• Journal of Soil and Groundwater Environment
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• v.9 no.4
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• pp.52-61
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• 2004

In order to remediate soils contaminated with oxyanionic As and cationic Zn and Ni through the pilot-scale acid washing, the effectiveness of acid washing and the properties of contaminated soils, fine soil particle and dissolved contaminants were evaluated. $H_{2}SO_4\;and\;H_{3}PO_4$ washing at pH $2{\sim}3$ enhanced the removal of As by the presence of competitive oxyanions and HCl washing effectively removed simultaneously As, Zn and Ni. The effectiveness of soil washing was little enhanced above the critical reaction time, and the carbonate, Fe/Mn oxide and organic/sulfides associated fraction were dominantly removed. The washing of coarse soil particles was highly efficient, but that of fine soil particles($<74{\mu}m$) was recalcitrant due to the enrichment with contaminants. Moreover, the physical separation of fine particles($<149{\mu}m$) enhanced the overall efficiency of soil washing. Therefore, both chemical extraction and separation of fine soil particles showed the high effectiveness of soil washing in the intersection point to minimize the amount of fine soil particles and to maximize the chemical extraction of contaminants.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.4
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• pp.368-375
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• 2006

Single and complex metal oxide catalysts supported onto a commercial DT51D $TiO_2$ have been investigated for gas-phase TCE oxidation in a continuous flow type fixed-bed reaction system to develop a better design approach to catalysts for this reaction. Among the $TiO_2$-supported single metal oxides used, i.e., $CrO_x,\;FeO_x,\;MnO_x,\;LaO_x,\;CoO_x,\;NiO_x,\;CeO_x\;and\;CuO_x$, with the respective metal contents of 5 wt.%, the $CrO_x/TiO_2$ catalyst was shown to be most active for the oxidative TCE decomposition, depending significantly on amounts of $CrO_x\;on\;TiO_2$. The use of high $CrO_x$ loadings greater than 10 wt.% caused lower activity in the catalytic TCE oxidation, which is probably due to production of $Cr_2O_3$ crystallites on the surface of $TiO_2$. $CrO_x/TiO_2$-supported $CrO_x$-based bimetallic oxide catalysts were of particular interest in removal efficiency for this TCE oxidation reaction at reaction temperatures above $200^{\circ}C$, compared to that obtained with $CrO_x$-free complex metal oxides and a 10 wt.% $CrO_x/TiO_2$ catalyst. Catalytic activity of 5 wt.% $CrO_x-5$ wt.% $LaO_x$ in the removal reaction was similar to or slightly higher than that acquired for the $CrO_x$-only catalyst. Similar observation was revealed for 5 wt.% $CrO_x$-based bimetallic oxides consisting of either 5 wt.% $MnO_x,\;CoO_x,\;NiO_x\;or\;FeO_x$. These results represent that such $CrO_x$-based bimetallic systems for the catalytic TCE oxidation on significantly minimize the usage of $CrO_x$ that is well known to be one of very toxic heavy metals, and offer a very useful technique to design new type catalysts for reducing chlorinated volatile organic substances.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.7
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• pp.483-490
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• 2009

The aims of this study were to evaluate the removal efficiency for various pollutants in urban storm runoff by a filtration device, and to determine design parameters depending on filter media properties. Appropriate selection of filter media will affect the size and life time of the filtration device. Sets of column tests were performed in order to evaluate the removal efficiency by perlite and a synthetic resin. An investigation of surface properties including CEC (cation exchange capacity) and zeta-potential suggested that the perlite had a superior adsorption capability for cationic pollutants. TCODcr and turbidity were analyzed to investigate the removal characteristic of particulate pollutant. In both columns, the particles in the collected storm runoff was almost completely capture with a small EBCT (empty bed contact time) of 2.5 minutes. Complete clogging at the EBCT of 2.5 minutes occurred after 630 minutes in the perlite column and 810 minutes in the resin column. The removal efficiency of TCODcr and turbidity at the EBCT of 2.5 minutes decreased to below 70% due to an wall effect. The removal efficiency for dissolved pollutant (SCODcr) was negligible due to the insufficient contact time for adsorption. The removal of heavy metals (Cu, Zn, Pb) was mostly ascribed to the filtration of particles containing metals, since the relationship between CEC and the removal efficiency was not apparent. The result of this study would be valuable for the application of filtration device to control of urban storm runoff.

• Analytical Science and Technology
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• v.12 no.5
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• pp.360-369
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• 1999

In this research, a study of adsorption kinetics of heavy metal ions on the Ulva pertusa and Hizakia fusiformis which is aiming at removing metal ions from water or every kind has been carried out. During the process of this research. Adsorption kinetics of Cd(II) and Pb(II) ions by the Ulva pertusa and Hizakia fusiformis, within five minutes reached at the maximum adsorption amount. The adsorption amoum by Ulva pertusa was more than the other. Adsorption ratio by Ulva pertusa were 15.0~100% of Cd(II) and 39.2~82.5% of Pb(II). Adsorption ratio by the Hizakia fusiformis were 18.3~100% of Cd(II) and 56.4~94.7% of Pb(II). Additionally, recovery ratio or Cd(II) from the Ulva pertusa presents 75.0~83.6% and that of Pb(II) ions presents 79.1~85.5%. Also, recovery ratio of Cd(II) from Hizakia fusiformis fusiformis were 66.7~85.0% of Cd(II) ions and 77.6~83.9% of Pb(II) ions respectively. As a result of this research. adsorption amount of Cd(II) and Pb(II) ions by Ulva pertusa was more than it by Hizakia fusiformis.

• Journal of Plant Biotechnology
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• v.35 no.4
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• pp.291-298
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• 2008

Methylmercury, an organic derivative, is the principal form of mercury that biomagnifies and causes neurodegenerative symptoms in animals. In recent years, living modified organism (LMO) resulting from biotechnology has played a highly visible and controversial role. Despite the potential benefits of this technology, public concerns have been raised about the environmental risk of LMO. The concern on the risk from LMO release has urged efforts to evaluate and manage the risks of the LMO. To build up the capacity building of risk assessment method for LMO used environmental remediation, we engineered Solanum nigrum L, expressing the modified bacterial gene, merB, encoding organomercurial lyase. Two independently isolated transgenic lines produced merB RNA. Transgenic Solanum nigrum leaf discs expressing merB gene showed organic mercury resistance, forming shoots well on growth medium containing $0.5{\mu}M$ methylmercury (II) chloride and $1{\mu}M$ phenylmercuric acetate while control plants breached. Transgenic merB seeds germinated and grew on growth medium containing $2{\mu}M$ methylmercury (II) chloride and phenylmercuric acetate. The merB transgenic plants will be used for risk assessment of natural environment.

• Economic and Environmental Geology
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• v.46 no.5
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• pp.411-424
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• 2013

Assessment and damage reduction strategy of acidic rock drainage were conducted in a section of ${\bigcirc}{\bigcirc}$ highway construction site. The geology of the studied section consists of Icheonri sandstone and intermediate to acidic volcanic rocks. Sulfides occur as a disseminated type in sandstone and volcanics which were altered by the hydrothermal solution of granite intrusion. Volcanics and sandstone with a high content of sulfide were classified as a potentially acid rock drainage(ARD) forming rock. The drainage originated from those rocks may acidify and contaminate the surrounding area during the highway construction. Therefore, the drainage should be treated before it is discharged. A slope landslide hazard due to the ARD was also expected and the coating technology was recommended for the reduction of ARD generation as a preemptive measure before reinforcement work for enhancing slope stability such as shotcrete and anchor. According to the ARD risk analysis, those rocks should not be used as cement aggregate, but only to be used as a bank fill material of a filling-up system that allows minimal contact with rainfall and groundwater.

• Korean Journal of Environmental Agriculture
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• v.11 no.1
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• pp.77-85
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• 1992

Of the cadmium-tolerant 162 bacterial strains isolated from soils, river waters or active sludges of waste-water disposal plants in the Gyeongnam province a strain C1, which showed considerably higher growth rate in the agar plate containing 2000 ppm than any other strains isolated, was identified as a Pseudomonas putida or its similar strain when analyzed by taxonomical characteristics. Optimum pH and temperature for the growth of the P, putida were 7.0 and $30^{\circ}C$, respectively. This strain was resistant to antibiotics(ampicillin, chloramphenicol and streptomycin), and heavy metals(lithium, cupper, lead and zinc). This strain utilized salicylate, naphthalene or xylene as a sole carbon source. The rate of cadmium accumulation in P. putida cell was enhanced at low concentration of Cd in the growth media. The maximum cadmium absorption by this strain grown in 1 and l0ppm of Cd was respectively 78% and 60% 24 hrs after culture, but in 100 ppm Cd, 40% 48 hrs after culture. Addition of a non-ionic surfactant Triton X-100(0.1%) to the medium enhanced the accumulation of cadmium in the P. putida up to approximately 37%.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.9
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• pp.641-647
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• 2014

In this study, sludge waste which has a difficulty in treating it was used to manufacture a fiber type of biosorbent. To solve the problems such as the release of organic pollutants and the difficulty in separating solid from treated water, entrapment method using Ca-alginate was used to immobilize sludge waste. Considering ease of manufacture as well as improvement of adsorptive ability, the biosorbent was manufactured in the form of fiber type. Optimum immobilization condition for minimizing the amount of alginate used and maximizing the performance of biosorbent was determined to be 10 g/L alginate concentration, 40 g/L sludge concentration, and 0.3-0.4 mm fiber diameter. The maximum Cd(II) uptake of the biosorbent was 60.73 mg/g. Pseudo-second-order kinetic model and Langmuir isotherm model adequately described the dynamic and equilibrium behaviors of Cd(II) biosorption onto the biosorbent, respectively. In conclusion, sludge waste generated from wastewater treatment process is a cheap raw material for the manufacture of biosorbent which can be used to remove toxic heavy metals from industrial wastewaters efficiently.

• Resources Recycling
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• v.17 no.4
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• pp.3-9
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• 2008

The total amount of fluidized bed incinerator ash, i.e. incombustion materials generated from the municipal solid waste incineration(MSWI) in Korea was approximately 14,000 tons in 2006. Most of the ash after ferrous metal separation is finally discard to the landfill sites. In the present work, possibility for recycling of the ash is studied to utilize the ash as raw materials for ceramic products. Incombustion materials obtained from the two different incinerators were used to recover the raw materials by applying the magnetic separation and screening process to remove metallic particles. The raw materials show relatively low heavy metals content obtained from the KSLP leaching tests. The ceramic products were prepared by mixing the clay with the various amounts of the raw material. The physical properties, i.e. shrinkage rate, absorbancy and compressive strength of the ceramic products sintered at $1,000^{\circ}C$ and $1,050^{\circ}C$, respectively were improved by increasing the addition amounts of the incinerator ash. Based on the leaching tests the ceramic products also be satisfied with the standard limits on the leachability of heavy metals because most of the metallic materials are effectively removed from the incombustion materials by appling the separation processes.

• Economic and Environmental Geology
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• v.41 no.3
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• pp.335-344
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• 2008

The acid rock drainage (ARD) production potential of rock was assessed for a tunnel construction area, Kimhae and the damage reduction strategy was discussed based on the ARD risk evaluation. The geology of the studied area consisted of Mesozoic quartz porphyry, sandstone, tuff and granite. Sulfides occurred as a disseminated type in quartz porphyry and granite, and a vein type in sandstone. Quartz porphyry and sandstone with a high content of sulfide were classified as a potentially ARD forming rock. The drainage originated from those rocks may acidify and contaminate the surrounding area during the tunnel construction. Therefore, the drainage should be treated before it is discharged. A slope stability problem due to the ARD was also expected and the coating technology was recommended for the reduction of ARD generation before the application of supplementary work for enhancing slope stability such as shotcrete and anchor. From the ARD risk analysis, those rocks should not be used as aggregate and be used as bank fill material with the system for the minimum contact with rain water and ground-water.