김영수 , 석원석 , 이춘성 , 정의호 , 이해금 Y . S . Kim , W . S . Suk , C . S . Lee , E . H . Jung , H . K . Lee

DOI: Vol.9(No.2) 75-83, 1993

For microbiological evaluation of water quality in the North Han river systems and the streams flowing into the East Sea, the quantitative distribution of coliforms was surveyed from 1988 to 1991. In the North Han river system, the median of total coliforms count was 59 MPN/100㎖ at upper streams and 490 MPN/100㎖ at down streams, and at the streams on the East Sea, the range of the medians was l30 MPN/100㎖ at Namdaechun in Kangneung. For the artificial reservoirs, the range of MPN index was 4 to 240 MPN/100㎖ (median =79) for lake Soyang, 13 to 790 MPN/ 100㎖ (median=79) for lake Chunchon and 130 to 1,700 MPN /100㎖ (median=490) for lake Uiam. Tweleve spp. of coliforms from fecal coliforms were identified from total coliforms cultures and two spp. of coliforms from fecal coliforms cultures.

정용 , 이자경 , 최윤호 Yong Chung , Ja Kyoung Lee , Yoon Ho Choi

DOI: Vol.9(No.2) 84-92, 1993

This study were conducted to compare the biodegradability of synthetic surfactants(8 kinds), shampoos(total 12 kinds - foregins; 3, homes;9) and the fatty acids soaps(8 kinds). The biodegradation of anionic surfactants was tested by aeiation method which was inclosed bubbling and shaking methods for activated sludge cultivation and the quantities of surfactants were analysed by MBAS(Methylene Blue Active Substances) method. The biodegradation of soaps was determined by using analysis of the fatty acids derivations with p-BPB which was detected with HPLC/UV. SLS(Sodium Laury Sulfate), ALS(Ammonium Laury Sulfate), natural SLES(Sodium Laury Ether Sulfate), SCI(Sodium Cocoyl Isothionate), acyl N-methyl sodium taurate(natural synthetic surfactants) were degradated more than 99% after 24 hrs. The components of the synthetic surfactants(petroleum or natural palm oil sources) significantly affected to the initial biodegradation rates of shampoos. The biodegradabilities of the fatty acid and soaps were differently depended upon the water hardness : soft water ; l2 hrs, hard water ; 18 hrs for 99% biodegradations. But natural SLS was degradated to 99% whithin 9 hrs.

허인량 , 이해금 , 최규열 , 박성빈 In Ryang Huh , Hae Keum Lee , Kyu Yol Choi , Sung Bin Park

DOI: Vol.9(No.2) 93-97, 1993

This study was initiated to perform a comprehensive evaluation of the water quality in Lake Soyang. Seasonal variation and the spatial distribution of COD and chl. a were monitored at 8 sites selected in Lake Soyang from June, 1991 to April, 1992. Result of regression analysis of COD vs chl. a concentration indicated positive correlation. Statistical analysis on the annual variation of COD showed a increasing pattern with time during the study period. The spatial average COD value at surface layer showed that the difference was not statistically significant at 95% level. With respect to the seasonal variation, however, it was significant at the same level. Average COD concentration of effluent layer was analyzed 2.02㎎/ℓ.

우승순 , 이찬기 , 김성석 , 최규열 , 이해금 Seung Soon Woo , Chan Ki Lee , Sung Seok Kim , Kuy Yol Choi , Hae Keum Lee

DOI: Vol.9(No.2) 98-104, 1993

A study was conducted to investigate the behavior of phosphorus forms at each stage in the sewage treatment processes. The total phosphorus concentration of the domestic wastewater in the sewage plant was 3.5㎎/ℓ and distribution of total reactive phosphorus (TRP), total acid-hydrolyzable phosphorus(THP) and total organic phosphorus(TOP) in the T P concentration was about 42%, 25% and 33%, respectively. The T-P concentration in the grit chamber was about 8 times higher than that in domestic wastewater, under the influence of inflowing thickner and digester supernatant. The removal ratios of THP and TOP at sewage plant were about 65%, 75%, respectively. It was found that the removed phosphorus forms were mostly SHP and SOP, but TRP was not removed at ail. The amount of T-P flowed into the sewage plant was 51.7㎏/10,000㎥/day, that removed by the sewage treatment processes was 23.0㎏/10,000㎥/day that loaded to lake was 28.7㎏/ 10,000㎥/day.

이승목 Seung Mok Lee

DOI: Vol.9(No.2) 105-113, 1993

김범철 , 허우명 , 전만식 , 김징호 Bom Chul Kim , Woo Myung Heo , Man Sik Jun , Jing Ho Kim

DOI: Vol.9(No.2) 114-121, 1993

The amount of phosphorus discharge per ㎏ feed from the aquaculture of Israeli carp (Cyprinus carpio) was determined by monitoring the phosphorus discharge in the effluent of culture tanks. 10 commercial fishfeeds were used in order to delineate the relationship between discharge rate of phosphorus from fish culture and the phosphorus content of feeds ranging from 1.0% to 2.1%. 52% of phosphorus in the ingested feed was released into water through excretion. 68% of excreted phosphorus was in particulate form and 32% was in dissolved form. Phosphorus discharge was higher for feeds of higher P-content and also increased with the feed conversion ratio. Higher phosphorus discharge for feeds of higher P-content was mostly contributed by the increase of particulate phosphorus excretion showing positive correlation, whereas dissolved P excretions were at the similar level regardless of P- content. The total phosphorus discharge rate was 8.4(gP/㎏ feed) when the P-content of feed was 1.5%. The discharge rate will be smaller, if the P-content of feeds and the feed conversion ratio are lowered.

구자공 , 김유리 , 문형부 , 이우범 Ja Kong Koo , Yu Ri Kim , Hyung Bu Mun , Woo Bum Lee

DOI: Vol.9(No.2) 122-130, 1993

Although Kwangyang bay (Chonnam, Korea) had a beautiful landscape, the inner bay had been polluted by the industrial wastewaters and domestic sewage since 1969 of industrialization. During two years from 1989, quality of sea water in the bay was surveyed and using the collected data, this study applied the Box model under the assumption that the water body was completely mixed in each Box. and performed the sensitivity analysis to estimate the effective loading for non-point sources. From summer to early fall, the water quality of the bay showed that the salinity was low and COD was over the environmental criteria. Because the calculated value by the Box model is well satisfied the measured value, it can be used for the predicition of water quality for salinity and COD at the Kwangyang bay. Result showed that the non-point COD unit loadings from farm dry field, paddy field for rice farming, silviculture area and the normal industrial and residential land in Kwangyang bay area are 31.04, 22.38, 4.15 and 383.64㎏ COD/ha-year respectively.

송교육 , 김종구 , 박청길 Kyo Ook Song , Jong Gu Kim , Chung Kil Park

DOI: Vol.9(No.2) 131-138, 1993

The present water quality condition of the Nakdong river is well above the third grade and hypereutrophic. Waste loads allocation was conducted to study the relationship between pollution loads and the resulting response of the receiving water using the enhanced stream quality model(Qual 2E) which was developed by U. S. EPA. Based on the field data, Qual 2E model was calibrated and verified and then used for waste loads allocation study. To control excessive growth of algae and maintain mesotrophic state, all tributary are required to be mesotrophic state and nitrogen and phosphorus loads from the Kumho river have to be reduce to 90% of the present loads or less. To improve the present water quality condition to the second grade with mesotrophic state, BOD loads from the Kumho river have to be reduce to 80% or less.