• 한국토양환경학회지
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• 제2권2호
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• pp.95-103
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• 1997

유기화합물로 오염된 지반을 정화하는 방법 가운데 화학약액을 주입하는 흙세척 방법은 매우 효과적인 것으로 알려져 있다. 이를 실험실에서 재현하는 경우에는 일반적으로 연성벽체의 주상실험을 실시하게 된다. 이때 유기화합물로 오염된 시편을 화학약액으로 세척하는 과정 중에서 일부의 유기화합물은 연성벽체를 통하여 확산되고, 확산된 양은 화학약액에 의한 세척효율 산정시 반드시 고려하여야 할 것으로 나타났다. 연성벽막을 통한 확산량을 조사하고자 다섯가지의 유기화합물(페놀, 아닐린, 나이트로벤젠, 퀴놀린, 및 2나프톨)을 이용하여 breakthrough 시험을 실시하였다. 나이트로벤젠은 75% 이상이 벽막을 통하여 확산되었다. 나머지의 유기화합물은 25%이하의 확산량을 보였다. 실험중 생분해 효과는 관찰되지 않았다.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2005년도 총회 및 춘계학술발표회
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• pp.114-116
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• 2005

Natural attenuation has been actively studied and often selected as final clean-up process in remediation of contaminated ground-water and soil for the last decade. Accordingly, understanding of natural processes affecting the fate and transport of contaminants in the subsurface becomes important for a success of implementation of the natural remediation strategy, Contaminant advection and diffusion processes in the unsaturated zone are naturally related to environmental changes in the atmosphere. The atmospheric pressure changes affecting the transport of contaminants in the subsurface are investigated in this study. Moisture content, trichloroethylene (TCE) concentration, temperature, and pressure variations in the subsurface were measured for the July, August, November, and December 2001 at Picatinny Arsenal, New Jersey. These data were used for a one-phase flow and one-component transport model in simulating the soil-gas flow and accordingly the TCE transport in the subsurface in accordance with the atmosphere pressure variations at the surface. The soil-gas velocities during the sampling periods varied with a magnitude of $10^{-6}\;to\;10^{-7}\;m\;s^{-1}$ at land surface. The TCE advection fluxes at land surface were several orders of magnitude smaller than the TCE diffusion fluxes. A sensitivy analysis indicated that advection fluxes were more sensitive to changes in geo-environmental conditions compared to diffusion fluxes. Of all the parameters investigated in this study, moisture content has the most significant effect on TCE advection and diffusion fluxes.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2003년도 총회 및 춘계학술발표회
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• pp.434-437
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• 2003

The fate and the behavior of polycyclic aromatic hydrocarbons (PAHs) and heavy metals in the environment are mainly controlled by their interactions with various components of soils and sediments. Due to their large surface area and abundance in many soils, smectites may greatly influence the fate and transport of the contaminants in the environment. In our experiment, PAH sorption by hexadecyltrimethylammonium (HDTMA)-modified smectite linearly increased in proportion to the amount of HDTMA added on the clay. However, trimethylammonium (TMA)-modified smectite did not show superiority in its sorption of PAH compared with the HDTMA-smectite or dodecyltrimethylammonium (DTMA)-smectite. Meanwhile, the smectites modified with the same cationic surfactants adsorbed Cd$^{2+}$ (heavy metal) significantly from water at low surfactant loading level, but the Cd$^{2+}$ adsorption linearly decreased as the loading of surfactant increased. The result shows that the sorption tendency of organoclays for organic or inorganic contaminants was significantly influenced by the amount and size of the surfactants added on the clay. It means that the stabilization and configuration of cationic surfactant formed on the clay interlayer according to the loading amount of each surfactant of different sizes may be an important factor in effectively sorbing environmental pollutants.nts.

• 한국환경농학회지
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• 제39권2호
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• pp.89-94
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• 2020

BACKGROUND: Persistent organic contaminants such as dichlorodiphenyltrichloroethane (DDT) are often found in agricultural soils decades after it was banned in Korea. This study uses hemoglobin and hemoglobin-containing blood meal to reduce the residual DDT in soil. METHODS AND RESULTS: Hemoglobin or blood meal with or without hydrogen peroxide (H₂O₂) was mixed with the DDT-spiked soil prepared for this study, and samples were taken over 14 d-degradation period to measure the residual DDT concentrations. With only hemoglobin, DDT was completely removed after 14 d, while with both hemoglobin and H₂O₂, 73%, on average, removal was observed. Similarly, the blood meal removed 73% of DDT, but with H₂O₂, the DDT removal was only 39%. The lower DDT removal in the presence of H₂O₂ can be attributed to the adverse effects of reactive species. Hemoglobin was more effective than blood meal for DDT removal in a given time; however, with additional blood meal injection, complete DDT removal was achieved. CONCLUSION: Overall, this study shows that the blood meal that is used as a fertilizer can potentially be used to remove residual contaminants such as DDT in agricultural soil.

• 한국안전학회지
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• 제27권3호
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• pp.89-95
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• 2012

The concentrations of Volatile Organic Compounds(VOCs) and Formaldehyde(HCHO) for interior materials of new vehicles are estimated and recognized by using the simulation program known as IAQx. The concentrations of contaminants are estimated and evaluated by the ventilation rates of new domestic vehicles and the required ventilation rates for new vehicles are estimated through the given contaminant data. This study is conducted to compare the ventilation rates for the contaminants between the discontinuously ventilated new vehicles and the continuously ventilated new vehicles using the simulation program. The equation of ventilation rate of new vehicles is acquired to be able to lower initial concentrations below the standard level under different conditions for both business and personal commuting.

• 한국지하수토양환경학회지:지하수토양환경
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• 제16권1호
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• pp.51-61
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• 2011

Germination tests were conducted to determine the practical concentration levels at which plants can reproduce naturally during the phytoremediation of soils contaminated with a high concentration of petroleum hydrocarbons and heavy metals. The effects of humic acids on plant growth and soil physicochemical properties were also investigated. The results show that phytoremediation can be applied in soils contaminated by multiple contaminants at the former soil contamination potential level of Korean soil quality standards considering successful natural reproduction. It was observed that germination rates of Helianthus annuus and Festuca arundinacea were high after all treatments, and transplantation was more appropriate for Phragmites communis in phytoremediation. Humic acids had a positive effect on the growth of both aboveground and belowground biomass of herbaceous plants. Growth inhibition by multiple contaminants is more severe in the case of aboveground biomass. Germination and growth tests suggest that Helianthus annuus is a suitable phytoremediation plant for soils contaminated with a high concentration of petroleum hydrocarbons and heavy metals. The addition of humic acids also caused changes in the physicochemical properties of contaminated soils. An increase in the carbon and nitrogen content due to the addition of humic acids and a correlation between cation exchange capacity(CEC) and the organic matter content were observed.

• 한국의류산업학회지
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• 제21권2호
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• pp.237-243
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• 2019

This study analyzed satisfaction with and washing of newborn clothing (especially the innerwear washing behaviors) which are considered to be the most basic items among newborn clothing.The survey was conducted on mothers with children under 24 months old. Using an average of 6.7 innerwear items that were changed average 2.3 times a day with baby formula and breast milk representing the main contaminants. When washing clothes for a newborn, respondents were mainly concerned with: rinsing residual detergent, removing stains and contaminants, and sterilization and disinfection. Items were washed by a laundry label to prevent clothes damage. A baby-friendly or environmentally-friendly detergent was used to wash before being worn after purchase was separated and washed in various washing courses of the washing machine every day, boiled, rinsed an average 3.6 times, and dried mainly in the sun. Environmentally friendly cotton (59.5%) and organic cotton (41.6%) products were mainly used; however, items were washed separately from regular laundry. Respondents were satisfied with methods of washing. Consumers are concerned about washing because they think that washing affects a newborn's health. Therefore, it is necessary to provide consumers with appropriate information on washing and establish regulations for the use of harmful substances in newborn clothing and detergents.

• Journal of Yeungnam Medical Science
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• 제35권2호
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• pp.156-164
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• 2018

Environmental contaminants are one of the important causal factors for development of various human diseases. In particular, the perinatal period is highly vulnerable to environmental toxicants and resultant dysregulation of fetal development can cause detrimental health outcomes potentially affecting life-long health. Perfluoroalkyl compounds (PFCs), emerging environmental pollutants, are man-made organic molecules, which are widely used in diverse industries and consumer products. PFCs are non-degradable and bioaccumulate in the environment. Importantly, PFCs can be found in cord blood and breast milk as well as in the general population. Due to their physicochemical properties and potential toxicity, many studies have evaluated the health effects of PFCs. This review summarizes the epidemiological and experimental studies addressing the association of PFCs with neurotoxicity and immunotoxicity. While the relationships between PFC levels and changes in neural and immune health are not yet conclusive, accumulative studies provide evidence for positive associations between PFC levels and the incidence of attention deficit hyperactivity disorder and reduced immune response to vaccination both in children and adults. In conclusion, PFCs have the potential to affect human health linked with neurological disorders and immunosuppressive responses. However, our understanding of the molecular mechanism of the effects of PFCs on human health is still in its infancy. Therefore, along with efforts to develop methods to reduce exposure to PFCs, studies on the mode of action of these chemicals are required in the near future.

• 상하수도학회지
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• 제34권6호
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• pp.445-462
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• 2020

Industrial wastewater often contains a number of recalcitrant organic contaminants. These contaminants are hardly degradable by biological wastewater treatment processes, which requires a more powerful treatment method based on chemical oxidation. Advanced oxidation technology (AOT) has been extensively studied for the treatment of nonbiodegradable organics in water and wastewater. Among different AOTs developed up to date, ozonation and the Fenton process are the representative technologies that widely used in the field. Based on the traditional ozonation and the Fenton process, several modified processes have been also developed to accelerate the production of reactive radicals. This article reviews the chemistry of ozonation and the Fenton process as well as the cases of application of these two AOTs to industrial wastewater treatment. In addition, research needs to improve the cost efficiency of ozonation and the Fenton process were discussed.

• Membrane and Water Treatment
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• 제9권6호
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• pp.405-419
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• 2018

Persulfates (i.e., peroxymonosulfate and peroxydisulfate) are capable of oxidizing a wide range of organic compounds via direct reactions, as well as by indirect reactions by the radical intermediates. In aqueous solution, persulfates undergo self-decomposition, which is accelerated by thermal, photochemical and metal-catalyzed methods, which usually involve the generation of various radical species. The chemistry of persulfates has been studied since the early twentieth century. However, its environmental application has recently gained attention, as persulfates show promise in in situ chemical oxidation (ISCO) for soil and groundwater remediation. Persulfates are known to have both reactivity and persistence in the subsurface, which can provide advantages over other oxidants inclined toward either of the two properties. Besides the ISCO applications, recent studies have shown that the persulfate oxidation also has the potential for wastewater treatment and disinfection. This article reviews the chemistry regarding the hydrolysis, photolysis and catalysis of persulfates and the reactions of persulfates with organic compounds in aqueous solution. This article is intended to provide insight into interpreting the behaviors of the contaminant oxidation by persulfates, as well as developing new persulfate-based oxidation technologies.