• 환경위생공학
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• 제19권3호
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• pp.13-21
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• 2004

This study was focused on the evaluation of Nanjido landfill site by leachate analysis. Several parameters, for example pH, BOD, $COD_{Mn},\;COD_{Cr}$, SS, TP, $NH_3-N$, Color, were selected as major leachate quality parameters. $BOD/COD_{Cr}$. was used to estimate the biodegradable portion in organic matter. Samples were collected at the leachate storage wells and leachate treatment facility inflow in each quarter of 2003. The results were as follows : 1. Inflow quality of treatment plant in 2003 was analysed as $pH\;7.3\~8.0,\;BOD\;12.4\~30.0mg/L,\;COD_{Mn}\;101.2\~130.3mg/L,\;COD_{Cr}\;122.5\~238.0mg/L,\;SS\;16.1\~115.3mg/L$, $T-P\;0.27\~0.80mg/L,\;NH_3-N\;208.0\~~354.0mg/L$, Color $110.3\~129.0$ unit. 2. $BOD/COD_{Cr}$ of inflow ranged between $0.07\~0.16$ indicating that the landfill had the properties of old-fill and organic portion in leachate was mostly persistent organic matter. 3. Though concentrations of BOD, COD, $NH_3-N$, Color in leachate storage wells were mostly higher in first landfill than in second landfill, $BOD/COD_{Cr}$ ranging from 0.03 to 0.20, showed reversely. 4. Correlation coefficient$(R^2)$ between color and other parameters related to organic matter showed mostly above 0.7 and especially highest value with $COD_{Mn}$ of 0.7985.

• 환경위생공학
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• 제12권3호
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• pp.19-29
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• 1997

The Chemical Oxygen Demand(COD) by potassium permanganate and potassium dichromate is used as a measure of the organic matter content of a sample. Newly proposed $K_{2}Cr_{2}O_{7}$ analysis method to be list at Korean Official Method was made from analysis and comparison of the experimental process on Japanese Industrial Standard(JIS), American Open Reflux and Closed Reflux Methods. New $K_{2}Cr_{2}O_{7}$ method had better the qualitative and reproducible COD results than another methods as a result of the tested four times repeatedly by using Lakes water Plant wastewater. The COD data ratio by $KMnO_{4}$ and $K_{2}Cr_{2}O_{7}$ methods was 2-3, 3, 2-17 and 3-4 times respectively when its data had compared with the lakes water and treated water of domestic and experimental wastewater, and raw wastewater which is generated at the manufacturing process of 6 steps and treated wastewater of chemistry source. Its ratio indicated to 2-4 and 2-3 times respectively on raw wastewater and plant wastewater of Chemistry, rubber and plastic, fiber, metal molding source. Oxidation ratio of benzene and ethyl benzene by $KMnO_{4}$ method was nearly zero, but the oxidation ratio by $K$_{2}Cr_{2}O_{7}$ method was 50%, 70% respectively. Also, Oxidation ratio of phenol by $KMnO_{4}$ and $K_{2}Cr_{2}O_{7}$ methods was 80%, 100% respectively, and trichloroethylene and tetrachloroethylene were not nearly oxidizd by $KMnO_{4}$ and $K_{2}Cr_{2}O_{7}$ methods. As the above contents, oxidation ratio and COD results by $KMnO_{4}$ and $K_{2}Cr_{2}O_{7}$ were different from various from various compounds and samples respectively.

• 한국환경과학회지
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• 제13권11호
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• pp.987-991
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• 2004

The purpose of this research is to evaluate the removal efficiencies of COD$\_$Cr/ and color for the dyeing wastewater by the different dosages of ferrous solution and H$_2$O$_2$ in Fenton process. In the case of H$_2$O$_2$ divided dosage for the Fenton's reagent 7:3 of H$_2$O$_2$ was more effective than 3:7 to remove COD$\_$Cr/ and color. The results showed that COD$\_$Cr/ was mainly removed by Fenton coagulation, where the ferric ions are formed in the initial step of Fenton reaction. On the other hand color was removed by Fenton oxidation rather than Fenton coagulation. The removal mechanism of COD$\_$Cr/ and color was mainly coagulation by ferrous ion, ferric ion and Fenton oxidation. The removal efficiencies were dependent on the ferric ion amount at the beginning of the reaction. However, the final removal efficiency of COD$\_$Cr/ and color was in the order of Fenton oxidation, ferric ion coagulation and ferrous ion coagulation. The reason of the highest removal efficiency by Fenton oxidation can be explained by the chain reactions with ferrous solution, ferric ion and hydrogen peroxide.

• 환경영향평가
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• 제8권1호
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• pp.81-92
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• 1999

This study discussed the appropriateness of organic matter indexes such as biochemical oxygen demand(BOD) and chemical oxygen demand with potassium permanganate($COD_{Mn}$) in water quality environmental standard of streams and lakes and the applicability of the items to water quality environmental standard to add or substitute COD with potassium dichromate ($COD_{Cr}$) and total organic carbon(TOC) being used as index of organic matter. And indexes of organic matter content and organic carbon concentration were distinguished between dissolved and particulate component in water sample to estimate their effect on pollutants loading in lake and stream. The ratio of $COD_{Cr}$/BOD was 5.1 under BOD concentration 3mg/L in river water quality environmental standard II, and 2.67 above it. This ratio was diminished to 2.04 when BOD concentration was more than 8mg/L, in river quality environmental standard IV. Also the ratio of $COD_{Mn}$/BOD showed 2.16 under 3mg/L(BOD), and 1.1 above it. This ratio is also diminished to 0.84 over 8mg/L(BOD). Accordingly, we should apply this ratio depending on the concentration level to add and change organic matter index of water quality environmental standard newly. The ratio $COD_{Cr}/COD_{Mn}$ both in lake and stream shows 2.37(r=0.986, p<0.001). But the ratios showed range of 2.34~2.50, which is no much difference of this ratio according to $COD_{Mn}$ concentration.

• 대한환경공학회지
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• 제34권8호
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• pp.517-522
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• 2012

본 연구에서는 오 폐수의 처리에 있어서 천연제올라이트 및 맥반석을 활용하여 오 폐수의 응집 및 흡착 메커니즘에 적용하여 수처리제로서의 타당성을 검토하고자 하였다. Jar test를 이용한 응집 전 후의 $COD_{Cr}$의 제거율을 평가하였다. 맥반석과 천연제올라이트를 수처리제로써 주입량을 400~1,200 g/L로 변화시켜 처리한 결과 $COD_{Cr}$ 최종제거율은 별 차이를 보이지 않았으나, 맥반석과 천연제올라이트를 $600^{\circ}C$로 소결하여서 도시하수를 처리할 경우 $COD_{Cr}$제거율이 각각 15%, 3%정도 상승하였다. 또한 맥반석과 천연제올라이트를 혼합하여 미용화장지 폐수처리에 적용하였으며, 또 다른 폐수처리제로서의 가능성을 검토하였다.

• 공업화학
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• 제21권6호
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• pp.610-615
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• 2010

본 논문에서는 실험실적 규모의 반응기에서 수용액상 bis(2-chloroethyl) ether (BCEE)의 오존산화반응에 대한 연구를 수행하였다. 오존산화반응은 BCEE 용액이 포함되어 있는 반응기 바닥에 오존 기체를 주입하여 진행하였으며 $50{\pm}10mg/L$의 오존 농도로 80 min 반응시켜 완결하였다. BCEE의 오존산화처리 효율을 $BOD_5$, $COD_{Cr}$, 그리고 TOC의 변화로 측정하였다. BCEE의 오존산화반응결과 $COD_{Cr}$가 62.79%, TOC의 57.25% 감소된 것은 생분해 가능한 중간체가 생성되었음을 알 수 있다($BOD_5/COD_{Cr}$ = 0.39). 본 연구의 결과는 BCEE와 같은 비생분해성 물질을 포함하는 폐수가 오존산화처리 후에 생물학적 처리를 함으로써 성공적으로 처리될 수 있다는 것을 보여주었다. $30^{\circ}C$에서 유사 1차 반응속도 상수는 $2.00{\times}10^{-4}sec^{-1}$, 활성화 에너지는 $10.02kcal{\cdot}mol^{-1}$로 나타났다.

• 대한환경공학회지
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• 제35권10호
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• pp.703-709
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• 2013

실험실적 규모의 순환형 회분식 반응기에서 Dimethyl phthalate (DMP)성분을 효율적으로 제거하기 위하여 $Al_2O_3$촉매의 주입 그리고 반응온도의 조건을 달리하여 오존산화 반응을 수행하였다. 산화 반응에서 오존의 유량은 $1.0Lmin^{-1}$, 오존 농도를 $300{\pm}10mgL^{-1}$로 일정하게 유지 하였으며, 산화 반응이 진행되는 60분 동안 10분 간격으로 pH, $COD_{Cr}$와 TOC를 측정하여 이를 비교 분석하였다. $O_3/Al_2O_3$에서는 $O_3$ 단독 공정에 비해 $COD_{Cr}$ 및 TOC 측정값에 기초한 제거효율은 증가하였으며, $20^{\circ}C$에서 $COD_{Cr}$ 및 TOC의 반응속도상수는 $3.65{\times}10^{-4}sec^{-1}$, $2.52{\times}10^{-4}sec^{-1}$, 활성화 에너지는 $0.75kcal{\cdot}mol^{-1}$, $0.70kcal{\cdot}mol^{-1}$로 각각 나타났다.

• 한국미생물·생명공학회지
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• 제24권5호
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• pp.597-603
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• 1996

This study was carried out to examine degradation characteristics of microalgae Chlorella vulgaris in methane fermentation. We measured COD and VS reduction, gas and methane productivity, VFA (volatile fatty acid), respectively. Then we calculated material balance and hydrolysis rates in soluble and solid material. The substrate concentration was controlled from 14 gCOD$_{cr}$/l to 64 gCOD$_{cr}$/l in batch cultures, and HRT (hydraulic retention time) controlled from 2 days to 30 days in continuous experi- ments. The results were as follows. In batch culture, accumulated gas productivity increased with the increase of the substrate concentration. The SS and VSS was removed all about 30% increase of substrate concentration and the most of the degradable material removed during the first 10 days. The curve of gas and methane production rate straightly increased until substrate concentration is 26 gCOD$_{cr}$/l. In continuous culture experiments, the removal rates at HRT 10days were 20% for total COD and TOC, respectively. At longer HRT, there was no increase in the removal efficiency. At HRT 15 days, the removal rates were 30% for SS and VSS, respectively. Soluble organic materials were rapidly degraded, and so there was no accumulated. Soluble COD concentration was not increase regardless of HRT-increasing. That meaned the hydrolysis was one of the rate-limiting stage of methane fermentation. The first-order rate constants of hydrolysis were 0.23-0.28 day$^{-1}$ for VSS, and 0.07-0.08 day$^{-1}$ for COD.

• 한국물환경학회지
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• 제31권1호
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• pp.29-34
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• 2015

The aim of this study is to understand the limitation of organic pollutant indexes ($BOD_5$, $COD_{Mn}$, $COD_{Cr}$) and estimate to set the TOC standard by comparing oxidation rates of $BOD_5$, $COD_{Mn}$, $COD_{Cr}$ and TOC based on the 487 organic compounds and 11 effluents from industrial wastewater containing various and unknown organic compounds. The range of ratio of theoretical oxygen demand (ThOD) to theoretical organic carbon (TOCt) was 0.00~5.33 and average ratio of classes of organic compounds was 2.68~3.70. According to classes of organic compounds, the average ratio of $O_2/C$ was 1.2 (range : 1.02~1.39). The order of oxidation rate for 15 organic compounds was TOC (90.7%) > $COD_{Cr}$ (88.8%) > $BOD_5$ (54.4%) > $COD_{Mn}$ (30.8%) indicating the lower oxidation rate of $BOD_5$ and COD compared with TOC. The ranking for average oxidation rate was $COD_{Cr}$ > $COD_{Mn}$ > $BOD_5$ indicating that $BOD_5$, $COD_{Mn}$ could be underestimated comparing with ThOD of organic compounds in case of industrial wastewater containing high concentration of refractory organic compounds. Most of the relationships between organic pollutant indexes and TOC were higher than 0.9. The ratio of TOC to organic compound indexes decreased in the order : $COD_{Cr}$ (3.4) > $COD_{Mn}$ > (1.9) > $BOD_5$ (0.7).

• 한국환경과학회지
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• 제7권1호
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• pp.81-88
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• 1998

This study was conducted to assess the characteristics of plgment wastewater and the removal rates of appropriate treatment by physical, chemical and biological Process, and the possibility of reuse for effluent. Based on the results, the wastewater qualities of pigment were pH 5.1$\pm$3.4, temperature 43.0$\pm$ 15.$0^{\circ}C$, BOD 1,431.4$\pm$589.6mg/l, COD 2,282.8$\pm$466.5mg/l, turbidity 1,340$\pm$820NTU, color 243.0$\pm$147.0unit, Pb 36.5$\pm$9.5mg/l and $Cr^+6$ 10.3$\pm$ 1.3mg/l, respectively. The removal rates of adsorption by activated carbon and filter process were BOD 40.6% , COD 57.0% , turbidity 89.6%, color 87.2%, Pb 86.0% and $Cr^+6$ 10.6%, respectively. And the removal rates of reduction, neutralization, coagulation and aP floatation process were BOD 18.2%, COD 24.3%, turbidity 74.3%, color 56.7%, Pb 68.6% and $Cr^+6$ 97.8%, respectively. The removal rates of activated sludge process were BOD 95.9%, COD 86.0%, turbidity 27.8%, color 25. 2%. Pb 26.9% and $Cr^+6$ 50.0% , respectively. The total removal rates of treatment by physical, chemical and biological process were BOD 98.0% , COD 95.4%, turbidity 98.1%, color 95.8%, Pb 97.0% and $Cr^+6$ 99.0%, respectively. According to the test results for possibility of reuse with coagulation-adsorption by activated carbon process of effluent, COD was higher than that of raw water and others were similar to that of raw water thus, it Is considered to be reused.