박상우 Sang Woo Park , 김수생 Soo Saeng Kim , 장철현 Cheol Hyeon Jang

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This study examined with carbonized sludge produced carbonating sewage sludge for using cutting media of chrysanthemum. Sewage sludge were carbonized at 700℃ during 20min. After carbonization, carbonized sludge were cooled in air. Analysis of heavy metal were determined below permition. Experiment for effect of carbonized sludge on chrysanthemum growth were carried out. Growth of subastral in cutting media, plant height and number of leaves, were better mixture of carbonized sludge than comparison. Two cases of cutting media using only carbonized sludge and carbonized sludge+perlite(1:1) were not combined. On the other hand, carbonized sludge+sphagnum peatmoss(1:1) were combined likely comparison.

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이성준 Sung Jun Lee , 정종수 Jong Soo Jurng , 이교우 Gyo Woo Lee , 이승우 Seoung Woo Lee

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Experiments on burning process of the industrial wastes were performed on a nozzle-type grate in an industrial waste incinerator with a capacity of 160 kilogram per hour. The temporal variations of combustion chamber temperature, exhaust gas temperature, with the waste bed temperature were measured as well as the gas composition of the exhaust during the burning process. As a test material, the typical industrial waste consisting of synthetic leather and poly-urethane with the moisture less than 2 % was used. The experimental results show that the CO concentration in the exhaust gas exceeds the limit, 600 ppm, and gas temperature fluctuates too much when 8 kg of waste was supplied every 3 minutes, equivalent to the capacity of 160 kg per hour, which is a typical situation with this type of industrial waste burning. On the other hand, using the smaller unit waste input, 6 kg per every 2 min 15 seconds, we could decrease the fluctuations in furnace gas temperature, CO and oxygen concentration and obtained a better incineration performance.

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서용칠 Yong Chil Seo , 유종익 Jong Ik Yoo , 정현태 Hyun Tae Joung , 윤기섭 Ki Sup Yoon , 김기헌 Ki Heon Kim , 최용철 Yong Cheol Choi

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The leaching tests, KSLT(Korea Standard Leaching Test), TCLP(Toxicity Characteristics Leaching Procedure), and European NEN 7341(Maximum Available Leaching Test ; MALT) methods were carried out for bottom and fly ashes from nine MSW(municipal solid waste) incinerators, which consisted of different types of furnaces and air pollution control devices in Korea, to investigate the relationships between heavy metal contents and leachate concentrations for each ash. In the course of leaching studies, numerous characteristic data in physical and chemical properties of ashes from MSW incinerators were obtained and some metals leaching exceeded the regulatory limit by KSLT even. Heavy metal contents in bottom ashes were higher in following order; Cu > Pb > Cr > Cd > As > Hg, and those in fly ashes were in following order; Pb > Cu > Cd > Cr > Hg > As. These results showed that the boiling and melting points of each heavy metals affected to the heavy metal contents in ashes. For some metals in fly ashes, it could be found the proportional relationships between heavy metal contents and leachate concentrations, but for most of heavy metals in bottom ashes could not showed any correlations between them. In the case of fly ashes, heavy metals were easily leached out because the vaporized metals were condensed and coagulated on the ashes under unstable conditions. However, the heavy metals in the bottom ashes, which were remained in the combustion environment i.e., well balanced state, could be more difficult to leach out than once vaporized metals in fly ashes. From the results, the most influence leaching factors of heavy metals from ashes were pH of leaching solution and pH of ashes. Additionally, KSLT method may estimate the concentrations relatively lower than the other leaching tests in heavy metals because leaching solution of KSLT were affected by sample pH.

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박상우 Sang Woo Park , 김수생 Soo Saeng Kim , 장철현 Cheol Hyeon Jang

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The objective of this research was to investigate the possibility of using sewage sludge after carbonization as a source to produce adsorbent for heavy metal removal. Surface area and pore structure characterization of the resultant carbonized sludge was evaluated using an accelerated surface area and porosimetry system(ASAP-2010). The effects of process parameters, temperature and hold time were found to be significant. Generally, the adsorption capacity of the carbonized sludge increased with temperature and time. In this study, the optimum temperature and hold time for maximum surface area and adsorption capacity development of carbonized sludge were found to be 700℃ and 30min, respectively. The highest BET surface area achieved was 43.8m2/g, when the highest iodine adsorption capacity achieved was 123.5mg/g. The Freundlich isotherms yield a fairly good fit to the adsorption data, indicating a monolayer adsorption of metals on to carbonized sludge. It can be produced adsorbent of adsorptivity superior.

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배우근 Woo Keun Bae , 박성준 Seong Jun Park , 정진욱 Jin Wook Chung

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The objective of the solidification/stabilization(S/S) treatment is reduction of toxicity of the hazardous wastes and prevention of migrating toxic compounds into the environment. The S/S treatment alters chemically the hazardous materials, such as hazardous organic matter and heavy metals, into materials having reduced toxicity and permeability. Therefore, it is important that the solidified materials have a proper strength to maintain the high physical integrity and the low permeability. The leaching concentration and the unconfined compressive strength(UCS) in cement solidification using real and synthetic plating sludges and the correlation of the UCS with leaching concentration were investigated. With plating sludges, the leaching concentration was exponentially decreased when the UCS of solidified matrix was increased. There was correlation between the UCS and the leaching concentration. In the case of synthetic sludges, The correlation between the compressive strength of a solidified material made from each metal hydroxide and the corresponding heavy metal leaching concentration were clearly inversely exponential.

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권덕희 Duck Hee Kwon , 민경석 Kyung Sok Min , 정용준 Yong Jun Jung

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This study was aimed at evaluating the stabilization of piggery wastewater with lime treatment and its composting with organic solid waste. Different physical and chemical methods were simultaneously adopted. The experimental results showed that the optimal amount of lime required and a reaction time for the stabilization of piggery wastes were 5～10% and 5 minutes, respectively. The lime treated material showed high pH(11～13) at the first step and then dropped to a range of pH 8～9 after drying. The amount of NH3 and H2S of exhaust gas was dropped to a very low 8 days later after stabilization. After 4 days of stabilization, the common bacteria, colitis germs and a parasite were more found to be disinfected more than 98%. After 20～30 days, the experimental results regarding compost revealed that the ranges of C/N ratio, temperature, pH and moisture content were 20～50, 30～40℃, 8～9 and 40～60% respectively. From experimental results, it is confirmed that the end-product of the compost was satisfied with the standard for a fertilizer usage.

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이경환 Kyong Hwan Lee , 김광호 Kwang ho Kim , 서영화 Young Hwa Seo , 신대현 Dae Hyun Shin , 윤왕래 Wang Lai Yun , 전상구 Sang Gu Jeon

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Liquid-phase degradation of waste HDPE (high-density polyethylene) over spent FCC (fluid catalytic cracking) catalyst was carried out with semi-batch operation. The effect of degradation conditions, such as reaction temperature, catalyst amount, carrier flow rate, deactivation and regeneration of catalyst, on the catalytic degradation of waste HDPE was discussed. It was stated that the proper selection of reaction temperature and catalyst amount, rather than carrier flow rate, makes it possible to control the optimized oil product. Spent FCC catalyst in the liquid-phase degradation of polymer at high temperature (>300℃) was not deactivated sharply. Regenerated- spent FCC catalyst showed much lower activity than spent FCC catalyst.

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최재석 Jae Seok Choi , 김영근 Young Geun Kim , 신판우 Pan Woo Shin

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In this study, cement applied products(hollow concrete blocks, concrete bricks, and concrete interlocking blocks for side walks and roads) were manufactured, which were mixed with 10wt%(28vol%) waste tire powder(WTP4), and their compliance with the provisions of KS(Korean Industrial Standards) was evaluated. As a result, they met all of the provisions of KS F 4002(type C of hollow concrete blocks), KS F 4004(thpe C of Concrete bricks) and KS F 4419(concrete interlocking block for side walk and road). Rapid freezing and thawing tests were also conducted using 100 cycles in order to check the durability of these products. These tests showed that the blocks had over 90% of their initial compressive strength, and that they had no problem in durability.

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박승조 Seung Cho Park , 유현철 Hyun Chul Yu , 김정섭 Jung Sup Kim , 곽명화 Myong Hwa Kwak , 이희인 Hee In Lee

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This study was conducted to compost the mixture of pig manure and gypsum. initial moisture contents of sample A (pig manure : saw dust = 6 : 4) and sample B ( pig manure : saw dust : gypsum = 6:2:2)were 64 and 55%. Also temperature and pH of A, B samples were nearly same. Final total nitrogen of sample A and B were about 10000 and 8800 mg/kg respectively and concentration of phosphate and alkalinity of A, B sample were nearly same . However This sample was needed a lot of time to mature as viewing cation exchange capacity(CEC) after experiment was over. We were suggested that gypsum have a roles of additive agent in composting process

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문병현 Byung Hyun Moon , 윤태경 Tae Kyung Yoon , 김상수 Sang Soo Kim , 윤조희 Cho Hee Yoon , 이강춘 Gang Choon Lee

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Effects of C/N ratio and salt concentration on floc characteristics and sludge thickening were investigated. Two SBRs for treating saline wastewater were run in oxic/anoxic operational mode about 400 days. The effects on floc characteristics were evaluated using fractal dimension and size of flocs. For analyzing fractal dimension of flocs, small angle laser light scattering (SALLS) method was applied using Diffraction Particle Sizer. The thickening characteristics of the sludge were determined by capillary suction time (CST). The removal efficiencies of organic and nitrogen decreased as influent salt concentration increased, but eventually reached a plateau. The fractal dimension and size of flocs also showed similar trend. However, the largest fractal dimension and size of flocs were produced at the salt concentration of 6000 mg/L and 8000 mg/L in C/N ratio 2 and 4, respectively. And the larger fractal dimension and size of flocs were obtained in C/N ratio 2 than 4. Effect of C/N ratio on the fractal dimension and size of flocs shown that larger size and less porous flocs were produced in higher nitrogen loading conditions. As the extracellular polymer(ECP) increased, the fractal dimension and size of flocs increased. The CST for characterizing sludge thickening was improved by the increased fractal dimension and size of flocs. These facts imply that the floc characteristics affect sludge thickening.

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이건주 Keon Joo Lee

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In this study the composition and physico-chemical characteristics of municipal solid waste (MWS) disposed of in landfills of the east area of Kyunggi-do were investigated. Hence, it is necessary to measure the characteristics of MSW and sludge to build the data-base and total managing of the landfill. In 2000, about 101.4ton/day of MSW which was generated in the east area of Kyunggi-do was treated in this landfill site. This MSW was composed of 32.54% of food wastes, 28.64% of papers, 22.15% of plastics and vinyls, 2.52% of textiles, 3.70% of wood, 0.52% of rubber and leathers, and others, respectively. Most of MSW are composed of food, paper and plastic waste and more than 70% was combustible waste. For three components, moisture is 21.32%, combustible component is 69.72% and ash is 8.96%. Moisture is highest in fall and in agricultural dwelling. The chemical element has the high order of carbon, oxygen, hydrogen on the dry basis of wastes. And the low heating value of the MSW which is measured by calorimeter is calculated as 2456.44㎉/㎏. In mixing of MSW and sludge, low heatng value of the MSW is calculated as 3688 ㎉/㎏.

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임남웅 Nam Woong Lim , 문대중 Dae Joong Moon

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To promote recycling of waste concrete as concrete aggregate, strength inprovement of recycled aggregate concrete was investigated using mineral admixtures such as fly ash, ground granulated blast furnace slag(GGBF), fly ash, and diatom. When high early hardening portland cement was properly used '0.725% of the total weight of mortar', the strength of mortar mixed with GGBF or diatom was better developed in comparison with that of mortar mixed with silica fume. The compressive strength of recycled aggregate concrete without mineral admixtures was 10% lower than that of natural aggregate concrete. However, compressive and tensile strength of recycled aggregate concrete was highly improved by mixing of fly ash and GGBF or diatom and highly increased at the age of 28days for mixing fly ash as the second step. The ratio of compressive development of recycled aggregate concrete was similar to depending on the mixing ratio of fly ash and GGBF or diatom.

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류보현 Bo Hyun Ryu , 박정균 Chung Kyun Park , 한필수 Pil Soo Hahn

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In order to understand the transport phenomena of contaminants in deep geological environment, migration experiments were carried out in an artificial granite fracture of 50x20cm scale. The tracers used in this experiments were tritiated water, anions, organic dye, and sorbing cations. To visualize migration phenomena, the migration plumes of the eosine were taken with a digital camera as a function of time and stored as a digital image file. Computer simulation was carried out not only for the hydraulic behavior such as distributions of pressure and flow vectors in the fracture but also for the elution curves. These simulation results were interpreted by comparing experimental ones, thus providing a way to understand migration behavior of tracers and interaction between rock and chemical species.

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김재호 Jae Ho Kim , 박태진 Tea Jin Park , 한성호 Sung Ho Han , 유경선 Kyung Seun Yoo , 이재구 Jae Goo Lee , 한춘 Choon Han , 김재권 Jae Kwon Kim

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The effects of catalyst content, reaction temperature, gas composition, and pressure on the activity and selectivity of Cu/ZnO/Al2O3 catalyst for the methanol synthesis have been investigated in a high pressure fixed bed reactor. Methanol yield shows a maximum value at around 250oC and increases with increasing reaction pressure. Among the catalysts used, Cu/ZnO/Al2O3(49:16:15) showed the highest catalyic activity. The methanol yield increases with increasing CO2 concentration up to 10% and then decreases with the increase of CO2 concentration due to the strong adsorption of H2O and CO2 on the active site of catalyst.

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유명진 Myong Jin Yu , 이광표 Kwang Pyo Lee , 김경미 Kyoung Mi Kim , 윤하연 Ha Yeon Yun

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The interests on the recycling of food waste are increasing in Korea. Many local governments, however, have had difficulty in making plans for the food waste management because the quantity of food waste generated and physical composition could not be precisely estimated. So, in this study, the sources of food waste generation were divided into 6 categories, the quantities and physical composition of food waste will be investigated. The result of this study will be applied to estimate the quantities and the variation of food waste generated according to different sources in the future. The results showed that the quantities of food waste generated in the apartment were 0.68㎏/household?day and in the detached house 0.56㎏/household?day. Seasonally, the quantities generated in summer were 1.4 - 1.6 times more than in spring. In food wastes investigated, vegetables and fruits were more than 70% and extraneous matters were 2.6～5.8 % of them. According to the type of business, the restaurants discharged 2.13～7.25 kg/worker?day and bars, Korean restaurants, and Chinese restaurants showed a large amount of food waste. Mass feeding facilities generated about 0.03～0.31 kg/person?day. Among mass feeding facilities, the food wastes were generated more in those of universities and companies. The quantities of food wastes in tourist accommodation were 0.67 kg/room?day and in large retail shop 0.21～14 g/pyeong?day. The types of food wastes from the business places were mostly vegetables and grains. As for extraneous matters, large retail shop and restaurants generated the most and mass feeding facilities in universities and companies discharged next.

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