Oxidized activated carbons were prepared by reacting steam-activated carbon developed from pecan shells with nitric acid of varying strength (15, 30, 45 and 60%). The textural properties and the chemistry of the surface of the non-oxidized and of the oxidized carbons were determined from nitrogen adsorption and base neutralization capacities. The uptake of Pb(II) and Cd(II) from aqueous solution by these carbons was determined by kinetic and equilibrium experiments as well as by the column method. Treatment with nitric acid brought about drastic decrease in surface area and remarkable increase in the pore size of the carbon with these changes depending on the strength of nitric acid. Nitric acid increased the surface acidity by developing new surface oxygen functional groups of acidic nature. HNO3-oxidized carbons exhibited high adsorption capacities for Pb(II) and Cd(II). The adsorption of these ions increased with the decrease of the surface pH of the carbon and with the increase of the solution pH from 2.5 to 6 and 7. The amount adsorbed from lead and cadmium was also related to the amount of surface acidity, the pH of the point of zero charge and on some metal ion parameters. Cadmium and lead uptake by the investigated carbons followed pseudo-second order model and the equilibrium sorption data fitted Langmuir adsorption model.

2001년 1-12월 서울시 가락농수산물시장에서 총 951건의 수산물(어류 34종 468건, 패류 17종 373건, 갑각류 10종 39건 그리고 두족류 등 11종 71건)을 대상으로 중금속 함량[average(minimum∼maximum), Unit:㎎/㎏]을 분석한 결과, Hg 0.025(N.D.∼0.19), Cd 0.288(N.D.∼1.85), pb 0.227(ND∼1.68)이었다. Hg의 경우, 패류[0.003((N.D.∼0.19)]>두족류 등[0.026(N.D.∼0.11)]>갑각류[0.026(N.D.∼0.09)]>어류[0.018(N.D.∼0.19)]순이었고, 가장 높은 함량은 미꾸라지(0.19)와 꼬막(0.19)이었으며, Pb의 경우 패류[0.223(N.D.∼1.38)]>어류[0.213(N.D.∼1.68)]>두족류 등[0.151(N.D.∼0.39)>갑각류[0.144(N.D.∼0.44)]순이었고, 가장 높은 함량은 미꾸라지(1.68)>빙어(1.44)>바지락(1.38)>뱀장어(1.35) 순이었다. 한편, Cd의 경우 패류[0.288(N.D.∼1.85)]중 가장 높은 함량은 꼬막(1.85)이었다.

본 연구는 합성 모데나이트(Na6.6Al6.6Si41.4O96·20.4H2O, Na-MOR)를 이용한 다양한 중금속의 포획 연 구를 하기 위한 기초 단계로, 고분해능 X-선 분말 회절을 이용하여 치환체의 격자상수 및 부피 변화를 이해 하기 위한 목적으로 실험을 진행하였다. 열중량 분석법(Thermogravimetric analysis, TGA)으로 측정한 결과, 1가 양이온 치환체(Cs-MOR, Na-MOR)는 단위포 당 19.4, 20.4개의 물분자가 존재하였으며, 2가 양이온 치환 체(Pb-MOR, Sr-MOR, Cd-MOR)는 단위포 당 21, 23.1, 23.2개가 존재하는 것을 확인하였다. 측정한 모든 물 질은 사방정계에 속하는 Cmcm의 공간군을 가지는 것으로 확인할 수 있었다. 치환 전 물질인 Na-MOR과 비 교했을 때, 치환체의 (110)면과 (200)면의 회절강도가 명확하게 변화하였으나, 전체적인 피크의 위치는 거의 유사하게 나타나는 것을 확인할 수 있었다. 또한 Na-MOR에서는 확인이 되지 않았던 (220)면의 피크가 Pb-, Cd-, Sr-MOR에서 뚜렷하게 관찰되었다. 이를 통해서 양이온 치환에 따른 원자들의 분포 변화가 주로 ab-평 면상에서 나타나지만, 격자상수의 변화는 미세할 것으로 짐작할 수 있었다. Whole profile fitting 방법을 사용 하여 치환된 모데나이트의 미세한 격자상수의 변화를 관찰하였다. 치환체의 격자상수 및 격자부피의 변화는 치환된 양이온의 반경 및 전하수에 따라 서로 다른 경향성을 보였다. 1가 양이온의 경우, 이온반경이 증가할 수록 a-축의 길이는 증가하지만, 반면에 b- 및 c-축의 길이는 감소하였다. 2가 양이온의 경우, 이온반경이 증 가할수록 대체적으로 a-축의 길이가 감소하고, b- 및 c-축의 길이는 증가하였다. 격자부피는 1가 또는 2가 양 이온 치환체들이 각각 독립된 경향성을 가지며, 이온반경에 따라 증가하는 것을 확인할 수 있었다.

The aim of this study was to examine the morphological responses of Hosta longipes, an ornamental plants for heavy metal contaminated soils in urban landscaping, to heavy metals Cd, Pb, and Zn. Plants were grown in artificial soil amended with Cd, Pb, and Zn at concentation of 0, 100, 250, and 500 mg/kg. Plant height, leaf length, leaf width, total leaf number, deaf leaf number, new leaf number, chlorophyll contents, and ornamental value were monitored from May to August. At 4 months after planting, the survival and morphological responses of H. longipes grown in soil amended with Cd at concentrations ≥ 100 mg/kg were severely affected compared to those grown in the control soil. Relative leaf length rate and relative leaf width rate were significantly decreased when the concentration of Pb was increased. Total leaf number, chlorophyll contents, and ornamental value were the lowest value in plants grown in soil amended with Pb at level of 500 mg/kg. Relative leaf length rate and relative leaf width rate, total leaf number, dead leaf number, new leaf number, and ornamental values had a tendency of decrease when plants were grown in soils amended with Zn. However, no significant difference was found among treatments except for plants were grown in soils amended with 500 mg/kg Zn. Therefore, Hosta longipes might be useful for phytoremediation of Zn contaminated sites as herbaceous ornamental plants.

This study attempted to facilitate various groundcover plants, related to phytoremediation material, and advance shade plants with a heavy metal tolerance to contaminated soil in an urban shade space. Saxifraga stolonifera, which has commonly been used a landscape shade plants, was evaluated to determine its heavy metal tolerance to different concentrations(Control, 100mg․kg-1, 250mg․kg-1and 500mg․kg-1 treatment) of Cd, Pb and Zn in soil. The growth of Saxifraga stolonifera showed no significant tendency after the initial transplantation, but showed distinct changes with the respective treatment heavy metal types and concentrations over time. Especially, severe chlorosis, with more yellowish green leaves, was observed, with inhibition at Cd concentrations greater than 100mg․kg-1. Conversely, no external symptoms or growth retardation were observed with Pb and Zn concentrations less than 500mg․kg-1. Therefore, Saxifraga stolonifera can be applied as a long term phytoremediation species in soil contaminated with low concentrations of heavy metal in urban shade spaces.

AtHMA3 is one of P1B-ATPase of Arabidopsis thaliana which transports and/or stores Cd and Pb in the plant cell. To test whether AtHMA3 can be used to develop enhanced resistance plant to Cd and Pb for phytoremediation, we overexpressed AtHMA3 in Columbia-0 using a pBI121vector containing the 35S promoter. To evaluate their Cd and Pb resistance, seeds of three different T3 homozygous(HMA3-1~3) and wild type plants(col-0) were germinated and grown on agar plates containing 50μM Cd, 500μM Pb and 50μM Cd+ 500μM Pb for 3 weeks. 35S::AtHMA3 grew better than wild type plants about 1.1-to 1.8-fold in Cd or Pb containg mediums. Fresh weights of all three lines of transgenic plants were 1.2-to 1.5-fold higher than those of wild type plants in Cd or Pb-containing medium. In addition to, we measured Cd and Pb content in both wild type and transgenic plants grown in solution with 50μM Cd, 500μM Pb and 50μM Cd+ 500μM Pb for 6 d. AtHMA3-overexpressing plants had consistently higher Cd and Pb contents than wild type plants. Chlorophyll contents were not significant difference between overlines and wild-types. These results show that HMA3 contributes to Cd and Pb resistance, and it might be useful for the phytoremediation.

둥굴레 근경의 증자 및 열처리 중 수용성 고형분 및 Pb, Cd 제거율의 변화를 확인하기 위하여 반응표면분석(RSM)을 활용하였다. 중심합성계획법에 따라 증자시간( min), 볶음온도() 및 볶음시간( min)을 달리하여 16구간으로 제조된 시료의 수용성 고형분 함량, Pb 및 Cd 제거율을 측정하고 회귀분석을 실시하였다. 예측된 가용성 고형분의 최대값은 이었으며, 이때의 증자 및 볶음조건은 증자시간 65.24분, 볶음온도 및 볶음시간 37

The thiophene or furan-containing hexadentate ligands 1,12-bis (2-theophene)-2,5,8,11-tetraazadodecane(Thiotrien ․4HCl) and 1,12-bis (2-furan)-2,5,8,11-tetraazadodecane(Furatrien․4HCl) were synthesized as their tetrahydrochloride salt and characterized by EA, IR, NMR, and Mass spectrum. Their protonation constants (logKnH) and stability constants (logKML) for Cd2+, Pb2+, Zn2+ and Cu2+ ions were determined in aqueous solution by potentiometry and compared with 1,12-bis(2-pyridyl)-2,5,8,11-tetra-azadodecane(Pytrien) of pyridyl-containing ligand. The effect stability constants of ligands and metal ion for removal of heavy metals in aqueous solution were described.

Three kinds of toxic heavy metals, such as lead, copper, and cadmium, existing abundantly in contaminated soils were selected to investigate pH change, electroosmotic flow, and the removal rate in the application of electrokinetic process. In the change of pHs, they reached to about 12 and 2 at each cathodic and anodic region, respectively, and maintained for reaction being proceeded. Electroosmotic flow rates were not influenced by the kind of metal species but by electropotential gradient. On the soils contaminated by each metal, the removal rate of Cd was the fastest among three as in the order of Cd>Pb>Cu. While on the soils contaminated by mixed metal species, Cu was the fastest. Metal species transported by electrokinetic processes were distributed in between 0.9 and 1.0 of normalized region. In the case of soils contaminated by one kind of metal. the relative concentrations of Pb and Cd estimated in between normalized region 0.9 and 1.0 were 5.2 and 5.7, respectively.

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 1 ㎖/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 hornerl, 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 from algae is shown higher in acidic or neural conditions than It in alkalis ones. Pb(Ⅱ) ion is recovered relatively more than Cd(Ⅱ) ion in our system.