이유대 , 김창원 , 김동윤 , 박병남 , 이기종 You Dae Lee , Chang Won Kim , Dong Youn Kim , Byung Nam Park , Ki Jong Lee

DOI: Vol.6(No.1) 1001-1007, 1990

The sedimentation processes and heavy metal distributions at the Nakdong estuary were investigated during October 1987 and September 1988. The depositional sedimentary environment of the studied area was estuarine environments and was devided into three provinces depending on its textural parameters such as barrier, tidal flat, and water passes. The relationship between the textural parameters showed that the barrier was under strong wave action, that the tidal flat was under relatively weak wind-induced currents, and that the water passes were under strong and continuous tidal currents. Each environment was resulted from different transport mechanism. The sand-barrier sediments were transported by all three populations including suspension, saltation, and bed load. And the water pass-deposited sediments were by the bed-load with some suspension population. In water mass over the studied area, the concentrations of heavy metals including Cu, Cd, Cr^(+6), Pb, and Zn were recorded to be 27.9, 6.7, 20.4, 16.3, and 37.3 ppb in their highest concentrations, respectively. And those in sediments were 20.0, 1.65, 25.4, 15.4, and 132.9 ppm, respectively. The total uptake factors of Cu, Cd, Cr^(+6), Pb, and Zn by V. Mu¨iller (Corbicula fluminea) were 1600, 310, 310, 490, and 7900, respectively.

김동윤 , 김종원 , 김창원 , 전영화 , 이학영 Dong Yun Kim , Jong Won Kim , Chang Won Kim , Young Hwa Jeon , Hak Young Lee

DOI: Vol.6(No.1) 1008-1017, 1990

This study is to find biochemical and biological water quality of the Sooyoung estuary. We found characters of water quality depending to seasonal, spring and neap tide, high and low tide. Following results were obtained, 1. Concentration of down stream of biochemical pollutants was wholly lower than it of up stream. 2. The concentration of BOD was 2.00∼69.85 ㎎/ℓ The concentration of DO was 0.00∼7.04 ㎎/ℓ The concentration of SS was 15∼120 ㎎/ℓ 3. Bacterial estimation of water pollution level by Tsuda & Morisita was polysaprobicity in 1987. But, there was a tendency of improvement and it was β-mesosaprobicity in 1988. 4. A total of 121 diatom species were identified, and only Nitzschia palea was collected from all sampling sites. So, Nitzschia palea is suitable for diatom indicator of Sooyoung estuary water pollution.

김동윤 , 김종원 , 김창원 , 전영화 , 유평종 Dong Yun Kim , Jong Won Kim , Chang Won Kim , Young Hwa Jeon , Pyung Jong You

DOI: Vol.6(No.1) 1018-1023, 1990

Sooyoung estuary were surveyed from May 1987 to February 1988 and the result are as fellows: 1. Diffusion coefficient of Sooyoung estuary were 1.63-22.16 ㎢/d, deoxygenation coefficient were 0.10-1.80/day. 2. Deoxygenation coefficient were determined as fellows: 1) K_d(BOD decay coeff.): 0.030-0.230/day 2) K_(11)(org-N decay coeff.): 0.001-0.075/day 3) K_(22)(NH₃ -N decay coeff.): 0.003-0.030/day 4) K_(33)(NO₃-N decay coeff.): 0.050-0.300/day 3. On the basis of BOD, 90-95% of influent BOD loading should be removed for marine water supply class I of sooyoung river. 4. On the basis of DO, to acheive the marine water supply class I of sooyoung river 90-95% removal of BOD, 10% removal of NOD are needed as the primary treatment and 45-50% sedment of sooyoung river should be removed.

박영규 , 이철희 , 서유덕 Yung Kyu Park , Chul Hee Lee , You Duk Seo

DOI: Vol.6(No.1) 1024-1030, 1990

The eutrophication in lakes has been known as one of the most significant problems in water quality management. The problems due to the eutrophication are increases in algal biomass, oxygen depletion in lakes, teate and odour, and clogging of sand filter beds in a domestic water supply process. In this paper, a simple water quality model was developed and applied for the Andong dam with respect to the control of eutrophication. As a result of micro-computer based modeling approach, the BOX model demonstrated good performances in terms of the accuracy of prediction in water quality in a lake.

최성용 , 조광명 Seung Yong Choi , Kwang Myeung Cho

DOI: Vol.6(No.1) 1031-1037, 1990

The purpose of this study was to investigate the effects of volumetric organic loading on the removal efficiency and nitrifications of a biofilm process. An experiment was performed by feeding a synthetic organic wastewater into an aerated reactor packed with porous plastic media. The results of the research showed that the packed bed biofilm process was very effective for the treatment and nitrification of organic wastewaters. The SBOD and SCOD removal efficiencies were found to be 99% and 96%, respectively at BOD loadings of 0.2∼0.8 ㎏/㎥-day. The TKN removal efficiency was 90∼93% and the combined effluent nitrite and nitrate concentration was 15∼20 ㎎/ℓ at an influent TKN concentration of 31∼32 ㎎/ℓ. The quantity of nitrogen synthesized to cells increased in proportion to the organic loading, and the nitrification efficiency decreased as the organic loading increased. Consequently, as the organic loading increased, the effluent was less acidic and the quantity of alkalinity required for removal of TKN and nitrification became less.

이현동 , 김원만 , 김갑수 Hyun Dong Lee , Won Man Kim , Kap Soo Kim

DOI: Vol.6(No.1) 1038-1049, 1990

The objective of this investigation was to furnish the practical data to be utilized for a sewer construction of planned new city. For this purpose Kwachun city was selected because this city was a new community lately constructed with separate sewer. The investigation was conducted through the field survey on the status of a sewer system, the misconnection of sewerage, the capacity of transportation and the unit loading, etc. The results are as follows; 1. The water quality of upstream in Munwon-dong, Kwachun city as district for migrants, becomes more polluted than other upper areas, indicating 7.3 ㎎/ℓ of BOD, because domestic sewage, due to the sewerage of combined system, is discharged into the stream. 2. Generally the water quality of Yangjae stream is extremely influenced by domestic sewage discharged into the stream, corresponding to the time that the most domestic sewage is generated. 3. The ratio of misconnection of sewer system in Kwachun city was investigated to be about 5.1 % in the first section, 28.8% in the second and 7.3% in the third, respectively. 4. The daily average per capita rate in Kwachun city is 253.8 /pcd in terms of sewage flow rate and 25.0 gpcd by pollution loading, respectively. Also its value in distric for migrants are 183.1/pcd,20.98 gpcd and Apt, seventh site is 288.3 /pcd, 37.2 gpcd respectively.

양병수 , 박남배 , 이재관 Byung Soo Yang , Nam Bae Park , Jae Kwan Lee

DOI: Vol.6(No.1) 1050-1060, 1990

This research is aimed to suggest any possibilities of upgrading nitrogen and phosphorus removal in the exsisting activated sludge process with simple modification. The comparition between a partially aerated (A/O) and fully aerated activated sludge process was made at different mixing and aeration time, and sludge recycle to evaluate the effect of compartalized reaction tank on COD, nitrogen and phosphorus removal. The COD removal efficiency showed up to 95% in the A/O process as well as fully aerated activated sludge process. In the A/O process the substrate removal efficiency remained constant irrespective of anoxic/oxic reactor retention time ratios. Nitrogen and phosphorus removal efficiency in the A/O process was higher than that in the fully aerated activated sludge process. The efficiency in the A/O process was strongly affected by recycling rate. The total nitrogen removal efficiency increased with increasing recycle rate in the range of 25% to 200%. Phosphorus removal efficiency in this process trended to increase as the anoxic reactor volume in the system increased. Sludge settleability improved greatly as the first reactor volume to total reactor volume decreased.

민경석 Kyung Sok Min

DOI: Vol.6(No.1) 1061-1067, 1990

This study was conducted to evaluate the effect of nightsoil addition to D municipal wastewater treatment plant in Dae Gu whose influent concentration was one-half to one-third of the designed concentration. Maximum applicable flow rates of nightsoil for grit chamber and sludge digester were respectively 0.26% and 0.28% of the influent and BOD and SS removal efficiencies were respectively 87%, 84%, which are almost to those efficiencies obtainable only with municipal wastewater. Also VS removal efficiency and gas production rate of sludge digester were increased from 56% with 0.73 ㎥gas/kgVS_(rm) to 62% with 0.80 ㎥gas/kgVS_(rm).