이상은 , 박철휘 , 서윤수 , 류재근 , 임연택 Sang Eun Lee , Chun Hwei Park , Yoon Soo Suh , Jae Keun Ryu , Yeon Taek Rim

DOI: Vol.4(No.1) 1001-1010, 1988

The use of electrolytic respirometer for characterization of chemical compounds and waste water is introduced. From BOD curve generated by the respirometer, the first order biokinetic constant(K), ultimate BOD (BODu) and adaptation period were estimated. The estimated ultimate BOD values of the known chemical compounds were very close to the theoretical oxygen demand values. Using K values, the relative biodegradability of the chemicals could be compared while adaptation period for each compound could vary with the type of the seed microorganisms used. It was found that BOD_5 values determined by conventional method have no or very little, if any, meaning as far as biological characteristics of industrial wastewaters are concerned The biological characterization of 3 industrial wastewaters indicated that, except for the wastewater from plating industry, other two types of industrial wastewaters would be readily treated biologically. The BOD curves for wastewaters consisting of 2 or 3 different compounds could be divided into several stages while those for the combined wastewaters could be expressed as one curve.

이문호 , 김동군 , 서윤수 Mun Ho Lee , Dong Gun Kim , Yoon Soo Suh

DOI: Vol.4(No.1) 1011-1015, 1988

Decomposition of Anabaena flos-aquae and Chlorella vulgaris in a dark condition was examined. Change of pH. DO, heterotrophic plate count, protozoa number, dissolved ortho-phosphorus and dissolved total phosphorus during the algae decomposition was also determined. The results are as follows: Although 80% of Anabaena cells were decomposed after 8 days, the Chlorella cells were decomposed only 13% after 9 days. The decomposition rate was markedly different with the algal species. Aerobic bacteria and protozoa play a important role in the decomposition of algae even though under the closed system. The change of pH during the decomposition of algae was negligible. Meanwhile, DO was sharply decreased in the initial stage of the decomposition and progressively decreased in the latter stage. Phosphorus concentration in the solution increased with the decomposition of algae. Especially the dissolved total phosphorus concentration increased abruptly with the lysis of protozoa, the number of which had increased previously with the decomposition of algae.

신응배 , 최용수 E . B . Shin , Y . S . Choi

DOI: Vol.4(No.1) 1016-1025, 1988

The objective of this study is to design a rational research and development plan for water quality problems and to make recommendations to the government as to appropriate allocation of financial resources to carry out the plan. The current status of problems and needs for wastewater management and water pollution control are identified as they are related to the areas of sewage and wastewater conveyance system, agricultural wastewater management, industrial wastewater management. sludge handling, ocean and inshore water quality. surface water quality, ground water and others. Research and development program is classified Into 5 groups and they are water quality management technology, treatment technology, wastewater conveyance system technology. survillance/monitoring technique and effect studies. The classified research topics are properly coded. 107 research topics are selected as priority projects that should be carried out in next five years.

이인선 , 이길철 , 신상철 , 정동일 , 최훈근 I . S . Lee , K . C . Lee , S . C . Shin , D . I . Jung , H . K . Choi

DOI: Vol.4(No.1) 1026-1036, 1988

This study was carried out to grope for Water Quality Index (WQI) which is able to use as a practical method evaluating water quality concerned with degree of pollution. 8 variables for determining the pollution were selected such as pH, DOs, Water temperature (WT), BOD, SS, TC, NH₃-N and NO₃-N and the results are summarized as follow. 1. Each WQI value was calculated by exponential equations (graph) described below. At the range. of pH 3.0 to 6.8, Y=10^((0.08394 x pH + 0.74921)) and pH 8.5 to 11.7, Y=10^((-0.21843 x pH + 3.85664)) At the range of DOs 30 to 100%, Y=10^((0.00999 x DOs + 1.00147 )) and DOs 100 to 130%, Y= 10^((-0.02330 x DOs +4.32990)) At the range of WT 28 to 34℃, Y=10^((-0.11650 x WT + 5.26186)) At the range of BOD 0.8 to 10.0 ㎎/ℓ, Y=10^((-0.075975 x BOD + 2.06078)) At the range of SS 2.6 to 37 ㎎/ℓ, Y=l0^((-0.018891 x SS + 2.056673)) At the range of TC 50 to 200,000 MPN/100㎖, Y=10^((-0.19416 x log TC + 2.33007)) At the range of NH₃-N+NO₃-N 0.4 to 3.4㎎/ℓ, Y=10^((-0.23299 x (NH₃-N + NO₃-N) + 2.09320)), Where Y is index value of each water quality. 2. The weights of each variable were 0.04 for pH and WT, 0.11 for DOs, 0.18 for TC, 0.21 for BOD, SS and NH₃-N+NO₃-N, respectively.

한상욱 , Paul H . M . Guo Sang Wook Han , Paul H . M . Guo

DOI: Vol.4(No.1) 1037-1044, 1988

In the design of a water quality monitoring systems, many factors have to be taken into consideration. Great caution has to be exercised in the selection of suitable monitoring sites, collection of representative samples and determination of sampling frequency. Much attention has to be paid to sampling technique and analytical methods to ensure that the data collected from different laboratories are meaningful and comparable. In addition, the availability and constraints of human and financial resources in a country should be taken into consideration in the design of water quality monitoring programmes.

정동일 , 이길철 , 서윤수 Dong Il Jung , Kil Chul Lee , Yoon Soo Suh

DOI: Vol.4(No.1) 1045-1049, 1988

The main objective of this study was to study and evaluate the performance of a 15㎥ anaerobic digester with 40% sludge return. The solids retention time(SRT) with a hydraulic detention time (HDT) of 3 days and organic loading rate were 16 days and 1.06㎏ TVS/㎥.d (1.46㎏ COD/㎥.d), respectively. TVS and COD removal efficiencies were 77.6% and 77.3%, respectively. These values were higher than those without sludge return at longer HDT. Gas production was 0.25㎥/㎏ TVS fed.