• Korean Journal of Soil Science and Fertilizer
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• v.45 no.6
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• pp.1230-1236
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• 2012

To verify that the electrokinetic remediation is effective for decreasing salinity of fields of the plastic-film house, field tests for physical property, chemical property, and crop productivity of soils have been conducted. The abridged result of those tests is as follows. In the EK treatment, the electrokinetic remediation has been treated at the constant voltage (about 0.8 V $cm^{-1}$) for fields of the farm household. At this time, an alternating current (AC) 220 V of the farm household was transformed a direct current. The HSCI (High Silicon Cast Iron) that the length of the stick for a cation is 20cm, and the Fe Plate for an anion have been spread out on the ground. As the PVC pipe that is 10 cm in diameter was laid in the bottom of soils, cations descend on the cathode were discharged together. For soil physical properties according to the EK treatment, the destruction effect of soil aggregate was large, and the infiltration rate of water was increased. However, variations of bulk density and porosity were not considerable. Meanwhile, in chemical properties of soils, principal ions of such as EC, $NO_3{^-}$-N, $K^+$, and $Na^+$ were better rapidly reduced in the EK treated control plot than in the untreated control plot. And properties such as pH, $P_2O_5$ and $Ca^{2+}$ had a small impact on the EK. For cropping season of crop cultivation according to the EK treatment, decreasing rates of chemical properties of soils were as follows; $NO_3{^-}$-N 78.3% > $K^+$ 72.3% > EC 71.6% $$\geq_-$$ $Na^+$ 71.5% > $Mg^{2+}$ 36.8%. As results of comparing the experimental plot that EK was treated before crop cultivation with it that EK was treated during crop cultivation, the decreasing effect of chemical properties was higher in the case that EK was treated during crop cultivation. After the EK treatment, treatment effects were distinct for $NO_3{^-}$-N and EC that a decrease of nutrients is clear. However, because the lasting effect of decreasing salinity were not distinct for the single EK treatment, fertilization for soil testing was desirable carrying on testing for chemical properties of soils after EK treatments more than two times. In the growth of cabbages according to the EK treatment, the rate of yield increase was 225.5% for the primary treatment, 181.0% for the secondary treatment, and 124.2% for third treatment compared with the untreated control plot. The yield was increased by a factor of 130.0% for the hot pepper at the primary treatment (Apr. 2011), 248.1% for the lettuce at the secondary treatment (Nov.2011), and 125.4% for the young radish at the third treatment (Jul. 2012). In conclusion, the effect of yield increase was accepted officially for all announced crops.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.7
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• pp.445-453
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• 2012

An investigation for removal of 1-indanone (1-ID), which were commonly produced from the biological and/or chemical treatment and natural weathering of the PAHs-contaminated soils, via oxidative transformation mediated by birnessite in the presence of various phenolic mediators is described. This study also examines the potential effect of the natural occurring substance humic acid (HA) on the oxidative transformation. The experiment was carried out in aqueous phase as a batch test (10 mg/L 1-ID, 0.3 mM phenolic mediators, $1.0g/L\;{\delta}-MnO_2$, at pH 5). All of the 11 tested phenoilic mediators belong to the group of natural occurring phenols and are widely used as model constituents of humic substances. From the results of HPLC analysis, it is demonstrated that 1-ID was not reactive to birnessite itself, but it can be effectively removed in birnessite-mediated cross coupling reactions in the presence of the phenolic mediators. The percent removals of 1-ID after 2 day incubation were ranged from 9.2 to 71.2% depending on the phenolic mediators applied. The initial rate constant ($K_{int}$, $hr^{-1}$) values for the 1-ID removals obtained from the pseudo-first-order kinetic plots also widely ranged from 0.18 to 15.0. Results of the correlative analysis between the removal efficiencies and structural characteristics of phenolic mediators indicate that the transformation of the 1-ID was considerably enhanced by the addition of electron-donating substituents (e.g., -OH, $-OCH_3$) at the benzne ring, and much less enhanced by the addition of electron-withdrawing substituents (e.g., -COOH, -CHO). The presence of HA showed that removal efficiencies of 1-ID in the birnessite-phenolic mediator systems decreased with increasing HA concentrations. However at low concentration of HA (< 2 mg/L), it caused some enhancement in the removals of 1-ID as compared to the control.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.8 no.6
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• pp.1-12
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• 2005

Treatment level and pond reactions of a pond system were examined from May to October 2002. The system was constructed in July 2000 for purifying water of Sinyang stream that flows into Koheung Estuarine Lake located in the southern part of the Korean Peninsula. The system was composed of a primary and a secondary pond in series and established on the rice field near the lake. Water pumped from the stream was funneled into the primary pond, whose effluent was discharged into the secondary pond by gravity flow. Effluent from the secondary pond was funneled into wetlands. About 130 $m^3$/day of water was pumped into the primary pond and detention time of the primary and secondary pond was about 2 days. DO from the surface to the 1.0 m depth of the primary and secondary pond was in the rage of 5.2 to 11.0 mg/L and 4.3 to 0.7 mg/L, respectively. DO at the bottom layer of the primary pond was 0 mg/L and that of the secondary pond ranged 3.0~4.7 mg/L. The primary pond functioned as a facultative pond and the secondary as an aerobic one. The temperature difference between the surface and bottom layers of the ponds in August was about $2.5^{\circ}C$ and that in May and October was about $1.0^{\circ}C$. Thermocline was observed in the primary pond during the high ambient temperature of August. The sludge depth of the primary pond in May, August, and October was 2.4, 1.9, and 2.2 cm, respectively. That of the secondary pond was 1.2, 1.0, and 1.1 cm, respectively. SS, $BOD_5$, T-N, and T-P concentrations in influent averaged 16.64, 6.71, 6.21, and 0.23 mg/L and those in effluent from the primary pond averaged 11.48, 4.97, 4.81, and 0.17 mg/L, respectively. The removal rates of the primary pond for SS, $BOD_5$, T-N and T-P were 31%, 26%, 22%, and 24%, respectively. Average concentrations of SS, $BOD_5$, T-N, and T-P in effluent from the secondary pond were 9.81, 4.07, 4.03, and 0.14 mg/L, respectively and the abatement rates of the secondary pond for SS, $BOD_5$, T-N and T-P were 20%, 12%, 13%, and 15%, respectively. SS, $BOD_5$, T-N and T-P concentrations in effluent from the primary pond were significantly low(p=0.001) when compared with those from the secondary one.

• Korean Journal of Ecology and Environment
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• v.35 no.4 s.100
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• pp.249-256
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• 2002

The variation of trophic state was measured in a reservoir (Lake Andong, Korea) from 1993 to 2000. Phosphorus loading from the watershed was estimated by measuring total phosphorus concentration in the main inflowing stream (the Nakdong River). Phosphorus discharge from the pen-type fish farms was estimated from the amount of fish feed and the rate of phosphorus excretion per feed weight. The transparency in summer was about 2.0 m in 1993 and 1994, but it decreased to about 1.2 m in 1997 and 1998, and recovered to about 2.3 m in 1999 and 2000. TP increased from $11-30\;mgP/m^3$ in 1993 to $18-42\;mgP/m^3$ in 1998, but recovered to $8-13\;mgP/m^3$ in 2000, whereas TN decreased slightly from 1.81-2.96 mgN/L in 1993 to 1.17-1.80 mgN/L in 2000. TN/TP ratios decreased from 82-281 in 1993 to 21-143 in 1998, but again increased to 101-209 in 2000 due to the decrease of TP. The average chlorophyll-a concentration in growing season was in the range of $4.8-16.2\;mg/m^3$ from 1993 to 1997, but it decreased to $3.7-5.2\;mg/m^3$ after 1998. Trophic State Index had shown a gradual increase until 1996, and since then it has declined. The major cause of the trophic state recovery is thought to be the removal of fish farms in April 1998.

• Analytical Science and Technology
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• v.34 no.1
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• pp.23-35
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• 2021

In order to measure the volatile organic compounds (VOCs) of a sample which is too large to use commercially available chamber, a stainless steel vacuum chamber (VC) (with an internal diameter of 205 mm and a height of 50 mm) was manufactured and the temperature of the chamber was controlled using an oven. After concentrating the volatiles of the sample in the chamber by helium gas, it was made possible to remove residual volatile substances present in the chamber under reduced pressure ((2 ± 1) × 10-2 mmHg). The chamber was connected to a purge & trap (P&T) using a 6 port valve to concentrate the VOCs, which were analyzed by gas chromatography-mass spectrometry (GC-MS) after thermal desorption (VC-P&T-GC-MS). Using toluene, the toluene recovery rate of this device was 85 ± 2 %, reproducibility was 5 ± 2 %, and the detection limit was 0.01 ng L-1. The method of removing VOCs remaining in the chamber with helium and the method of removing those with reduced pressure was compared using Korean drinking water regulation (KDWR) VOC Mix A (5 μL of 100 ㎍ mL-1) and butylated hydroxytoluene (BHT, 2 μL of 500 ㎍ mL-1). In case of using helium, which requires a large amount of gas and time, reduced pressure ((2 ± 1) × 10-2 mmHg) only during the GC-MS running time, could remove VOCs and BHT to less than 0.1 % of the original injection concentration. As a result of analyzing volatile substances using VC-P&T-GC-MS of six types of cell phone case, BHT was detected in four types and quantitatively analyzed. Maintaining the chamber at reduced pressure during the GC-MS analysis time eliminated memory effect and did not affect the next sample analysis. The volatile substances in a cell phone case were also analyzed by dynamic headspace (HT3) and GC-MS, and the results of the analysis were compared with those of VC-P&T-GC-MS. Considering the chamber volume and sample weight, the VC-P&T configuration was able to collect volatile substances more efficiently than the HT3. The VC-P&T-GC-MS system is believed to be useful for VOCs measurement of inhomogeneous large sample or devices used inside clean rooms.

• Economic and Environmental Geology
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• v.36 no.1
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• pp.39-48
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• 2003

The removal of chromate from aqueous solution using finely ground pyrite and biotite was investigated by batch experiments and the kinetics and the mechanism of chromate reduction were discussed. The chromate reduction by pyrite was about hundred times faster than that by biotite and was also faster at pH 3 than at pH 4. When pyrite was used, more than 90% of initial chromate was reduced within four hours at pH 4 and within 40 min. at pH 3. However, more than 400 hours was taken for the reduction of 90% of initial chromate by biotite. The results indicate that the rate of chromate reduction was strongly depending on the amount of Fe(II) in the minerals and on the dissolution rate of Fe(II) from the minerals. The reduction of chromate at pH 4 resulted in the precipitation of (Cr, Fe)(OH))$_3$$_{ (s)}$, which is believed to have limited the concentrations of dissolved Cr(III) and Fe(III) to less than expected values. When biotite was used, amounts of decreased Fe(II) and reduced Cr(Ⅵ) did not show stoichiometric relationship, which implying there was not only chromate reduction by ferrous ions in the acidic solution but also heterogeneous reduction of ferric ions by the structural ferrous iron in biotite. However, the results from a series of the experiments using Pyrite showed that concentrations of the decreased Fe(II) and the reduced Cr(Ⅵ) were close to the stoichiometric ratio of 3:1. It was because the oxidation of pyrite rapidly created ferrous ions even in oxygenated solutions and the chromate reduction by the ferrous ions was significantly faster than ferrous ion oxygenation.

• Tuberculosis and Respiratory Diseases
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• v.54 no.2
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• pp.219-229
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• 2003

Background : The management of thoracic empyema and complicated parapneumonic effusion requires adequate antibiotics use and prompt drainage of infected pleural space. Tube thoracostomy for loculated empyema has low success rate and is also an invasive procedure with potential morbidity. Complications include hemothorax, perforation of intra-abdominal or intra-thoracic organs, diaphragmatic laceration, empyema, pulmonary edema, and Horner's syndrome. Given the potential morbidity of traditional chest tube insertion, use of the image-guided pigtail catheter drainage(PCD) of empyema has been employed. We retrospectively analyzed the medical records of patients with empyema or complicated parapneumonic effusion to determine the efficacy of percutaneous pigtail catheter drainage. Materials and Methods : 45 patients with complicated parapneumonic effusions or empyema were treated at Gil medical center from January 1998 to June, 1999. All were initially given PCD procedure and the following data were collected: clinical symptoms at the time of diagnosis, alcohol and smoking history, the characteristics of pleural effusion, radiologic findings (at the time of catheter insertion, removal and 1 month after catheter removal), the amount of effusion drained for initial 24 hours, the time from catheter insertion to removal and the use of surgical approach. Results : Male gender was more frequent (42 men vs. 3 women), the mean age of the study population was 52(range: 21~74) years. Empyema was found in 23 patients, complicated parapneumonic effusion in 22 patients. Four patients(three, parapneumonic effusion and one, with empyema) with PCD only treated, were cast off. Among the available patients, 36(80%) patients were treated with PCD only or PCD with urokinase. Among the 23 patients with empyema, surgical approach was required in five patients(27.1%, one required decortication, four open thoracostomy), one patient, treated with surgical procedure, died of sepsis. There was no significant difference of the duration of catheter insertion, the duration of hospital admission after catheter insertion and the mean amount of effusion drained for initial 24 hours between the patients with only PCD treated and the patients treated with PCD and urokinase. The duration of catheter insertion($9.4{\pm}5.25days$ vs. $19.2{\pm}9.42days$, p<0.05) and the duration of hospital admission after catheter insertion($15.9{\pm}10.45days$ vs. $38.6{\pm}11.46days$, p<0.01) of the patients with only PCD treated were more longer than those of the patients treated with surgical procedure after PCD. They were same between the patients treated with urokinase after PCD and the patients treated with surgical procedure after PCD($11.1{\pm}7.35days$ vs. $19.2{\pm}9.42days$, p<0.05, $17.5{\pm}9.17days$ vs. $38.6{\pm}11.46days$, p<0.01). In 16 patients(44.4%) with only PCD treated or PCD and urokinase treated, the amount of effusion at the time of catheter removal was decreased more than 75% and in 17 patients(47.2%) effusion decreased 50~75%. .In one patient effusion decreased 25~50%, in two patients effusion decreased less than 25%. One month after catheter removal, in 35 patients(97.2%, four patients were cast off), the amount of pleural effusion was successfully decreased more than 50%. There were no complications related to pigtail catheter insertion. Conclusion : In this study, PCD seemed to be an early efficacious procedure in treating the patients with complicated parapneumonic effusion or empyema without any serious procedure related complication.

• Applied Chemistry for Engineering
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• v.10 no.1
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• pp.154-159
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• 1999

EDTA (ethylenediaminetetraacetic acid), a chelating agent is most widely used in industrial applications, especially for cleaning of metals in water, frequently prohibits metal removal from water in conventional water treatment technologies. It could be easier to remove aqueous metal ions by the breakdown of DETA complexed bonds first. This study investigated the availability of $TiO_2$ photo-catalysis for the aqueous phase oxidation of Cu(II)-EDTA, under an aerobic condition at $20^{\circ}C$ with $TiO_2$ (Degussa P-25) and 1.79mM of Cu(II)-EDTA. When $TiO_2$ loading was 2.0 g/L, the photo-catalytic oxidation of Cu(II)-EDTA was maximal. The tendency of EDTA adsorption onto the catalyst surface was affected by $TiO_2$ surface charge, and the oxidation rate of Cu(II)-EDTA by photo-catalysis was shown to be dependent upon the tendency of EDTA adsorption before photo-irradiation.

• Korean Journal of Plant Resources
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• v.26 no.1
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• pp.68-74
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• 2013

This study was conducted to analyse the effectiveness of shading on growth and arsenic absorption of Pteris multifida, known as hyperaccumulator of arsenic, from paddy soils contaminated with heavy metals. Study was carried out in paddy soil polluted by arsenic near the former Janghang smelter. P. multifuda in the same growth stage was planted with $20{\times}20cm$ intervals in each experimental plot ($2{\times}2m$), and cultivated for 24 weeks. The growth of P. multifuda according to shading conditions was evaluated, the accumulated amount of arsenic in plants and arsenic variation in the soil was analyzed using ICP. In the result of this study, the growth of P. multifida cultivated under shading treatment was vigorous than non-shading. Accumulated amount of arsenic in aerial parts of P. multifida cultivated under non-shading ($169.8mg{\cdot}kg^{-1}$) was slightly higher than shading ($140.9mg{\cdot}kg^{-1}$), and those in underground part were almost the same. But the growth was great in 70% shading treatment. Therefore, arsenic contents absorbed from soils was much higher in shading treatment. Arsenic translocation rate (TR) of P. multifida was very high (0.87~0.89) regardless of shading conditions. So arsenic in soil could be efficiently eliminated by removal of aerial parts.

• The Korean Journal of Mycology
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• v.15 no.3
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• pp.175-182
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• 1987

A raw starch saccharifying enzyme from Aspergillus sp. SN-871 was purified by ammonium sulfate precipitation, DEAE-cellulose column chromatography, CM-Sephadex C-50 column chromatography and Sephadex G-75 gel filtration. The specific activity of purified enzyme was 18 fold and the yeild was 13.40%. The molecular weight of the purified enzyme was estimated as approximately 40,000 dalton by the method of Andrews gel filtration. The optimum pH and temperature for this enzyme were found to be 4 and $40^{\circ}C$, respectively and the stable range of pH was 2 to 5. The enzyme was themostable at below $60^{\circ}C$ and inactivated at $70^{\circ}C$. It showed a tendency to increase the enzyme activity under the presence of 0.01 M $BaCl_2$, but under 0.01 M$Pb(NO_3)_2$, $AgSO_4$, and $K_3Fe(CN)_6$ and citric acid etc. inhibited it completely. The substrate specifity of enzyme showed a tendency to increase the enzyme activity under addition of dextrin and glycogen, but under saccharose inhibited it. COD removal rate of Aspergillus sp. SN-871 was approximately 67 to 68%.