 위하여 수행하였으며, 산성광산배수 중의 중금속 성분을 제거하기 위한 실험을 실시하였다. 대상 중금속은 구리, 카드뮴, 크롬, 납으로 선정하여 산성광산배수 모사액을 제조하였고, 석탄회 첨가량, 시험용액의 초기 중금속 농도에 대한 제거실험을 실시하였다. 실험결과, 석탄회 농도가 중량물 시료 15 g/L, 경량물 시료 10 g/L로 첨가된 조건에서 총 중금속의 제거능은 각각 30.8 mg/L, 46.4 mg/g로 나타났다. 이후 비소를 추가하여 5종 중금속에 대한 최대 제거능을 파악하기 위하여 장기 컬럼실험을 실시하였으며, 각각의 중금속 성분에 대한 제거능을 조사하였고, 약 60일간 가동 후 pH 9.25에서 최대 중금속 제거능은 23.6 mg/g이었다.

• 한국물환경학회지
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• 제30권6호
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• pp.647-652
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• 2014

The aim of this study was to investigate the heavy metal removal and biomass productivity in the Acid Mine Drainage (AMD) using eggshell and microalgae. The experiment was operated 6 days in the eggshell and microalgae hybrid system, and using eggshell powder and microalgae as Chlorella vulgaris. The obtained result indicated that the biomass productivity of 2.82 g/L/d from 1.12 g/L initial concentration in 6 days was reached with light transmittance of 97% at a 305 mm depth in the optical panel photobioreactor (OPPBR). The total removal efficiency of Fe, Cu, Zn, Mn and Cd was found to be 98.92%, 99.91%, 98.78%, 88.99% and 98.00% in the AMD using eggshell and Chlorella vulgaris hybrid system, respectively. Additionally, there were significant relationships between biomass and concentration of each heavy metal ($R^2$ = 0.8771, 0.8643, 0.8669, 0.9134 and 0.6277 for Fe, Cu, Zn, Mn and Cd). These results indicated that the eggshell and microalgae hybrid system was highly effective for heavy metal removal when compared to the conventional biological process in the AMD. Therefore, the eggshell and microalgae hybrid system was effective for heavy metal removal and biomass productivity and can be applied to treat AMD in treatment plant.

• 한국환경과학회지
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• 제5권2호
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• pp.195-201
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• 1996

This study was conducted for the efficient utilization of a scoria, which is abundantly found in Cheju island, as adsorbent and the scoria was examined for its performance in clarification of adsorption of heavy metal ions. The order in heavy metal ions adsorbed on scoria was; Pb+>Cd^{2+}$>Cu^{2+}$>Ag^+$>Co^{2+}$>Zn^{2+}$>Cr^{3+}$>Cr^{6+}$. This tendency was relatively consistent with the decreasing order of radius of hydrated metal ion. Also, the smaller scoria size and the larger amounts of scoria showed higher removal efficiency for heavy metal ions. The same scoria size showed more effective removal efficiency for heavy metal ions at lower initial concentration than at higher initial concentration. The adsorption abilities of original scoria and chemically treated scoria were compared. Adsorption isotherm of scoria was generally obeyed to Freundlich formula than langmuir formula and Freundlich constant, than was obtained in the range of 0.2~0.4.

• Membrane and Water Treatment
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• 제9권1호
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• pp.63-68
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• 2018

Molecular dynamics simulations were used to study the removal of Cd(II) as a heavy metal from wastewater using armchair carbon nanotube, boron nitride nanotube and silicon carbide nanotubes under applied electric field. The system contains an aqueous solution of $CdCl_2$ as a heavy metal and a (7,7) nanotube as a nanostructured membrane, embedded in a silicon nitride membrane. An external electric field was applied to the considered system for the removal of $Cd^{2+}$ through nanotubes. The simulation results show that in the same conditions, considered armchair nanotubes were capable to remove $Cd^{2+}$ from wastewater with different ratios. Our results reveal that the removal of heavy metals ions through armchair carbon, boron nitride and silicon carbide nanotubes was attributed to the applied electric field. The selective removal phenomenon is explained with the calculation of potential of mean force. Therefore, the investigated systems can be recommended as a model for the water treatment.

• 생태와환경
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• 제40권4호
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• pp.537-545
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• 2007

The heavy metal removal capacity of filamentous green alga Cladophora sp. cultured together with wet-mixed solidified soil (loess) was tested. A Cladophora sp. was cultured for 5d, with added Chu No. 10 medium, in stream water contaminated by high concentration of heavy metals from a closed mine effluent. Heavy metal ion concentrations of the medium and in algal tissue were measured every day during the experiment. Dissolved metals (Al, Cd, Cu, Fe, Mn, Zn) in medium were rapidly removed (over 90% elimination) within 1-2d when alga and loess were added. Dissolved heavy metals dropped by only 10% when algae were cultured without loess. The Cladophora sp. accumulated much more heavy metals when cultured with loess than when the alga was cultured alone. Cladophora sp. exhibited a maximum uptake capacity for Al ($17,000{\mu}g^{-1}$ algal dry weight). The metal bioremoval capacities of the algae were in the order Al, Fe, Cu, Mn, Zn and Cd. The heavy metal removal capacity of Cladophora sp. showed significant increases when wet-mixed solidified soil was added to culture media.