• 한국환경보건학회지
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• 제29권3호
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• pp.50-58
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• 2003

Removal of heavy metal ions (Cd$^{2+}$, Cr$^{3+}$, Cu$^{2+}$, Pb$^{2+}$) by several chitosans was studied and the molecular weight of chitosan was investigated in order to examine the effect of autoclaving. Chitosan were divided into 3 groups (A type, controlled chitosan; B type, autoclaved for 15 min; C type, autoclaved for 60 min). The heavy metal removal capacity and rate of B type chitosan were higher than those of A type and B type chitosan. The molecular weight of chitosan was decreased by the increase of autoclaving time. Therefore, the heavy metal capacity was not well correlated to the molecular weight. Freundlich and Langmuir isotherm was determined from the experimental results of equilibrium adsorption for individual heavy metal ions on chitosan. Langmuir isotherm was well fitted to this experimental data. The heavy metal removal capacity of B type chitosan was in the order of Pb$^{2+}$ > Cu$^{2+}$ > Cd$^{2+}$> Cr$^{3+}$.3+/.$.3+/.

• KSBB Journal
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• 제14권2호
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• pp.141-145
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• 1999

본 연구에서는 농산물의 부산물로 다량 폐기되고 있는 생물질재료 중 건조 밤껍질과, 포르말린 처리한 밤껍질, 인산화 처리한 밤껍질을 이용하여 pH 변화에 따른 중금속 흡착상태를 실험하였다. $Cd^{2+},\;Fe^{2+},\;Cr^{6+},\;Mn^{2+},\;Cu^{2+},\;Pb^{2+}$중금속 등에 대한 시간의 영향은 $Mn^{2+}$은 5분 경과 후, $Cd^{2+}$와 $Cr^{6+}$-는 10분 경과 후, $Fe^{2+}와 Cu^{2+}$는 20분 경과 후에 약간의 흡착 경향성을 보였고, $Fe_{2+}$는 5분 경과 후 계속 흡착이 증가하는 것을 보였다. $Cd^{2+},\;Fe^{2+},\;Cr^{6+},\;Mn^{2+},\;Cu^{2+},\;Pb^{2+}$중금속 등에 대한 pH의 영향은 $Cr_{6+}$인 경우 pH 2의 범위에서 가장 높은 흡착 결과를 보였으며, 나머지 중금속 이온의 겸우 pH 7.0~9.0에서 높은 흡착 경향성을 보였다. 밤껍질에 의한 중금속 이온의 제거율은 pH 7.0-9.0 에서 $\Fe^{2+},\;Mn^{2+},\;Cu^{2+},\;Pb^{2+}$ 들은 70% 이상을, 포르말린 처리한 밤껍질의 경우 $\Fe^{2+},\;Mn^{2+},\;Cu^{2+},\;Pb^{2+}$들은 50% 이상을, 인산화 처리한 밤껍질의 경우 $Cd^{2+},\;Fe^{2+},\;Mn^{2+},\;Cu^{2+},\;Pb^{2+}$들은 60% 이상을 보인 것으로 보아 밤껍질을 포르말린과 인산화 처리한 경우 중금속 이용이 제거율 향상에는 큰 효과가 나타나지 않음을 알 수 있었다.

• Bulletin of the Korean Chemical Society
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• 제33권11호
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• pp.3788-3792
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• 2012

Spherical-shape melanin nanoparticles with good water-dispersibility were successfully synthesized by a simple oxidation polymerization of 3,4-dihydroxy-phenylalanin (DOPA) with $KMnO_4$. Similar features to those known from natural and synthetic melanin polymers were observed from prepared melanin nanoparticles by FT-IR, UV-Vis., and ESR spectroscopic methods. Their binding ability with several heavy metal ions from aqueous solution was quantitatively investigated, and the maximum binding capacities with melanin nanoparticles to lead, copper, and cadmium ions were obtained as 2.45, 2.17 and 1.88 mmol/g, respectively, which are much larger values than those reported from natural and synthetic melanin polymers. The large binding capacity and fast binding rate of melanin nanoparticles to metal ions can make them an excellent candidate for the remediation of contaminated water.

• 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.

• Membrane and Water Treatment
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• 제10권3호
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• pp.239-244
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• 2019

Plating wastewater containing various heavy metals can be produced by several industries. Specifically, we focused on the removal of copper (Cu2+) and nickel (Ni+) ions from the plating wastewater because all these ions are strictly regulated when discharged into watershed in Korea. The application of both nanofiltration (NF) and reverse osmosis (RO) technologies for the treatment of wastewater containing copper and nickel ions to reduce fresh water consumption and environmental degradation was investigated. In this work, the removal of copper (Cu2+) and nickel (Ni+) ions from synthetic water was studied on pilot scale remove by before using two commercial nanofiltration (NF) and reverse osmosis(RO) spiral-wound membrane modules (NE2521-90 and RE2521-FEN by Toray Chemical). The influence of main operating parameters such as feed concentration on the heavy metals rejection and permeate flux of both membranes, was investigated. Synthetic plating wastewater samples containing copper ($Cu^{2+}$) and nickel ($Ni^{2+}$) ions at various concentrations(1, 20, 100, 400 mg/L) were prepared and subjected to treatment by NF and RO in the pilot plant. The results showed that NF, RO process, with 98% and 99% removal for copper and nickel, respectively, could achieve high removal efficiency of the heavy metals.

• 한국환경보건학회지
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• 제18권2호
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• pp.106-116
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• 1992

In order to examine the influences of diluent, DVB, and ligand content, in the adsorption velocities and capacities of chelating resins to heaw metal ions, the chelating resins containing the PO$_3$H, amide, and PO$_3$H+amide were prepared from AN-STR-DVB copolymer. The adsorption capacities of chelating resins were measured by ICP-AES. The major results of the studies are as follows: The optimized compositions of the chelating resins having the highest adsorptivity for the heavy metal ions were found to be DVB=7 wt%, toluene= 100 vol%. The adsorption rate of the chelating resins to the heaw metal ions was PO$_3$H > PO$_3$H+Amide > Amide in order.

• Environmental Engineering Research
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• 제19권1호
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• pp.15-22
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• 2014

In this study, the performances of various adsorbents-red mud, zeolite, limestone, and oyster shell-were investigated for the adsorption of multi-metal ions ($Cr^{3+}$, $Ni^{2+}$, $Cu^{2+}$, $Zn^{2+}$, $As^{3+}$, $Cd^{2+}$, and $Pb^{2+}$) from aqueous solutions. The result of scanning electron microscopy analyses indicated that the some metal ions were adsorbed onto the surface of the media. Moreover, Fourier transform infrared spectroscopy analysis showed that the Si(Al)-O bond (red mud and zeolite) and C-O bond (limestone and oyster shell) might be involved in heavy metal adsorption. The changes in the pH of the aqueous solutions upon applying adsorbents were investigated and the adsorption kinetics of the metal ions on different adsorbents were simulated by pseudo-first-order and pseudo-second-order models. The sorption process was relatively fast and equilibrium was reached after about 60 min of contact (except for $As^{3+}$). From the maximum capacity of the adsorption kinetic model, the removal of $Pb^{2+}$ and $Cu^{2+}$ were higher than for the other metal ions. Meanwhile, the reaction rate constants ($k_{1,2}$) indicated the slowest sorption in $As^{3+}$. The adsorption mechanisms of heavy metal ions were not only surface adsorption and ion exchange, but also surface precipitation. Based on the metal ions' adsorption efficiencies, red mud was found to be the most efficient of all the tested adsorbents. In addition, impurities in seawater did not lead to a significant decrease in the adsorption performance. It is concluded that red mud is a more economic high-performance alternative than the other tested adsorption materials for applying a removal of multi-metal in seawater.

• 한국환경과학회지
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• 제7권6호
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• pp.803-809
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• 1998

Heavy metal ions in water were removed using algal biomass as adsorbents. Absorbents were dried for 3 days, ground them by 40~60 mesh and then were swelled in a buffer solution for 1hr. After being packed in the column, commercially available standard solution of Cd(II) and Pb(II) ions were diluted to get the suitable concentration and then it was eluted with the rate of 1mι/min. Heavy metals on the adsorbents were recovered with nitric acid. More amounts of Cd(II) or Pb(II) ions in green algae, Ulva pertusa, than in brown algae, Sargassum horneri, were adsorbed. Pb(II) ion was adsorbed more than Cd(II) ion in both algae. The pH effect of adsorbed amounts of Cd(II), Pb(II) ions on the biomass was shown the following order ; pH 10.5 ＞ 8.5 ＞ 7.0 ＞ 5.5 ＞ 3.5. Recovery ratio of metal ions front algae is shown higher in acidic or neutral conditions than it in alkalic ones. Pb(II) ion is recovered relatively more than Cd(II) ion in our system.

• 대한환경공학회지
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• 제22권6호
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• pp.1021-1026
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• 2000

음이온계면활성제인 sodium di[2-ethylhexyl] sulfosuccinate(AOT)를 isooctane에 용해하여 조제한 W/O형 마이크로에멀젼을 이용하여 수용액중의 카드뮴, 구리 및 크롬 등의 중금속이온을 조작이 간단하고 효과적이며 대량으로 분리처리할 수 있는 시스템을 개발하였다. $Cd^{2+}$, $Cu^{2+}$ 및 $Cr^{3+}$는 W/O형 마이크로에멀젼에 의한 분리 후 3~7분 후에 평형에 도달하였고, 분리율과 분리속도는 수용액의 pH가 증가할수록 증가하였으며 $Cr^{6+}$ 는 전 pH 영역에서 분리제거가 되지 않았다. pH 3.5에서 $Cr^{3+}$는 5분 후에 90%이상 제거되었다. 분리속도식은 유사1차식으로 나타낼 수 있으며, 초기 물질전달계수(Jo)와 수용액 pH의 상관관계를 제시하였다.

• 환경위생공학
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• 제11권3호
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• pp.21-27
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• 1996

Chitosan is a natural polyelectrolytic compound. Researches of adsorption capacity using chitosan have been doing actively. We prepared bead type gel, simple modifier of chitosan, And then experimented adsorption test of heavy metals (Cd etc) using it. According to the result adsorption capacity of chitosan bead was five times higher than chitosan powder. Removal rate of cadmium resulted 90% over in the test that initial concentration of Cd was 100mg/L and bead dosage was 6g/100mL. Adsorption type of heavy metals was similar to general adsorption curve. And optical pH range was 4 - 10 in the adsorption test. In the experiments of other heavy metals (Pb, Zn, Cu, Mn) adsorption types had two stages, highly removal rate-stage at the short time (20minutes) and then slow rate-stage at the after. And removal efficiency at the variable pH ranges revealed relatively good.