• KSBB Journal
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• v.15 no.6
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• pp.578-583
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• 2000

Biofiltration has been identified as a promising method of odor, VOCs and air toxic removal from waste gas streams because of low capital and operating cost, low energy requirements and an absence of residual products requiring further treatment of disposal. Because biofiltration units are microbial systems in-corporationg microorganisms grown on a porous solid media like compost, peat, soil and mixtures of these materials, there is a need to study of the adsorptive behavior of these supports. The purpose of this study was to investigate the major parameters of adsorptive process. We adsorbed VOCs onto peats and bark, and examined the correlations between the interphase mass transfer coefficients and transfer units, at different stream flow rates, VOCs inlet concentrations and bed lengths.

• Proceedings of the KSR Conference
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• 2002.10a
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• pp.587-595
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• 2002

Geotextile containers for restoration of slopes form the interface between the containers during the restored to lost slopes, and therefore the relation displacements are developed including the sliding on the surface. Since, the shear strength on these interfaces is less than that of fill material in the container, the characteristics of shear strength on the interface governs the behavior of the restoration slopes. In general, a lot of natural properties of geotexiles is required to evaluate the safty of the geotextiles, Among the properties, the shear characteristics between geotextiles and soil is a important variable to assess the safety. From the results of full scale direct shear test, the residual shear strength is recommanded to use for design factors since a large deformation possibly occures on the geotextile containers.

• Journal of Soil and Groundwater Environment
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• v.11 no.6
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• pp.8-17
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• 2006

Laboratory scale experiments were performed to investigate the removal efficiency of the in-situ chemical oxidation method and the air-sparging method for diesel contaminated soil and groundwater. Two kinds of diesel contaminated soils (TPH concentration : 2,401 mg/kg and 9,551 mg/kg) and groundwater sampled at Busan railroad station were used for the experiments. For batch experiments of chemical oxidation by using 50% hydrogen peroxide solution, TPH concentration of soil decreased to 18% and 15% of initial TPH concentration. For continuous column experiments, more than 70% of initial TPH in soil was removed by using soil flushing with 20% hydrogen peroxide solution, suggesting that most of diesel in soil reacted with hydrogen peroxide and degraded into $CO_2$ or $H_2O$ gases. Batch experiment for the air-sparging method with artificially contaminated groundwater (TPH concentration : 810 mg/L) was performed to evaluate the removal efficiency of the air-sparging method and TPH concentration of groundwater decreased to lower than 5 mg/L (waste water discharge tolerance limit) within 72 hours of air-sparging. For box experiment with diesel contaminated real soil and groundwater, the removal efficiency of air-sparging was very low because of the residual diesel phase existed in soil medium, suggesting that the air-sparging method should be applied to remediate groundwater after the free phase of diesel in soil medium was removed. For the last time, the in-situ box experiment for a unit process mixed the chemical oxidation process with the air-sparging process was performed to remove diesel from soil and groundwater at a time. Soil flushing with 20% hydrogen peroxide solution was applied to diesel contaminated soils in box, and subsequently contaminated groundwater was purified by the air-sparging method. With 23 L of 20% hydrogen peroxide solution and 2,160 L of air-sparging, TPH concentration of soil decreased from 9,551 mg/kg to 390 mg/kg and TPH concentration of groundwater reduced to lower than 5 mg/L. Results suggested that the combination process of the in-situ hydrogen peroxide flushing and the air-sparging has a great possibility to simultaneously remediate fuel contaminated soil and groundwater.

• Korean Journal of Environmental Agriculture
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• v.15 no.4
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• pp.501-505
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• 1996

Azimsulfuron [1H-pyrazole-5-sulfonamide,N-(((4,6-dimethoxy-pyridine-2-yl-aminocarbonyl-4-(2-methyl-2H-tetrazole-5-yl)] is a new sulfonamide herbicide that selectively controls a wide range of weeds in lowland rice (Oryza sativa). It effectively controlled Cyperus serotinus, Eleocharis kuroguwai, Sagittaria pygmaea, S. trifolia, and Scirpus juncoides at 7.5 - 30 g ai/ha. In the tolerance test on grasses carried out in a nutrient solution containing 0.3 - 30 ppm of azimsulfuron, greater inhibition occurred in roots of both rice and barnyardgrass (Echinochloa crus galli) than in shoots. However, rice root was approximately 5-fold more tolerant than that of barnyardgrass. The downward movements as determined by 50% growth inhibition of S. juncoides were 4-cm in clay loam and 6.5-cm in sandy loam soil with 3-cm/day leaching for 3 days. When incubated at 20 and $30^{\circ}C$, the residual effect in clay loam soil lasted for 30 and 21 days, respectively. In a soil column applied at 15 g ai/ha of azimsulfuron followed by 3-cm/day leaching for 3 days, dry weights of S. trifolia emerging at 5, 10, and 15-cm depth were reduced to 87, 85, and 79% of the corresponding untreated control, respectively. Susceptibility of S. trifolia to azimsulfuron did not greatly vary with the emergence depth.

• Korean Journal of Soil Science and Fertilizer
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• v.31
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• pp.36-44
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• 1998

우리 나라에서 토양의 점토광물에 관한 최초의 연구는 1958년 김제지방의 답 토양에 관한 연구로 (Dewan, 1958)시작되었다. 1960년대 시작하여 1970년대 까지는 주로 토양점토광물의 동정이 이루어 졌다. 점토광물의 동정(同定)에 사용된 잔적토(殘積土)(Residual Soil)로는 화강암(花崗岩), 화강편마암(花崗片麻岩), 현무암(玄武岩), 석회암(石灰岩), 혈암(頁岩), 제(第)3기층(紀層), 홍적층(洪積層) 유래 토양과 토양종류별(土壤種類別)로는 과부식회색토(寡腐植灰色土), 염류토(鹽類土), 충적토(沖積土), 적황색토(赤黃色土), 화산회토(火山灰土), 퇴적토(堆積土), 갈색토(褐色土), 암쇄토(岩碎土), 저위생산답(低位生産畓)이였으며, 토양점토광물(土壤粘土鑛物)과 작물수량성(作物收量性) 관계에 관한 연구가 실시되었다. 1980년대에 들어와서는 토양중의 1차광물과 점토광물의 풍화에 대한 안정도와 1차광물의 동정이 행해졌으며, 이밖에 Kaolinite 입자의 전하에 관한 연구등 점토광물의 흡착과 활성 연구, 점토광물의 토양개량재로서의 흡착과 화학적 특성 변화 연구와 점토광물의 토양개량 시용효과에 관한 연구가 행해졌다. 1990년대에 들어와서는 토양 중의 1차광물과 점토광물의 정량에 대한 자료가 축척되었고, 토양의 풍화에 대한 안정성과 생성기작, Zeolite와 새로운 광물이 합성되었다. 또한 합성광물을 이용한 농업과 산업광물로의 응용성 환경 산업에서의 적용가능성에 대한 평가가 시도되었다. 토양의 점토광물의 조성에 관한 연구는 토양 모재를 중심으로 이루어졌는데, 화강암(花崗岩)에서는 Halloysite, 화강편마암(花崗片麻岩)에서는 Kaolinite, Metahalloysite, Illite, 산성암(酸性岩)에서는 Kaolinite, Venrmiculite와 Chlorite의 중간광물, 현무암(玄武岩)에서는 Illite, Kaolinite, Vermiculite, 석회암(石灰岩)에서는 Vermiculite-Chlorite 중간광물, Kaolinite와 Illite, 혈암(頁岩)에서는 Kaolinite, Halloysite, Illite 외 Vermiculite-Chlorite, 화산회토(火山灰土)에서는 Allophane이 주광물이었다. Soil Taxonomy와 토양광물과의 관계에서, 답 토양에서는 Entisols의 주점토광물은 2:1형과 1:1형 광물이지만 Inceptisols와 Alfisols에서는 Halloysite가 대부분이다. 밭 토양의 경우는 Alfisols의 주점토광물은 Vermiculite, Illite, Kaolinite이었고, Ultisols에서는 Vermiculite-Chlorite 중간광물이었다. 산림토양에서는 Inceptisols중에서 Andept는 Allophane, Alfisols에서는 2:1 광물이지만, Ultisols에서는 Halloysite이다. 모재별 조암 광물의 풍화와 점토광물의 생성과정에서 화강암(花崗岩)과 화강편마암(花崗片麻岩)의 장석류(長石類)는 kaoline광물로, 이 밖의 운모광물(雲母鑛物), 녹니석(綠泥石), 각섬석(角閃石), 휘석(輝石)으로부터 생성된 illite, chlorite, vermiculite는 풍화중간에 혼층단계(混層段階)를 거쳐서 kaoline 광물로 풍화된다. 석회암(石灰岩) 토양의 smectite가 Mg농도가 높은 토양용액으로부터 침전되어 생성되었거나 운모 또는 chlorite에서 유래된 vermiculite의 변성작용에 의해 생성되고, 혈암(頁岩)토양의 점토에 illite가 주로 풍화에 저항성이 큰 미립자의 함수백운모(含水白雲母)로부터 유래되며, 현무암(玄武岩) 중의 장석류(長石類)는 kaoline광물로, 휘석(輝石)은 chlorite${\rightarrow}$illite의 풍화과정을 거친다. Zeolite, 함불석 Bentonite, Bentonite 등 우량점토 광물이 분포과 광물조성, 이화학적 특성이 조사되었고, 토양의 물리적, 화학적 성질의 개선을 필요로 하는 토양의 개량을 위해서 Bentonite, Zeolite, Vermiculite 등의 토양 개량재(改良材)로서의 기초연구와 이들 개량재 시용효과에 관한 연구 등이 주로 논토양에서 수행되었다. 점토광물과 수량관계를 보면 Montmorillonite를 주점토광물로 함유된 답 토양의 수도수량이 1:1 광물을 주점토광물로 함유하고 있는 토양에서의 수도수량 보다 높았다. 토양광물에 관한 기초연구(基礎硏究)로서 양이온교환능과 포화이온의 영향, 입자의 전기화학적 성질, 흡탈착 성질, 표면적과 등전점, 해성점토에 대한 압밀점토(壓密粘土)의 변형율(變形率)의 추정 등이 주로 연구되었다. 부가가치가 낮거나 폐기되는 광물을 이용하여 토양개량재 혹은 흡착제를 형성하는 연구가 알카리 처리에 의한 Zeolite 합성에 집중되었다.

• Korean Journal of Environmental Agriculture
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• v.16 no.1
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• pp.72-79
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• 1997

Adsorption, leaching, and retention of the Flupyrazofos(KH-502), a new active ingredient for insecticide, in the soils under laborarory and field conditions were investigated to provide the basic data for the safety use and to assess a secondary impact of this insecticide on soil and water environments. A significant power function relation was found between the adsorbed KH-502 and time, representing that 45% of the added KH-502 was adsorbed within 30 min. but a quasiequilibrium was reached after 6 to 12 hr with a slower adsorption. Adsorption phenomena followed th first-order kinetics and time required for 50% adsorption was 5.8 hr. The equilibrium adsorption isotherm was explained by the Freundlich equation and was classified as S-type. The amounts of KH-502 leached through the soil column (C) as compared to initial conc. ($C_0$) were very low and these relative concentrations ($C/C_0$) were 0.073 and 0.017 in SL and CL soils, respectively. The residual conc. of KH-502 in the surface soil was comparatively low and decreased with time. Half-lives of KH-502 in the surface soil was comparatively low and decreased with time. Half-lives of KH-502 under the field conditions were estimated to be 20 and 18 days in the SL and CL soils, respectively. The KH-502 cone, transported to the subsurface soils was extremely low. These results demonstrate that KH-502 has a low pollution risk potential to the surrounding environment as far as it is used following the recommended guideline.

• The Korean Journal of Pesticide Science
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• v.15 no.2
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• pp.160-165
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• 2011

Monitoring of pesticide residues were conducted at three sites in the Southern Area of Seoul, Korea (Gang-nam, Gang-dong and Song-pa). We measured pesticide residues within soil samples using multi-pesticide residues analysis. Samples were collected at the three sites with 60 sampling spots. The amount of pesticide residues in the soil samples were as follows [(minimum-maximum), mg/kg] endosulfan 0.002-0.999, procymidone 0.002-1.200, diazinon 0.003-0.024, metalaxyl 0.012-0.075. In soil treated with 0.445 mg/kg of endosulfan, the pesticide absorbed by chamnamul, was 0.157 mg/kg (Absorption rate : 35.3%). However, in soil treated with 0.358 mg/kg of endosulfan, the pesticide absorbed by lettuce, was 0.004 mg/kg (Absorption rate : 1.1%).

• Journal of the Korean Geosynthetics Society
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• v.17 no.2
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• pp.33-40
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• 2018

Characteristics of interface friction between cohesionless soils and geotechnical structure surfaces play an important role in the analysis of earth load and resistance on the structure. In general, geotechnical structures are mainly composed of either steel or concrete, and their surface roughnesses with respect to soil particle sizes influence the interface characteristics between soils and the structures. Accurate assessment of the interface friction characteristics between soils and structures is important to ensure the safety of geotechnical structures, such as mechanically stabilized earth walls reinforced with inextensible reinforcements, piles embedded into soils, retaining wall backfilled with soils. In this study, based on the database of high quality interface friction tests between frictional soils and solid surfaces from literature, equation representing peak interface friction angle is proposed. The influential factors of the peak interface friction angle are relative roughness between soil and solid surface, relative density of frictional soil, and residual (constant volume) interface friction angle. Futhermore, for the developed equation of the interface friction angle, its uncertainty was assessed statistically based on Goodness-of-fit test results.

• Korean Journal of Environmental Agriculture
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• v.29 no.3
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• pp.273-281
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• 2010

Concentration of antibiotics including a tetracycline group (TCs) of tetracycline (TC), chlortetracycline (CTC), and oxytetracycline (OTC), a sulfonamide group (SAs) of sulfamethoxazole (SMX), sulfathiazole (STZ), and sulfamethazine (SMT), an ionophore group (IPs) of lasalocid (LSL), monensin (MNS), and salinomycin (SLM), and a macrolide group (MLs) of tylosin (TYL) was determined from samples collected from the agricultural soil, stream water, and sediment. For the agricultural soil samples, the concentration of TCs had the highest value among all tested antibiotic's groups due to its high accumulation rate on the surface soils. The lower concentrations of SAs in the agricultural soils may be resulted from its lower usage and lower distribution coefficient (Kd) compared to TCs. The concentration of TCs in stream water was significantly increased through June to September. It would be likely due to soil loss during an intensive rainfall event and a reduction of water level after the monsoon season. A significant amount of TCs in the sediment was also detected due to its accumulation from runoff, which occurred by complexation of divalent cations, ion exchange, and hydrogen bonding among humic acid molecules. To ensure environmental or human safety, continuous monitoring of antibiotics residues in surrounding ecosystems and systematic approach to the occurrence mechanism of antibiotic resistant bacteria are required.

• Korean Journal of Environmental Agriculture
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• v.31 no.4
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• pp.293-299
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• 2012

BACKGROUND: Soil utilization pattern can be the main factor affecting soil physico-chemical properties, especially in soil phosphorus (P). Understanding the distribution and bioavailability of P is important for developing management to minimize P release from arable soils to environment. This study was conducted to evaluate the potential bioavailability of soil organic P by using phosphatase hydrolysis method. METHODS AND RESULTS: Twenty-four soils from onion-rice double cropping and 30 soils from plastic film house were selected from Changyeong and Daegok in Gyeongnam province, respectively. The P accumulation pattern (total P, inorganic P, organic P, residual P) and water soluble P were characterized. Commercial phosphatase enzymes were used to classify water-extractable molybdate unreactive P from arable soils into compounds that could be hydrolysed by (i) alkaline phosphomonoesterase (comprising labile orthophosphate monoesters), (ii) a combination of alkaline phosphomonoesterase and phosphodiesterase (comprising labile orthophosphate monoesters and diesters), and (iii) phytase (including inositol hexakisphosphate). Available P was highly accumulated with 616 and 1,208 mg/kg in double cropping system and plastic film house, respectively. Dissolved reactive P (DRP) and dissolved unreactive P (DUP) had similar trends with available P, showing 24 and 109 mg/kg in double cropping and 37 and 159 mg/kg in plastic film house, respectively, indicating that important role of dissolved organic P in the environments had been underestimated. From the result of phosphatase hydrolysis, about 39% and 66% of DUP was evaluated as bioavailable in double cropping and plastic film house, respectively. CONCLUSION(S): Orthophosphate monoester and orthophosphate diester accounted for high portion of dissolved organic P in arable soils, indicating that these organic P forms give important impacts on bioavailability of P released from P accumulated soils.