• Proceedings of the Korean Geotechical Society Conference
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• 2006.03a
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• pp.330-337
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• 2006

Resistivity cone penetrometer test (RCPT) can be employed at a relatively low cost for delineation of subsurface contamination in situ, and then be supplemented with a minimum confirmatory sampling and laboratory testing program. While the resistivity measurement have potential to investigate the subsurface contamination, resistivity measurements alone will lead to some degree of ambiguity in the results. In this study, capacitance measurement was incorporated into the RCPT to overcome the ambiguity inherent in electrical resistivity measurements for delineating the subsurface contamination. This study is focused on verifying the applicability of resistivity and capacitance measurements on CPT module to provide information on contaminated subsurface by heavy metal and petroleum hydrocarbon. Laboratory model tests were performed to evaluate the sensitivity of the measured resistivity and relative capacitance on the water content and different types of contaminants. Test results show that simultaneous measurement of electrical resistivity and capacitance can give more reliable information on subsurface contamination.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.48 no.12
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• pp.791-797
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• 1999

Recently the ozone generation system is well used for cleaning the contaminated water by using the strong oxidization effects of ozone. In this paper the concentration, yield and generation quantity of the ozone by the Surface-Silent Discharge According to the Length of Coaxial Electrode is described. The electrodes composed of 3 electrodes-2 gaps are coaxial type and the ozone generation tube were designed and fabricated from the point of view of the energy efficiency, stability and easy control. To investigate the ozone generation dependency on electrode length, a few discharge tubes with different lengths were fabricated. The experimental equipments were provided with cooling system and dehumidifier for the many testing conditions. The main results show that the concentration, yield and generation quantity of ozone are improved by decreasing gas temperatures and increasing electrode lengths.

• Journal of the Korean Ceramic Society
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• v.48 no.1
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• pp.20-25
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• 2011

Since 1980's, many mines have been closed and abandoned due to the exhaustion of deposits and declining prices of international mineral resources. Because of the lack of post management for these abandoned mines, Farm land and rivers were contaminated with heavy metal ions and sludge. We studied on the solidification/stabilization of heavy metal ions, chromium ions and lead ions, using magnesia-phosphate cement. Magnesia binders were used calcined-magnesia and dead-burned magnesia. Test specimens were prepared by mixing magnesia binder with chromium ions and lead ions and activators. We analyzed the hydrates by reaction between magnesiaphosphate cement and each heavy metal ions by XRD and SEM-EDAX, and analyzed the content of heavy metal ions in the eruption water from the specimens for the solidification and stabilization of heavy metal ions by ICP. The results was shown that calcined magnesia binder is effective in stabilization for chromium ions and dead-burned magnesia binder is effective in stabilization for lead ions.

• Proceedings of the Korean Environmental Health Society Conference
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• 2002.04a
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• pp.9-12
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• 2002

Diffusive transport of volatile organic compounds(VOCs) and their degradation by bacteria in unsaturated soils are couple by poorly understood mass transfer kinetics at the gas/water interface. Determination of the fate of VOCs in unsaturated soil is necessary to evaluate the feasibility of natural attenuation as a VOC remediation strategy. The objective of this study was to develop a mechanistically based mathematical model that would consider the interdependence of VOC transport, microbial activity, and sorptive interaction in a moist, unsaturated soil. Because the focus of the model was on description of natural attenuation, the advective VOC transport that is induced in engineered remediation processes such as vapor extraction was not considered. The utility of the model was assessed through its ability to describe experimental observations form diffusion experiments using toluene as a representative VOC in well-defined soil columns that contained a toluene degrading bacterium, Pseudomonas Putida, as the sole active microbial species. The coefficient for gas-liquid mass-transfer, K$\sub$LA/, was found to be a key parameter controlling the ability of bacteria to degrade VOCs. This finding indicates that soil size and geometry are likely to be important parameters in assessing the possible success of natural attenuation of VOCs in contaminated unsaturated soils.

• Journal of Environmental Health Sciences
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• v.31 no.5 s.86
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• pp.404-410
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• 2005

The pH efforts on the removal of 1,4-dioxane and the biodegradobility enhancement of dioxane contaminated water were investigated using $O_3/H_2O_2$ baled advanced oxidation process. Experiments were conducted using a bubble column reactor under different initial pH. The $O_3/H_2O_2$ process effectively converted 1,4-dioxane to more biodegradable intermediates which had a maximum $BOD_5$ enhancement at pH 11 within the experimental range, precisely, when the initial pH increased, $BOD_5$ enhanced. However, in case of removal efficiencies of 1,4-dioxane during $O_3/H_2O_2$ oxidation the optimum condition was shown at pH 9 compared with pH 6 and 11. TOC and COD values were not largely changed for all reaction time. From the results of 1,4-dioxane removal efficiency, TOC, COD, and $BOD_5$ enhancement with reaction time, it was surely observed that 1,4-dioxane was just converted to biodegradable materials, not completely oxidized to carbon dioxide.

• Korean Journal of Ecology and Environment
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• v.40 no.4
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• pp.537-545
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• 2007

The heavy metal removal capacity of filamentous green alga Cladophora sp. cultured together with wet-mixed solidified soil (loess) was tested. A Cladophora sp. was cultured for 5d, with added Chu No. 10 medium, in stream water contaminated by high concentration of heavy metals from a closed mine effluent. Heavy metal ion concentrations of the medium and in algal tissue were measured every day during the experiment. Dissolved metals (Al, Cd, Cu, Fe, Mn, Zn) in medium were rapidly removed (over 90% elimination) within 1-2d when alga and loess were added. Dissolved heavy metals dropped by only 10% when algae were cultured without loess. The Cladophora sp. accumulated much more heavy metals when cultured with loess than when the alga was cultured alone. Cladophora sp. exhibited a maximum uptake capacity for Al ($17,000{\mu}g^{-1}$ algal dry weight). The metal bioremoval capacities of the algae were in the order Al, Fe, Cu, Mn, Zn and Cd. The heavy metal removal capacity of Cladophora sp. showed significant increases when wet-mixed solidified soil was added to culture media.

• Advances in environmental research
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• v.6 no.2
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• pp.147-158
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• 2017

This paper represents a set of experimental tests on remediation of nickel-contaminated kaolin by Electrokinetic method. For this purpose, we conducted unenhanced and EDTA-enhanced Electrokinetic tests in one, three, and five days of treatment. In unenhanced tests, we used deionized water as an electrolyte in the anode and the cathode compartments. In the EDTA-enhance tests, we used ethylenediaaminetetra acetic acid 0.1 Molar in the cathode and sodium hydroxide 0.1 Molar in the anode. The average nickel removal for unenhanced tests after three and five days of treatment was 19 and 23 percent, respectively. High buffer capacity of the soil is responsible for low removal efficiency in the unenhanced tests, which maintained pH close to the initial amount that restrained nickel as an adsorbed or precipitated forms. The average nickel removal for EDTA-unenhanced tests after three and five days of treatment was 22 and 12 percent, respectively. Lower ionic mobility of EDTA-Ni complex in comparison with $Ni^{+2}$, which is the main transportation mechanism for this complex, could be responsible for less removal efficiency in EDTA-enhanced test.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.9
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• pp.4185-4197
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• 2016

Chronic arsenicosis is a major environmental health hazard throughout the world, including India. Animals and human beings are affected due to drinking of arsenic contaminated ground water, due to natural mineral deposits, arsenical pesticides or improperly disposed arsenical chemicals. Arsenic causes cancer with production of free radicals and reactive oxygen species (ROS) that are neutralized by an elaborate antioxidant defense system consisting of enzymes and numerous non-enzymatic antioxidants. Dietary antioxidant supplements are useful to counteract the carcinogenesis effects of arsenic. Oyster mushroom lectins can be regarded as ingredients of popular foods with biopharmaceutical properties. A variety of compounds have been isolated from mushrooms, which include polysaccharides and polysaccharopeptides with immune-enhancing effects. Lectins are beneficial in reducing arsenic toxicity due to anticarcinogenetic roles and may have therapeutic application in people suffering from chronic exposure to arsenic from natural sources, a global problem that is especially relevant to millions of people on the Indian subcontinent.

• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.1238-1243
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• 2009

As Social Overhead Capital(SOC) has been expanded, the highway road construction has been accelerated and city road system has been more complicated. So, long road tunnels have been increased and traffic flow rate also has been raised. Accordingly, the exhausting gas of vehicle cars seriously deteriorates the tunnel inside air quality and driving view. In order to improve tunnel inside air quality, it is needed to introduce a compulsory ventilation system as well as natural ventilation mechanism. The former, that is, a special compulsory ventilation facility is very useful and helpful to prevent a tunnel of being contaminated by traffic in most case. In the case of obtaining clearer and longer driving view, the ventilation systems have to be considered in order to remove floating contaminants or exhaust gas from engines. In this paper, discharge electrode design technology will be discussed.

• Toxicological Research
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• v.24 no.3
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• pp.161-167
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• 2008

Recently, arsenic-toxicity has become the major focus of strenuous assessment and dynamic research from the academy and regulatory agency. To elucidate the cause and the mechanism underlying the serious adverse health effects from chronic ingestion of arsenic-contaminated drinking water, numerous studies have been directed on the investigation of arsenic-toxicity using various in vitro as well as in vivo systems. Neverthless, some questions for arsenic effects remain unexplained, reflecting the contribution of unknown factors to the manifestation of arsenic-toxicity. Interestingly, very recent studies on arsenic metabolites have discovered that trivalent methylated arsenicals show stronger cytotoxic and genotoxic potentials than inorganic arsenic or pentavalent metabolites, arguing that these metabolites could play a key role in arsenic-associated disorders. In this review, recent progress and literatures are summarized on the metabolism of trivalent methylated metabolites and their toxicity on body systems including cardiovascular system in an effort to provide an insight into the future research on arsenic-associated disorders.