• Journal of the Korea Organic Resources Recycling Association
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• v.12 no.3
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• pp.119-125
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• 2004

Sugar beet stillages were used as a substrate for the production of single cell protein by a thermotolerant yeast Candida rugosa. 3 Stillage substrates were nutritionally optimized for the better production of yeast biomass and for the reduction of COD. The addition of Phosphorus(P) was required for all stillages, but Nitrogen(N) only when the residual sugar remained. The addition of P increased the biomass production to 23-61%. The addition of N increased the biomass production only a little, but when added together with P increased to 90%. The COD decreased to 26-46% when P was added, but decreased to 85% when P was added together with N.

• Journal of the Korea Organic Resources Recycling Association
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• v.13 no.4
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• pp.100-106
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• 2005

Sugar beet stillages were used as a substrate for the production of single cell protein by the thermotolerant yeasts Candida rugosa, Kluyveromyces marxianus and C. utilis. The biomass production increased in accordance with the increase of pH-value, but protein content decreased. C. rugosa showed the highest crude protein production as 3.68g/l and C. utilis 2.9g/l, Kl. marxianus 2.30g/l, respectively. The rate of COD reduction in stillage versus crude protein production of C. rugosa showed the highest value as 0.35~0.39g/l as a good strain for single cell protein production using sugar beet stillages.

• Analytical Science and Technology
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• v.8 no.3
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• pp.281-284
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• 1995

The effect of permanganate concentration and refluxing time on the test COD results were investigated, as a validation test of the revised procedure. The amended protocol involves the use of a more dilute(1/2.5) permanganate solution(0.010N) and a shorter(1/3) refluxing period(20 min). This revision resulted only 70% of the COD value determined by the old procedure with 8 somewhat improved precision(CV 4.6%${\rightarrow}$3.3%). The dominant factor that influences the decrease in the COD result is the oxidant concentration, being two thirds of the overall effect. The same results were obtained in the comparison test using seawater samples.

• Proceedings of the Korea Water Resources Association Conference
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• 2019.05a
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• pp.424-424
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• 2019

수질오염 저감을 위한 유기물질의 처리를 위해 생물학적 처리에 중점을 둔 하 폐수 처리시설의 증가에 따라 BOD로 대표되는 생분해성 유기물질은 꾸준히 감소하였으나, COD농도의 경우 뚜렷한 감소를 보이지 않고 있다. 유기물질 중 특히 난분해성 물질의 증가는 상수원으로 사용되는 하천의 경우 조류 증식 등을 유발하고 여과공정에 영향을 미쳐 상수처리의 효율을 떨어뜨리는 등의 환경적인 문제를 야기할 수 있다. 기존 BOD, COD로 대표되는 유기물질의 경우 각 유기물질별 상관관계 및 유출특성 등에 대한 연구는 많이 이루어졌으나, 난분해성 물질에 대한 조사는 상대적으로 미진한 실정이다. 특히 동진강수계는 '새만금 제2단계 수질개선종합대책' 등 장기적인 수질개선 대책들이 추진되면서 하천의 BOD5 및 TP는 감소추세를 보이고 있으나, COD는 개선되지 않고 증가하는 추세를 보이고 있다. 동진강의 말단부의 경우 COD/BOD5의 비율이 지속적으로 증가하는 추세를 보이고 있어 상대적으로 난분해성 유기물질에 대한 관리의 중요성이 대두되고 있다. 이러한 COD 및 COD/BOD5의 증가 추세는 국내 4대강에서 전반적으로 나타나고 있는 추세로서, 정부는 2013년부터 하천 및 호소의 생활환경기준에 TOC 항목을 도입하여 2016년부터 호소환경기준의 대표항목을 COD에서 TOC로 대체하였으며, 폐수배출시설에 대해서도 점차적으로 확대 적용할 계획으로, 난분해성물질을 포함하는 총유기물질 관리를 위해서 수질 및 수생태계 환경기준에서 유기물질에 대한 환경기준을 BOD5와 COD에서 TOC로 변경하는 정책을 추진 중에 있다. 본 연구에서는 동진강 유역의 본류 및 지류에서 TOC등 유기물질의 시공간적인 분포와 오염원별 배출특성을 현장조사를 통해 조사 분석하였다. 조사 시기는 건기시, 강우시로 구분하여 수행하였으며 조사항목은 일반수질항목, 유기물질 항목, 유기물질 성상 분석 등에 대하여 수행하였다. 난분해성물질 관리를 위한 기초자료확보를 통하여 새만금호의 수질개선 및 목표수질 달성에 기여 할 것으로 판단된다.

• 한국생물공학회:학술대회논문집
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• 2002.04a
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• pp.355-358
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• 2002

In this study, we have tried to find the maximum microbial efficiency at the various dissolved oxygen (DO) concentration conditions in the treatment of pharmaceutical wastewater. Experiments of activated sludge process were performed to examine the relation between microbial activity and DO concentration in a continuous bioreactor. The reduction rate of COD (chemical oxygen demand) was low at the DO concentration between 0 ppm and 1.0 ppm, but it went higher and showed maximum between 1.5 ppm and 3.0 ppm. Then the COD reduction rate was quickly decreased above the DO concentration of 3.0 ppm.

• Applied Chemistry for Engineering
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• v.24 no.3
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• pp.279-284
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• 2013

In this study, the feasibility of a single-stage thermophilic aerobic process for the treatment of high-strength food wastewater produced from the recycling process of food wastes was examined to substitute anaerobic digestion process. Also, the removal and stability of thermophilic aerobic process were assessed according to the changes of hydraulic retention times (HRTs) and organic loading rates (OLRs). When the OLR increased from 9.2 to $37.2kgCOD/m^3d$, a pH value in R1 (HRT : 5 d) significantly decreased to 5.0, due to the organic acid accumulation. On the other hand, the pH value in R2 (HRT : 10 d) was stable and R2 showed the high removal of COD, organic acid and lipid, even though the OLR increased from 4.6 to $18.6kgCOD/m^3d$. In R1, the COD loading rates for COD removal was suddenly dropped, as the COD loading rate increased from 18.6 to $28.4kgCOD/m^3d$. In contrast, R2 showed that the COD loading rates for COD removal increased with regard to increment in the loading rates of 3.61, 7.05, 9.43 and $12.2kgCOD/m^3d$, indicative of the high COD removal efficiency. Therefore, the results demonstrated that over 10-d HRT, the high concentration of raw food wastewater was efficiently treated in the single-stage thermophilic aerobic process.

• Korean Journal of Environmental Agriculture
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• v.18 no.1
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• pp.54-60
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• 1999

Three different types of lab-scale anaerobic bioreactors, AF and two-stage ASBF-PR and ASBF-SP, were evaluated in treating swine wastewater by operating at $1{\sim}2$ days of hydraulic retention time with increasing organic loading rate upto 6.3 $kg-COD/m^3{\cdot}d$ at $35^{\circ}C$. Seeding the anaerobic bioreactors with waste anaerobic digester sludge from a municipal wastewater treatment plant was effective and a 40-day acclimation period was required for steady-state operation. Three anaerobic bioreactors were effective in treating swine wastewater with COD removal efficiency of $66.4{\sim}84.9$% and biogas production rate of $0.333{\sim}0.796m^3/kg-COD_{removed}{\cdot}d$. Increases of organic loading rate by increasing influent COD concentration and/or decreasing hydraulic retention time caused decreases in COD removal efficiency and increases in biogas production rate. At relatively high organic loading rate employed in this study, the treatment efficiency of AF and ASBF-PR were similar but superior than that of ASBF-SP, indicating that porosity and pore size of the media packed in the bioreactors are more important factors contributing the performance of to bioreactors than specific surface area of the media. TKN in swine wastewater must be removed prior to the anaerobic processes when anaerobic process is considered as a major treatment process since influent TKN concentration of $1,540{\sim}1,870mg/L$ to the bioreactors adversely affect the activity of methanogenic bacteria, resulting in decreases of treatment efficiency and biogas production rate by 50%.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.11
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• pp.2047-2058
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• 2000

The effects of operating parameters on performance of upflow anaerobic sludge blanket(UASB). anaerobic filter(AF), and two-stage anaerobic sludge bed filter (ASBF) bioreactors in treating swine wastewater were evaluated by operating the lab-scale bioreactors upto hydraulic retention time(HRT) of 1 day and organic loading rate (OLR) of $5.1kg-COD/m^3{\cdot}d$ for 200 days. Swine wastewaters of which characteristics were affected by types of hog raising and seasons contained high concentrations of COD, SS, and ammonia. Inoculation of the bioreactors with waste sludge from anaerobic treatment facility of local municipal wastewater treatment plant was effective in developing biomass in the bioreactors. Acclimation period of the bioreactors with swine wastewaters required approximately 40 days, but that for AF and two-stage ASBF, which were filled with media, was faster than VASB. The bioreactors showed high and stable COD removal efficiency of 77~91% at influent T-N concentrations of 370~800mg/L but low and unstable COD removal efficiency of 24~94% at influent T-N concentrations of 760~1,310mg/L. It is essential to remove ammonia prior to anaerobic treatment since the concentrations of ammonia in swine wastewaters showed toxic effects to methanogenic bacteria. The bioreactors were effective in treating swine wastewaters with COD removal efficiency of 78.9~81.5% and biogas generation rate of $0.39{\sim}0.59m^3/kg-COD_r$ at OLR of $1.1{\sim}2.2kg-COD/m^3{\cdot}d$: however, an increase of OLR by reducing HRT and increasing influent COD caused decrease of COD removal efficiency. The extent of decrease in COD removal efficiency was higher in UASB than AF and two-stage ASBF. AF and two-stage ASBF anaerobic bioreactors were effective in treating varing characteristics of swine wastewaters since they showed high and stable COD removal efficiency at high OLR due to effective retention of biomass by media and staging.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.3
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• pp.429-439
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• 2000

Various wastewater treatment technologies were applied for decolorization and disposal of the wastewater containing the pigments, which consist of Lake Red C(Barium) or/and Lithol Rubine(Calcium) pigments. In an application of ozonation $COD_{Mn}$ was generally decreased with an increase of amounts of ozone applied, however, the decolorization effect was not that good except for Lithol Rubine series. In an application of Fenton oxidation and electrochemical process, a good $COD_{Mn}$ removal effect for all the pigment wastewater and a slight decolorization effect for a part of Lithol Rubine series were observed. In an application of ultra filtration(UF) and reverse osmosis(RO), an excellent $COD_{Mn}$ removal and decolorization(almost 100%) effects of all the pigment wastewater were observed. Thus the water treated by the UF and RO could be reusable and thus save operating costs of the pigment manufacturing plants.

• 한국생물공학회:학술대회논문집
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• 2005.04a
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• pp.272-276
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• 2005

Food wastewater derived from three-stages methane fermentation system showed high concentrations of sCOD, T-N and $NH_{3}-N$. To treat the organic wastewater, the optimal operating conditions for high efficiency $UV/TiO_{2}$ photocotalytic system have been investigated. In the first process, wastewater was pre-treated with $FeCl_{3}. The optimum pH and concentration for coagulation were 4.0 and 2000 mg/L, respectively. Through this process, 52.6% of $COD_{cr}$ was removed. The second process was $UV/TiO_{2}$ photocatalytic reaction. The optimum conditions for the operation of $UV/TiO_{2}$ photocatalytic system developed in this lab have been studied. In this process, CODcr was removed from 2890 to 184 mg/L and T-N was removed from 2496 to 914 for 24 hours, respectively.