• Applied Chemistry for Engineering
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• v.28 no.3
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• pp.318-325
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• 2017

Wastewater including ethanolamine used in the second generation of nuclear power plants is filtered out in the ion exchange resin of the condensate polishing plant. In the regeneration process of ion exchange resin, a strong acidic wastewater containing ethanolamine and a lager amount of ionic substances are released. In this study, the process involving UV oxidation part with or without absorbents was developed for treating wastewater released from the ionic exchange resin. The effect of adsorbents on the wastewater treatment was investigated by using UV oxidation system developed by us. As a result, the COD removal efficiency of UV/GAC process with the granular activated carbon (GAC) as an adsorbent was 71.3% at pH 12.8. The removal efficiency was 21.8% higher than that of the wastewater treated using UV oxidation process without any adsorbents at the same condition. The removal of T-N was 88.6% at pH 12.8 when using UV oxidation with the GAC absorbent, which was 18.0% higher than that of using the UV oxidation process without any absorbents. It is thought that ethanolamine adsorbed on the absorbent improved the efficiency of UV oxidation process. Therefore, the UV/GAC adsorption oxidation process can be more effective in treating wastewater containing ethanolamine than that of using the process without any absorbents.

• Korean Journal of Ecology and Environment
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• v.37 no.4 s.109
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• pp.363-367
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• 2004

For comparative analysis of the eubacterial community structure at 8 sampling sites throughout the Nak-Dong River, FISH (fluorescence in situ hybridization) method was employed. The total ratio of each determined eubacterial group such as ${\alpha}\;{\cdot}\;{\beta}\;{\cdot}\;{\gamma}-subclasses$proteobacteria and Cytophaga-Flavobacterium(CF) group to total counts(DAPI) at each site varied 9.3-42.5% with the highest value at uppermost part. And each ratio of determined eubacterial groups reached mostly under 10% except that of CF group (23%) at uppermost part. Furthermore, compared to lower part, upper part represented unexpectedly higher proportions of ${\gamma}-subclass$ proteobacteria comprised almost fast growing bacteria on degradable organics. Also the variations of ammonia-oxidizing bacteria ranged from $2.7{\times}10^4$ to $18.0{\times}10^4$ cells $mL^{-1}$ with the lowest value in lower part and the highest value in mid part whereas those of nitrite-oxidizing bacteria varied 5.2-7.7{\times}10^4$ cells $mL^{-1}$ without noticeable differences throughout the sites. Additionally, the ratio of nitrifying bacteria to total counts ranged from 1.0% to 13.6% with no differences between ammonia-oxidizing bacteria and nitrite-oxidizing bacteria. In conclusion, FISH method introduced in this study for monitoring, normally used for the quantitative analysis of bacteria, provided also good information on their environmental status in the Nak-Dong River.

• Korean Journal of Plant Resources
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• v.29 no.5
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• pp.579-587
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• 2016

The final goal of this research is to develop a miniaturized botanical biofilter using a wick-typed automatic humidifier for stabilizing soil moisture content (SMC) and purifying indoor air pollutants by the biofilter. This new biofilter equipped with wick-typed automatic humidifier was manufactured as more compacted design removing an absorption tower-typed humidifier compared with the previous big-sized biofilter made in 2015. This study was performed to compare changes of SMCs among floors depending on the number of wicks installed on the humidifier within the novel biofilter, and to compare changes of SMCs and plant growth parameters before and after planting Spathiphyllum wallisii ‘Mauna Loa’ on the biofilter. SMCs among floors depending on the number of wicks were similar, and all regression lines of SMCs showed almost horizontal lines because of long-term stability on SMCs. Comparing plant growth parameters of S. wallisii ‘Mauna Loa’ before planting and at 30 days after planting on the biofilter, all growth parameters were not statistically significant. Thus, SMCs of the biofilter were more stabilized using this humidifying apparatus regardless of the number of wicks than the previous biofilter using absorption tower-typed humidifying apparatus.

• Economic and Environmental Geology
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• v.38 no.5 s.174
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• pp.563-570
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• 2005

The purposes of this study are to examine a field test on heavy metal removal efficiency for AMD(Acid Mine Drainage) using fish bone and apatite, and to compare those results of the laboratory & the field tests. The duration of the field test was about one month and flow rates of AMD varied from 2.53 l/min to 12.8 l/min. From the result of the field test, removal efficiencies of apatite and those of fish bone are high for As, Fe, and Pb while those of fish born is higher than those of apatite far Al, Cd, Cu and Zn which are similar to the result of the previous laboratory test. In particular, average arsenic removal efficiency of apatite is higher$(84\%)$ than that of fish bone$(75\%)$ like the result of the previous laboratory test. In case of precipitates of phosphate compounds which are generated from chemical reaction between apatite/fish bone and AMD, those generated from apatite/AMD reactionform powder-shape while those created from fish bone/AMD reaction seem to be sludge. Therefore, apatite will be used as a precipitant for mine drainages having wide range of pH based on previous studies while fish bone will be applied as a precipitantfor AMD having lower PH and high concentration of heavy metals.

• Korean Journal of Environmental Agriculture
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• v.28 no.1
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• pp.69-74
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• 2009

In Korea, large amounts of chestnut shell as by-products are produced from food industries. However, most of the by-products exist with no disposal options. Biosorption uses biomass that are either abundant or wastes from industrial operations to remove toxic metals from water. Objective of this research was to evaluate the feasibility of using chestnut shell as by-products for removal of metal ions(Pb, Cu and Cd) from aqueous solution. The chestnut shell was tested for its efficiency for metal removal by adopting batch-type adsorption experiments. The adsorption selectivity of chestnut shell for metals was Pb > Cu > Cd at solution pH 5.5. The Langmuir isotherm adequately described the adsorption of chestnut shell for each metal. Using The maximum adsorption capacity predicted using Langmuir equation was 31.25 mg $g^{-1}$ 7.87 mg $g^{-1}$ and 6.85 mg $g^{-1}$ for Pb, Cu and Cd, respectively. Surface morphology, functional group and existence of metals on chestnut shell surface was confirmed by FT-IR, SEM and EDX analysis. The chestnut shell showed an outstanding removal capability for Pb compared to various adsorbents reported in the literatures. The overall results suggested that chestnut shell might can be used for biosorption of Pb from industrial wastewater.

• Korean Journal of Environmental Biology
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• v.37 no.2
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• pp.129-135
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• 2019

Juvenile Paralichthys olivaceus (mean weight 685.3±36.7 g) were raised in different and closed recirculating bio-floc system (control, bio-ball, and shelter) for 7 months. The water environment such as water temperature, dissolved oxygen, salinity, pH, and alkalinity according to the difference of closed recirculating system remained stable during the rearing period. No significant changes were observed in dissolved inorganic nitrogen such as ammonia, nitrite, and nitrate were observed in different closed recirculation system. The final weights according to the difference of closed recirculating were 1,524 g (control), 1,674 g (bio-ball), and 1,630 g (shelter). The survival rate was higher than 98%, and the final FCRs (Feed coefficient ratio) were 1.2, 1.1, and 1.2. The results of this study indicated high growth and survival rate in all systems.

• 한국해양학회지
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• v.15 no.1
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• pp.49-57
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• 1980

Toxicity of Machete on the mortality of the three different life stages, namely, hatching period, prelarval stage, and juvenile stage of carp(Cyprinus carpio Linne) was observed. The effect of the various exposure times on the mortality of the prelarval stage, and the effect of different temperatures on the toxicity during juvenile stage were also analysed. Hatchability and duration time of the carp were shown to be related to the concentration of Machete. In general, hatchability and duration time were shown to be decreased when the concentration of Machete was increased. For prelarval stage, 24hr and 48hr LC 50, and 24hr and 48hr EC 50 were observed to be 0.86mg/l and 0.43mg/l, and 0.35mg/l and 0.20mg/l, respectively. For juvenile stage, 24hr, 48hr, 96hr, and Incipient LC 50 were found to be 0.625mg/l, 0.365mg/l, 0.180mg/l, and 0.135mg/l, respectively. Apparently it was appeared that eggs were most resistant, and prelarvae were most sensitive to Machete among the three life stages. Although fish were removed from the Machete solution(3.2mg/l, and 1.8mg/l) prior to their death, continuous mortality was observed. Below 1.mg/l range, however, when concentration of Machete was lowered, the toxic effect of Machete on carp was reduced considerably even to the longtime exposure(24hours) Toxicity of Machete appeared to be related to water temperature, and it was observed that higher temperature reflected more toxicity.

• Journal of Korea Soil Environment Society
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• v.1 no.1
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• pp.11-17
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• 1996

Trichloroethylene(TCE) is the organic compound which is used variously at the industrial areas. It contaminates soils and groundwater by leaked storage tank, careless treatment in field and the effluent from waste landfills. This study was carried out to identify adsorptive behavior of TCE by soil. Batch experiments were conducted at different soil-organic matter content and lime treatment to determine Freundlich isothermal adsorption equation constant, k and n, for TCE. Sewage sludge cake was applied to make different soil-organic matter content with the level of Oton/ha(S1), 50ton/ha(S2), 100ton/ha(S3). Lime(calcium hydroxide) was treated with the level of 2ton/ha, 4ton/ha, 6ton/ha, 10ton/ha. Freundlich isothermal adsorption equations obtained from experiment with sewage sludge cake were as follows (on condition that the level of TCE applied to soil ranged from 0.5ng/g soil to 2.5 ng/g soil.) : S1 :x/m = 0.393 $C^2$, S2 : x/m = 0.436 $C^2$, S3 : x/m = 0.636 $C^2$Value of k was increased in higher order of 51, 52, 53 with increased level of sewage sludge cake application. From this results, soil which was applied higher level of sewage sludge cake had a good ability on TCE adsorption. With increased the level of lime application, pH of the soil was increased and the ability of the soil in TCE adsorption was decreased.

• Journal of Soil and Groundwater Environment
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• v.14 no.6
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• pp.101-107
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• 2009

Carboxymethyl cellulose (CMC) as stabilizer is expected to facilitate in-situ delivery of zero-valent iron (ZVI) nanoparticles in a contaminated aquifer because it increases dispersity of ZVI nanoparticles. This work investigated the transport of CMC-stabilized ZVI nanoparticles (CMC-Fe) using column breakthrough experiments. The ZVI nanoparticles (100 mg/L Fe) were transportable through sand porous media. In contrast, non-stabilized ZVI nanoparticles rapidly agglomerate in solution and are stopped in sand porous media. At pH 7 of solution approximately 80% CMC-Fe were eluted. When the pH of solution is below 5, 100% CMC-Fe were eluted. These results suggest that the mobility of CMCFe was increased as pH decreases. In the mobility test under different ionic strengths using $Na^+$ and $Ca^{2+}$ ions, there was no signigficant difference in the mobility of CMC-Fe. Also, in the experiments of effect of clay and natural organic mater (NOM) on the mobility of ZVI, there was no significant difference in the mobility of CMC-Fe not only between 1 and 5% clay, but 100 and 1000 mg/L NOM. The results from this work suggests that the CMC-Fe nanoparticles could be easily delivered into the subsurface over a broad range of ionic strength, clay and NOM.

• Journal of Environmental Policy
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• v.4 no.2
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• pp.83-101
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• 2005

Because of its strong potential for health hazards, the concentration levels of airborne lead (Pb) have been circumscribed by environmental laws in many countries. In this study, we made a comparative study on the environmental behavior of Pb for the acquisition of its distribution characteristics using data sets collected from major cities in Korea for a period of 6 years (1998 through 2003). According to this study, Pb concentration decreased slowly in most industrialized cities of Koreathroughout the whole study. period. In contrast, such temporal signals were not evident in data sets collected from residential, commercial, and grassland areas. Although seasonal patterns generally exhibited the occurrences of high Pb concentration during the spring, results appear to reflect the influence of Asian Dust (AD) in the springtime. The results of our study clearly indicate that Pb distribution is strongly influencedby source types in relation to their land use patterns. Comparison of our Pb data sets with that of other countries indicates that Pb concentration levels obtained from relatively cleaner districts of Korea are still significantly higher than other countries. The results of this analysis generally indicate that Pb concentrations in most areas are affected by the type and strength of man-made activities. Considering that most areas are affected by a variety of pollutants, continuous efforts are needed to control Pb concentrations in the atmosphere.