• Proceedings of the Korean Environmental Sciences Society Conference
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• 2003.05a
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• pp.183-187
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• 2003

신천에 금호강물을 혼합한 이후의 수질개선에 대한 효과를 알아보기 위해 수질조사를 하였다. 3월부터 9 개월 동안 신천의 물을 측정한 결과 부유물질의 농도는 1.2mg/$\ell$~18.7mg/$\ell$의 범위로 나타났으며, 상동교 지점에서 금호강물 유입이 시작된 5월 말부터 측정한 부유물질의 농도는 2.8mg/$\ell$~8.6mg/$\ell$의 범위로 나타내었다. 생화학적산소요구량의 농도는 0.6mg/$\ell$~7.9mg/$\ell$의 범위로 나타났으며, 상동교 지점에서 5월 말부터 측정한 생화학적산소요구량의 농도는 2.9mg/$\ell$~7.2mg/$\ell$의 범위로 나타났다. 무태교 지점에서 생화학적산소요구량의 농도는 3.6mg/$\ell$~5.6mg/$\ell$의 범위로 높았다. 암모니아태 질소의 농도는 0.12mg/$\ell$~0.79mg/$\ell$~의 범위로 나타났으며, 상동교 지점에서 5월 말부터 측정한 암모니아태 질소는 0.15mg/$\ell$~0.67mg/$\ell$~의 범위로 나타났다. 무태교 지점에서의 암모니아태 질소의 농도는 0.43mg/$\ell$~0.79mg/$\ell$의 범위이었다. 총인의 농도는 0.16mg/$\ell$~l.12mg/$\ell$의 범위로 나타났으며, 상동교 지점에서 5월 말부터 측정한 암모니아태 질소의 농도는 0.33mg/$\ell$~0.88mg/$\ell$~의 범위로 나타났다. 무태교 지점에서의 총인의 농도는 0.52mg/$\ell$~0.99mg/$\ell$~의 범위이었다. 신천에 금호강물을 혼합한 이후에도 부유물질, 생화학적산소요구량, 암모니아태 질소, 총인 등의 농도가 개선되지 않았다. 즉 금호강물의 혼합은 신천수질환경사업소에서 배출되는 방류수에 함유되어 있을 2차 오염물질의 희석이라는 이점외의 수질개선효과는 확인되지 않았다.

• Resources Recycling
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• v.18 no.2
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• pp.16-29
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• 2009

This paper describes characteristics of pollutants in wastewater from the pulp and paper industry and biological technologies for the wastewater treatment. The wastewater from the pulp and paper industry contains high concentrations of biochemical oxygen demand (BOD) and chemical oxygen demand (COD) and shows high toxicity and strong black-brown color. In particular, organic chlorinated compounds such as dioxins and furans may be formed by the chlorination of lignin in wood chips. Thus the pulp and paper industry is recently trending toward total chlorine-free (TCF) bleaching processes. All biological technologies for pulp and paper wastewater treatment are based on the contact between wastewater and bacteria, which feed on organic materials in the wastewater, thus they reduce BOD concentration in it. Both aerobic and anaerobic treatments were found to be effective for the wastewater treatment. Furthermore, advanced technologies such as fungal application and combined biological-filtration process have been also introduced to the wastewater treatment field. These technologies would be useful for water recycling to reduce water consumption throughout pulp and paper making process.

• Water for future
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• v.19 no.4
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• pp.321-328
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• 1986

Bottom sediment-river water samples were studied to determine the extent of biodegradable matter and to examine the reduction of COD, TKN and TOC by using of warburg and aerated batch reactor. Warburg studies were conducted to study the Oxygen Uptake Rates, Reaction Rate Constants and CBOD. Bacth reator studies were conducted to determine the reduction of COD, TKN and TOC. Results from the batch recator study indicate high concentration of COD in samples. Less than 10 precent of the Organic Carbon was found to be biodegradable in 48 hours of Warburg experiment. Appreciable Immediate Oxygen Demand of sediments suggests that dredging of the river bottom is likely to deplete dissolved significantly in the river water.

• Journal of the Korea Organic Resources Recycling Association
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• v.17 no.3
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• pp.82-90
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• 2009

Disintegration of sewage sludge (SS) was investigated by batch experiments using mechanical pre-treatment. Mechanical disintegration of SS increased the amount of soluble chemical oxygen demand (SCOD), protein and carbohydrate due to the break-up of cell walls. The mechanical disintegration incorporated with alkaline pre-treatment demonstrated higher amount of SCOD compared with mechanical one only. In terms of anaerobic biodegradability, mechanical pretreatment enhanced the anaerobic biodegradation of SS, leading to the methane production improvement. The improvement in BMP for SS treated with mechanical and alkaline-mechanical pre-treatments were 24.1% and 44.5%, respectively. This result suggested that disintegration of SS was effective for improving anaerobic biodegradability.

• Proceedings of the Korea Water Resources Association Conference
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• 2019.05a
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• pp.415-415
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• 2019

본 연구에서는 낙동강 본류에서 10년(2008~2017) 동안 관측된 자료의 월별 평균 자료를 이용하여, DO, BOD, COD의 시공간 변동 및 그 영향인자들과의 상관관계를 분석하였다. 관측소별 수질은 상류에서 하류로 갈수록 나빠졌으며, BOD와 COD는 ST5에서 가장 높았다. 10개 관측소별 수질성분의 상관성을 분석한 결과, DO와 수온의 상관계수는 -0.90 이상이고, BOD와 Chl-a의 상관계수는 0.48~0.85, COD와 TOC의 상관계수는 ST5와 ST10 관측소를 제외하고 0.65 이상이었다. 모든 관측소 자료를 이용한 회귀분석 결과, 수온과 DO는 감소하는 선형함수로서 결정계수는 0.90, chl-a와 BOD는 증가하는 파워함수로서 결정계수는 0.83, TOC와 COD는 증가하는 로그함수로서 결정계수는 0.58 정도이었다. 10개 관측소별 TOC 분해율을 산정한 결과, BOD에 의한 분해율의 평균은 15.5~36.3%, COD에 의한 분해율의 평균은 57.4~89.6%의 범위로 나타났다.

• Journal of Environmental Science International
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• v.4 no.1
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• pp.71-80
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• 1995

A discrete state space model for a multiple-reach river system is formulated using the dynamics of biochemical oxygen demand(BOD) and dissolved oxygen(DO). A hierarchical optimization technique, which is applicable to large-scale systems with time-delays in states, is also described to control stream quality in a river as an optimal manner based on the interaction prediction method. The steady state tracking error of the proposed method is determined analytically and a necessary and sufficient condition on which a constant target tracking problem has zero steady-state error is derived. Computer simulations for the river pollution model illustrate the algorithm.

• Journal of the Korea Organic Resources Recycling Association
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• v.16 no.3
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• pp.83-90
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• 2008

The ultrasonic pre-treatment of sewage sludge (SS) was investigated to increase soluble organic material and to improve anaerobic biodegradability. Ultrasonic disintegration of SS increased the amount of soluble chemical oxygen demand (SCOD), protein and carbohydrate concentrations whereas particle size decreased due to the break-up of cell walls. In terms of anaerobic biodegradability, ultrasonic pre-treatment enhanced the anaerobic biodegradation of SS, leading to the methane gas production improvement. Biochemical methane potential (BMP) of SS was 211.3 ml $CH_4/gVS$ whereas BMP after ultrasonic pre-treatment was 294.3 ml $CH_4/gVS$. The improvement in BMP for SS treated with ultrasonic disintegration was as high as 40 %. This result indicated that disintegration of SS was efficient for enhancing anaerobic biodegradability.

• Journal of Korea Water Resources Association
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• v.56 no.5
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• pp.337-345
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• 2023

Monitoring river microplastics is a challenging task since it is a time-consuming and high-cost process. The use of a physical model to have a better understanding of river microplastics' behaviors can complement the challenging monitoring process. However, there have been very limited studies on modeling river microplastics. In this study, therefore, we evaluated the applicability of one commonly used river water quality model, i.e., the Water Quality Analysis Simulation Program (WASP), in simulating the microplastic concentration in the river environment. We simulated the microplastic concentration in the Anyangcheon stream using the WASP's biochemical oxygen demand (BOD) and suspended solid (SS) variables as possible surrogate variables for the microplastics. Simulation analyses indicate that the SS state variable performs better than the BOD state variable to mimic the observed concentrations of microplastics. This is because of the characteristics of each water quality parameter; the BOD variable, a biochemical indicator, is inappropriate for modeling the behaviors of microplastics, which have generally constant biochemical features. In contrast, the SS variable, which has similar physical behaviors, followed the observed patterns of the microplastic concentrations well. To build a more advanced and accurate model for simulating the microplastic concentration, comprehensive and long-term monitoring studies of the river microplastics under different environmental conditions are needed, and the unit of microplastic concentration should be carefully addressed before its modeling application.

• Korean Journal of Microbiology
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• v.31 no.1
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• pp.85-92
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• 1993

To investigate the eutrophication process and pollution characteristics in Paldang Lake, Korea, water and sediment samples were analysed during July 1986~June 1987. The transparency, chlorophyll-a concentration, dissolved oxygen concentration and biochemical oxygen demand in Paldang Lake ranged 0.5~3 m, 3-17 ${\mu}gI^{-1}$, 7.2~12.3 ppm and 0.5~2.3 ppm, respectively. Heterotrophic bacterial number fluctuated seasonally between $3.0{\times}10^{3}/ml and 5.0{\times}10^{5}/ml$ in the water column and between $2{\times}10^{6} and 1{\times}10^{8}$ in the I g dry sediment. Water turbulence and water quality of up-stream seem to play important roles for determining the water quality in Paldang Lake particularly where the hydraulic retention time is so short as about 5 days. The present water quality in Paldang Lake according to the criteria of lake water quality was shown to be between mesotrophic and eutrophic state by secchi depth(O.5 ~ 3 m) and chlorophyll-a concentration (3~17 ${\mu}gI^{-1}$). The distribution of coliform bacteria showed that the pollution was mainly due to the human activities in this area and it is needed to establish countmeasurements for the problems.

• Journal of Korea Water Resources Association
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• v.52 no.3
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• pp.207-217
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• 2019

This study aims at development and application of a facility that is capable of reducing pollution in water quality by reducing nonpoint source pollutants (NPSP). NPSP originated from the initial rainfall caused not only large catchment of urban area pass a river but also small watershed pass a stream. For this purpose, the performance tests carried out with the field models from the facility based on the preceding study. And the tests induced reduction efficiency of biochemical oxygen demand (BOD), chemical oxygen demand (COD), total nitrogen (T-N) and suspended solid (SS), respectively. The average reduction efficiency obtained by time interval, and the result showed an excellent reduction performance. As a result, the facility satisfied reduction efficiency of NPSP of the proposed standard by the National Institute of Environmental Research, and thus it can be used in practical applications.