김용진 Yong Jin Kim , 정승미 Seung Mi Jeong , 배성진 Sung Jin Bae , 이동훈 Dong Hoon Lee

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Abstract

In this study, phytocapping which was widely and deeply studied in USA and Australia was investigated among the methane oxidation technology for the surface emission reduction, and the consideration matter to apply the technology was also suggested. The selection of plants to be suitable in climate and soil condition is the key factor when phytocapping would be introduced. In the United States, a fast growing, perennial and deep-rooting tree species are used for landfill covers or contaminated soil areas, and even understory grasses are chosen based on regional characteristics. However this phytocapping would have regional limitation, especially precipitation is an important environmental factor.

Key Words

Phytocapping, Landfill, Final cover, Methane oxidation

홍용희 Yong Hee Hong , 손준익 Jun Ik Son , 김영란 Young Lan Kim , 오길종 Gil Jong Oh , 김기헌 Ki Heon Kim

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Abstract

This paper examined reasonable operating factor for treatment of carcass burial leachate in High Temperature Thermal Desorption (HTTD) and calculated the amount of fuel used in each device using heat and mass balance under condition of 4 scenarios. As a result, we concluded that rotary kiln for dryness and thermal desorption shoud be separated dual type and mixing ratio of sawdust and soil should be restricted no more than 1 : 14. Also, operating temperature should be kept 260, 550, 850 or higher in dryer kiln, thermal desorption kiln and secondary chamber respectively and residence time should be kept 30min in each kiln. The total amount of fuel used in each device was compared under 4 scenarios on the mixing ratio. According to a study, it showed the highest value under the scenario of 1 : 1, which showed 2.5 times higher than the scenario of 1 : 14 in terms of treatment of leachate per unit of LNG.

Key Words

High Temperature Thermal Desorption, Heat and mass balance, Operating parameter

최성우 Sung Woo Choi , 정연호 Youn Ho Jung

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Abstract

Microwave pyrolysis of SF6 on alumina-based catalyst doped with cerium sulfate was investigated. Silicon Carbide (SiC) used as a microwave susceptor. The catalysts were characterized by X-ray diffraction (XRD) and the destruction and removal efficiency (DRE) of SF6 was evaluated by GC-TCD. We found that the optimal cerium content was 20wt% at microwave pyrolysis of SF6. The catalysts modified by cerium showed higher DRE at lower reaction temperature compared with original catalysts. The highest DRE of SF6 on CeA (20) was 80% at 600oC reaction temperature and the DRE was up to 95% when the reaction temperature over 700oC. It showed the alumina-based with cerium promotes the removal efficiency of SF6 at a mild reaction temperature. From XRD results, modified catalysts could be higher stability because of no transformation of the crystal phase after reaction.

Key Words

SF6, Microwave pyrolysis, Cerium sulfate, Silicon carbide

안양진 Yang Jin An , 문경주 Kyung Ju Mun , 윤성진 Seong Jin Yoon , 이민희 Min Hee Lee , 송영찬 Young Chan Song , 김용로 Yong Ro Kim

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Abstract

This study is regarding the property evaluation of mortar for ‘ONDOL’ floor (Korean floor heating system) finishing with reduced drying and shrinking properties to use it in the form of ready-mixed concrete mortar. The mortar utilized furnace slag based inorganic binding agent NSB, which has the characteristic of CaO included in HCFA generated from the fluidized-bed-firing power plant. Based on the test results, it is judged that mortar for ‘ONDOL’ floor finishing based on NSB including HCFA can be used in the form of ready-mixed concrete. According to site test construction, the flow property was relatively poor because fine gravel at ready-mixed concrete factory was used. However, since finishing property, crack resistance and water content are good, it is believed that it can be used at construction site in the form of ready-mixed concrete mortar. More study on adhesion property with floor plate would be required in the future.

Key Words

Industrial by-products, Finishing Mortar in Ondol Floor, High-Calcium Fly Ash

임동현 Dong Hyun Lim , 기광석 Kwang Seok Ki , 최순호 Sun Ho Choi , 이현준 Hyun June Lee , 김태일 Tae Ile Kim , 박성민 Seong Min Park , 권응기 Eung Gi Kwon , 박수범 Su Bum Park

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Abstract

This study was carried out to investigate the effect of DDGS hydrolysate (H-DDGS) and rumen-protected lysine-choline complex (RPLC) on milk production and blood metabolites in dairy cows. Feeding trials was performed to latin-square design using the 4 mid-lactational cows for 8 weeks, and treated with T1 (H-DDGS 1.1 kg), T2 (H-DDGS 0.73 kg + RPLC 0.15 kg), T3 (H-DDGS 0.37 kg + RPLC 0.30 kg) and T4 (H-DDGS 0.37 kg + RPLC 0.15 kg) according to the content of protein source. Dry matter intake (DMI) of TMR and average weight showed no significant difference between treatments. The milk production of T1, T2 and T4 were significantly higher than T3 treatment (p < 0.05), and milk/DMI efficiency tend to increase in the T1. Milk components showed no significant difference between treatments, however, the milk protein of T2 increased to 0.15% than T1. Also blood metabolites showed no significant difference between treatments. But T-CHO level numerically represented a lower trend in the treatments of adding to RPLC compared with T1. This result suggests that the high level (1.1 kg) of H-DDGS is expected to improve the feed utilization without the negative impact on weight gain, feed intake and milk production as the lactation stage of dairy cows proceeds, and 0.15 kg of RPLC under the same feeding conditions of H-DDGS may be useful on fat metabolism.

Key Words

Dairy cow, DDGS, Hydrolysis, Lysine, Choline

강준구 Jun Gu Kang , 이동진 Dong Jin Lee , 김기헌 Ki Heon Kim , 오길종 Gil Jong Oh , 이성수 Sung Su Rhee

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Abstract

this study, the feasibility of the biogas production by anaerobic digestion with agricultural byproducts, which are stems and leaves of hot pepper or sweet pepper from one of the agricultural villages in South Korea, was investigated. The physico-chemical compositions of the agricultural byproducts of hot and sweet pepper were analyzed and they were found to be favorable with anaerobic digestion. Theoretical methane potentials of the test materials were estimated as 393.1 L CH4/kg VS for hot pepper and 372.6 L CH4/kg VS for sweet pepper. Biochemical methane potentials were analyzed by Biochemical Methane Potential (BMP) test and those of hot pepper and sweet pepper were 107.9 and 193.4 L CH4/kg VS, respectively. Silage was chosen to be long-term storage method for biogasification. Biochemical methane potential of hot pepper was increased by silage storage, while that of sweet pepper was decreased. In the case of silage chopping size, ensiled material with 30 mm size showed higher biochemical methane potential than that with 3 mm size. Most of test materials showed higher biochemical methane potentials with microbial additives containing Bacillus Circulans than that containing Bacillus Subtilis.

Key Words

Agricultural byproduct, Biogas, Anaerobic digestion, Methane potential, Silage

박장우 Jang Woo Park , 박기병 Ki Byung Park , 이준석 Jun Seok Lee , 이은영 Eun Young Lee

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Abstract

This study is about making artificial soil for wall greening using Spent Mushroom substrates (SMS) & Superabsorbent polymer (SAP). and developing new material for wall greening whilst monitoring the physico-chemistry & germination ability of the plant, plant growth and developmental condition of the artificial soil. It was found that the larger the particle size of the superabsorbent polymer the more absorption increased. This showed the plant’s germination rate in soil when Spent Mushroom substrates & Superabsorbent polymer (SAP) were mixed. In the Bermuda grass, the Artificial soil (SMS & SAP 0.5%) showed a 100% germination rate over a period exceeding 7 days compared to Peat-moss that showed a 94% germination rate. In the Kentucky blue grass, however, there was no difference between the Peat-moss and Artificial soil. When general perlite soil was compared with artificial soil in the chicory seed, the Artificial soil showed better results than the general perlite soil in length, leaf volume and fresh-weight. In the plant length, it showed an increase of over 105% (SAP 0.5% or more), 187% (SAP 1% or more). in the leaf volume, an increase of over 123% (SAP 0.5% or more), 145% (SAP 1% or more), in the fresh-weight an increase of over 130% (SAP 0.5% or more), 285% (SAP 1% or more). The artificial soil (SMS & SAP 1%) showed an excellent result in the plant growth and development. Thus, it was found that artificial soil using the SMS & SAP were the only suitable soil materials for wall greening hence suggesting that it could be used for the greening of a blighted area or desert and a variety of agriculture.

Key Words

Spent Mushroom substrates, Superabsorbent polymer, Wall greening, Artificial soil, Compost

정다위 Da Vid Chung , 최효현 Hyo Hyun Choi , 윤철우 Cheol Woo Yoon , 김우일 Woo Il Kim , 전태완 Tae Wan Jeon , 신선경 Sun Kyoung Shin

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Abstract

waste pressure vessel are generated during the collecting and sorting processes of steel scrap. Recently, environmental problems have occurred because of the use of steel scrap that contained contaminants and was not separated properly. And this has also affected the quality of iron products made of steel scrap. Particularly, contaminated soil is highly likely to contain various hazardous substances including heavy metals, which is why proper management standards for contaminated soil are necessary. In this study, concentrations of heavy metals, BTEX, TPH, PAHs, and hazardous materials in contaminated soil were analyzed. It was found that the concentrations of lead and zinc were higher than other heavy metals and iron also showed high concentration. The very high TPH concentration in contaminated soil implies that contaminated soil was polluted by diesel, fuel oil or lubricant. So the comprehensive management regulatory plan and management standard for the hazardous materials are necessary for environmentally-friendly recycling of steel and iron scrap.

Key Words

Steel scrap, Contaminated soil, Heavy metals, PAHs, Recycling

이승욱 Seung Uk Lee , 장용철 Yong Chul Jang , 김보생 Bo Saeng Kim

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Abstract

The development of recycling technology and process of waste electrical and electronic equipment (WEEE), also called electronic waste is becoming a growing interest in the world from the perspective of material recovery and resource conservation. In this study we examined the recycling technology levels of WEEE by both group category and recycling process using expert surveys. Based on the results of the expert surveys conducted, the level of large home appliances was found to be approximately 81.1% (± 6.2% std) when compared with that of the advanced countries, while small home appliances and IT equipment and audio/video equipment were 73.5% (± 6.2% std) and 76.2% (± 6.2% std), respectively. In case of recycling pre-treatment process (e.g., disassembly, size reduction, and separation), the technological levels was found to be approximately 82.2%, while the material recovery process followed by the pretreatment process was estimated to be approximately 68.5%. The results of reliability test for the expert survey showed that the values of coefficient of variation (CV) for the pre-treatment process and material recovery process by group category and recycling process are less than 0.5, which is a guidance limit for the coefficient. Based on the statistical tests (ANOVA and t-test), there is no significant difference of the recycling technological levels among the group category (large home appliances, small home appliances, IT equipment, and audio/video equipment. However, the statistical difference between the pre-treatment process and material recovery process within the group category existed (p-value < 0.05) using t-test. In this study, the results imply that there is still a need for developing a variety of more advanced recycling technologies of WEEE to effectively recover valuable metals and materials from it, especially in the fields of metal recovery and extraction processes.

Key Words

WEEE, E-waste, Recycling, Technology level

강종우 Jong Woo Kang , 전용우 Yong Woo Jeon , 이동훈 Dong Hoom Lee

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Abstract

Inline mixer, mixing device combined mechanical and hydraulic mixing, has been demonstrated many times to be effective in mixing process for coagulation. But most of inline mixer are difficult to utilize in relevant domestic industry since it is a foreign technology. So the development of domestic inline mixer is strongly needed. In this study, we compared mixing characteristics through computational fluid dynamics(CFD) analysis with different shape of impeller for the development of domestic inline mixer. The shape of the flow field by velocity vectors and the concentration distribution of injected coagulant were analyzed for comparison of the results. We chose two shapes of impeller(plate and screw), the CFD analysis for them was conducted to simulate actual field conditions. The screw-shaped impeller showed more well-mixing characteristics than the plate-shaped impeller from the results. On the other hand, short-circuiting flow could occur when the shape of impeller was plate.

Key Words

Inline mixer, Mixing, CFD, Coagulation

유동주 Dong Ju You , 한혜정 Hye Jeong Han , 김동수 Dong Su Kim

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Abstract

The effect of temperature on the removal process of Cr(VI) ion contained in wastewater by a precipitation method has been investigated for the improvement of its design and operation. The distribution diagram of chromium ion was constructed by employing the MINTEQ program and the quantitative feature of Cr(VI) depending on pH was investigated. As the temperature increases, the relative amount of H2CrO4 was examined to be raised and the pH range in which H2CrO4 exists as a stable form was also investigated to be extended according to the temperature. Cr(VI) ion was shown to be changed from HCrO4 ? to Cr2O7 2? as the concentration of Cr(VI) ion is increased in the neutral pH condition and the concentration of Cr(VI) ion which is necessary for the ionic transformation was observed to rise in the acidic and alkaline conditions. The major reactant which involved in the reduction reaction for the removal of Cr(VI) ion was examined to be HCrO4 ? and the reduction of Cr(VI) ion to Cr(III) ion was investigated to be influenced much by the temperature change at higher pH conditions. The reduction reaction of Cr(VI) ion for its removal as a precipitate was examined to be promoted as the temperature decreases and pH is lowered. In addition, the stable region of Cr(OH)3 was shown to be enlarged with temperature based on the thermodynamic estimation and it was thought to be necessary to design and control the precipitating process of Cr(VI) ion by considering the thermal characteristics of reduction and precipitation stage.

Key Words

Chromium ion, Reduction, Precipitation, Temperature, Thermodynamic calculation

최수철 Su Cheol Choi , 이우근 Woo Keun Lee

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Abstract

In the previous result, the flexural strength of geopolymer prepared was affected by the evaporation of water content or the shrinkage rate in the curing process of specimen. We investigated the effect of SiO2/H2O ratio on the physical property of geopolymer prepared in this research. The specimen of geopolymer tile was made from mine tailing and melting slag. The maximum flexural strength was obtained at SiO2/H2O ratio of 0.21 under our experimental condition. And the lowest was obtained at SiO2/H2O 0.41. EDS analysis was acted to elucidate this cause. According to the results, it was due to the extent of geopolymerization at the inside and outside of specimen.

Key Words

Geopolymer, Mine tailing, Melting slag, Alkali activator, Flexural strength

조재범 Jae Beom Cho , 장훈 Hoon Jang , 손무정 Moo Jeong Sohn , 김민길 Min Gil Kim , 김상중 Sang Jung Kim , 한승철 Seung Chul Han

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Abstract

This study was performed to evaluate the removal feasibility of nitrogeneous malodor compounds using AlPO4 zeolite manufactured by total phosphorus sludge (herein after TPS), which was produced from sewage treatment plant. Adsorbents in this study were activated carbon treated by H3PO4 (herein after AC), bead (herein after B-TPS) and pellet type adsorbents (herein after P-TPS) manufactured from total phosphorus sludge which was generated from sewage treatment plant. The breakthrough time of AC for ammonia gas (herein after NH3) removal was approximately 320 min, while those of BTPS and P-TPS were 1,140 min and 820 min, respectively. For trimethylamine (herein after TMA) removal, the breakthrough time of AC was 400 min, B-TPS and P-TPS were 1,180min and 1,100 min, respectively. From the results, it judged that adsorbents produced by TPS could be used to replace AC.

Key Words

Total phosphorus sludge, Activated carbon, Ammonia, Trimethylamine

이동항 Dong Hang Lee , 황철비 Chul Bee Hwang , 이관호 Kwan Ho Lee

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Abstract

In this study, the prefabricated lightweight plastic foundation which was made of recycled plastic for sewage pipeline was developed and PE triple flexible pipe was used to evaluate the fundamental characteristics of foundation for sewage pipeline. Two types of prefabricated plastic foundations were adopted. The basic properties of each plastic material were evaluated, such as density, elastic modulus, unconfined compressive strength, and bending stress. The allowable load at 5% of pipe deformation was 1.49 ton for 100% new plastics foundation, and 1.35 ton for composite plastic foundation. The use of fabricated lightweight plastic foundation shows 100% of higher load support than without foundation.

Key Words

Deformation, PE triple flexible pipe, Prefabricated lightweight plastic foundation, Recycled plastic, Strength

정봉진 Bong Jin Jung

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Abstract

This study described characteristics of product gases emitted during high temperature pyrolysis of sewage sludge in the temperature range of 800 ~ 1,200oC for determining the possibility of energy recovery as one of the sewage sludge treatment methods. Char yield of each sewage sludge decreased with increasing reaction temperature until 1,000oC during pyrolysis experiment, but above 1,000oC it is nearly constant due to the total release of volatile matter contained in samples. Major gas components emitted from high temperature pyrolysis experiment of sewage sludges are CO2, H2, CO, and CH4. These major combustible gases except CO2 can be used as major energy source. Also major sulfur-containing gases known as the pollutant gas emitted during high temperature pyrolysis experiments are H2S, COS, and CS2. The principal sulfur gaseous product is H2S and concentrations of H2S and CS2 increases with increasing temperature, but in the case of COS its concentration is nearly constant with variation of temperature. So efficient treatment of sulfurcontaining gases emitted from thermal treatment of sewage sludge should be needed.

Key Words

Sewage sludge, Pyrolysis, Hydrocarbon Gas, Sulfur-containing gas

김경 Kyung Kim , 박진규 Jin Kyu Park , 윤석표 Seok Pyo Yoon , 이남훈 Nam Hoon Lee

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Abstract

In order to accelerate the biodegradation of easily organic materials in landfilled waste before excavating a closed solid waste landfill and prevent to be dried the landfilled wastes at the same time, this study has suggested the Dual Step Biostabilization System (DSBS), which could inject air with dry fog into its body. In addition, the applicability of the DSBS was estimated by means of field test at a closed landfill. As a result of field test, the reduction of oxygen consumption rate for landfilled wastes (48%) stabilized by air with dry fog was higher than that of landfilled wastes (38%) stabilized by only air. Three lysimeter experiments were, also, performed for the landfilled wastes sampled from the closed landfill. The production of cumulative carbon dioxide for landfilled wastes stabilized by air with dry fog was estimated to be highest (1,144.8 mL). In case of lysimeter that moisture was not introduced was found to be 1,051.9 mL, while another lysimeter that moisture was introduced through horizental trenches was 1,095.8 mL. It is clear that the DSBS can accelerate the biodegradation of organic compounds. In terms of volatile solids, the reduction amount of volatile solids for air with dry fog was higher than that of the other conditions.

Key Words

Solid waste, Sustainable landfill, Pre-Stabilization, Dual Step Bio-stabilization System Dry fog

전관수 Kwan Soo Jun

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Abstract

Food waste, food leachate and livestock wastes from an usual farm and a farm using much disinfectant were mixed to incubate within anaerobic serum bottle for BMP test. The methane yield rate and lag phase were determined by the modified Gompertz model and the Logistic model. The maximum methane yield rates by the modified Gompertz model were 15.9 ~ 41.0 mL CH4/g VS and higher than by the Logistic model. The modified Gompertz model was more appropriate than the Logistic model to have higher determination coefficient R2. The methane fermentation of mix with sole livestock waste from the farm using much disinfectant had ninefold lag phase and 40% or lower maximum yield rate comparing with the mix with sole usual livestock waste. The methane yield rate from a tonne of mix was increased as the ratio of food waste and food leachate increased. The cumulative methane yield was in the proportion of 40 m3 to a tonne of food wastes. The results of BMP test were analyzed by a response surface methodology (RSM) and modelized to a binomial expression, which was verified by analysis of variance (ANOVA) and to be appropriate for this case.

Key Words

Co-digestion, Food waste, Livestock waste, Disinfectant, BMP test