• Economic and Environmental Geology
• /
• v.45 no.3
• /
• pp.255-264
• /
• 2012

The stabilization using limestone ($CaCO_3$) and steel making slag as the immobilization amendments for Cu and Pb contaminated farmland soils was investigated by batch tests, continuous column experiments and the pilot scale feasibility study with 4 testing grounds at the contaminated site. From the results of batch experiment, the amendment with the mixture of 3% of limestone and 2% of steel making slag reduced more than 85% of Cu and Pb compared with the soil without amendment. The acryl column (1 m in length and 15 cm in diameter) equipped with valves, tubes and a sprinkler was used for the continuous column experiments. Without the amendment, the Pb concentration of the leachate from the column maintained higher than 0.1 mg/L (groundwater tolerance limit). However, the amendment with 3% limestone and 2% steel making slag reduced more than 60% of Pb leaching concentration within 1 year and the Pb concentration of leachate maintained below 0.04 mg/L. For the testing ground without the amendment, the Pb and Cu concentrations of soil water after 60 days incubation were 0.38 mg/L and 0.69 mg/l, respectively, suggesting that the continuous leaching of Cu and Pb may occur from the site. For the testing ground amended with mixture of 3% of limestone + 2% of steel making slag, no water soluble Pb and Cu were detected after 20 days incubation. For all testing grounds, the ratio of Pb and Cu transfer to plant showed as following: root > leaves(including stem) > rice grain. The amendment with limestone and steel making slag reduced more than 75% Pb and Cu transfer to plant comparing with no amendment. The results of this study showed that the amendment with mixture of limestone and steel making slag decreases not only the leaching of heavy metals but also the plant transfer from the soil.

• Korean Journal of Environmental Agriculture
• /
• v.37 no.2
• /
• pp.141-145
• /
• 2018

BACKGROUND: Agricultural soils are vulnerable from contamination of heavy metal derived from industrial waste. Monitoring on heavy metals on agricultural soils around industrial complexes and evaluation on distributional state on the concentrations of heavy metals in soil have been carried out for problem assessment on soil condition. METHODS AND RESULTS: Soil samples of 1,200, were collected from sixty site of industrial complexes located Gyounggi, Chungbuk, Cheonbuk, and Gyoungnam provinces. Total concentration of Cu, Pb, Zn, Ni, and As were analyzed. Heavy metal concentrations in most soil samples were below warning criteria, except 1 site of Pb, Ni, and As, separately. The comparison of mean values of heavy metal concentrations between soils around industrial complexes and paddy soils, showed similar levels of heavy metals, except Pb. The concentrations of lots of heavy metals were distributed between from warning criteria to one fifth level of warning criteria. However, in the case of Cu and Pb, more than 30% were distributed below one twenties level of warning criteria. These results were very similar with the distribution state of heavy metals in upland soils. The concentrations of heavy metals in surface soil and subsoil were similar among the heavy metals in soils around industrial complexes. CONCLUSION: The concentrations of heavy metals in soils around industrial complexes were distributed close to warning criteria. Long term and continous monitoring and evaluation on heavy metals in agricultural soils are required for food safety and sustainable soil management.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.24 no.4
• /
• pp.535-547
• /
• 2019

In this study, the heavy metal analysis in sediments (surface sediments, sediments cores and settling particles) from Shihwa Lake has been carried out to evaluate the changes of metal pollution levels in sediments after the operation of Tidal Power Plant (TPP). The average concentrations of metals in surface sediments sampled in 2015 were 8% (Cd)~31% (Zn, Hg) lower than in 2009 before TPP operation. Results of calculating the pollution load index (PLI) with 8 metals, the PLI value in 2015 showed a 18% decrease compared to 2009. However, Cu, Zn, Pb concentrations of surface sediments in 2015 at the upper region around industrial complex still exceeded the TEL (threshold effect level) values for sediment quality guideline in Korea. After the operation of TPP, the metal contaminated depths were increasing from 15 cm to 30 cm at S6 site and from 8 cm to 20 cm at S7 site, respectively. Our data showed that the mean concentration of heavy metals in core samples decreased but the contaminated depth increased. The average of the total sedimentation flux for particulate matter increased by 3.2 times from 32.5 g/㎡/d in 2009 to 103.5 g/㎡/d in 2015. This showed that the bottom sediments were resuspended by the operation of TPP, resulting in an increase of particulate matter in the water column. These results suggest that the sediments contaminated with heavy metals seem to be resuspended and relocated due to the water current caused by the operation of TPP. Cr, Cu, Zn, Pb and Cd were highly exceeding the TEL values in the upstream region and accumulated more than 40 cm of sediment depth, indicating that heavy metal contamination through industrial activity were still a serious environmental problem of Shihwa Lake. Although the metal pollution of Shihwa Lake has been slightly reduced, the contaminated sediments with heavy metals inside of Shihwa Lake might be discharged to outer sea after the resuspension by TPP operation. It is necessary for the advanced scientific approach and political decision to drastically reduce the heavy metal pollution of the study region.

• Economic and Environmental Geology
• /
• v.36 no.6
• /
• pp.457-467
• /
• 2003

Soil Precise Investigation(SPI) for river deposits and farmland soils around Goro abandoned Zn-mine, Korea was performed to assess the pollution level of heavy metals(As. Pb, Cd, Cu) and to estimate the remediation volume for contaminated soils. Total investigation area was about 950000 $m^2$, which was divided into each section of 1500 $m^2$ corresponding to one sampling site and 545 samples for surface soil(0-10cm in depth) and 192 samples for deep soil(10-30cm in depth) from the investigation area were collected for analysis. Concentrations of Cu, Cd, Pb at all sample sites were shown to be lower than Soil Pollution Warning Limit(SPWL). For arsenic concentration, in surface soils, 20.5% of sample sites(104 sites) were over SPWL(6mg/kg) and 6.7%(34 sites) were over Soil Pollution Counterplan Limit(SPCL: 15mg/kg) suggesting that surface soils were broadly contaminated by As. For deep soils, 10.4% of sample sites(18 sites) were over SPWL and 0.6%(1 site) were over SPCL. Four pollution grades for sample locations were prescribed by the Law of Soil Environmental Preservation and Pollution Index(PI) for each soil sample was decided according to pollution grades(over 15.0 mg/kg, 6.00-15.00 mg/kg, 2.40-6.00 mg/kg, 1.23-6.00 mg/kg). The pollution contour map around Goro mine based on PI results was finally created to calculate the contaminated area and the remediation volume for contaminated soils. Remediation area with over SPWL concentration was about 0.3% of total area between Goro mine and a projected storage dam and 0.9% of total area was over 40% of SPWL. If the remediation target concentration was determined to over background level concentration, 1.1% of total area should be treated for remediation. Total soil volume to be treated for remediation was estimated on the assumption that the thickness of contaminated soil was 30cm. Soil volume to be remediated based on the excess of SPWL was estimated at 79,200$m^3$, soil volume exceeding 40% of SPWL was about 233,700 $m^3$, and soil volume exceeding the background level(1.23 mg/kg) was 290,760 TEX>$m^3$.

• Economic and Environmental Geology
• /
• v.40 no.5
• /
• pp.651-660
• /
• 2007

Acid drainage has been recognized as an environmental concern in abandoned mine sites for long time. Recently, the environmental and structural damage by acid drainage is a current issue in construction sites in Korea. Here, the author introduces the type of damages by acid drainage in construction sites and emphasizes the importance of geoscience discipline in solving the problem. Metasedimentary rock of Okcheon group, coal bed of Pyeongan group, Mesozoic volcanic rock. and Tertiary sedimentary and volcanic rocks are the major rock types with a high potential for acid drainage upon excavation in Korea. The acid drainage causes the acidification and heavy metal contamination of soil, surface water and groundwater, the reduction of slope stability, the corrosion of slope structure, the damage on plant growth, the damage on landscape and the deterioration of concrete and asphalt pavement. The countermeasure for acid drainage is the treatment of acid drainage and the prevention of acid drainage. The treatment of acid drainage can be classified into active and passive treatments depending on the degree of natural process in the treatment. Removal of oxidants, reduction of oxidant generation and encapsulation of sulfide are employed for the prevention of acid drainage generation.

• Restorative Dentistry and Endodontics
• /
• v.25 no.1
• /
• pp.46-55
• /
• 2000

During bonding procedure of composite resin, the prepared cavity can be contaminated by saliva. In this study, marginal microleakage and shear bond strength of a composite resin to primed enamel and dentin treated with artificial saliva(Taliva$^{(R)}$) were evaluated. For the marginal microleakage test, Class V cavities were prepared in the buccal surfaces of fifty molars. The samples were randomly assigned into 5 groups with 10 samples in each group. Control group was applied with a bonding system (Scotchbond$^{TM}$ Multi-Purpose plus) according to manufacture's directions without saliva contamination. Experimental groups were divided into 4 groups and contaminated with artificial saliva for 30 seconds after priming: Experimental 1 group ; artificial saliva was dried with compressed air only, Experimental 2 group ; artificial saliva was rinsed and dried. Experimental 3 group ; cavities were etched with 35% phosphoric acid for 15 seconds after rinsing and drying artificial saliva. Experimental 4 group ; cavities were etched with 35% phosphoric acid for 15 seconds and primer was reapplied after rinsing and drying artificial saliva. All the cavities were applied a bonding agent and filled with a composite resin (Z-100$^{TM}$). Specimens were immersed in 0.5% basic fuschin dye for 24 hours and embedded in transparent acrylic resin and sectioned buccolingually with diamond wheel saw. Four sections were obtained from one specimen. Degree of marginal leakage was scored under stereomicroscope and their scores were averaged from four sections. The data were analyzed by Kruscal-Wallis test and Fisher's LSD. For the shear bond strength test, the buccal or occlusal surfaces of one hundred molar teeth were ground to expose enamel(n=50) or dentin(n=50) using diamond wheel saw and its surface was smoothed with Lapping and Polishing Machine(South Bay Technology Co., U.S.A.). Samples were divided into 5 groups. Treatment of saliva-contaminated enamel and dentin surfaces was same as the marginal microleakage test and composite resin was bonded via a gelatin capsule. All specimens were stored in distilled water for 48 hours. The shear bond strengths were measured by universal testing machine (AGS-1000 4D, Shimaduzu Co., Japan) with a crosshead speed of 5 mm/minute. Failure mode of fracture sites was examined under stereomicroscope. The data were analyzed by ANOVA and Tukey's studentized range test. The results of this study were as follows : 1. Enamel marginal microleakage showed no significant difference among groups. 2. Dentinal marginal microleakages of control, experimental 2 and 4 groups were lower than those of experimental 1 and 3 groups (p<0.05). 3. The shear bond strength to enamel was the highest value in control group (20.03${\pm}$4.47MPa) and the lowest value in experimental 1 group (13.28${\pm}$6.52MPa). There were significant differences between experimental 1 group and other groups (p<0.05). 4. The shear bond strength to dentin was higher in control group (17.87${\pm}$4.02MPa) and experimental 4 group (16.38${\pm}$3.23MPa) than in other groups, its value was low in experimental 1 group (3.95${\pm}$2.51 MPa) and experimental 2 group (6.72${\pm}$2.26MPa)(p<0.05). 5. Failure mode of fractured site on the enamel showed mostly adhesive failures in experimental 1 and 3 groups. 6. Failure mode of fractured site on the dentin did not show adhesive failures in control group, but showed mostly adhesive failure in experimental groups. As a summary of above results, if the primed tooth surface was contaminated with artificial saliva, primer should be reapplied after re-etching it.

• Economic and Environmental Geology
• /
• v.56 no.6
• /
• pp.715-728
• /
• 2023

Tracksite of pterosaurs, birds, and dinosaurs in Chungmugong-dong in Jinju was designated as a natural monument in 2011 and is known as the world's largest in terms of the number and density of pterosaur footprints. This site has been managed by installing protection buildings to conserve in 2018. About 17% of the footprints of pterosaur, theropod, and ornithopod in this site under management in the 2nd protection building are of great academic value, but observation of footprints has difficulties due to continuous physical and chemical damage. In particular, the accumulation of milk-white contaminants is formed by the gypsum and air pollutant complex. Gypsum remains evaporated with a plate or columnar shape in the process of water circulation around the 2nd protection building, and the dust is from through the inflow of the gallery windows. The aqueous solution of gypsum, consisting of calcium from the lower bed and sulfur from grass growth, is catchmented into the groundwater from the area behind the protection building. Pollen and a few minerals other constituents of contaminants, go through the gallery window, which makes it difficult to expel dust. To conserve the fossil-bearing beds from two contaminants of different origins, controlling the water and atmospheric circulation of the 2nd protection building and removing the contaminants continuously is necessary. When cleaning contaminants, the steam cleaning method is sufficiently effective for powder-shaped milk-white contaminants. The fossil-bearing bed consists of dark gray shale with high laser absorption power; the laser cleaning method accompanies physical loss to fossils and sedimentary structures; therefore, avoiding it as much as possible is desirable.

• Journal of Korean Society of Forest Science
• /
• v.90 no.4
• /
• pp.495-504
• /
• 2001

The objectives of this study were to understand the characteristics of Cd and Pb accumulation in various tissues of poplar species and the effects of ectomycorrhizal inoculation on the accumulation of above two heavy metals in the tissues. The mycelial inoculum of ectomycorrizal fungus, Pisolithus tinctorius was produced in peatmoss and vermiculite mixtures, and inoculated into potted soil with fresh cuttings of four species of Populus, P. alba ${\times}$ glandulosa (Pag). P. koreana ${\times}$ nigra var. italica (Pkn), P. nigra ${\times}$ maximowiczii(Pnm), and P. euramericana(Pe). The potted soils were added with 0, 30, and 80 ppm Cd, and 0, 50, and 300 ppm Pb. The cuttings were grown outdoors for about five months until the plants were harvested for measurement of growth, mycorrhizal infection, and metal contents in leaves, stems, and roots. The total dry weight of Pe treated with Cd and Pb was increased by mycorrhizal inoculation, while that of three other species was not affected by the inoculation. Cd was accumulated in the highest concentration in Pag and its concentration was increased by four times by mycorrhizal inoculation. The Pag accumulated Cd in the highest concentration in the leaves, while three other species accumulated Cd most in the roots. Pb was accumulated in the highest concentration in the roots of all the four species, while Pkn accumulated Pb in the leaves as much as in the roots. Without mycorrhizal inoculation Pe accumulated Pb most among the four species, while Pkn with mycorrhizal inoculation accumulated Pb two times more than in the same species without mycorrhizal inoculation. It was concluded that Pag was the most effective species among the four poplar species in Cd absorption from contaminated soil, and that Pe instead effectively absorbed Pb. Mycorrhizal inoculation increased the Cd accumulation in the tissues by four times in Pag and also increased Pb accumulation by two times in Pkn, with leaves being the major sites of metal accumulation. It may be possible to use these two poplar species in remedying the metal in the soil through the raking and removing the litter out of the contaminate site.

• Economic and Environmental Geology
• /
• v.37 no.1
• /
• pp.61-72
• /
• 2004

The soil samples were collected from the paddy field near the mine tailing dumps in the abandoned Duckum mine in Korea. In the laboratory, the soil solution was extracted from the soil using centrifuge, and analysed for the chemical composition. Physical and chemical soil properties were also analysed. Kaolinite is the main clay minerals in the paddy soil and the CEC value is therefore relatively low. Nearly all soil samples show enrichment in their trace elemental concentrations(Cd, Cu, Pb and Zn) compared with natural background level. Some soil samples exceed the soil remediation intervention values for Cd, Pb and Zn and target value for Cu, when compared with Dutch standard, whereas As, Ni and Cr are in normal range. Lead concentrations in some samples near the mine tailing dumps also exceed the standard for remediation act for agricultural area set by Korean soil conservation law. The trace elemental concentrations are higher in the paddy soil nearer the mine tailing dumps and lower for the samples from distance. Similar trend with distance is found for the soil solution chemistry but the decrease with distance from the mine tailing dumps are sharper than the changes in soil chemistry. Cadmium, Cu and Pb concentrations in the soil solution are very low, ranging from a tenth and hundredths to a maximum of several mg/l, whereas their concentrations in soils are highly enriched for natural background. Most of the trace elements are thought to be either removed by reduced iron sulphides or iron oxides, depending on the redox changes. Geochemical equilibrium modelling indicate the presence of solubility controlling solid phases for Cd and Pb, whereas Zn and Cu might have been controlled by adsorption/desorption processes. Although pollutants migration through solution phase are thought to be limited by adsorption onto various Fe, Mn solid phases, the pollutants exist as easily releasable fractions such as exchangeable site. In this case, the paddy soil would act as pollutant pool, which will supply to plants in situ. whenever the geochemical conditions favour.

• Journal of the Korean earth science society
• /
• v.39 no.2
• /
• pp.119-130
• /
• 2018

Aerosol Optical Properties (AOPs) are retrieved using the geostationary satellite instruments such as Geostationary Ocean Color Imager (GOCI), Meteorological Imager (MI), and Advanced Himawari Imager (AHI) through Yonsei AErosol Retrieval algorithm (YAER). In this study, the retrieved aerosol optical depths (AOD)s from each instrument were intercompared and validated with the ground-based sunphotometer AErosol Robotic NETwork (AERONET) data. As a result, the four AOD products derived from different instruments showed consistent results over land and ocean. However, AODs from MI and GOCI tend to be overestimated due to cloud contamination. According to the comparison results with AERONET, the percentage within expected errors (EE) are 36.3, 48.4, 56.6, and 68.2% for MI, GOCI, AHI-minimum reflectivity method (MRM), and AHI-estimated surface reflectance from shortwave Infrared (ESR) product, respectively. Since MI AOD is retrieved from a single visible channel, and adopts only one aerosol type by season, EE is relatively lower than other products. On the other hand, the AHI ESR is more accurate than the minimum reflectance method as used by GOCI, MI, and AHI MRM method in May and June when the vegetation is relatively abundant. These results are explained by the RMSE and the EE for each AERONET site. The ESR method result show to be better than the other satellite product in terms of EE for 15 out of 22 sites used for validation, and they are better than the other product for 13 sites in terms of RMSE. In addition, the error in observation time in each product is found by using characteristics of geostationary satellites. The absolute median biases at 00 to 06 Universal Time Coordinated (UTC) are 0.05, 0.09, 0.18, 0.18, 0.14, 0.09, and 0.10. The absolute median bias by observation time has appeared in MI and the only 00 UTC appeared in GOCI.