• Journal of Environmental Science International
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• v.14 no.10
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• pp.919-928
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• 2005

This study introduces the development of new supercritical water oxidation(SCW)(multiple step oxidation) to destruct recalcitrant organic substances totally and safely by using sodium nitrate as an oxidant. This method has solved the problems of conventional SCW, such as precipitation of salt due to lowered permittivity, pressure increase following rapid rise of reaction temperature, and corrosion of reactor due to the generation of strong acid. Destruction condition and rate in the supercritical water were examined using Polyvinyl Chloride(PVC) and ion exchange resins as organic substances. The experiment was carried out at $450^{\circ}C$ for 30min, which is relatively lower than the temperature for supercritical water oxidation $(600-650^{\circ}C)$. The decomposition rates of various incombustible organic substances were very high [PVC$(87.5\%)$, Anion exchange resin$(98.6\%)$, Cationexchange resin$(98.0\%)$]. It was observed that hetero atoms existed in organic compounds and chlorine was neutralized by sodium (salt formation). However, relatively large amount of sodium nitrate (4 equivalent) was required to raise the decomposition ratio. For complete oxidation of PCB was intended, the amount of oxidizer was an important parameter.

• Korean Journal of Organic Agriculture
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• v.9 no.4
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• pp.135-148
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• 2001

Antibiotics supplementation in animal feeds results in bacterial resistance to the antibiotics and residue of the antibiotics in animal products, which can cause serious problems in human health. Therefore, the finding of new substances replacing antibiotics are needed. New substances are egg york antibody, probiotics, organic acid, mannanoligosaccharide(MOS), fructooligosaccharide(FOS), and chitosan etc. Egg york antibody is antibody to obtain from egg york of the chicken injected the specific antigen. Probiotics can prevent the problems of residue of the antibiotics and resistance to the antibiotics. Organic acids ctrl preservation of colostrum inhibit the rottenness and increase the beneficial bacteria. MOS and FOS increase the beneficial bacteria, too. Chitosan is used the immune material to active the anti-bacteria.

• Membrane and Water Treatment
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• v.1 no.4
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• pp.283-296
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• 2010

During the disinfection of potable water, humic substances present in the solution react with chlorine to form potential carcinogenic compounds. This study evaluates the feasibility of using a submerged membrane photocatalysis reactor (SMPR) process for treatment of humic substances through the characterization of both organic removal efficiency and membrane hydraulic performance. A simple SMPR was operated and led to the removal of up to 83% of the polluting humic matters. Temporal rates of organic removal and membrane fouling were found to decrease with filtration time. Using tighter membrane in the hybrid process resulted in not only higher organic removal, but also more significant membrane fouling. Under the experimental conditions tested, optimum $TiO_2$ concentration for humic removal was found to be 0.6 g/L, and increasing initial pollutant concentration expectedly resulted in a more substantial membrane fouling. The importance of the influent nature and pollutant characteristics in this type of treatment was also assessed as various water sources were tested (model humic acid solution vs. local water containing natural organic matters). Results from this study revealed the promising nature of the SMPR process as an alternative technique for organic removal in the existing water treatment system.

• Journal of Korean Society of Water and Wastewater
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• v.37 no.5
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• pp.253-259
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• 2023

Bioreactors are devices used by sewage treatment plants to process sewage and which produce active sludge, and sediments separated by solid-liquid are treated in anaerobic digestion tanks. In anaerobic digestion tanks, the volume of active sludge deposits is reduced and biogas is produced. After dehydrating the digestive sludge generated after anaerobic digestion, anaerobic digested wastewater, which features a high concentration of organic matters, is generated. In this study, the decomposition of organic carbon and nitrogen was studied by advanced oxidation process. Ozone-microbubble flotation process was used for oxidation pretreatment. During ozonation, the TOC decreased by 11.6%. After ozone treatment, the TOC decreased and the removal rate reached 80.4% as a result of the Ultra Violet-Advanced Oxidation Process (UV-AOP). The results with regard to organic substances before and after treatment differed depending on the organic carbon index, such as CODMn, CODCr, and TOC. Those indexes did not change significantly in ozone treatment, but decreased significantly after the UV-AOP process as the linkage treatment, and were removed by up to 39.1%, 15.2%, and 80.4%, respectively. It was confirmed that biodegradability was improved according to the ratio of CODMn to TOC. As for the nitrogen component, the ammonia nitrogen component showed a level of 3.2×10² mg/L or more, and the content was maintained at 80% even after treatment. Since most of the contaminants are removed from the treated water and its transparency is high, this water can be utilized as a resource that contains high concentrations of nitrogen.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2002.09a
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• pp.191-194
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• 2002

Humic acid, fulvic acid and humin present in volcanic ash soil were isolated by IHSS standard procedure and their characteristics were analyzed as a basic study to evaluate the effect of humic substances on the behaviour of pollutants in contaminated surface soil. The volcanic ash soil contained 42.1 % of total organic matter based on the oven-dried soil, and humin, humic and fulvic acids corresponded to 67.5 %, 15.2 %, 7.6 % of TOM respectively. Structural informations of the humic fractions were obtained from their elemental analysis and IR, CPMAS C-13 NMR spectral analysis and the differences among them are discussed with their C/H, O/C ratios and distributions of carbon types in the molecules.

• Textile Coloration and Finishing
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• v.15 no.5
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• pp.340-347
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• 2003

Present situation of Korean textile products regarding European eco-label criteria was assessed by analyzing harmful substances including pH, PCP & TeCP, formaldehyde, heavy metals, cleavable arylamines, allergenic dyes, pesticides, organic carriers, TBT as well as color fastness as the minimum quality requirement. Fabric specimens were submitted from six typical textile companies for product eco-testing. In six product groups selected, arylamines, allergenic dyes, halogenated organic carriers and color fastness were found to be parameters that failed to meet the criteria. Source elucidation of harmful substances were presented with their instrumental analysis results.

• Journal of environmental and Sanitary engineering
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• v.22 no.4
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• pp.23-32
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• 2007

Changes in the characteristics of dissolved organic matter was studied at selected stations in the Nakdong river basin using physical and chemical methods. Characteristics of dissolved organic matters were analysed and assessed. Production of disinfection byproducts were also investigated. Distribution of the organic compounds according to the Molecular weight(MW) indicate that MWs higher than 100K were highest with cattle excrement wastewater and MW between 100-10K were highest with waters from forest streams. Low MW compounds (Jess than 1K) were highest with the effluents from environmental facilities. Results of resin fractionation study show that acidic hydrophobic substances(AHS) were dominant in many stations. The values were higher in the samples from mainstreams and sidestreams where the influence of organic matter is higher than the water from environmental facilities. Hydrophilic neutral substances(HoN) such as hydrocarbon, pesticides and detergents were higher in the wastewater treatment facilities. HoN values of water from the forest streams were 4.7% indicating there is no synthetic pollutant.

• Korean Journal of Environmental Agriculture
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• v.27 no.3
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• pp.285-291
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• 2008

A global binding agreement was adopted with the leading of United Nations Environment Program (UNEP) on May 22, 2001 in Stockholm to regulate the production and distribution on persistent organic pollutants (POPs). The agreement took effectuation with the ratification of 59 countries from the approval of 151 countries on May 17, 2004. After the approval on October 4, 2001, South Korea performed systematical investigation on POP-related substances such as chlordane, dichloro diphenyl trichloroethane (DDT), hexachlorobenzenes (HCB), heptachlor, polychlorinated biphenyls (PCBs) to get ready for the ratification of the convention with country-specific exemption. The domestic distributions of those chemical substances have been officially prohibited since the late 1960s to the early 1980s. Although there were occasional reports for the detection of some of those chemical substances, those performed minute signification in their existence in the environment. A series of investigation with documentary examination and fact-finding survey showed the possibility for the ratification on the convention without country-specific exemption.

• Journal of Korean Society on Water Environment
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• v.22 no.5
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• pp.926-932
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• 2006

A series of bench-scale membrane filtration experiments were performed to systematically investigate the removal mechanisms of reverse osmosis (RO) and nanofiltration (NF) membranes for BTEX (benzene, toluene, ethylene, xylene), trichloroethylene (TCE) and tetrachloroethylene (PCE). The molecular weight of these organic compounds ranged from 78 to 166 dalton. The rejection of organic compounds by RO/NF membranes varied significantly from 59.6 to 99.2% depending on solute and membrane types. Specifically, experimental results demonstrated that the removal efficiency of RO/NF membranes increased as solute molecular characteristics such as W/L (molecular width/length) ${\times}$ $M_W$ (molecular weight) and octanol-water partition coefficient increased. This observation suggested that the rejection of small organic compounds by RO/NF membranes was determined by the combined effect of physical (molecular size and shape) and chemical (hydrophobicity) properties.

• Journal of Marine Bioscience and Biotechnology
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• v.8 no.1
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• pp.10-17
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• 2016

A wide-spread contamination of persistent organic pollutants (POPs) such as dioxins, PCBs, PBDEs in the aquatic ecosystem has generated a great concern over the potential risk for these substances to impact marine biotas and food web. Since a major exposure route of these substances to the humans is through the consumption of food including fish and marine byproducts, the consumption of contaminated products has been a great public health concern. Exposure to POPs has been associated with a wide spectrum of adverse effects including reproductive, developmental, immunologic, carcinogenic, and neurotoxic effects. This review covers the background information of key POPs substances and the recent development of toxicity studies including the mode of action. Because neurotoxic effects of some POPs have been observed in humans at low concentrations, polychlorinated biphenyl (PCB), a representative chemical of POPs, is focused to discuss the possible mode(s) of action for the neurotoxic effects. This review provides the updates of toxicity studies on POPs and paves ways to discuss a possible implication of contaminated marine biota over the human health among the marine biotechnology researchers.