• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2004.09a
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• pp.207-210
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• 2004

Effect of electron accepters on anaerobic degradation of petroleum hydrocarbons by an anaerobic sludge taken from a sludge digestion tank in a soil artificially contaminated with 10,000 mg/kg soil of diesel fuel was tested. Treatments of soil with 30 mL of the digestion sludge (2,000 mg/L of vss (volatile suspended solids)) were incubated under several anaerobic conditions including nitrate reducing, sulfate reducing, methanogenic, and mixed electron accepters conditions for 120 days. Treatments with the digested sludge showed significant degradation of diesel fuel under all anaerobic conditions compare to control treatments with an autoclaved sludge and without the sludge. The amount of TPH degradation after 120days incubation was the largest in the treatment with the sludge and mixed electron accepters (75% removal of TPH) followed in order by sulfate reducing, nitrate reducing, methanegenic condition as 67%, 53％, 43%, respectively. However, the rate of TPH degradation in the nitrate- and sulfate reducing condition within 105 days were comparable with that of the mixed electron accepters condition. Microorganisms in each electron acceptor condition were plated on solid mediums containing nitrate or sulfate as sole electron acceptor and several nitrate- and sulfate reducing bacteria showed effective degradation of diesel fuel within 30 days incubations. These results suggest that anaerobic degradation of diesel fuel in soil with digested sludge is effective for practical remediation of soil contaminated with petroleum hydrocarbons.

• Korean Journal of Environmental Agriculture
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• v.12 no.3
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• pp.281-297
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• 1993

Nitrogen is an element required to meet optimal plant growth. However, when it was applied (as chemical fertilizer or animal waste) more than the demand of plant and managed it unreasonably can be accumulated in subsoil and leached from soil system. Nitrogen also can be act as an pollutant to soil and water through water contamination if its concentration exceed the critical level. The concentration and downward movement of nitrate in soil is influenced by cultural practices and soil properties. High level of nitrate nitrogen in drinking water is harzadrous for animal and human health, especially for infants and the restoration of the quality of groundwater is impossible by now. Therefore it is the only way to prevent from leaching of nitrate nitrogen to keep the quality of groundwater as vital water resource. The aims of the presentation of this review paper are to understand the relationship between agricultural practices and the concentration of nitrate nitrogen in groundwater and to suggest further informations for the rational management methods to reduce the leaching of nitrate nitrogen in soil.

• Journal of Radiation Protection and Research
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• v.15 no.2
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• pp.27-39
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• 1990

Appreciable radiation exposures certainly were occurred in the reactor burn-up, the nuelear fall-out and the surroundings of nuclear installations with radioactive effluents. Therefore, radioactive nuclides is not only potentially hazardous to workers of nuclear power plants and related industrials, but also the wokers who handle radioactive nuclides in biochemical research and nuclear medicine diagnostics. And in the case of occurring the nuclear accidents, the early medical treatment of radiation injury should be necessary but little is established medical procedures to decontaminate the victims of internal contamination of radioactive nuclides in korea. Accordingly, to achieve the basic data for protective roles and medical treatment of radiation injury, the present studies were carrid out to evaluate the decontamination of uranium by the chemical drugs. The results observed were summarized as follows: 1. The combined treatmet group of sodium bicarbonate and saline with uranyl nitrate injection simultaneously and the dithiothreitol group that was administered 30 minutes after uranyl nitrate injection were increased significantly in the change of body weight than uranyl nitrate-only group (P<0.005). 2. All the experimental groups were increased the fluid intake and urine volume on the uranyl nitrate-induced acute renal failure. but the combined treatment group of sodium bicarbonate and saline with uranyl nitrate injection simultaneously and the dithiothreitol group that was administered 30 minutes after uranyl nitrate injection have the higher increment of fluid intake and urine volume (P<0.05). 3. When sodium bicarbonate and saline was treated with uranyl nitrate injection simultaneously. and dithiothreitol was administered 30 minutes after uranyl nitrate injection. there was significantly reduced in BUN concentration (P<0.01). 4. When dithiothreitol was administered 30 minutes after uranyl nitrate injection. there was reduced more significantly on the increment of serum creatinine concentration than that observed in uranyl nitrate-only group(P<0.01). but when the combined treatment of sodium bicarbonate and saline with uranyl nitrate simultaneously, there was still. albeit much less marked. decrease in serum creatinine concentration. 5. The sodium bicarbonate and saline was treated with uranyl nitrate simultaneously and dithiothreitol was administered at 30 minutes after uranyl nitrate were excreted markedly higher urine creatinine concentration than the uranyl nitrate-only group. 6. Uranyl nitrate has been used in experimental animals to produce hydropic degeneration and swelling of proximal tubules, disappearance of microvilli and brush border or necrosis in the kidney and centrilobular necrosis, congestion, and telangiectasia of the liver. When the sodium bicarbonate and saline was treated with uranyl nitrate simultaneously, and dithiothreitol was administered. 30 minutes after uranyl nitrate, there was more marked the protective effect than uranyl nitrate-only group. Finally, if the sodium bicarbonate and saline may administered as quickly as possible each time that some risk for internal contamination, with uranium, and dithiothreitol is administered 30 minutes after uranium contamination, there ameliorates the course of uranyl nitrate-induced acute renal failure.and this effect is assocciated with prevention of uranium (heavy metal)-induced alterations in BUN, serum creatinine, urine creatinine, fluid intake, urine volume and body weight.

• Economic and Environmental Geology
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• v.37 no.6 s.169
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• pp.647-655
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• 2004

To identify the influential factors and their relative significance on spatial distribution of $NO_3-N$ in urban ground water, spatial analysis was conducted using GIS and statistical approaches in the Seongnae-Koduk watersheds, where rapid urbanization has been proceeded. Several factors were considered including land-use type, distance to sewage lines, the ratio of impervious surface, and the ratio of green area. The spatial distribution of $NO_3-N$ in the land-use types shows differences between urban and crop field possibly due to the sewage networks in urban areas and the agrochemical uses in crop field. Nitrate concentrations in ground water were decreased with the distance to sewage lines to approximately 60-75 m. Concentrations of nitrate and distances to sewage lines showed negative correlation, indicating that the nitrate contamination was induced from the sewage system and specially significant in urban areas. The negative correlation of the ratio of impervious surface to the nitrate concentration in urban areas also suggested that the source materials of nitrate are introduced from the surface. Consequently, in areas of urbanization processes, systematic management of past-and-present land-use types and sewage systems are the most significant factors in preventing ground water from nitrate contamination.

• Journal of Soil and Groundwater Environment
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• v.15 no.3
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• pp.44-51
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• 2010

Contamination of groundwater from point and non-point sources is one of major problems of water resource manangement in Jeju island. This study characterized groundwater and soil contamination in Hallim area which is one of the areas of significantly contaminated soil and groundwater in Jeju Island. The amount of loaded contaminant (ALC) of Jeju area was estimated as 13,212 ton N/yr and 3,210 ton P/yr, The ALC of Hallim area was amounted to 2,895 ton N/yr and 1,102 ton P/yr, which accounted for 21.9% and 34.3% of the Jeju's ALC, respectively. The soil pH values (5.6-5.9) were not much different in land use areas. By contrat, average cation exchange capacity (CEC) of 14.1 $cmol^+/kg$ was high comparing to the nationwide range of 7.7-10.9 $cmol^+/kg$. Further, Sodium adsorption ratios (SARs) of horse ranch, pasture, and cultivating land for livestock were as high as 0.19, 0.17, and 0.16 respectively, comparing to the other landuse areas. Nitrate nitrogen at 22.2% of total groundwater wells exceeded 10 mg/L (the criteria of nitrate nitrogen for drinking water), averaginged 6.62 mg/L with maximum 28.95 mg/L. Groundwater types belonged to Mg-$HCO_3$, Na-$HCO_3$, Ca-$HCO_3$, and Na-Cl, among which Mg-$HCO_3$ type occupied more than 70% of the total samples, indicating the presence of anthropogenic sources. The concentration of nitrate nitrogen was negatively related to altitude and well depth, and positively related to the concentration of Ca, Mg, and $SO_4$ which might originate from chemical fertilizer. The ratio of nitrogen isotopes was estimated as an average of 8.10$^{\circ}/_{\circ\circ}$, and the maximum value of 17.9$^{\circ}/_{\circ\circ}$. According to the nitrogen isotope ratio, the most important nitrogen source was assessed as chemical fertilizer (52.6%) followed by sewage (26.3%) and livestock manures (21.1%).

• 한국생물공학회:학술대회논문집
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• 2003.10a
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• pp.392-396
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• 2003

Leaking underground storage tanks are a major source of groundwater contamination by petroleum hydrocarbons. Aerobic bioremediation has been highly effective in the remediation of many fuel releases. Bioremediation of aromatic hydrocarbons in groundwater and sediments is ofen limited by the inability to provide sufficient oxygen to the contaminated zones due to the low water solubility of oxygen. Nitrate can also serve as an electron acceptor And nitrate is less expensive and more soluble than oxygen. it may be more economical to restore fuel-contaminated aquifers using nitrate rather than oxygen. And denitrifying bacteria are commonly found in the subsurface and in association with contaminated aquifer materials. These studies have shown that BTEX and MTBE can be degraded by the nitrate-amended microcosms under aerobic and anaerobic conditons. Biodegradation of the toluene and ethylbenzne compounds occurred very quickly under denitrifying conditions. MTBE, benzene and p-xylene were recalcitrant under denitrifying conditions in this study.

• Journal of Powder Materials
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• v.10 no.4
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• pp.228-234
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• 2003

In the present study, the focus is on the synthesis of titanium carbide/cobalt composite powder by the spray thermal conversion process using metallic salt solution as the raw materials. Two types of oxide powders of Ti-Co-O system were prepared by the spray drying of two types of metallic salt solutions : titanium chloride-cobalt nitrate and $TiO_2$ powder-cobalt nitrate solutions. These oxide powders were mixed with carbon black, and then these mixtures were carbothermal reduced under a flowing argon atmosphere. The changes in the phase structure and thermal gravity of the mixtures during carbothermal reduction were analysed using XRD and TG-DTA. In the case of using the titanium chloride-cobalt nitrate solution, it could not be obtained TiC/Co composite powder due to contamination of the impurities during the spray drying of the solution. However, in tile case of using the $TiO_2$ powder-cobalt nitrate scullion, TiC-15 wt. %Co composite powder could be synthesized by the spray thermal conversion process. The synthesized TiC-15 wt. %Co composite powder at 120$0^{\circ}C$ for 2 hours has average particle size of 150 nm.

• The Journal of Engineering Geology
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• v.12 no.3
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• pp.285-294
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• 2002

The origin of nitrate in confined groundwater was studied using oxygen ($\delta$180), hydrogen ($\delta$D), and nitrogen ($\delta$15N) stable isotopes, along with chemical data of NO3-N. We analyzed groundwaters from more than sixty manufactories producing natural mineral waters around the country During the period of 1998-2001, an average value of nitrate was fair]y low (0.95 mg/$\ell$), however, groundwaters from six sites showed more than 2 mg/$\ell$ of nitrate. The stable isotope data of the groundwaters are -8.3~-11 $\textperthousand$ $\delta$8O, -60~-75 $\textperthousand$ $\delta$D, which lies in an average range of the groundwaters. The nitrogen isotope data with -11.8~-5.1$\textperthousand$ $\delta$15N suggest that manure, organic nitrate, and fertilizers can not be the origin of nitrate in the goundwaters.

• Environmental Engineering Research
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• v.25 no.3
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• pp.393-399
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• 2020

The use of different types of wastewater (WW) for the cultivation of microalgae and cyanobacteria during recent decades has provided important economic and environmental benefits. However, direct use of WW can lead to growth inhibition and biomass contamination. In the present study, we separated the key WW nutrients, namely nitrate and phosphate, by adsorption and regeneration and used the resulting regenerated water to cultivate the cyanobacterium Spirulina platensis. The adsorbent was granular γ-alumina derived from waste aluminum cans. This procedure recovered 19.9% of nitrate and 23.7% of phosphate from WW. The cyanobacterial cultures efficiently assimilated the nutrients from the medium prepared using regenerated WW, and the growth and nutrient uptake were similar to those in a synthetic medium. In addition, imposing nutrient limitations to increase carbohydrate productivity was easily achieved using regenerated wastewater nutrients, without requiring additional dilution or complex processing. In acute toxicity tests, the harvested biomass in a regenerated medium had similar toxicity levels compared to the biomass obtained from a synthetic medium. The proposed method of using regenerated WW to produce contamination-free biomass has broad potential applications.

• Journal of Environmental Health Sciences
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• v.46 no.6
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• pp.646-654
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• 2020

Objectives: Users of parks or children's play facilities have pointed to pets' bowel movements as the most serious problem when using them. In prior studies, a very low detection rate of parasites (eggs) in sand flooring materials has been found. Even though feces have been identified, no parasites (eggs) have been detected. Method: A standard solution of nitrate nitrogen was used to verify the reliability of a new nitrogen analysis method. The linearity, precision, and accuracy of the nitrate nitrogen analysis method were verified. Using this method, the pollution distribution of the sand flooring material and the degree of pollution at each point were investigated. Results: As a result of the verification of the nitrogen analysis method, the linearity was found to be good at r2=0.999 when distilled water is mixed in a standard substance solution. The standard substance additive solution r2=0.968 was found to be good. Precision represented 0.01 to 0.06% RSD for peak height. The recovery rate was 92.4 to 104.0 percent, indicating high accuracy. According to the same method of analysis, the flooring material sand at a general amusement facility with the largest number of concealed spaces was nitrate nitrogen 6.1 times higher than at the entrance of the playground. Also, in a comparison between clean sand and sandy flooring, the average nitrogen concentration of the sand flooring material was 24.4-167 times higher than pure sand. Conclusions: As such, no parasites (eggs) were detected at all points under investigation, but the sand flooring was exposed to animal fecal contamination. Therefore, the management of nitrogenous components should allow accurate identification of animal fecal contamination so that the timing of sand replacement can be managed hygienically and safely.