• 한국환경과학회지
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• 제9권5호
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• pp.409-414
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• 2000

In order to examine the availability and effectiveness of crab shell for the removal of heavy metals in aqueous solution the crab shell was compared with cation exchange resin(CER), zeolite granular activated carbon (GAC) and powdered activated carbon(PAC) on aspects of heavy metal removal capacity rate and efficiency. In the removal of Pb, Cd and Cr, the heavy metal removal capacity of crab shell was higher than those of any other sorbents (CER, zeolite, GAC, PAC) and the order of heavy metal removal capacity was crab shell>CER>zeolite>PAC GAC. However in the removal of Cu, the result of crab shell was slightly lower than that of CER. The initial heavy metal removal rate was affected by the sorts of sorbents and metals. In all heavy metals the heavy metal removal rate of crab shell was higher than those of any other sorbents. Under the heavy metal concentration of 1.0 mmole/$\ell$ the heavy metal removal efficiency of crab shell was maintained as 93~100% which was much higher than those of any other sorbents.

• 한국환경과학회지
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• 제2권4호
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• pp.357-365
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• 1993

This study was conducted for the efficient utilization of biomaterials such as starch residue, tangerine skin, and green tea residue, which are agricultral by-products discarded in Cheju Province annually, as adsorbents and biomaterials were examined for their removal ability of heavy metal ions in waste water by batch adsorption experiments. The removal efficiency of biomaterials for heavy metal ions was above 80-90% and almost similar to activated carbon and the adsorption ability of those treated with 포르말린 was improved in the green tea residue only for $Pb^{2+}$, $Cu^{2+}$, and $Zn^{2+}$. In the conditions of pH, the removal efficiency of heavy metal ions was high in the range of 5-7. In the solutions which heavy metal ions were mixed, the removal efficiency was similar at $Ag^+$, $Pb^{+2}$ and reduced to about 10% at the other ions, as compared with the solutions they were not mixed. Adsorption isotherm of biomaterials was generally obeyed to Freundlich formular than Langmuir formular and Freundlich constant, 1/n were obtained in the range of 0.1-0.5.

• 한국환경보건학회지
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• 제45권6호
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• pp.561-568
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• 2019

Objectives: The most commonly detected heavy metals in rocks and soils, including Pb, Cd, Cu, Fe, Mn and As, are representative pollutants discharged from abandoned mines and have been listed as potential sources of contamination in drinking water. This study focused on increasing the removal efficiency of heavy metals from drinking water resources by surface modification of natural adsorbents to reduce potential health risks. Methods: Iron oxide coating and graft polymerization with zeolites and talc was conducted for bipolar surface modification to increase the combining capacity of heavy metals for their removal from water. The removal efficiency of heavy metals was measured before and after the surface modification. Results: The removal efficiency of Pb, Cu, and Cd by surface modified zeolite showed 100, 92, and 61.5%, respectively, increases compared to 64, 64, and 38% for non-modified zeolite. This implies that bipolar surface modified natural adsorbents have a good potential use in heavy metal removal. The more interesting finding is the removal increase for As, which has both cation and anion characteristics showing 27% removal efficiency where as non-modified zeolite showed only 2% removal. Conclusions: Zeolite is one of the most widely used adsorptive materials in water treatment processes and bipolar surface modification of zeolite increases its applicability in the removal of heavy metals, especially As.

• 한국물환경학회지
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• 제28권2호
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• pp.277-284
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• 2012

This study developed a new ceramics in which natural zeolite was mixed and calcined with industrial by-product such as converter slag, red mud, and fly ash and evaluated the feasibility of the ceramics for removal of heavy metals in acid wastewater. The removal rate of heavy metal by ceramics increased in the order of ZS (zeolite and slag) > ZR (zeolite and red mud) > ZF (zeolite and fly ash) ceramics. The alkalinity increment and coherence of ceramics were increased in the order of ZS > ZR > ZF ceramics. The mixing ratio of natural zeolite to industrial by-product for maximum removal efficiency of heavy metal was 1:1 for ZS ceramics and 1:3 for ZR and ZF ceramics. The order of removal efficiency of heavy metal was observed to be ZS > ZR > ZF ceramics under the mixing ratio of 1:1 for ZS ceramics and 1:3 for ZR and ZF ceramics. The removal efficiency of heavy metal by ZS ceramics with 1:1 mixing ratio was Al 100%, Cd 54.6%, Cr 99.9%, Cu 98.7%, Fe 99.9%, Mn 42.2%, Ni 59.9%, Pb 99.8%, Zn 87.6%, respectively. In addition, the removal capacity of heavy metal by ZS ceramics was observed to be Al 2.01 mM/g, Cd 0.27 mM/g, Cr 1.02 mM/g, Cu 0.83 mM/g, Fe 0.95 mM/g, Mn 0.41 mM/g, Ni 0.55 mM/g, Pb 0.25 mM/g, Zn 0.70 mM/g, respectively. The comparative evaluation in the light of removal capacity, alkalinity increment, and coherence of ceramics showed the ZS ceramics had higher feasibility as a media than others for removal of heavy metals in acid wastewater.

• 한국지하수토양환경학회지:지하수토양환경
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• 제18권7호
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• pp.41-53
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• 2013

The study is to propose the optimal separation technique of heavy metals (Pb and Zn) contaminated in soil for improving the removal efficiency by various applicable techniques. The heavy metal contaminated soil samples near abandoned mine X-1 and X-2 were used for the study. Firstly, the wet classification process was shown more than 80% of removal efficiency for lead and zinc. Meanwhile, the magnetic separation process was shown low removal efficiency for lead and zincs because those heavy metals were non-magnetic materials. For the next step, the flotation separation process was shown approximately 24.4% of removal efficiency for zinc, while the gravity concentration process was shown approximately 57% of removal efficiency for lead, and 19.9% of removal efficiency for zinc, respectively. Therefore, zinc contaminated in soil would be effectively treated by the combination technique of the wet classification and the flotation technique. Meanwhile, lead contaminated in soil would be effectively treated by the combination technique of the wet classification process and the flotation process. Furthermore, the extraction of organic matter was shown more effective with aeration, 3% of hydrogen peroxide and 3% of lime such as calcium hydroxide.

• 한국환경보건학회지
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• 제23권1호
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• pp.105-108
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• 1997

For the removal of heavy metals, Cd, Cu and Cr were used. The initial concentration of Cd and Cu were 1-10 ppm, the removal efficiency of Cd and Cu was 76.2-89.0% and 69.0-79.0%, respectively. The initial concentration of Cr were 1~5 ppm, and the-removal efficiency was low especially at high concentration. In general, the initial concentrations of heavy metals had no relation to the removal efficiency. At the beginning, the removal efficiency was very high, but it was maintained at constant concentration. The trends of accumulations of heavy metals in the stem increased in proportion to the initial concentration. The removal efficiency of heavy metals increased a little bit when nutrients existed in the solution. So that, the initial concentration of Cd and Cu were 1-10 ppm, the removal efficiency of Cd and Cu was 84.8-91.0% and 75.9-82.0%. The initial concentration of Cr were 1-5 ppm, the removal efficiency was 25.0-67.0%.

• 자원리싸이클링
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• 제31권4호
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• pp.49-55
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• 2022

본 연구에서는 인덕션 탑플레이트(induction top plate) 소재로 사용된 후 폐기되는 사용 후 Li₂O-Al₂O₃-SiO₂계 결정화 유리를 활용하여 중금속 용액 내 존재하는 중금속(Pb, Cd, Cr⁶⁺, Hg) 이온들의 제거 실험을 진행하였다. 중금속 흡착제로 사용된 흡착제의 양, 흡착 반응 시간, 초기 중금속 원소의 농도, 초기 용액의 pH 등의 반응 조건에 따른 중금속 제거 효율의 변화를 조사하였다. 사용 후 LAS 첨가량이 증가할수록 중금속 제거 효율이 상승하였다. 흡착 반응 시간은 흡착 특성에 큰 영향을 미치는 것으로 확인되었으며, 모든 중금속 원소들의 제거 효율이 상승하였다. 특히 반응 시간에 따라서 Cd의 경우 흡착제거 효율이 크게 개선되었다. 초기 중금속 용액 농도는 중금속 제거 효율에 영향을 미치지 않았다. 중금속 용액의 pH는 중금속 제거 효율에 영향을 미쳤는데, Cd의 경우 pH증가에 따라 중금속 제거 효율이 증가하였으며, Pb, Cr⁶⁺는 감소하였다. Hg는 pH가 흡착 특성에 큰 영향을 미치지 않았다.

• 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.

• 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.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2002년도 추계학술발표회
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• pp.40-43
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• 2002

Electrokinetic remediation was studied for the removal of toxic heavy metals from tailing soils. This study emphasized the dependency of removal efficiency upon heavy metal speciation, as demonstrated by different extraction methods (sequential extraction, total digestion, and 0.1 N HC1 extraction). The tailing soils examined showed different physicochemical characteristics, in view of initial pH, particle size distribution, and major mineral constituents, and contained high concentrations of target metal contaminants in various forms. The electrokinetic removal efficiency of heavy metals was significantly influenced by their partitioning prior to treatment, and by the pHs of the tailing soils. The mobile and weakly bound fractions of heavy metals, such as exchangeable fraction, were easily removed by electrokinetic treatment (more than 90% in removal efficiency), whereas immobile and strongly bound fractions, such as organically bound and residual fractions, were not effectively removed (less than 20% in removal efficiency).