• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.32 no.4
• /
• pp.409-415
• /
• 1999

To evaluate the purification capacity of pollutants (COD, $PO_4^{3-}-p$, $NO_3^{-}-N$, Cu, Cd, Pb) in the three tidal flats, Eueunri, Gyewhado, Chunjangdae, the experiments were carried out with the batch reactor equipped with artifical tidal flats. Eueunri tidal flat was $98.8\%$ content of silt and clay and Chungjangdae was $97.84\%$ content of sand. The organic matters (I.L., $COD_{sed}$, POC) in Eueunri tidal flat were 2$\~$8 times higher than other tidal flats. The purification capacity of COD was 0.75 kg/ha/12 hr in Eueunri, 0.60 kg/ha/12 hr in Gyewhado and 0.55 kg/ha/12 hr in Chunjangdae. The mean purification capacity of COD in three tidal flats was 1.27 kg/ha/day. The calculated purification capacity of COD was 25.4 ton/day in the disappeared tidal flat areas (20,000 ha) of the Saemangeum reclamation. The purification capacity of phosphorus was 0.21 kg/ha/12 hr in Gyewhado, 0.39 kg/ha/12 hr in Eueunri and 0.22 kg/ha/12hr in Chunjangdae. The nitrate was 0.53, 0.74 and 0.43kg/ha/12hr, respectively. The purification capacity of heavy metals (Cu, Cd, Pb) were 88.9g/ha/12hr, 11.0g/ha/12hr, 1.7g/ha/12hr in Gyewhado, 89.1g/ha/12hr, 18.0g/ha/12hr, 2.6g/ha/12hr in Eueunri and 55.3g/ha/12hr, 18.0g/ha/12hr, 2.1g/ha/12hr in Chunjangdae, respectively. Accordingly, the purification capacity of pollutants in Eueunri tidal flat with high contents of organic matter were higher than other tidal flats. So, the purification capacity of pollutants were affected by physical and/or chemical characteristics of tidal flats.

• Journal of Korean Society of Forest Science
• /
• v.90 no.1
• /
• pp.83-89
• /
• 2001

This study was conducted to test the Cd accumulation and Cd-tolerance of Pisotithus tinctorius(Pt). Pt was isolated from Pinus thunbergii forest in Muan, Chonnam Province in 1997. Pt was cultured on MMN medium supplemented with $CdSO_4{\cdot}5H_2O$ at the final concentration of 0, 0.2, 0.5, 2, and $10{\mu}g/m{\ell}$ for 40 days. Growth rate and tolerance index of the fungus were measured every week, while Cd concentration, superoxide dismutase(SOD), and glutathione reductase(GR) of the fungus were analyzed at the end of the culturing, Pt showed growth reduction in vitro at $2{\mu}g/m{\ell}$ Cd in the medium and almost stopped growth at $10{\mu}g/m{\ell}$ Cd. Tolerance index of Pt decreased with increasing Cd concentration. Cd concentration of Pt was the highest at $10{\mu}g/m{\ell}$ Cd. Activities of SOD did not show significant difference between Cd concentrations, but GR of Pt increased at $0.5{\mu}g/m{\ell}$ Cd, and decreased at $2{\mu}g/m{\ell}$ Cd. Consequently Pt could be called Cd accumulator with a tolerance mechanism to Cd. Their tolerance to Cd were expressed through the higher production of antioxidants such as GR. Pt may be used for revegetation and decontamination of soil polluted by heavy metals.

• Journal of Soil and Groundwater Environment
• /
• v.12 no.4
• /
• pp.78-85
• /
• 2007

This study provides an attempt to evaluate sanding wastes, generated from a chemical company as a reused adsorbent. Organic impurities in the raw sanding wastes were removed by calcination at $550^{\circ}C$. Aluminum was a major inorganic composition in the raw sanding wastes and increased from 29.09% to 52.73% after calcination. Dissolved concentrations of heavy metals from the calcined sample were below 0.3 mg/L in a stability test at pH 2. From the pH-edge adsorption experiments with the calcined sanding wastes, As (V) was found to follow an anionic-type adsorption. Adsorption isotherm obtained with variation of the dosage of the calcined sanding wastes was better described by Freundlich equation than Langmuir one. Freundlich constants of K and 1/n were 4.244 and 0.316, respectively. The As (V) adsorption capacity of calcined sanding wastes estimated from Langmuir isotherm was 13.25 mg/g. From this study, the calcined sample was identified as a good reusable adsorbent in the view point of stability and adsorption capacity on As (V).

• Journal of Korean Society of Environmental Engineers
• /
• v.22 no.2
• /
• pp.203-210
• /
• 2000

The preparative methods of a chitosan-deposited activated carbon and its characteristics were studied by using three kinds of chitosan with different degree of deacetylation and average molecular weight. The procedure was consisted of the dissolution of chitosan into acid solution, impregnation of activated carbon, agitation, evaporation, and drying. When the chitosan-dissolved acid and its concentration, amounts of chitosan deposited, and agitation conditions were changed, the specific surface area, deposition state on surface, and stability were investigated, and amounts of Cr(VI) adsorbed was measured. In the preparation process, it was proper to agitate the chitosan-dissolved acetic acid solution at room temperature for 1hr. In the deposition of chitosan with low molecular weight, the specific surface area of activated carbon was greatly decreased even at low chitosan loading, but in the case of high molecular weight it was not nearly changed to 10wt% loading. It was known that chitosan was uniformly and physically deposited on activated carbon. The chitosan-deposited activated carbon was stable into the solution over about pH 6. The removal of Cr(VI) was remarkably enhanced by adding the adsorption function of chitosan to the surface of activated carbon with about 5wt% chitosan. It may be therefore used as an adsorbent for removing the pollutants in air and wastewater.

• Horticultural Science & Technology
• /
• v.29 no.5
• /
• pp.413-419
• /
• 2011

This study was conducted to find out the cadmium (Cd) accumulation and tolerance of Iris pseudacorus and Acorus calamus as aquatic plants native to Korea for Cd removal in water. In the range of Cd concentration from $10{\mu}M$ to $130{\mu}M$, the Cd lethal dose 50 ($LD_{50}$) was $78.5{\mu}M$ in I. pseudacorus and $47.6{\mu}M$ in A. calamus. In I. pseudacorus, superoxide dismutase and peroxidase as antioxidants were relatively effective against oxidative stress caused by Cd, while catalase, superoxide dismutase, and polyphenolics were effective in A. calamus. The polyphenolics known as typical antioxidants were not detected in I. pseudacorus. In both species, the Cd accumulation in plants increased with the higher Cd concentration and the longer processing period. Also, the absorbed Cd was accumulated mainly in the roots. The amount of Cd accumulated in the shoot part was maximally $548.1mg{\cdot}kg^{-1}$ (82.1% to Cd accumulated in the root part) in I. pseudacorus and $121.4mg{\cdot}kg^{-1}$ (13.7%) in A. calamus, which implied that both species all were enough evaluated as Cd hyper-accumulators based on 0.01% or more Cd accumulation in the shoot. Especially I. pseudacorus showed outstanding ability to move well Cd into the shoots from the roots and high tolerance to Cd stress.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.20 no.11
• /
• pp.224-231
• /
• 2019

Recently, the pollution of groundwater has become serious. In particular, the contamination of groundwater near livestock farms is becoming increasingly severe and it is difficult to drink with drinking water. In this paper, a groundwater purifier apparatus that can be installed in a community well was designed. The designed groundwater purifier apparatus enables a RO membrane filter and UV sterilization to remove pollutants, such as heavy metals, bacteria, and organic compounds. In addition, electrical conductivity, pressure, and flow sensors were added for remote monitoring. Remote monitoring of the system can determine the level of fouling and contamination of RO membrane filters through pressure and flow sensor data, and can record changes in the contamination and condition of groundwater through the electrical conductivity of the feed water. The designed groundwater purifier apparatus was installed at a farmhouse and remote monitoring. The result after 15 days of operating a groundwater purifier apparatus and analyzing the monitoring data revealed an average permeate water flow rate of 2.67L/min and an average water pressure of 7.09kgf/㎠, indicating that the RO Membrane filtered without fouling and clogging. The average electrical conductivity was 796.6 S/㎠ of the feed water and 55.6 S/㎠ of permeate water, which is similar to that of general tap water. Through this, it was confirmed that no pollutant occurred in the surroundings. Therefore, the designed groundwater purifier apparatus can confirm the replacement time of the RO membrane filter in advance through remote monitoring, and check the pollution state of the groundwater.

• Applied Biological Chemistry
• /
• v.44 no.3
• /
• pp.185-190
• /
• 2001

Alginate, a well-known biopolymer, is universally applied for immobilization of microbial cells. Biosorption characteristics of lead by waste biomass of immobilized A. niger beads, used in fermentation industries to produce citric acid, were studied. The immobilized A. niger beads, prepared via capillary extrusion method using calcium chloride, were applied in the removal of lead. Pb uptake was the highest in A. niger beads cells grown for 3 days with medium producing citric acid (12% sucrose, 0.5% $NH_4NO_3$, 0.1% $KH_2PO_4$, and 0.025% $MgSO_4$). Lead uptake by the immobilized A. niger beads and free A. niger mycellia beads increased sharply with time. However, while uptake by the immobilized A. niger beads continued to increase slowly, that by free A. niger mycellia beads stopped after 30 min. The optimum pH and temperature of lead uptake were found to be 6 and $35^{\circ}C$, respectively. The maximum uptake of lead was achieved with $50{\sim}100$ beads and 50 ml lead solution in a 250-ml Erlenmeyer flask, while, at over 100 beads, uptake of the lead decreased. The order of biosorption capacity for heavy metals was Pb>Cu>Cd. Pb uptake capacity of the immobilized A. niger beads treated with 0.1 M $CaCI_2$, 0.1 M NaOH, and 0.1 M KOH decreased compared to the untreated beads. On testing the desorption of Pb from the immobilized A. niger beads, re-uptake of Pb was found possible after desorption of the binding metal with 0.1 M HCI.

• Applied Microscopy
• /
• v.35 no.1
• /
• pp.15-22
• /
• 2005

Metallothionein (MT) is a low molecular weight, cysteine-rich, metal-binding, and non-enzymatic protein. The present study was carried out to investigate the expression of MT gene as well as the localization of MT in regenerating rat liver. In partial hepatectomized rats, MT mRNA was detected as early as 1 hr and reached a maximal level by 8 hr after the operation. Thereafter, this level decreased gradually until 24 hr, and it became similar to that of sham control. Meanwhile, time course of MT immunoreactivity using immunogold-labelling revealed that the number of gold particles in hepatocytes increased significantly by 12 hr, but decreased at 48 hr after partial hepatectomy. Ultrastructurally, immunogold particles indicating the presence of MT were distributed in both the cytoplasm and the nucleus of the rat hepatocytes, particularly the particles were distributed at rough endoplasmic reticulum and nucleolus and did not seem to adhere to mitochondria or lysosomes in proliferating hepatocytes. Briefly, high level of MT mRNA expression and the intense immunoreactivity and/or the specific localization of MT was observed during liver regeneration. These results suggest that MT possibly involves hepatocyte proliferation via the storage or the supply of various metal ions in the regenerating rat liver.

• Resources Recycling
• /
• v.9 no.1
• /
• pp.52-62
• /
• 2000

In order to maximize the recycling of converter slag to the more valuable fields, such as high quality aggregates for construction, cement industry and flux for ion making. It will be very important to control the compositions and properties of converter slag to suit the purpose of utilizastion. In this study, converter slag (STELCO, CANADA) was mixed with 5%~30% $SiO_2$and 7% carbon, and then reduced at $1650^{\circ}C$. After the reduction was completed, the reformed slags were cooled to room temperature in the furnace. All of the slags were then characterized using SEM-EDX, XRD and chemical analysis. Also the compressive strengths and densities of the reformed slags were measured to compare with natural aggregates. XRD analysis shows that th phases of reformed slags are changed from bredigite+merwinite mixed phases of 10% $SiO_2$added reduction to akermanite phases of 20% and 30% $SiO_2$ added reduction. But the SEM-EDX analysis revealed that the phase distribution of the reformed slags was changed very sensitively and complicately depends on the change of slag compositions. And also the properties of reformed slags are changed very much depend on the phase distribution. About one third of Cadmium and on fifth of Vanadium are remained in reduction reformed converter slag. Another heavy metal elements such as cobalt, zinc, lead are removed up to more than 90-95% of original slag. The compressive strength and density of 25% $SiO_2$ added and reformed slag is very near to natural granite. This is superior more than 10% to Thyssen's $SiO_2$ added and oxidized converter slag aggregates.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 2001.09a
• /
• pp.164-167
• /
• 2001

본 연구에서는 포항제철소에서 제철부산물로 발생되는 제강분진을 전처리 없이 산화촉매로 사용하여 김포 수도권 매립지의 침출수 처리공정에서 펜톤산화조에 유입되는 원수를 대상으 로 과산화수소를 이용한 연속식 산화처리 실험을 수행하였다. 먼저 회분식 실험결과를 바탕 으로 최적 반응조건에서 lab-scale 연속식 기초반응실험과 자체 설계.제작한 연속산화공정에서의 처리실험을 수행하였다. 또한 기존의 펜톤산화공정에서 Fe 공급원으로 사용되고 있는 FeSO$_4$.7($H_2O$)와의 반응성 비교실험도 수행하였다. 반응기간동안 일정 pH를 유지하기 위해 pH controller를 사용하였으며 침출수 수질은 CODcr로 나타내었다. 반응 pH 3.5, 체류시간 1 hr, 과산화수소 주입량 1,500mg/1에서 제강분진과 FeSO$_4$.7($H_2O$)를 각각 주입하여 수행한 연속처리 기초실험에서는 제강분진을 산화반응촉매로 사용한 경우에 침출수CODcr 처리율 62%, 과산화수소의 분해율 52%를 나타내었다. FeSO$_4$.7($H_2O$)를 산화반응 촉매로 사용한 경우에는 약 65-70%정도의 다소 높은 처리효율을 나타낸 반면에 과산화수소의 소비량은 제강분진의 경우보다 약 20%이상의 높은 값을 나타내었다. 연속산화공정 실험에서는 운전 3시간 이후에 유출수 중의 CODcr과 $H_2O$$_2$의 농도가 안정된 값을 나타내었다. 이 때 산화 반응조의 침출수 CODcr 제거효율은 약 43%이었으며, 처리수의 농도는 현재의 침출수 방류기준 이하로 나타났다. 결론적으로 침출수의 연속식 산화처리 실험결과, 처리효율과 경제성에서 제강분진의 산화촉매활용 공정의 개발 가능성이 매우 높은 것으로 나타났다.ell에 의해 완전분해 되었으며, 함께 존재시 TC는 Fe$^{\circ}$만으로는 분해가 되지 않았지만 cell에 의해 완전분해 되었으며, 함께 존재시 TCE분해에 저해작용을 미치는 것으로 나타났다.술의 첨가가 요구되고 있다. 따라서, 산성광산배수 오염지대에 대해 획일적으로 같은 처리방법을 채택하여 사용하는 것보다 각 지역 또는 광산산성폐수가 유출되어 나오는 광산폐기물의 특성 등을 고려하여 거기에 맞는 기술들을 복합적으로 또는 단독으로 사용하되 처리방법 채택 시 신중을 기할 것이 요망된다.정시에는 SeaWiFS 위성과 관련된 global algorithms 중에서 490nm와 555nm의 복합밴드를 포함하는 OC2 알고리즘(ocean color chlorophyll 2 algorithm)을 사용하는 것이 OC2 series 및 OC4 알고리즘보다 좋은 추정 값을 도출할 수 있을 것으로 기대된다.환경에서는 5일에서 7월에 주로 이 충체의 유충이 발육되고 전파되는 것으로 추측되었다.러 가지 방법들을 적극 적용하여 금후 검토해볼 필요가 있을 것이다.잡은 전혀 삭과가 형성되지 않았다. 이 결과는 종간 교잡종을 자방친으로 하고 그 자방친의 화분친을 사용할 때만 교잡이 이루어지고 있음을 나타내고 있다. 따라서 여교잡을 통한 종간잡종 품종육성 활용방안을 금후 적극 확대 검토해야 할 것이다하였다.함을 보이고 있다.X> , ZnCl$_{3}$$^{-}$같은 이온과 MgCl$^{+}$, MgCl$_{2}$같은 이온종을 형성하기 때문인것 같다. 한편 어떠한 용리액에서던지 NH$_{4}$$^{+}$의 경우 Dv값이 제일 작았다. 바. 본 연구의 목적중의 하나인 인체유해 중금속이온인 Hg(II), Cd(II)등이 NaCl같은 염화물