생활폐기물의 배출원별 발생량 및 질적 특성

박종웅,권기홍,박상철,유호원,이학영 경산대학교(대구한의과대학) 1998 環境硏究 Vol.3 No.1

This study aims to investigate generation and physicochemical characteristics of Municipal Solid Wastes(MSW) generated from different sources in Kyungju. The source are apartments(low, high-rise), single family houses(centra1, outer), traditional market, office(city hall), factory, school, Park. The unit waste discharge rate of residential MSW excluding recyclable solid wastes was 0.47 kg/(capita . day). The maximum coefficients of variation for month and season were 1.23, 1.17, respectively. The bulk density of solid wastes was largely different for each sampling site, and the bulk densities of apartment district, single family house district and public area were 232㎏/m, 247kg/m, 170kg/m, respectively. The load factory of vehicle was 457kg/m. The percentage of combustible material to solid wastes was 86.5%. The physical compositions of solid wastes were food of 36.2%, Paper of 32.3%, plastic of 11.9%, glass of 6.5%, metal of 4.6%, textile of 3.0%, rubber of 1.8% and wood of 1.3%. The proximate analysis results of solid wastes showed moisture of 45.7%, volatile solids of 45.2%, and ash of 9.1%. In case of moisture content, the maximum value showed 66.7% in high-rise apartment district and the minimum value 14.0% in school district. Carbon, hydrogen, oxygen, nitrogen, sulfur and chlorine contents of combustible solid wastes were 48.4%, 7.0%, 25.9%, 1.3%, 0.2% and 0.4%, respectively. The low heating values of combustible solid wastes were 1,365 ~ 2,896kca1/kg (average 1,892kca1/kg) in residential area and 1,200∼3,878kca1/kg (average 2,178kca1/kg) in public area. Especially, the generation rate and the moisture content of residential MSW separating food wastes decreased 2.7 and 1.7 times and the low heating increased 2.1 times in apartment district.

Improvement Strategy of Medical Waste Management System

김석완 경산대학교(대구한의과대학) 1999 環境硏究 Vol.4 No.1

Medical waste has been regulated legally by "Isolated and related medical waste treatment rule" enacted in 1981. Recently, quantity of the medical waste has been increased according to the expansion of medical facilities caused by rise in living standard and usage of non-recyclable medical instruments. The management of medical waste still is not well established because of insufficient recognition in hospital, small scale of medical waste treatment industry and deficiency of treatment facilities, In this study, an improvement strategy of medical waste management system in Seoul city was established by considering present collection system and introducing the possibility of exclusive medical waste incinerator. For doing this, EPA's WRAP program was used to obtain an optimum solution that can minimize cost of the collection and the treatment of medical wastes. Therefore new collection system was proposed to minimize collection distance, costs and the risk of secondary infection. This study also proposed an optimal site and needed capacity for exclusive medical waste incinerator and the market opportunity of exclusive medical waste incineration enterprise.

A study on the Fractionation of Dissolved Organic Carbon in Lake and River Waters

Lee, Shun-Hwa,Kim, Yong-Hwan,Park, Jong-Woong 경산대학교(대구한의과대학) 1999 環境硏究 Vol.4 No.1

Dissolved organic carbon(DOC) in Lake Kasumigaura, its inflowing rivers and several DOC sources in its catchment area was fractionated using three resin adsorbents into classes : aquatic humic substances (AHS=humic acid+fulvic acid), hydrophobic neutrals (HoN), hydrophilic acids(HiA), bases(BaS) and hydrophilic neutrals(HiN). The DOC fractionation produced interesting fraction distributions that were significantly different depending on the origin of sample. AHS and HiA prevailed over AHS in the lake while AHS and HiA existed at almost the same level in the rivers. AHS seems to be a more important component in river water than lake water. The dominance of organic acids was also observed for the waters of the DOC sources : forest stream(FS), Plowed field percolate(PFP), paddy field outflow(PFO), domestic sewage(DS) and sewage treatment plant effluent(STPE). However, the DOC fraction distributions reulted in more different distribution patterns. AHS dominated FS and PFP. HiA dominated PFO, DS and STPE. Only DS contained a significant amount of HoN, which may be due to the presence of LAS-like DOC. The ultraviolet absorbance over D0C(UV:D0C) ratio was found to a useful indicator for reflecting the characteristics of DOC, AHS and HiA and the origin of sample. The UV:D0C ratio in both lake and river waters was in the order of AHS, DOC, HiA. The lake water exhibited the lower ratios in DOC, AHS and HiA than the river waters did. Autochthonous DOC and AHS, which have been reported to have a lower UV:D0C ratio, may contribute significantly those in the lake. For AHS dominated FS and PFP, the ratio was in the order of DOC, AHS, HiA and DOC, HiA, AHS, respectively. PFO had the greatest UV:D0C ratio of AHS among the samples studied, indicating that the paddy field added up more pedogenic AHS to its overlaying water. For DS, the UV:D0C ratios of DOC, AHS and HiA were the lowest among fhe sanmles. Its AHS showed an UV:D0C ratio even less than those of HiA in all the other sarmp1es.

호수저질의 영양염 용출에 관한 실내실험적 연구

김용환 경산대학교(대구한의과대학) 1998 環境硏究 Vol.3 No.1

인공호수내에 있어서 영양염의 변화에 미치는 영향을 고찰하기 위하여 저질에서의 영양염의 용출영향을 보면, 수온에 따른 저질에서의 영양염 용출실험의 결과, 혐기성 상태에서 영양염 용출은 10℃, 20℃, 30℃로 변화시켰을 때, 각각 TIN은 2.70, 3.31, 3.78g/㎡/d로 용출되었고, T-P의 용출량은 0.61, 0.74, 0.76 g/㎡/d였으며, 수온이 높을수록 용출량이 높게 나타나 온도의 의존성이 있다고 판단된다. pH에 따른 저질에서의 영양염 용출실험을 한 결과, 혐기성 상태조건에서 PO₄-P의 용출은 pH가 높을수록 비례적으로 용출량이 많았으나 TIN의 경우는 pH의 의존성이 인의 경우보다 낮게 나타났다. DO에 따른 용출량 변화는, 호기계에서 보다 혐기계인 상태에서 용출이 많이 일어나고 있으며, 호기계에서 용출이 적은 이유는 DO가 저층에 있는 저질에서의 영양염 용출이 일어나는 것을 억제했기 때문이이라고 판단된다. In generally, nutrient release experimental method practiced in Artificial lake sediment was used to laboratory core method. Results show that TIN release rates were 2.70. 3.31, 3.78 g/㎡/d, and those of T-P were 0.61, 0.74, 0.76 g/㎡/d at the 10℃, 20℃, 30℃. respectively, indicating the effects of temperature on nutrient release in the sediments, It can also be shown from the experimental result that the release rate PO₄-P increases with increasing pH while that of TIN is not so much affected by the pH, and the nutrient release is more active in anaerobic condition than in aerobic condition indicating that DO suppresses the nutrient release in the lake sediments.

발생원별 산업폐기물의 물리화학적 특성

권기홍 경산대학교(대구한의과대학) 1998 環境硏究 Vol.3 No.1

This study was carried out to evaluate the quantity of industrial waste generated in Korea and the physico-chemical characteristics with generative dewatered sludges at wastewater treatment process of 6 different industry types. Sludge generation rate according to the industrial types was 2,148ton/yrear at chemical plant industry, 720ton/year at textile industry, 588ton/year at coke· petroleum industry and 480ton/year at 1st metal industry, respectively. Moisture of sudges were 81.5% in textile industry, 81.4% in frame metal industry, 80.7% in 1st metal industry, Volatile solid were 22.1% in hide · rubber industry, 21.9% in coke·petroleum industry. Fixed solid were 18.5% and 17.7% in the 1st metal industry and frame metal industry. High heating value by wet base were 1,850kca1/kg-wet waste in coke·petroleum industry, 1,220 kcal/kg-wet waste in hide·rubber industry, but the 1st metal industry and frame metal industry's sludge were impossible to incinerate because it was mostly inorganic sludge. In comparison with the Korean extraction limit, some of discharged sludge at hide·rubber. chemical, frame metal industry exceeded the limit and was classified as the specific waste. And in other industries it was lower than the limit.

역삼투압공정을 이용한 방류수 재활용 시스템 연구

김동일 경산대학교(대구한의과대학) 1998 環境硏究 Vol.3 No.1

In case of industrial wastewater, it has various pollutions, high concentration and different physical, chemical properties each other in accordance with classification of wastewater. Therefor, after inquiring into the influence on the membrane of the dissolved pollutants, the reverse osmosis process should select the membrane of best efficient quality. As results of experiments on pilot plant test, optimum operating pressure for fouling removal was 34∼36 Bar, the efficiency of recovery ratio was 75 %. One of the main goals in current research is to develop better membrane that can operate at low pressure(around 17~20bar) and still yield relatively high product rates of the order of recovery ratio 75%. Once these difficulties are overcome, R/O could become a process of widespread application in the field of wastewater treatment.

海洋 動植物 中 有機鹽素系 農藥의 殘留分析

김정호,문영수 경산대학교(대구한의과대학) 1999 環境硏究 Vol.4 No.1

To obtain the residual pesticides in the coastal environment, analysis of residual organochlorine pesticides in the plant and animals on the ocean environment are surveyed. The plate height(H) on the GC-ECD is 5.16 of daconil, 5.35 of kelthane and 1.36 of orthocide. The number of theoretica] plates(N) for daconil, kelthane and orthocide is 484, 467 and 1830, respectively. Ihe resolution of daconil and kelthane is 1.658, which separate on the base line. The resolution of kelthane and orthocide is 0.688, which not separate on the base line. The detection limit on the GC-ECD is 0.55pg of daconil, 2.32pg of kelthane and 0.96pg of orthodde. The qualified defection concentration of daconil, kelthane and orthodde in the plant and animal is 0.020ng/g, 0.092ng/g and 0.036ng/g, respectively. Daconil, kelthane and orthocide of pesticides used in the fann on the Cheju Island are not detected seaweed cava(Eck1onia Cava), Agar(Ge1idium amansii), turban sell(Batillus cornutus) and sea urchin(Anthocidaris crassispina).

혼합폐플라스틱의 열분해반응 모델 개발

김석완 경산대학교(대구한의과대학) 1998 環境硏究 Vol.3 No.1

Reaction kinetics at various temperatures for the pyrolysis of mixed plastic waste including polyethylene(PE) and polystyrene(PS) were modeled in terms of five types of overall pyrolysis reaction. The model development was based on the assumption that as plastic wastes were heated in a non-reactive environment, they were decomposed homogeneously to various products of gas, oil and char by a first-order rate, irreversible reaction, and isothermal condition. Among the five models, the type Ⅱ model in which the activated polymer exists as an intermediate product was the most accurate one in predicting the pyrolysis products of pure PE and pure PS. And also, for mixtures of plastics both type Ⅱ and Ⅳ models can be used to explain the composition of pyrolysis and the products. Futhermore, from the analysis of variance(ANOVA), the mixing ratio and the temperature were shown to be the parameters that have the greatest effect on the pyrolysis reaction of plastic waste mixture.

혐기성 매립조와 준호기성 매립에서 도시폐기물의 생분해 특성에 관한 비교 연구

송종민,박종웅 경산대학교(대구한의과대학) 1999 環境硏究 Vol.4 No.1

The objective of this study is to compare the biodegradable characteristics of municipal solid waste in the anaerobic and semiaerotac column. The experimental investigations were to conduct such tests as leachate, gas production and composition, and stabilization during 70 weeks. The initial concentration ranges of BOD and COD in anaerobic column were decreased from 57,000∼64,000㎎/ℓ, 80,000∼87,000mg/ℓ to 6,100㎎/ℓ, 8,100㎎/ℓand those in semiaerobic column were decreased from 7,800∼15,400㎎/ℓ, 11,400∼16,200㎎/ℓto 22.0㎎/ℓ, 300㎎/ℓ. The concentadon ranges of T-N, NH4+-N, and T-P in anaeobic column were decreased from 2,000∼2.400㎎/ℓ, 1,500∼1,800㎎/ℓ, 250∼300㎎/ℓ to 225㎎/ℓ, 185㎎/ℓ, 70㎎/ℓand those in semiaerobic column were decreased from 1,100∼1,400㎎/ℓ, 1,000 -l3OO㎎/ℓ, 11.1~28.8㎎/ℓto 220㎎/ℓ, 16㎎/ℓ, 3.2㎎/ℓ. The leaching amounts of BOD, COD, T-N, and T-P in anaerobic column were shown 22, 11, 1.4, 9.7 times larger than those in semiaerobic column, respectively. The settlement rate and decreasing weight, as stabilization and biodegradation index of solid waste in semiaerobic column, were shown 2 times more remarkable difference than those values in anaerobic column. Based on BOD, the decay coefficient of organic matter in seniaerotac column was shown 3.2 times more rapid than those in anaerobic column. Gas production in anaerobic column was rapidly increased after 28 weeks, the characteristics consisted of H₂, CO₂, N₂, CH₄and the components of gas were 0.24%, 27.5%, 36.8% and 22.1%, respecctively. Gas production rate constant k(week-¹) calculated from equation(3) was 2.4xl0-⁴ and carbon conversion rate was 2.3%.

하수처리의 문제점과 연속접촉회분식 반응조를 이용한 고도처리

신항식,남세용,이상형 경산대학교(대구한의과대학) 1999 環境硏究 Vol.4 No.1

The volume of sewage increases as the population grows and the standard of living rises, and also varies in direct proportion to the volume of available water supply. Present1y(at the end of 1998), the sewage treatment ratio is 60%, and 85 facilities are woiking for sewage treatment While sewage treatment plant has been constructed in large cities and heavily industrialized cities, the most treatment plant employ one type of process, i.e. activated sludge process, which may not be desirable for some cities in economical point of view and also in terms of process optimization. Moreover, poor sewer systems resulted in lower strength influet than the designed strength. In this study, to develop a proper process for treating low strength sewage several existing sewage treatment plants were diagnosed. A continuously contacted sequencing batch reactor composed of pre-anoxic contact zone and intermittently aerated zone was operated for biological nitrogen removal. The removal efficiencies of organic matter (SCOD) and total nitrogen (T-N) were 89% and about 60% at the TCOD/T-N ratio as low as 6.0, respectively.