손동헌 , 조경열 , 김귀자 Dong Hun Sohn , Kyung Yol Cho , Gui Ja Kim

DOI: Vol.3(No.1) 1001-1006, 1987

From 17 tap water sampling points throughout the metropolitan Seoul supplied from paldang, Gueui, Bokwang, Noryang jin and Dukdo water treatment plant, using Han river as water source, trihalomethane concentration were measured 3 times during July, August, and September, 1984. Total trihalomethane were high in tap water samples from Noryang jin and Dukdo water treatment plant and low from Gueui water treatment plant. Average trihalomethane concentrations were 32.2㎍/ℓ, 19.1㎍/ℓand 9.8㎍/ℓfor July, August, and September respectively, and by comparing with the trihalomethane concentrations of August and September, that of July was obviously high. It is noted that average CHCl₂Br concentration of tap water supplied from Noryang jin water treatment plant in July was 12.9 ㎍/ℓ which were attained to about twice of total average concentration of 6.5㎍/ℓ.

고순순 , 송준상 Soon Soon Kho , Jun Sang Song

DOI: Vol.3(No.1) 1007-1016, 1987

Cresol has been used as a disinfectant. But this chemical is not only toxic to the biota, but recalcitrant environmental pollutant. This study was carried out to examine the o-cresol biodegradation by isolated strains in nature. The following results were obtained. From twenty samples, 4 strains were isolated. One of the strains, was identified as Acinetobacter sp., the rest were identified as Pseudomonas sp. Each strain showed very different diversity in the substrate utility, as a sole carbon and energy source. Substrates were all 44 kinds including carbohydrates, amino acids, alcohols and other aromatic compounds. In the measurement of respiration rate by each strain, strain No. III was an excellent degrader in respiration rate as 344ng O₂/g·biomass·hr. In the test of biodegradation activity, strain No. III degraded o-cresol-1500 ㎎/ℓ of 92 percent for 84 hr.

이형진 , 이홍근 Hyung Jin Lee , Hong Keun Lee

DOI: Vol.3(No.1) 1017-1029, 1987

Simplified phosphorus budget models are used to be effective tools in planning water quality management in the lake or reservoir. This study was carried out for the purpose of testing fitness of simple phosphorus budget models and evaluating trophic state for Dae Cheong Reservoir. The morphometry of the reservoir, such as mean depth (Z), flushing rate (ρ), hydraulic residence time (Tw), and areal water loading (ｑs), and the total phosphorus budgets were in-vestigatea in this study from April to November 1986. It was analyzed that Vollenweider model and Kirchner/Dillon model closely ?? to Dae Cheong Reservoir among the various Vollenweider types, and the trophic state level of Dae Cheong Reservoir was eutrophic.

오영숙 , 김상종 Young Sook Oh , Sang Jong Kim

DOI: Vol.3(No.1) 1030-1039, 1987

A total of 96 strains of petroleum-degrading bacteria isolated from the Nakdong River Estuary by liquid-enrichment method. isolated strains were confirmed as petroleum-degrading bacteria and characterized using numerical taxonomy. The isolates were examined for 54 biochemical, cultural, morphological, and physiological characters. The data were analyzed by computer, using simple matching coefficients and clustering was achieved by the average linkage method. From the dendrogram, 10 phenetic groups were defined at the 75% similarity level. Identified groups were Aeromonas, Enterobacteriaceae, Flavobacterium, Lucibacterium, Pseudomonas, and Vibrio with Enterobacteriaceae as dominants. It was concluded that degradation of petroleum in the estuarine environment was accomplished by indigenous bacteria of numerous genera and high proportion of the phenetic groups were specific to the environmental conditions of sampling sites.

안규홍 , 최승휘 , 신항식 Kyu Hong Ahn , Sung Hui Choi , Hang Sik Shin

DOI: Vol.3(No.1) 1040-1048, 1987

To adequately describe biofilm system, mass transfer resistances must be included. Especially the external mass transfer resistance, existing between bulk liquid and biofilm surface, was very important for design and operation of reactor. But the research of it was scarcity. In this paper, the external mass transfer coefficient which has research to reaction and mass transfer within biofilm was estimated. The following conclusions were made in this study. 1. It is acceptable to regard the substrate removal rate as first order reaction of substrate in this experimental condition. 2. Substrate was mostly removed within 100 um depth, although the effective depth became large enough. 3. The external mass transfer coefficient was proportional to 1.38 power of rotational speed of inner cylinder.

정지봉 , 정용 Jee Bong Cheong , Yong Chung

DOI: Vol.3(No.1) 1049-1060, 1987

As regards to the cost on installation and operation of the waste water treatment facilities, the objective 436 companies from 34 kinds industries registered to Environment Administration, the Government Office of Korea from 1984 to 1985, were analyzed. The results were as follows: 1. The biological treatment method was applied to about 80% in the food and food products industries, the chemical treatment about 90% in metal machinery, plating, chemical products manufactures, and the consolidated treatment about 90% in the leather, paper and textile industries. 2. Average cost of the installation for the waste water treatments required US$ 979.11 per ㎥ of facility for the capacity of treatment plant less than 100 ㎥/day, US$ 299.79 per ㎥ for the capacity of treatment plant less than 1,000 ㎥/day, and US$ 56.14 per ㎥ for the capacity of treatment plant less than 10,000 ㎥/day, respectively. It was shown that the greater the capacity of treatment required, the less the installation cost per the unit facility capacity. The installation cost can be expressed as a function of the concentration of BOD and scale of treatment facilities. Formula was as follows; Y_J = -1836.183 1/log_(l0) BOD + 2094.022 1/log_(l0) S where, Y_J : installation cost, 10³ Won/㎥ -day S : capacity of facilities, ㎥ -day

구자공 , 이병국 , 한상욱 Ja Kong Koo , Byung Kook Lee , Sang Uk Han

DOI: Vol.3(No.1) 1061-1070, 1987

The purpose of this study is the development of regional water quality management schemes considering low treatment cost and high dissolved oxygen level for the construction of new treatment plant. In this study, water quality simulation model QUAL2E, mixed integer programming, and fuzzy set concept were utilized. The Joong Ryang-Cheon basin in the east-north part of Seoul, Korea during August, 1983 was selected as the study area. After analyzing the relationship between pollution source load and water quality effect by using QUAL2E, the optimization techniques were used to minimize the total treatment cost of the study basin by the selection of optimal plant sites and by the utilization of the self-purification capacity which is one of the environmental resource. The fuzzy set concept was applied to optimization technique for the acquisition of dissolved oxygen levels in the setting of zoned standard by using minimum operator and linear membership function. The followings are the results of this study: 1) The attainable uniform dissolved oxygen standard in JoongRyang-Cheon at August, 1983 where the potential seven treatment plants were located was 3.5 ㎎/ℓ. 2) Using mixed integer programming, the location and number of treatment plants, and the optimal treatment levels could be determined. 3) As in the method of zoned standard, the spatial flexibility can save the unnecessary huge expenditure on the environmental control, especially in the region of higher environmental quality levels. 4) By using the fuzzy set concept, it was possible to know beforehand the maximum & optimal attainable standards of dissolved oxygen concentration at the checking points without heavy computational burden by excluding the iteration step in setting standards.