• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.2
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• pp.280-286
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• 2020

Cards made from PVC and PET materials do not oxidize or decompose readily, so they are generally incinerated or landfilled after use and cause pollution problems, such as environmental hormones and combustion gases during incineration. In addition, there is a problem of environmental pollution because they are discarded as semi-permanent refuse without being decomposed at landfill. This study attempted to solve this problem using polylactic acid (PLA), which is a representative biodegradable material as a substitute material that can solve the issues with these cards. On the other hand, when the thin card core sheet is made from only PLA material, the physical properties of the material are insufficient, such as the low temperature impact strength, high temperature stability, and poor bending properties, so its use is limited. To solve this problem, the compositional ratio of PLA was reviewed, and the optimal biodegradable compound composition was determined through an examination of the compositions, such as crystallization nucleating agents, additives, and nano compound technology. The high functionalization as a biodegradable card was verified through a laminating process using annealing technology.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.12
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• pp.1327-1331
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• 2005

This study was to investigate the reduction of hydration heat by utilizing industrial by-products such as BFS(Blast Furnace Slag). DM(Dredged Mud) was used by parent soil and Ordinary portland cement was used by cementing material. Additive added to reduce the heat of hydration was BFS. From the results of experiment, hydration heat was decreased in accordance with the addition of BFS. The reason was that surface of BFS coated with aluminosulfate. Initial uniaxial strength was low, neither was not long term uniaxial strength. It was concluded that silica rich layer($H_2SiO_4^{4-}$) in solid phase early in the reaction of hydration was difficultly moved in liquid phase due to the increase of ZP(Zeta Potential). However, the ZP in the later hydration was decreased due to the acceleration of mobility of silica rich layer($H_2SiO_4^{4-}$). Therefore, long term physical properties such as uniaxial strength revealed.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.9
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• pp.933-938
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• 2008

In the present study, carbon dioxide was converted to methane, using bio-hydrogen. Here, the bio-hydrogen was produced from organic waste. The anaerobic microorganism was cultured using only carbon dioxide and hydrogen for duration of 3 months. Therefore methane was not produced with acetogenotrophs. During methane production, carbon dioxide and hydrogen are taken in different ratios; among which 1 : 5 ratio has shown the highest methane yield. Carbon dioxide and hydrogen were introduced into the reactor at the rate of 8 mL/min and 40 mL/min, respectively. In this case, 92% of carbon dioxide was reduced and 2.2 m$^3$/m$^3$ day amount of methane was produced. Thus, the process has been successful in conversion of carbon dioxide into methane by purging it into methane fermentation reactor with bio-hydrogen using batch process.

• Journal of Korean Society for Atmospheric Environment
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• v.23 no.2
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• pp.183-190
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• 2007

In this study, we have investigated waste incinerators which are one of the major HAPs emission sources. In order to obtain more reliable HAPs emission data from waste incinerators, direct sampling for the possible pollutants from the stack was carried out and the analysis was performed. The purpose of study was to understand the emission status from waste incinerators and recognize the problems and finally to set up a strategy to reduce the HAPs emissions from waste incinerators. The emission concentrations of 8 species of heavy metals and 16 species of PAHs have been analyzed for the first time in Korea. Not only the emission characteristics of HAPs from waste incinerators were identified, but also the analysis of reduction efficiencies for control devices such as BF and wet scrubbing systems was carried out.

• Journal of Korean Society for Atmospheric Environment
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• v.33 no.6
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• pp.533-543
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• 2017

As the public interest in environmental issues increased, the "Act On The Integrated Control Of Pollutant-Discharging Facility" was enacted. Through the integrated environmental pollution prevention act in which 19 industries with large environmental impacts are sequentially applied, pollutants can be managed in a medium-integrated manner and integrated permission of the business unit is possible and BAT can be applied to enable a scientific and proactive environmental management system. In order to facilitate the implementation of integrated environmental pollution prevention act with these advantages, the BAT BREF should be published, modified and revised every 5 years considering the level of scientific development. This study reviewed the issues to be considered in applying BAT and the types of BAT and focused on presenting improvements and development direction when revising and supplementing the standards in the future based on these contents. For this purpose, when revising the standards, it will be necessary to reflect on the domestic situation, to expand the TWG(Technical Working Group) of small-scale workplace experts, and to exchange opinions with business places that have similar processes for each waste type through a systematic total inspection. In addition to these methods, by establishing a resident participation system through information disclosure, it is expected to be used as a guideline for environmental management of business places not subject to integrated permission of less than 3 types as well as those subject to integrated permission.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.6
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• pp.609-614
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• 2010

In the present study, bioethanol was produced using batch style reactor from food wastes which has organic characteristics. Pretreatment was required to reduce its particle size and produce fermentable sugar. Two different enzymes such as carbohydrase and gulcoamylase were tested for saccharification of food waste. The efficiency of carbohydrase saccharification (0.63 g/g-TS) has shown higher than glucoamylase saccharification(0.42 g/g-TS). Saccharomyces cerevisiae produced bioethanol via separate hydrolysis & fermentation (SHF) method and simultaneous saccharification fermentation (SSF) method. The production amount of bioethanol was 0.27 g/$L{\cdot}hr$ for SHF and 0.44 g/$L{\cdot}hr$ for SSF.

• Journal of Adhesion and Interface
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• v.6 no.2
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• pp.6-12
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• 2005

The plasma generally, ionized gas state, is the 4th material state composed the universe. Generating the plasma artificially has been studied by spending energy and it has a lot of applications in human's life. There are several merits to modify the surface of polymer using plasma. Above all, plasma maintains the property of polymer because of it changes the property of surface only. Also, it doesn't use a organic solvent and it is the environment friendship because of there are no waste under processing. Furthemore, in case of high-pressure plasma, it is possible that automated-processing continuously. In this study, we tried the reforming of surface to rise the adhesive strength between the material of polymer, experimented the rising of adhesive strength through a experiment of peel strength by virtue of processing time and using gas, confirmed the change of polymer's surface through measuring the surface contact angle analyzer and scanning electron microscopy (SEM).

• Journal of environmental and Sanitary engineering
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• v.8 no.2
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• pp.49-64
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• 1993

The present waste problems require a change of thinking with regard to conventional economics. It has been generally believed that competitive markets maximize social welfare. But, the other hand, a few economists argue that "the competitive markets cannot always be relied on to provide all goods in the efficient amount." One of the best examples of the latter contention is the environmental problem. What is the basic thinking of the conventional economics that causes this problems \ulcorner What is the present problem that requires the change of conventional economic thinking \ulcorner The environmental problem result from the conventional economic thinking such as pursuing the limitless of the Gross National Product(GNP), believing the increasing returns in economics of scale and the efficiency of competitive market. This economic principles, howe- ver, does not apply currently to public goods, especially environmental amenity and natural resource because the price of markets does not reflect the natural goods of services. We call this eternality. Externalizes are no considered by either buyers or sellers of goods of which production or use results in an eternality. This leads to market failure are causes an waste problem in the economic activities. Today, it is almost impossible to say in a word what the solution for waste problems is because they are by-products complicated and entangled human activities. In this paper, I have introduced the causes of environmental problems only from the economic point of view. I have also described the needs of conversion of conventional economic thinking. Firstly, sustainable development, maintaining the natural resources, should be the basis of the economic growth rather that pursuing the limitless growth of GNP. Secondly, an appropriate scale of human's production activity should be taken into account to reduce the impact to the natural environment. Thirdly, internalization of eternality is asked to correct the market failure. This requires the public policy such as imposing a talsubsidy, assigning a property right or implement a more detailed environmental quality standard through, because use of the natural resources can be. allocated optimally by the intervention of government or social associations.

• Journal of Korea Soil Environment Society
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• v.4 no.1
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• pp.85-96
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• 1999

Biofiltration is an attractive technique for elimination of VOCs and odorous compounds from low-concentration, high-volume waste gas streams because of its simplicity and cost-effectiveness. The objective of this study was to estimate the removal characteristics of Odorous Compounds including $H_2$S, $NH_3$End BTEX in MSW landfill gases. This Study was conducted at Nanjido landfill site. A compost from the Nanjido composting facility was used as a filling material for biofiltration. Extracted landfill gases were injected into biofilter reactors after mixing with air. Experiments were performed in an incubator being set to $20^{\circ}C$ $H_2$S concentrations were monitored at the depths of 25, 50, 75 and 100cm from the bottom Of the biofilter reactors. 98% of $H_2$S was removed at the filling depth of only 25cm. NH$_3$removal rate was about 85%. Toluene removal rate was the highest among BTEX. Significant pH drop of a filling material was not observed during the biofilter operation of 1 month. Without mixing the landfill gas stream with all, the removal rate of $H_2$S decreased down to 30%.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 1998.11a
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• pp.86-92
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• 1998

부산 지하수의 오염실태와 그 특성을 파악하기 위하여 1996년과 1997년에 분석된 지하수 수질자료 중에서 pH, TS, KMnO$_4$소비량, Cl, SO$_4$등을 통계분석 하였다. 각 성분의 평균치는 pH가 모두 7.3, TS는 216.0 mg/$\ell$와 242.3 mg/$\ell$, KMnO$_4$소비량은 2.6 mg/$\ell$와 6.3 mg/$\ell$, Cl은 35.7과 50.1mg/$\ell$, SO$_4$는 25.4와 33.9mg/$\ell$이다. 2년 동안 pH의 음용수 기준치 초과 비율은 0.55와 0.47%, TS는 1.89와 2.50%, KMnO$_4$소비량은 0.73과 1.17%, Cl은 1.41과 2.18%, 그리고 SO$_4$는 0.37과 0.86% 이다. 따라서 성분별로 비교해 볼 때, pH의 음용수 기준치 초과비율이 가장 적고, Cl의 초과비율이 가장 크다. Cl 및 SO$_4$이온의 음용수 기준치(각각 100 mg/$\ell$, 200mg/$\ell$) 초과지점과 이 이온들의 평균치보다는 훨씬 큰 100 mg/$\ell$이상되는 지점들의 분포를 분석한 결과, 해안가보다는 내륙에 더 많이 초과지점들이 분포한다. 따라서 부산지하수는 해수에 의한 영향보다는 내륙에서 생활하수나 기타원인(공장폐수, 오염된 하천수, 폐기물 매립 등)에 의한 오염이 훨씬 큰 것으로 보인다. 1996년에 5개 성분의 음용수 기준치 초과비율은 5.06%이고, 1997년의 초과비율은 6.87%로 전년도에 비하여 약간 증가하였다. 그러나 부산이 바다에 접하고 또한 인구과밀 지역임을 고려할 때, 부산의 지하수 수질은 양호한 편이다. 따라서 앞으로 부산 지하수의 보전 및 관리가 적절하게 진행된다면 부산에서 지하수는 시민의 생활용수로서의 역할을 증대해 나갈 수 있을 것이다.