• Journal of Soil and Groundwater Environment
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• v.13 no.6
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• pp.62-71
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• 2008

Soil quality standards (SQS) are necessary to protect the human health and soil biota from the exposure to soil pollutants. The current SQS in Korea contain only sixteen substances, and it is scheduled to expand the number of substances. Chemical ranking and scoring (CRS) system is very effective to screen the priority chemicals for the future SQS in terms of their toxicity and exposure potential. In this study, several CRS systems were extensively compared to propose the assessment factors that required for the screening of soil pollutants The CRS systems considered in this study include the CHEMS-1 (Chemical Hazard Evaluation for Management Strategies), SCRAM (Scoring and Ranking Assessment Model), EURAM (European Union Risk Ranking Method), ARET (Accelerated Reduction/Elimination of Toxics), CRSKorea, and other systems. The additional assessment factors of CRS suitable for soil pollutants were suggested. We suggest soil adsorption factor as an appropriate factor of CRS system to consider chemical transport from soil to groundwater. Other factors such as soil emission rate and cases of accident of soil pollutants were included. These results were reflected to screen the priority chemicals in Korea, as a part of the project entitled ‘Setting the Priority of Soil Contaminants'.

• Journal of Aquaculture
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• v.13 no.3
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• pp.223-230
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• 2000

A rearing experiment of the olive flounder was performed in a set of water-reuse system to test the reusability of the water in culture system with (i) a foam fractionator to separate particles from water and (ii) a culture tank contain mineral particles to filter the metabolic wastes by adsorption and/or decomposition. Two kinds of commercially processed loess particles and a dolomite particle (all 50 ${\mu}$diameter) were tested. The mineral particles were suspended in the culture tank and the water was pumped into the foam fractionator, where the particles were separated and drained out with foam from the system. In a circular culture tank of 4.8 m in diameter with 10 d water, the juvenile olive flounders (23.1 g/fish, 5,555 fish, 128 kg total body weight) were stocked. 90 % of the rearing water was reused and turnover rate of the water in the tank was two times per hour. Water temperature was maintained 17${\pm}$1$^{\circ}C$. At the end of 75 day-experimental rearing, 5,532 flounders, weighing 468 kg, were harvested. An individual flounder grew to 84.6 g of body weight. The final stocking density was 26.0 kg/$m^2$. No diseases were observed during the experiment.

• Proceedings of the KSEEG Conference
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• 2002.06a
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• pp.81-100
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• 2002

While most of regulatory communities in abroad recognize ' 'natural attenuation " to include degradation, dispersion, dilution, sorption (including precipitation and transformation), and volatilization as governing Processes, regulators prefer "degradation" because this mechanism destroys the contaminant of concern. Unfortunately, true degradation only applies to organic contaminants and short- lived radionuclides, and leaves most metals and long-lived radionuclides. The natural attenuation Processes may reduce the potential risk Posed by site contaminants in three ways: (i)contaminants could be converted to a less toxic form througy destructive processes such as biodegradation or abiotic transformations; (ii) potential exposure levels may be reduced by lowering concentrations (dilution and dispersion); and (iii) contaminant mobility and bioavailability may be reduced by sorption to geomedia. In this review, authors will focus will focul on "sorption" among the natural attenuation processes of hazardous inorganic contaminants including radionuclides. Note though that sorption and transformation processes of inorganic contaminants in the natural setting could be influenced by biotic activities but our discussion would limit only to geochemical reactions involved in the natural attenuation. All of the geochemical reactions have been studied in-depth by numerous researchers for many years to understand "retardation" process of contaminants in the geomedia. The most common approach for estimating retardation is the determination of distrubution coefficiendts ($K_{d}$) of contaminants using parametric or mechanistic models. As typocally used in fate and contaminant transport calculations such as predictive models of the natural attenuation, the $K_{d}$ is defined as the ratio of the contaminant concentration in the surrounding aqueous solution when the system is at equilibrium. Unfortunately, generic or default $K_{d}$ values can result in significant error when used to predict contaminant migration rate and to select a site remediation alternative. Thus, to input the best $K_{d}$ value in the contaminant transport model, it is essential that important geochemical processes affecting the transport should be identified and understood. Precipitation/dissolution and adsorption/desorption are considered the most important geochemical processes affecting the interaction of inorganic and radionuclide contaminants with geomedia at the near and far field, respectively. Most of contaminants to be discussed in this presentation are relatively immobile, i.e., have very high $K_{d}$ values under natural geochemical environments. Unfortunately, the obvious containment in a source area may not be good enough to qualify as monitored natural attenuation site unless owner demonstrate the efficacy if institutional controls that were put in place to protect potential receptors. In this view, natural attenuation as a remedial alternative for some of sites contaminated by hazardous-inorganic components is regulatory and public acceptance issues rather than scientific issue.

• Korean Journal of Environmental Agriculture
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• v.16 no.2
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• pp.181-186
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• 1997

Since volcanic ash soils in Cheju island have high capacities of adsorption and immobilization of phosphate, a relatively high rate of P application has been recommended in citrus orchards for many years and such a large amount of P application could be problematic both in agricultural and environmental point of view. The objective of this study was to test whether arbuscular-mycorrhizae can be used to improve P availability in Cheju citrus orchard soils. Soil, root and leaf samples were taken from 14 citrus orchards of different location and soil texture. Mycorrhizal spore distribution in the soils, mycorrhizal infection ratio on the citrus roots, and mineral nutrients in leaf samples were determined. Numbers of mycorrhizal spore were in the range of $9,000{\sim}40,000/100g$ soil. The population level was not correlated with any of the soil characteristics examined. Mycorrhizae were found in all of the examined orchards and root infection ratio varied between $14{\sim}60%$. The mycorrhizae infection ratio differed substantially in different soils. Although root infection was high at soils with low extractable P level, it was not significantly correlated with other soil factors measured. Since a positive correlation was observed between leaf P concentration and root infection, enhancement of P uptake seemed to be associated with mycorrhizal infection. These results indicate that mycorrhizae could be a useful method to reduce P applications in Cheju citrus orchards.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.9 no.2
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• pp.23-32
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• 2006

Total suspended solids (TSS), five-day biochemical oxygen demand ($BOD_5$), total nitrogen (T-N), and total phosphorous (T-P) concentrations around and under a floating island were examined from October 2002 to September 2003. The island was installed in July 2002 on the surface of an agricultural irrigation reservoir located in the southern part of the Korean Peninsula. It was composed of six polyethylene panels. Each panel was 2 m (length) ${\times}$ 1 m (width) ${\times}$ 0.02 m (thick) and had about thirty-two holes each with a diameter of eight centimeters, through which plant roots grew down into the water. Coconut fibers of nine-centimeters in height were placed on the panel, which sustained plants rhizomes and roots. Both the fibers and the panel were raped with polyethylene wire mashes. About thirty irises (Iris pseudoacorus) were planted into the fibers of each panel. The concentrations of TSS, $BOD_5$, T-N and T-P below the island during the iris-growing season averaged 9.70, 2.59, 3.61 and 0.14 mg/L, respectively and those around it averaged 9.99, 2.83, 4.07 and 0.16 mg/L, respectively. The average concentrations of TSS, $BOD_5$, T-N and T-P below it during the iris non-growing season were 8.68, 2.37, 3.25 and 0.14 mg/L, respectively and those near it were 8.76, 2.43, 3.34 and 0.15 mg/L, respectively. At a significance level of ${\alpha}$=0.05, $BOD_5$, T-N and T-P concentrations under the island during the iris-growing season were significantly low when compared with those around it except TSS. No differences in TSS, $BOD_5$, T-N and T-P concentrations between around and near it were found at a significance level of ${\alpha}$=0.05 during the iris non-growing season. The removal of $BOD_5$, T-N, and T-P during the growing season were significantly high when compared with those during the non-growing season. TSS abatement of the floating island was very low during both the growing and non-growing seasons. The island's reductions of $BOD_5$, T-N and T-P were good during the growing season, especially T-N and T-P, which have been considered as primary pollutant sources causing the water quality degradation of reservoirs. The removal of T-N and T-P was primarily attributed to the absorption of nitrogen and phosphorous by the irises during the growing season.

• Asian Journal of Turfgrass Science
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• v.24 no.2
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• pp.199-204
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• 2010

Much of the coal ash by thermal power plant has gradually been increased, however researches on the recycling of bottom ash has not been investigated enough so far. In this research, the lysimeter test was conducted to find out the possibilities of bottom ash as soil amendment to improve the physiochemical properties of sandy topsoil of turfgrass in golf course. The turfgrass growth test and leaching test were conducted on the lysimeter. The lysimeter columns were manufactured with various topsoil mixing ratios of 0, 10, 20, 30, and 50% of bottom ash with sand. As a result of leachate analysis through the lysimeter column, the higher ratios of bottom ash mixed affect significantly on water holding capacity of topsoil sand media with decreasing of the percolation rate. The results of leachate analysis in every three days interval, the pH of leachate increased with the bottom ash ratios, but the volume of $NO_3$-N, $NH_4$-N and K decreased significantly. However, the level of EC of leachate had constantly maintained. These results indicate that the application of bottom ash may improve turfgrass growth with water holding capability and fertility of sandy topsoil. However, the negative effects of the bottom ash also evaluated by reducing water permeability and solubility of $PO_4$-P by adsorption into soil particles. The results indicates that the reasonable mixing ratio of the bottom ash as soil amendment should be less than 20% (v/v) with sand which has a low water-holding and fertility in golf course topsoil layers.

• Journal of Korean Society of Environmental Engineers
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• v.33 no.10
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• pp.709-716
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• 2011

Effect of inorganic coagulants dosing on the performance of electro-chemical process was studied when treating hospital wastewater having low electrolyte concentration. It is thought that adding inorganic coagulants caused increase in concentration of electrolyte and this caused increase in free chloride concentration and consequently, caused increase in indirect oxidation effect. Thus, COD removal efficiencies more than doubled in percentage terms at the 2 hrs of reaction time and current density of $1.76A/dm^2$ compared with the results obtained from the parallel experiments without adding inorganic coagulants. T-N removal efficiencies approximately doubled in percentage terms at the 2 hrs of reaction time and 700 ppm of coagulants addition and applied current density of $1.76A/dm^2$ due to the increase of free residual chlorine such as HOCl caused by increase of electrolyte concentration through the addition of inorganic coagulants. Under the same experimental condition, more than 90% of T-P removal efficiencies was obtained. The reason can be explained that increase of chemical adsorption rate between phosphate and insoluble metal compounds caused by dissolved oxygen generated from anode by the increased electrolyte concentration through inorganic coagulants addition make a major role in improving T-P removal efficiencies. It can be concluded that inorganic coagulants addition as the supplemental agent of electrolyte is effective way in improving organic and nutrient salt removal efficiency when treating hospital wastewater having low electrolyte concentration.

• Food Science and Preservation
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• v.13 no.3
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• pp.285-291
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• 2006

The effects of sorbitol mixture as plasticizers on moisture sorption property (MSP), water vapor permeability (WVP), color, tensile strength (TS), elongation at break (E), and total soluble matter (TSM) of soy protein isolate (SPI) films were investigated. Two different types of sorbitols, aqueous and crystalline, were added to film-forming solutions in various ratios of crystalline to aqueous (0:1, 0.25:0.75, 0.5:0.5, 0.75:0.25, or 1:0, based on weight). In addition, the characteristics of the SPI films plasticized by sorbitol mixtures and glycerin were compared with moisture sorption rate against time. Sorbitol-plasticized films had higher in TS, but lower in WVP and E than the glycerin-plasticized films. However the properties of SPI films did not differ appreciably by the type of sorbitol added to film-forming solutions. To explain the high solubility and low WVP of sorbitol-plasticized films, cumulative amounts of moisture content gained during adsorption and lost during desorption of films were compared between sorbitol and glycerin-plasticized films. The result suggest that use of sorbitol as a plasticizer for preparing SPI films improves moisture barrier properties of the films. However the high solubility of sorbitol-plasticized films needs to be reduced for improving the functionality of SPI films in potential packaging applications.

• KSBB Journal
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• v.18 no.4
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• pp.266-271
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• 2003

This study was worked out to investigate the compounds of antioxidant constituents extracted from Stachys Sieboldii MiQ. and their effects on antioxidant activity by DPPH method, ferric thiocyanate method, and nitrite scavenging ability. Solvents such as methanol, hexane, chloroform, ethyl acetate, butanol, and water were used for this purpose. Total concentrations of polyphenols and flavonoids were measured in the methanol fraction. The ethyl acetate fraction showed the strongest activity by DPPH method, ferric thiocyanate method, and nitrite scavenging ability. The ethyl acetate extract was fractionated on a silica gel column using elution solvent (chloroform: methanol: water ＝ 70 : 30 : 5 lower phase) at a flow rate of 1.0 mL/min. UV-VIS spectral data of each fraction showed adsorption maxima in the range of 284～330 nm. Among fractions, the fraction 1 that has λ$\_$max/ (nm) of 284 nm showed the strongest activity by DPPH method. The UV-VIS spectral data of phenolic compounds were known to lie in the range of 210～290 nm and 300～550 nm. Therefore, the results of our study suggested that Stachys sieboldii MIQ. contains phenolic compounds showing natural antioxidant activity.

• Applied Chemistry for Engineering
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• v.29 no.4
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• pp.432-439
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• 2018

Metal catalysts such as Fe, Co, Mn, and Pd supported on the activated carbon (AC) were prepared to improve functional groups for the chemical adsorption and catalytic ozonation. Following ascending orders of the phenol decomposition rate, dissolved ozone decomposition ratio and TOC (total organic carbon) removal from experimental results of advanced oxidation process (AOP) were observed: Fe-AC < AC < Co-AC < Mn-AC < Pd-AC. BET analysis results showed that the physical properties of the metal impregnated activated carbon had no effect on the catalytic ozonation, and the catalytic effect was dependent on the kind of impregnated metal. The ratio of the formed concentration of OH radical to that of ozone (RCT) was measured by using the decomposition outcome of p-chlorobenzoic acid, a probe compound that reacts rapidly with OH radical but slowly with ozone. The measured values of RCT were $5.48{\times}10^{-9}$ and $1.47{\times}10^{-8}$ for the ozone alone and activated carbon processes, respectively, and $2.13{\times}10^{-9}$, $1.51{\times}10^{-8}$, $4.77{\times}10^{-8}$, and $5.58{\times}10^{-8}$ for Fe-AC, Co-AC, Mn-AC, and Pd-AC processes, respectively.