중학교 환경교욱을 위한 멀티미디어 CAI 프로그램의 개발

이정자,정장표,이승훈 慶星大學校 環境問題硏究所 2001 環境硏報 Vol.11 No.1

The purpose of this study was to develop multimedia CAI program for enhancing environmental education for middle school students. In developing the program, the related literature study and new multimedia technology analysis were carried out to establish development directions and design strategies. Authorware 5.0 for Windows from Macromedia Co. was used to develop the program as hypermedia, which is composed of various kinds of multimedia such as images, videos, etc. The final product was to be disseminated in the form CD-ROM title. This program will have important role in enhancing environmental education as follows, 1) The program is the most updated multimedia tool for environmental education of middle school based on the contents and purpose of the 7th educational course. 2) This program consists of four divisions including various images and videos and it is attractive to learners by exploring the virtual scenarios. 3) Based on situated learning, the students have to retrieve and analyze the information storage while solving the environmental pollution problems. 4) Though the activities of environmental preservations, the students obtain the appropriate attitude toward the environmental preservation.

해양매립에서 준설토 매립시 환경오염 영향 및 대책연구

엄태규, 윤종태 경성대학교 환경문제연구소 2000 環境硏報 Vol.10 No.1

The main findings through this study are summarized as conclusion below ; When dredge soil (ill to sea area, suspended soil widely spread from main area to north of ga-duk island without the pollutant's fence, Especially, the total area of ung-dong bay is more than 20㎎/ℓ as SS concentration and the pollution of north of gaduk Island is considerable. Therefore dredge was needed the pollutant's fence, Consequently the only that main area is more than 20㎎/ℓ as SS concentration, decreasing of pollution is explicitly acknowledged on the ocean because the others except for dredged area is less than 2∼8㎎/ℓ as SS concentration with the pollutant's fence. It is only considered SS concentration of dredge soil, because concentration of BOD, TN and TP were very lower than not concentration. Heavy metal concentration of the dredge soil is lower than not only the standard of heavy metal in the sea-water but heavy metal concentration including sediments with dredged area. It is decided that the polluted surrounding area has been little by heavy metal.

정수 슬러지의 처분방식별 비용에 관한 비교연구

이재복,임성진 慶星大學校 環境問題硏究所 2002 環境硏報 Vol.12 No.1

The objective of this study is to investigate the cost for disposal alternatives of waterworks sludge. Current disposal systems such as landfill, ocean dumping and incineration were compared with the sludge reuse through modification from economical point of view. When the cost spent in producing cover soil using waterworks sludge mixed with hydrated lime as a main material was assessed for Busan Metropolitan City area, the disposal cost was estimated to about 20,128 won per ton of waterworks sludge, which had more economical advantages than any other disposal methods. Environmental and economical benefits of sludge modification will include decrease of disposal cost, procurement of cover soils and reduction of landfill area.

순환유동식 건식세정기에서의 HCl제거에 관한 실험적 고찰

황상규,정장표,이상권 慶星大學校 環境問題硏究所 1999 環境硏報 Vol.9 No.1

Dry scrubbing has drawbacks of low removal efficiency and generation of much exhausted sorbents, but one the other hand dry scrubbing has merits of simple equipment, composition and cost-effectiveness. Also Dry scrubbing has received considerable attention since exhausted sorbents can be stably disposed and reused. This presentation addresses experimental results from a established circulating fluidized bed scrubber for HCl removal with using lime(Ca(OH)₂) prior to developing a circulating fludized bed scrubber for simultaneous removal of SOx/NOx/HCl. Injected lime through screw feeder was fluidized in the reactor and intensely reacted with HCl at 2.5 m/s velocity. Experimental results show HCl removal efficiency greater than 90% at 0.7 of Ca/Cl removal efficiency.

공동주택 주방공간을 대상으로 한 실내공기오염실태와 개선에 관한 연구

최지희,이민아 慶星大學校 環境問題硏究所 2002 環境硏報 Vol.12 No.1

The purpose of this paper is to examine the situation of Indoor Air Quality environment as to the kitchen in the group housing, and to present appropriate improvement device in the kitchen indoor air ventilation through the survey, measurement methods. The conclusions are as follows; (1) Especially, the contaminated air situation of the kitchen area spreads wide in open plan between living and kitchen by the characters of architectural plan type and occupant's behavior habits. Therefore, we need to control IAQ, and should renew range hood system for active ventilation importation.(2) The using condition of gas-range, ventilation hood, the number of smokers, the various behavior of occupant's influence IAQ level, for example, the consistency of CO2exceeds a permitted limit by the gas-range using over 5 minutes.(3) Dust and CO2 exceed closely the allowable value level of the contamination, so, this paper claims to establish the permission limit related with the using of gas-range, the appropriates frequency of ventilation and the smoking in the group housing. (4) This paper indicates several points about the improvement of the current range-hood system. The important problem is the noise, so the diminution of the range-hood system noise needs to improve this part urgently. The second problem is the filter change and the cleaning of range-hood system without difficulty for ventilation route if this system actively air-supply and air-evacuation with synchronously.

연속추출법에 의한 폐광산 지역의 중금속 오염토양의 용출 가능성 평가

신현무 慶星大學校 環境問題硏究所 1999 環境硏報 Vol.9 No.1

Soils were sampled from two abandoned metal mines and analyzed by Korea Soil Analytical Method(KSAM) and the sequential extraction procedure(SEP). In order to evaluate the potential leaching possibility, the results obtained by two kinds of analytical methods were compared. Almost heavy metal concentrations analyzed by KSAM were much higher than summed fractions of water soluble and exchangeable, which was extremely low and useable fraction by plants. It indicated that those fractions were leached for a long time by soil weathering processes. Thus, almost residual fractions after weathering processes were composed of organic bound, carbonate bound, sulfide bound, and crystal form and not readily dissolved by rain water. The total concentrations of each fraction by SEP were higher than those of KSAM, which demonstrated that analysis by KSAM could overestimate the potential leaching fraction.

시멘트페이스트의 自己收縮에 관한 연구

현철 慶星大學校 環境問題硏究所 1998 環境硏報 Vol.8 No.1

Autogenous shrinkage of concrete has been defined as decrease in volume duv to hydration of cement, not due to other causes such as evaporation, temperature change and external load and soon. For ordinary concretes, autogenous shrinkage is so little compared to the other deformations that it has been dignored. It has recently been proved, however, that autogenous shrinkage considerably increase with decrease in water to cement ratio. And it has been reported that cracking can be caused by autogenous shrinkage, when high-strength concretes were used. In this study, we propose an anlytical system to represent autogenous shrinkage in cement paste in order to control crack due to autogenous shrinkage. The system is composed with the hydration model and pore structure model. Contrary to the usual assumption of uniform properties in the hydration progress, the hydration medel to refine Tomosawa's represents the situation that inner and outer products are made in cement paste. As such, this tool can be used to study the effect of curing condition, mix-proportions etc. on early age development and related progblems. The pore structure model is based upon the physical phenomenon of ion diffusion in cement paste and chemical phenomenon of hydration in cement particle. The proposed model can predict the pore volume ratio and the pore structure in cement paste under variable enviromental conditions satisfactorily. The autogenous shrinkage prdiction system with regard to pore structure development and hydration at early ages for different mix-proportions shows a reasonable agreement with the experimental data.

SOLID-LIQUID SEPARATION PROPERTIES OF ACTIVATED SLUDGES

Kwon, Il,Lee, Jae-Bok 慶星大學校 環境問題硏究所 1999 環境硏報 Vol.9 No.1

하수처리장에서 발생하는 슬러지의 효율적인 처리를 위하여 슬러지의 고액분리 측성에 관한 해석이 필요하다. 하수처리장의 활성 슬러지에 대하여 고형물 농도의 범위가 800㎎/ℓ에서 2,100㎎/ℓ로 변화할 때 침전속도는 최대변화량으로서 1.4m/hr의 차이를 나타내었다. 활성 슬러지의 침전에 대하여 상기의 고형물 농도범위는 천이구간에 해당하는 것으로 판단되었다. 회분식 침전실험의 결과에 대하여 지수형 침전모형식을 결정하였다. 슬러지의 침전특성을 평가하기 위하여 침전속도와 슬러지 체적지수의 살관관계를 조사하였다. 하수처리장의 침전조에서 고형물 농도에 따라 고형물 플럭스는 큰 폴의 변화를 나타내었다. The distribution of seddimentation velocities showed the maximum difference as musch as 1.4m/hr where solid concentration was ranging from about 800㎎/ℓto 2,100㎎/ℓ. This range was regarded as a transition zone. Through the application of sedimentation models to the data obtained in batch sedimentation test, an exponential model was determined. In order to examine the sedimentaion characteristics of sludge, the relationship between the sedimentation velocity and sludge volume index was studied. The solids flux would make large variation according to MLSS in sedimentation basin.

전해식 폐수처리 시스템의 전극오염 제어에 관한 연구

이재복,정종식 慶星大學校 環境問題硏究所 2001 環境硏報 Vol.11 No.1

The objective of this study is to control of electrode fouling in the electrolytic wastewater treatment systems. In this study, scales mass, CODcr removal efficiency, current efficiency and specific energy consumption were investigated. Auxiliary electrode was adopted during the continuous electrochemical oxidation process of pigment wastewater for removal of attached scales in cathode electrode. In the auxiliary electrode application study, the mass of attached scales in cathode was increased according to the operation time. Attached scales negatively affected on CODcr removal efficiency and current efficiency. The result of continuous electrolytic wastewater treatment with auxiliary electrode showed a complete removal of scales. The CODcr removal efficiency, current efficiency, and specific energy consumption were maintained normally during the continuous operation.

SBR에 있어서 메디아 충진율변화에 따른 질소제거특성에 관한 연구

엄태규,한동엽,손양주 慶星大學校 環境問題硏究所 2002 環境硏報 Vol.12 No.1

Because of its high construction cost of canalization, large municipal wastewater treatment plants, which usually planted and constructed in urban city in korea, is not proper for small town and village especially with low population density. In this study as treatment plant for the small town, a SBR (Sequencing Batch Reactor) using media was selected and operated to remove organic pollutants and nutrients such as nitrogen and phosphorus which can cause eutrofication in lakes and rivers. Laboratory batch experiments were conducted, at 25±2℃, to investigate ways of optimizing the packing ratio of SBR using media. During the experiment period, packing ratio is variated from 5 to 20%. The removal of TCOD about each packing ratio were greater than 90%. Nitrification percentage and rate of Mode 1, 2, 3, 4 were 56, 67, 75, 77% and 1.9, 1.6, 1.3, 1.71 mgNH_4^+ -N/gMLSS/hr. It is to not matter with packing ratio. Denitrification of Mode 1, 2, 3 and 4 were 50, 50, 64 and 75%, denitrification is increased according to increasing packing ratio. Denitrification rate of Mode 1, 2, 3 and 4 were 1.3, 1.0, 1.11 and 1.88 mgNO_3^- -N/gMLSS/hr.