정재춘 Jae Chun Chung , 이재웅 Jae Woong Lee , 김경숙 Kyong Sook Kim

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This paper is a literature review concerning microorganisms present in the municipal solid waste and their fate. Enteric bacteria, enteric protozoa, enteric virus and fungi are human pathogens associated with the municipal solid waste. Considerably high concentration of total coliform, fecal coliforms, fecal streptococci are present in the municipal solid waste. The ratio of fecal coliforms to fecal streptococci is approximately 0.2. This indicate that the source is dominantly from animals. The major source of human pathogens in the municipal solid waste is sludge and biosolids, domestic pet waste and disposable diapers. It was found that enteric pathogenic microorganisms survive relatively short period in the landfill site due to high temperature generated from the solid waste. Enteric pathogenic microorganisms persent in the leachate decrease rapidly and survive for a long time in low concentration. Enteric virus seems to decrease most rapidly. Human pathogens present in the composting of municipal solid waste decrease rapidly due to high temperature in the compost pile. However, Aspergillus fumigatas which become dominant in the maturation period have some potential to cause health hazard to the workers contacting by aerosol forms.

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노재성 Jae Seong Rho , 이병기 Byoung Ky Lee , 황의환 Eui Hwan Hwang , 길덕수 Deog Soo Kil

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In order to recycle the FRP wastes from SMC bathtubes, polymer-modified mortars containing a fine powder of fiber-rainforced plastics(FRP) as a part of the sand were prepared with various FRP replacements for sand and polymer cement ratios. The polymer modifier used was polyacrylic ester(PAE) emulsion. The FRP waste fine powder was obtained by pulverizing FRP Wastes. The the mortar were tested and the results compared to those of ordinary cement mortar and polymer-cement mortar. As the results, compressive and flexural strengths of ordinary portland cement mortars containing FRP Wastes fine powder were remarkably decreased with an increase of a content of FRP wastes fine powder. But those strengths of ordinary portland cement mortars were greatly improved by adding PAE emulsion. When the replacement ratios of FRP wastes fine powder and adding ratios of PAE emulsion were 5, 10, 20wt% and 10, 15, 20wt% respectively, the compressive and flexural strength of PAE-modified mortar containing FRP wasted fine powder were showed as much those strengths of ordinary portland cement mortar. Otherwise heat curing of PAE-modified mortar containing FRP wastes fine powder accelerated the improvement of early compressive and flexural strengths. But the compressive and flexural strengths of PAE-modified mortar containing FRP wastes fine powder were remarkably decreased after hot water immersion test.

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배재근 Chae Gun Phae , 황진우 Jin Woo Hwang , 고현백 Hyun Beak Ko , 고병산 Byung San Ko

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The study was done for develpment of incineration system conbined with dryer for sewage sludge treatmenet and investigated management methods and suitable process combination through investigation of sludge characteristics and to construct reasonable and effective incineration system. Sludge that was used in study showed high VS content, which was 62.63% and 59.97% as per dried solid. The things which showed low degree calorific value, it was verified that it would be better to burn after drying as it has high water content. If sludge itself starts decomposing in 250℃ and finish in 550 ℃ showned in TGA analysis, it is needed to consider the characteristics of heat decomposition at the time of designing of dry machine and incinerator. When adhesion(glue zone) was checked by flow-ability and compressed strength of sewage sludge, flow-ability was fine in less than 47% of water content and the highest of intensity showed in 59%. According to increase of water content, adhesion of sludge decreased and before and after 70% is the area where mechanical burden doesn't occur. Likewise, it is proved that to design and drive avoiding adhesion section of which water content is 50～70% in incineration system combined with dryer increases treatment effectiveness.

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황택성 Taek Sung Hwang , 노재성 Jae Seong Rho , 이병기 Byoung Ky Lee , 황의환 Eui Hwan Hwang

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In order to recycle the FRP fine powder wasted from SMC bathtubes, the physical properties of SBR-modified mortar containing wastes FRP powder were investigated. The formulations for specimens were prepared with various replacements of wastes FRP powder as parts of fine aggregate and various polymer-cement ratios. It showed that compressive and flexural strengths of OPC(ordinary portland cement) mortar containing wastes FRP powder were decreased with an increase of wastes FRP powder. It was found, however that those strengths of mortars were improved by adding SBR latex to it. Flexural strength of SBR-modified mortar containing wastes FRP powder was especially improved. The water absorption rate of SBR-modified mortar was greatly improved than that of OPC mortar. The optimum substitution amount of wastes FRP powder was appeared to bi 20wt% when SBR altex was added 20wt%. compressive and flexural strengths of SBR-modified mortar when specimens were heat-cured were increased than that of standard curing method. Therefore, improvement of early strengths of SBR-modified mortar containing wastes FRP powder can bi achieved by heat curing method subjected to that the 15wt% of wastes FRP powder was substituted, when SBR latex was added 20wt%. The optimum substitution amount of wastes FRP powder was appeared to bi 15wt% when SBR latex was added 20wt%. Compressive and flexural strengths of SBR-modified mortars were greatly decreased under immersion on hot water due to SBR polymer

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이성준 Sung Jun Lee , 정종수 Jong Soo Jurng , 이교우 Gyo Woo Lee , N/A Jochen Seier , 김병화 Byoung Hwa Kim

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Experiments were performed on the adsorption of mercury from the incineration flue gas by various adsorbents, including inorganic adsorbents, for example zeolites. Four different materials were tested as adsorbents of mercury in both the laboratory-scale test rig and the test facility using real incineration offgas, which was connected to the offgas line of TAMARA facility of Research Center Karlsruhe(FzK), Germany. The incinerator offgas was similar to the real offgas from waste incinerator. the concentrations of NO, CO, O2, CO2, H2O, HCl, were monitored as well as mercury concentration by Hg-MATⅡ developed by FzK. Mercury adsorbed by carbon, wood char as well as by commercial activated carbon was much larger than that by inorganic adsorbents, for example, natural zeolite and bentonite. Test results in the lab-scale test rig also gave the similar conclusion that inorganic adsorbents were not effective for mercury adsorption. The wood char from the gasification process of waste wood will be a possible alternative of the commercial activated carbon adsorbent.

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이지훈 Ji Hoon Lee , 송명재 Myung Jae Song , 양호연 Ho Yeon Yang , 육완이 Wan Yi Yuk , 하종현 Jong Hyun Ha

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The experiments were carried out using the modified lab-scale electrochemical decontamination process to develope the effective electrochemical process for decontamination of radioactive metal waste in nuclear power plants. The operational parameters such as current density, electrolyte concentration and reaction time in electrolytic process were investigated to decontaminate the carbon steels generated from nuclear power plants. Various kinds of neutral salt electrolytes were applied to the decontamination process to select optimum electrolyte. In case of surface contamination, most of the radioactivity is assumed to be localized in about 10 ㎛ thickness from the surface. When 1.5 M sodium sulfate were applied in modified process, 16㎛ thickness changes had been achieved in scrap metals. In a series of experiments above, it was found that the optimum current density and reaction time were 0.4 A/cm2 and 30 minute, respectively.

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정태학 Tai Hak Chung , 김규동 Gyu Dong Kim , 김희준 Hee Jun Kim , 이종훈 Jong Hoon Lee

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Radionuclide incorporation and leaching of the vitrified surrogate wastes produced by plasma melting were investigated. The raw materials used for production of the simulated incombustible low-level radioactive waste were concrete, glass, sand, Cs-133 and Co-59. Increase of sand fraction of the raw wastes decreased percent incorporation of the radionuclides because sand has much CaO contents. They acted as a network modifier in the vitrified product The incorporation efficiency of Cs-133 and Co-59 was 40~50% and 5-23%, respectively. Such a low incorporation might be due to the partial melting, which allows high volatilization of nuclides from the unmelted hot wastes in the course of vitrification. The TCLP test results showed that there was no relationship between incorporation and leaching of the radionuclieds, and the leaching mechanism of cesium was quite different from that of cobalt. The volume reduction ratio of the vitrified waste was 1.23 as an average, and a significant volume reduction could be achieved by the vitrification using plasma melting.

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오상은 Sang Eun Oh , 유영복 Yung Bok Yoo , 범민수 Min Su Bum , 김인수 In S. Kim

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This study was investigated the effect of methanol on autotrophic denitrification in the sulfur-packed reactors. Four laboratory-scale reactors were operated for about 380 days using the different methanol concentrations with 100 mg NO3--N/L in the influent. All reactors resulted in 97% nitrate removal at higher hydraulic retention times than 1.5 hr and as the methanol concentration increased, critical nitrate loading rate increased. In Column 3 (sulfur with 571 mg/L of methanol), autotrophic decitrification occurred even if methanol concentration was higher than stoichiometric amounts for heterotrophic denitrification which can be indicated by sulfate production and also influent DOC was removed by the heterotrophs. In the case of Column 2 (sulfur with 133 mg/L of methanol), 80-90% of DOC was removed. The turbidity in the effluent of Columns 3 and 4 was high and fluctuated with time compared with Columns 1 and 2 which resulted from the higher Y value.

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조병욱 Byung Wook Jo , 최재곤 Jae Kon Choi , 문성철 Sung Chul Moon , 최수경 Soo Kyung Choi , 윤두수 Doo Soo Yun , 류범영 Bum Young Ryu

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The effects of the interphase crosslinking on compatibility of the blends consisting of low density polyethylene(LDPE) and ground rubber tire(GRT) were studied. Dicumyl peroxide(DCP)was used as a crosslinking agent to increase compatibility. The blends were characterized by differential scanning calorimeter, Instron, dynamic mechanical thermal analyzer, scanning electron microscope. Glass transition temperature(Tg) of the LDPE in the blends increased with increasing DCP, but the values of △Hm, △Hc and Tc decreased. The interphase adhesion between the phases and mechanical properties of the blends were improved remarkably with increasing DCP content.

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김정환 Jeong Hwan Kim , 박승범 Seung Bum Park , 이택우 Taek Woo Lee

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The cost required water treatment would be saved affectively by recycling waste asphalt concrete. Furthermore we can have economic benefits by saving natural aggregate and asphalt, also we can get the effect to prevent environmental pollution by illegal abandonment and reclamation. Asphalt is deteriorated by outer factors and deterioration properties of recovered asphalt are not same as those of virgin asphalt. there remain some problems concerning long-term durability and repetitive recycling. This study analyzed physical properties of recovered asphalt(such as penetration, ductility, softening point and chemical composition) to obtain practical data about deterioration properties of recovered asphalt according to service time and layer of waste asphalt concrete pavement.

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김낙주 Nack Joo Kim , 김운겸 Woon Kyeom Kim

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The problems of recycling polyurethane wastes have major technological, economic and ecological significance because polyurethane itself is relatively expensive and its disposal whether by burning is also costly. Ingeneral, the recycling methods for polyurethane could be classified as mechanical, chemical and feedstock. In the chemical recycling method, there are hydrolysis, glycolysis, pyrolysis and aminolysis. In this study, the work was carried out glycolysis using sonication and catalyzed reaction. Different kinds of recycled polyols were produced by current method, catalyzed reaction and sonication as decomposers and the chemical properties were analyzed. The reaction results in the formation of polyester urethane diols, the OH value which is determined by the quantity of diol used for the glycolysis conditions. The glycolysis rates by sonication for the various glycols, increased as fallows: PPG

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이기호 Ki Ho Lee , 박준범 Jun Boum Park , 윤현석 Hyun Suk Yoon , 홍승철 Seung Cheol Hong

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The purpose of this study is to improve the understanding of the environmental reusability of industrial by-products. Sorption characteristics of BTE(Benzene, Toluene and Ethyl-benzene) on two different kinds of by-products, oyster shell and fly ash, were examined by sorption equilibrium and isotherm tests. In-situ application of by-products was also studied by performing the sorption test on the clay and weathered soil as reference materials. As a results of the sorption isotherm tests, a linear relationship was obtained between linear partition coefficient, Kd, and octanol-water partition coefficient, Kow, of each organic compound.

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임남웅 Nam Woong Lim , 장원호 Won Ho Jang , 반명수 Myoung Soo Van

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Effect of the pozzolans on the physical properties of the OPC(Ordinary Portland Cement) mortar with use of the remicon sludge waste(RSW) was studied. RSW was replaced with cement in the OPC mortar from 5%, 10% and 20%. The pozzolans were also substituted for RSW from 5%, 10% and 20% on a weight base. The cube specimens were cast in accordance with KS L 5109 and tested for compressive strength(CS), durability, pore size distribution (PSD), scanning electrum microscope(SEM) and X-ray diffraction(XRD). The results showed that the optimum amount of RSW to replace with cement in the OPC mortar was 10% and pozzolan to substitute for RSW was 20%, respectively. The physical properties(e.g., CS and durability) of the cement mortar with the use of the RSW and pozzolan(as above) at 7, 28 and 56 days were higher than that of the OPC mortar. XRD revealed that calcium silicate hydrates(Ca2SiO4 and Ca3SiO5) crystalline products were identically appeared in both OPC and RSW cement mortar, but less amount of CaO was exhibited in the RSW cement mortar compared to the OPC mortar. It was concluded that the pozzolans had an effect on improvement of the physical properties of the OPC mortar when 10% of the RSW was replaced for cement and 20% pozzolans were substituted for RSW.

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현재혁 Jae Hyuk Hyun , 김진춘 Jin Chun Kim , 이호용 Ho Yong Lee , 조재범 Jae Beom Cho , 나진성 Jin Sung Ra

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This study is to evaluate a charge of the physical properties of the landfill liner system under the unique domestic climatic condition of winter in Korea, i.e, 3 days harsh and 4 days mild climate. The two wats to estimate the climatic influence to the liner system were performed ; namely, permeability and uniaxial compression test. The samples used in this test were the mixture of the WGS (Weathered Granitic Soil) and MCG (Mullite Carbon Gypsum). Mixing ratio was in a weight basis of 95 : 5 , 90 : 10 , 85 : 15 , and 80 : 20, respectively. The compressive strength of the sample was mostly increased from 36% to 112% after freeze and thaw cycles. Moisture supply during freeze and thaw cycles gave an increase of the compressive strength of the sample, while the permeability was decreased. The results showed that the addition of MCG to the WGS could prevent the increase of permeability triggered by the MCG and WGS. The hydration products of MCG and WGS plugged the pores which once were filled by water.

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이희선 Hi Sun Lee

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The treating methods for infectious waste were studied in the viewpoint of health?sanitation and environment within the range of waste stream of waste management act to obtain the effective treating method by comparing and analyzing the methods used in Korea and developed countries. Incineration and steam sterilization were used as treating methods for infectious waste. However, incineration method is superior to stram sterilization in developed countries, especially, in European countries and Japan. Also, the same is in Korea. In the case of incineration, the generation and removal of hazardous discharging gas such as dioxin were difficult problem to treat properly infectious waste. In steam sterilization, uncertainty of sterilization, double treatment and generation of an offensive ordor were difficult. In order to solve these problems, the selection of incineration as teating method is better and medium and large size incinerator is essential in stead of small size incinerator, from which the specialization of treatment and improvement of technological development can be obta

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Treatment method, Infectious waste, Incineration and steam sterilization, Dioxin and offensive ordor