• KSBB Journal
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• 제19권5호
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• pp.390-393
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• 2004

Oxygen uptake rate (OUR) was used as an indicator of microbial activity. In this study OUR at dyeing wastewater in the pilot plant was monitored to examine biological activity. Correlation between inlet COD concentration and maximum OUR showed that maximum OUR was proportional to inlet COD concentration. Changes in the OUR values reflected the changing waste load in the reactor. Consequently, OUR can be used to estimate biological activity of inlet COD concentration. This study showed that biodegradable COD at dyeing wastewater could be calculated from OUR and yield coefficient. Non-biodegradable COD was able to be calculated from a difference between initial COD concentration and biodegradable COD.

• 산업기술연구
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• 제16권
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• pp.51-60
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• 1996

This research was performed for the fundamental data using a advanced treatment process of piggery wastewater. Characteristics of influent wastewater was divided with various methods in fixed biofilm batch reasctor. Fractons of organic were divided into readily biodegradable soluble COD(Ss), slowly biodegradable COD(Xs), nonbiodegradable soluble COD($S_I$), and nonbiodegradable suspended COD($X_I$). Experimental results were summerized as following : i) biodegradable organics fraction in piggery wastewater was about 88.1 percent, and fraction of readily biodegradable soluble COD was about 66.1 percent. ii) Fractions of nonbiodegradable soluble COD was 11~12 percent, and soluble inert COD by metabolism was producted about 6~8 percent. iii) Active biomass fraction of attached biofilm was about 54.7 percent, and substrate utilization rate and maximum specific growth rate of heterotrophs were $8.315d^{-1}$ and $3.823d^{-1}$, respectively.

• 상하수도학회지
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• 제18권1호
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• pp.29-36
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• 2004

Organics may be divided into biodegradable and nonbiodegradable fractions on the basis of biodegradability. Biodegradable organics may be subdivided into readily and slowly biodegradable fractions. As this biodegradability of organics in municipal wastewater has a great influence on the efficiency of a biological nutrient removal process, it has been assessed by respirometry. The respirometer, which consisted of a respiration chamber and a respiration cell, was used to measure the respiration rate of biomass utilizing the readily biodegradable organics. The readily biodegradable organics are about 10% of the COD in municipal wastewater. The adequate ratio of wastewater to sludge volume and the concentration of sludge are required in measuring the respiration rate due to the readily biodegradable organics. By using a biochemical oxygen demand test, the slowly biodegradable organics including biomass are estimated about 66% of COD. The soluble inert organics are about 11% of COD. On the basis of mass balance, the particulate inert organics are estimated about 13% of COD.

• 상하수도학회지
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• 제24권4호
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• pp.387-394
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• 2010

The influent COD of municipal wastewater has been divided into 4 fractions; readily soluble biodegradable, slowly particulate biodegradable, soluble and particulate unbiodegradable COD. The mathematical modeling of biological wastewater treatment processes and the design and operation of nutrient removal plants require a reliable and accurate estimate of the composition of influent wastewater COD. COD utilization rate is proportional to the oxygen uptake rate(OUR), so a batch biodegradation test with OUR measurement has been effectively used for the determination of COD fractionation. But the mathematical model of COD utilization and heterotrophs synthesis is essential to interpret the OUR measurement. Mamais method is another method for determining readily biodegradable soluble COD. Like the OUR test method, batch biodegradation test is necessary but it does not require mathematical model. These two methods for determining COD fractionation are introduced here in detail. Experimental results showed that COD composition by Mamais method is not different to that by OUR test method so, either of them can be used.

• 상하수도학회지
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• 제17권4호
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• pp.503-509
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• 2003

COD fractionation of primary settled municipal wastewater was conducted by respirometry. RBCOD (Readily Biodegradable COD) fraction was analyzed to be 21% of influent TCOD. However, SCOD fraction, analyzed by physical separation using $0.45{\mu}m$ membrane filter, was about 31% of TCOD. Therefore, 10% of soluble inert COD was comprised in TCOD. It means that kinetic analysis of activated sludge system was impossible because serious error would be occurred if SCOD was used as a biodegradable soluble component instead of RBCOD estimated from respirometry. In this study, RBCOD fraction of raw wastewater could be analyzed by respirometry within the error range of 57%. In addition, SBCOD (Slowly Biodegradable COD) content could be determined by kinetic simulation of the experimental results. SBCOD showed about 2-fold higher fraction (38% of TCOD) as compared with RBCOD.

• 상하수도학회지
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• 제18권2호
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• pp.113-120
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• 2004

The biodegradability of organics has become essential for the design and modeling of a biological nutrient removal process. Respirometry for the batch test just with wastewater has been conducted to estimate active biomass and readily biodegradable organics in municipal wastewater simultaneously. Municipal wastewater contains significant active biomass, which is estimated about 17% of COD. Compared to the batch test seeded with sludge, the batch test just with wastewater represents a little higher readily biodegradable organics. This might be due to the different environment of the logarithmic growth of active biomass. The nitrate uptake rate test has been also performed for the estimation of the readily biodegradable organics. The nitrate uptake rate test results in a little higher readily biodegradable organics compared to the batch test seeded with sludge and similar organics compared to the batch test just with wastewater. This might be caused by the different sludge of a sequencing batch reactor process. Taking the result of the previous research into account, the readily biodegradable, slowly biodegradable, active biomass, soluble inert, and particulate inert organics are estimated about 11%, 49%, 17%, 11%, and 12% of COD, respectively.

• 유기물자원화
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• 제24권3호
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• pp.35-43
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• 2016

하수처리장에서 배출되는 잉여슬러지 감량율을 증가시키기 위해 사용된 전처리 가용화시설에서, 가용화율에 따른 COD 성상변화를 살펴보았다. 대상하수처리장의 농축 잉여슬러지에 포함되어 있는 난분해성 COD는 총 COD의 37.0 % 이었다. 전처리 가용화시설에서 배출되는 잉여슬러지의 COD 세부성상 변화를 살펴보면 가용화율(5%, 10%, 20%, 30%, 35%)의 증가에 따라 고형성 생분해성 COD는 점차적인 감소를 보이고 있으며 이로 인한 용존성 생분해성 COD와 고형성 난분해성 COD가 증가하는 것을 볼 수 있었다. 잉여슬러지를 가용화하기 위하여 물리적 전처리시설을 적용할 때 생물학적 2차처리시설의 SRT가 상대적으로 길게 운영되면 잉여슬러지의 고형성 난분해성 COD의 함유율이 높고 상대적으로 고형성 생분해성 COD 농도가 낮게 된다. 고형성 생분해성 COD가 상대적으로 낮은 잉여슬러지의 경우 전처리 시설에 의한 가용화의 효과가 당초 예상보다 낮아질 수 있으므로, 가용화하여 혐기성 소화 할 경우 잉여슬러지에 대한 COD 성상 조사가 요구된다. 가용화율 5%에서 혐기성소화조에서의 COD 제거율은 2.1% 증가하였고, 가용화율 35%에서는 COD 제거율이 15.1% 증가 되었다. 전처리 시설에서 잉여슬러지 고형성 COD를 35% 가용화하였을 때 혐기성소화조에서의 COD 제거율은 25%에서 40%로 향상되었고 메탄가스발생량은 $607m^3$/일에서 $907m^3$/일으로 증가하는 것으로 나타났다.

• 한국물환경학회지
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• 제24권5호
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• pp.537-542
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• 2008

Textile industry has been recognized as an important pollution source due to its consumption of large volumes of water and chemicals. Textile wastewater contains very diverse chemicals in types and composition, among them the presence of dyes is highly visible and undesirable. In spite of these problems, there has not been a proper control for the wastewater because many dyes are difficult to be degraded or decolorized due to their complex structure and synthetic characteristics. This study has been progressed to evaluate more easily the potential decolorization of advanced treatment processes. It has been surveyed with the Y textile complex wastewater treatment plant, the raw wastewater has appeared very difficult biodegradability by 4.7 of $CODcr/BOD_5$ and 1,158.9 degree of color. In view of CODcr fractions, biodegradable COD portion was 46.4%, colloidal COD and real soluble COD was 45.3% and 31.5% each others. From research on unit processes, the degradable coefficient (k) became from 0.065 to $0.125d^{-1}$ by the processes, the decolorization appeared best efficiency by 30.1% (458.4 degree) in pre-ozone process. On the effluent from the biological process, the filterable CODcr became 129.3 mg/L, the biodegradable portion appeared 64.7% (83.6 mg/L), and the fixed dissolved solid (FDS), non-reactivity (NR), appeared very heavy portion by 80.5% (1,659.0 mg/L).

• 한국환경과학회지
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• 제24권11호
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• pp.1343-1362
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• 2015

As a result of analysis based on the observed data for BOD, COD and TOC in order to manage non-biodegradable organics in the Geumho River, COD/BOD ratio was analyzed as the occupying predominance proportion. In this study, the classification(changes in water quality measurement : increase, equal, decrease) and measurement of BOD and COD were analyzed for trends over the past 10 years from 2005 to 2014 in the Geumho River. The Geumho River is expected to need non-biodegradable organics management because BOD was found to be reduced 61.1% and COD was found to be increased 50%. As a result of the analysis of land use, the Geumho-A is a unit watershed area of $921.13km^2$, which is the most common area that is occupied by forests. The Geumho-B is a unit watershed area of $436.8km^2$, which is the area that is highest occupied by agriculture and grass of 24.84%. The Geumho-C is a unit watershed area of $704.56km^2$ accounted for 40.29% of the entire watershed, which is the area that is occupied by urban of 15.12%. Load of non-biodegradable organics, which is not easy biodegradable according to the discharge, appeared to be increased because flow coefficient of COD and TOC at the Geumho-B were estimated larger than 1 value. The management of non-point sources of agricultural land is required because the Geumho-B watershed area occupied by the high proportion of agriculture and field. In this segment it showed to increase the organics that biodegradation is difficult because the ratio of BOD and TOC was decreased rapidly from GR7 to GR8. Thus, countermeasures will be required for this.

• 펄프종이기술
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• 제37권3호
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• pp.50-58
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• 2005

It is generally known that paper industry is the second largest industry in the use of process water, and also have the highest environmental impact load in the contaminant sources. Paper is produced from the mixtures composed of 1% fibrous raw materials and 99% water. The optimum use of process water effects on the quality properties of paper and the environmental impact load of waste water treatment. In this research, the kinds of fibrous raw material & additives used in the paperboard production line were investigated, and the quantification of environmental loads and the environmental effects of process water on COD potential were evaluated. The NBDCODs were also analyzed from process water by the method of waste water treatment in paper mill and applied for the optimum use of recycling water, and zero effluent process. In the fibrous raw materials, KOCC caused the highest COD potentials, and sack paper & UKP was comparatively low. The NBDCOD of KOCC largely reduced after biological treatment because of easily biodegradable properties, but AOCC contained non-biodegradable materials. In chemical additives, COD was high in turns of rosin>starch>deaeration agent>dye, NBDCOD greatly reduced in starch and deaeration agent. In the case of 2 kinds of paperboard product, the COD potentials was mainly high in starch, AOCC and KOCC.