• The Korean Journal of Ecology
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• 제26권3호
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• pp.109-114
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• 2003

고층습지식물의 생리생태학적 특성을 규명하기 위하여 경상남도 양산시에 위치한 정족산 무제치늪에 서식하는 14과 22종의 식물을 대상으로 체내 무기양이온(K, Ca, Mg), 중금속이온(Al, Fe, Mn), 질소 및 인 함량의 계절적인 변화를 정량적으로 분석하였다. 무제치의 물은 15∼30 μ S/cm의 전기전도도(EC)와 pH 5.0∼5.6 (토양 4.3∼5.1)의 산도를 나타내었으며, Ca, Mg과 같은 2가 양이온의 함량이 낮은 반면 높은 중금속함량(특히 Al)을 보여 전형적인 산성토양의 특성을 보였다. 조사된 습지식물은 무기양이온함량에 있어 종간 뚜렷한 차이를 보였으며, 골풀, 진퍼리새, 기장대풀, 억새, 진달래, 산철쭉, 개미탑, 끈끈이주걱은 400 μ Mg DW 이하의 매우 낮은 함량을 나타내었으며, 동의나물, 숫잔대, 산제비난, 멱쇠채, 제비꽃, 바디나물은 체내 높은 무기양이 온 함량을 보였다. 특히 국화과의 멱쇠채와 제비꽃과의 제비꽃은 Ca과 Mg을 축적하는 경향성을 보였으며, 생육이 진전됨에 따라 오이풀과 꽃창포의 무기양이온 함량은 점차 감소하는 양상을 나타내었다. 한편 조사된 대부분의 식물들은 토양의 높은 중금속 함량에도 불구하고 체내 낮은 농도의 중금속을 함유하였으며, 축적된 총 중금속함량 및 조성은 식물 종간에 뚜렷한 차이를 보였다. 토양의 낮은 질소 및 인 함량에도 불구하고 조사된 대부분의 식물종들은 생육초기단계에 있어 비교적 높은 질소 및 인 함유하였으며, 생육이 진전됨에 따라 서서히 감소하는 양상을 나타내었다. 결론적으로 무제치늪에 서식하는 식물종들은 생육초기에 무기양이온 및 질소를 축적하고 생육과정에 이를 재이용하고, 중금속을 배제하는 기작을 발달시킴으로서 빈영양의 산성 환경을 극복하는 것으로 생각된다.

• 한국의류산업학회지
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• 제8권5호
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• pp.577-584
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• 2006

The binding of heavy metal ions onto cross-linked chitosan in dilute aqueous solution has been investigated as a function of pH (4.0 and 7.0), agitation period (10-180min) and concentration of various metal cations (5, 10, 50 and 100ppm). In order to obtain adsorbents that are insoluble and stable, and prevent the dissolution loss of chitosan into an acidic aqueous solution, chitosan flakes were cross-linked with epichlorohydrine (ECH) and its adsorption behavior was compared with that of the non cross-linked chitosan. An advantage of ECH is that it does not eliminate the cationic amine functional group of chitosan. In terms of adsorption ratio, the chitosan cross-linked at an ECH was inferior to original chitosan and was found that chitosan has a selectivity much remarkable than the cross-linked chitosan in low concentrated metal solutions. However, no significant decreases in the adsorption ratios were observed between the cross-linked ECH-chitosan and the non cross-linked chitosan concerning the adsorption of $Ni^{2+}$, $Co^{2+}$, $Pb^{2+}$ and $Zn^{2+}$ acidic solution.

• 한국염색가공학회지
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• 제26권1호
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• pp.7-12
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• 2014

Nowdays, fluorescent rhodamine chemosensors have attracted a worldwide interest due to its ability to selectively detect heavy and transition metal cations. Due to the importance in environmental and biological toxic effects, the developments of fluorescent chemosensors have been received considerable attention in recent. Especially, a rhodamine-based chemosensor probes have been proved to be useful by exhibiting the efficient "off-on" fluorescence switching toward selected metal cations. This fluorophore can undergo the transformation from non-fluorescent and colorless spirolactam derivative to fluorescent ring-open form. In this study, a new fluorescent chemosensor was synthesized using rhodamine B through two-step procedures, and its selectivity and related optical property were characterized. Selectivity and sensitivity was found toward $Cu^{2+}$ guest molecules and then related optical properties of rhodamine B based fluorescent chemosensor compound were characterized using discussed. In addition, computational calculation was used to determine the HOMO/LUMO values.

• 한국지하수토양환경학회지:지하수토양환경
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• 제16권4호
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• pp.23-30
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• 2011

Risk based pollution level of Pb and Cd in metal contaminated soils depending on physicochemical properties of soil in a target site was assessed using biotic ligand model. Heavy metal activity in soil solution defined as exposure activity (EA) was assumed to be toxic to Vibrio fischeri and soil organisms. Predicted effective activity (PEA) determined by biotic ligand model was compared to EA value to calculate risk quotient. Field contaminated soils (n = 10) were collected from a formes area and their risk based pollution levels were assessed in the present study using the calculated risk quotient. Concentrations of Pb determined by aqua regia were 295, 258, and 268 mg/kg in B, H and J points and concentrations of Cd were 4.73 and 6.36 mg/kg in G and I points, respectively. These points exceeded the current soil conservation standards. However, risk based pollution levels of the ten points were not able to be calculated because concentrations of Pb and Cd in soil solution were smaller than detection limits or one (i.e., non toxic). It was because heavy metal activity in soil solution was dominant toxicological form to organisms, not a total heavy metal concentration in soil. In addition, heavy metal toxicity was decreased by competition effect of major cations and formation of complex with dissolved organic carbon in soil solution. Therefore, it is essential to consider site-specific factors affecting bioavailability and toxicity for estimating reliable risk of Pb and Cd.

• 한국물환경학회지
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• 제33권5호
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• pp.556-562
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• 2017

Heavy metals in water systems are being managed on the concentration-based guidelines in Korea. However, various chemicals present in water can interact with heavy metals affecting their toxicity. Such interactions are not considered in the concentration-based guidelines. This study investigated the effect of hardness and coexisting heavy metals on heavy metal toxicity to emphasize the importance of having the effect-based guidelines together with the concentration-based guidelines in water management. The toxic effects of Cd, Zn, or mixtures of Cd and Zn were studied with Daphnia magna as a test species following the standard test method at different hardness conditions (100, 200, and $300mg\;L^{-1}$ as $CaCO_3$). The toxicities of single metal solutions and mixtures showed a decreasing trend with increasing hardness, and this can be attributed to the competition between heavy metals and cations such as calcium ions ($Ca^{2+}$) that cause hardness. The predicted toxicities of the heavy metal mixtures from the single metal toxicity deviated from the measured toxicities, and the predicted toxic effects tend to be greater than the measured toxic effects suggesting that Cd and Zn are in competition. This shows the limitations of using predicted toxic effects and the needs for further studies on mixture toxicities. Overall, this study shows that the management of heavy metals in waters needs to employ the effect-based guidelines together with the concentration-based guidelines.

• 멤브레인
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• 제27권2호
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• pp.129-137
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• 2017

본 연구에서는 수계 내 포함된 양이온들 중 특히 중금속 이온을 효율적으로 분리할 수 있는 양이온 교환막을 개발하였다. 기저 고분자로는 sulfonated polyetheretherketone (SPEEK)를 사용하였으며 이에 중금속 이온에 결합력이 강한 킬레이팅 수지를 파우더링하여 첨가하였다. 또한 양이온 교환막의 성능을 최적화시키기 위해 킬레이팅 수지의 함량 및 SPEEK의 이온교환용량을 제어하였다. 결과적으로 제조된 양이온 교환막을 막 축전식 탈염 공정(membrane capacitive deionization, MCDI)에 적용한 결과 중금속 이온 제거 효율이 20% 이상 향상됨을 확인할 수 있었다.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 1998년도 총회 및 춘계 학술발표회 논문집
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• pp.43-49
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• 1998

Retardation effect of heavy metals in soils caused by adsorption onto the surfaces of solids particles is well known phenomena. The adsorption of metal ions has been recognized more strong in clay mineral and organic matter contents rather than sands and gravels. In this study, we investigated the retardation effect in two sandy soils by conducting batch and column tests. The column tests were conducted to obtain the relationship between concentration and time known as breakthrough curve (BTC). We applied pulse type injection of ZnCl$_2$solution on the inlet boundary and monitored the effluent concentration at the exit boundary under steady state condition using EC-meter and ICP-AES. Batch test consisted of an equilibrium procedure for fine fractions collected from two sandy soils for various initial ZnCl$_2$concentrations, and analysis of Zn ions in equilibrated solution using ICP-AES. The results of column test showed that i) the peak concentration of Zn analyzed by ICP was far less than that detected by EC-meter for both soils and ii) travel times for peak concentration were more less identical for two different monitoring techniques. The first result can be explained by ion exchange between Zn and other cations initially present in the soil particles since ICP analysis showed a significant amount of Ca, Mg ions in the effluent. From the second result, we found that retardation effect was not present in these soils due to strong cation exchange capacity of Zn ion over other cations since we did not apply a solution containing more adsorptive cations such as Al. The result of batch test also showed high distribution coefficients (K$_{d}$) for two soils supporting the dominant ion exchange phenomena. Based on the retardation factor obtained from the Kd, we predicted the BTC using CDE model and compared with the BTC of Zn concentration obtained from ICP The predicted BTC, however, disagreed with the monitored in terms of travel time and magnitude of the peak concentrations. The only way to describe the prominent decrease of Zn ion was to introduce decay or sink coefficient in the CDE model to account for irreversible decrease of Zn ions in liquid phase.e.

• 한국지하수토양환경학회지:지하수토양환경
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• 제27권6호
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• pp.1-10
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• 2022

This study assessed the feasibility of iron oxide nanoparticles impregnated with biochar (INPBC), derived from woody biomass, as a stabilizing agent for the stabilization of farmland soil in the vicinity of an abandoned mine through pot experiments with 28 days of lettuce growth. The lettuce grown in the INPBC amended soils increased by more than 100% and the concentrations of inorganic elements (Cu, Ni, Zn) decreased by more than 40%. As, Cd and Pb were not transferred properly from the soils to the lettuce biomass. The bioavailability of arsenic and heavy metals in the INPBC amended soils were decreased by 26%~50%. It seems that the major mechanisms of stabilization were arsenic adsorption on iron oxides, heavy metal precipitation by soil pH increasing and heavy metal adsorption on organic matter. These results revealed that the lower bioavailability of the inorganic pollutants in the soils stabilized using INPBC induced lower transfer to the lettuce. Thus, INPBC could be used as an amendment material for the stabilization of farmland soils contaminated by arsenic and heavy metals. However, a pre-review of the chemical properties of the amended soil must be performed prior to applying INPBC in farmland soil because the concentration of the nutrients in the soil such as available phosphates and exchangeable cations (Ca, Mg, K) could be decreased due to adsorption on the surface of the iron oxides and organic matter.

• Bulletin of the Korean Chemical Society
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• 제19권2호
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• pp.218-222
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• 1998

Removal of Cd(Ⅱ), Zn(Ⅱ) and Cu(Ⅱ) from aqueous solutions using the adsorption process on magadiite has been investigated. It was found that the removal percentage of metal cations at equilibrium increases with increasing temperature, and follows the order of Cd(Ⅱ) > Cu(Ⅱ) > Zn(Ⅱ). Equilibrium modeling of adsorption showed that the adsorptions of Cd(Ⅱ), Cu(Ⅱ), and Zn(Ⅱ) were fitted to Langmuir isotherm. Kinetic modeling of the adsorption showed that first order reversible kinetic model fitted to experimental data. From kinetic model and equilibrium data, the overall rate constant (k) and the equilibrium constant (K) for the adsorption process were calculated. The overall rates of adsorption of metal ions follow the order of Cd(Ⅱ) > Cu(Ⅱ) > Zn(Ⅱ). From the results of thermodynamic analysis, standard Gibbs free energy (ΔG°), standard enthalpy (ΔH°), and standard entropy (ΔS°) of adsorption process were calculated.

• 한국토양비료학회지
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• 제45권5호
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• pp.738-743
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• 2012

Topographic conditions of agricultural fields work as a important factor to identify different soil properties. This study was conducted to investigate the selected soil chemical properties and the concentrations of heavy metals, Cd, Cr, Pb, Cu, Ni, and Zn, in the paddy fields of different topographic areas at four year intervals from 1999 to 2011. Three-hundred soil sampling sites in the paddy fields were selected from the different topographic areas that were local valley and fans, fluvio-marine deposits, alluvial plains, and diluvial terraces. The mean values of soil pH ranged 5.7~5.8 that were within optimal range for rice cultivation. The mean values of other properties such as soil organic matter (SOM) content, the concentrations of exchangeable cations, $K^+$, $Ca^{2+}$, and $Mg^{2+}$, and available silicate concentration were lower or close to the optimal values, but the mean concentrations of available phosphorus were exceeded the range of optimal value, $80{\sim}120mg\;kg^{-1}$, in many paddy fields. In particular, The concentrations of available phosphorus in the paddy fields of local valley and fans, alluvial plains, and fluvio-marine plains were mostly declined. However, in diluvial terrace areas, the phosphorus concentrations unexpectedly increased; furthermore, they were significantly higher than those in other topographic areas. The mean concentrations of 0.1 M HCl-extractable heavy metals, Cd, Cr, Pb, Cu, Ni, and Zn, in the paddy fields were slightly and gradually declined during the study years, but the Pb concentrations were not statistically changed. In addition, the concentrations of heavy metals were widely ranged depending on the different sampling sites. Nevertheless, the concentrations of heavy metals were significantly lower than the levels of Soil Contamination Warning Standard (SCWS) for agricultural lands (1-region) presented in Soil Environment Conservation Law (SECL).