• Journal of Korean Society of Environmental Engineers
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• v.22 no.12
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• pp.2239-2245
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• 2000

For the treatment of wastewater being discharged in large quantities as in these modern times, qualitative and quantitative concepts should be introduced in consideration of the recycling. In view of a qualitative concept, high rate aeration process is known as the most effective process up to now. However, Lee suggested UHR process showing the superiority over high rate process in treatment rate and quantity. Therefore, this study was performed to investigate the basic sphere of design and treatment quality, such as applicable $BOD_5$-loading and influent wastewater concentration of UHR process, based on Lee's suggestions1). Consequently, this process showed applicable $BOD_5$-loading of $2.2{\sim}7.0kg-BOD_5/kg-MLSS{\cdot}day$, exceeding three times or more of high rate process with maximum applicable loading of $2.25kg-BOD_5/kg-MLSS{\cdot}day$. Meanwhile, with the range of influent wastewater concentration from 200 to 450 mg/L. it showed the treatment rate from 94.7 to 97.3%, it indicated very good condition. In view of quantitative concept of treatment, UHR process is considered an epoch-making treatment process being superior to existing ones.

• Journal of Korean Society on Water Environment
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• v.31 no.1
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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).

• Journal of Environmental Impact Assessment
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• v.26 no.1
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• pp.68-77
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• 2017

In order to estimate the non-point pollution loads from each watersheds among 209 watersheds, the calibration and validation of HSPF model were carried out based on 2012 in 2013 years. In the case of flow rate, R2 of calibration and validation were 0.71~0.93 and 0.71~0.79, which were relatively good values. With the respect to calibration of water quality, % differences between measured and simulated values were 0.4 ~ 9.7 of DO, BOD 0.5 ~ 30.2% and TN 1.9~28.6% except for Hwhangkang B site. In case of validation, DO was 0.2 ~ 13.7%, BOD 1.3~23% and TN 0.5~24.3% excluding Hwhangkang B. However, since the concentration of TP was very small compared with other items, the range of difference was large as 0.8~55.3%. level. As the result of calculating annual accumulative BOD loads for each watershed, it was found that RCH 123 (Uryeong, Gyeongsangnamdo), RCH 121 (Jinju, Gyeongsangnamdo) and RCH 92 (Daegu) were the high ranked. The unit watersheds including various landuse type susch as forest and agricultural sites in mainstream areas have a higher BOD nonpoint pollution load than those in dam regions. However, the results of the annual cumulative loading of the basins for nutrients did not appear to be consistent with the BOD annual cumulative loading ranks. Other factors that represent watershed characteristics such as landslope and soiltypes, including landuse pattern, have been found to be closely related to nonpoint pollutant loads.

• Journal of the Korea Organic Resources Recycling Association
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• v.19 no.2
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• pp.55-69
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• 2011

Use of disposer at the kitchens of Korean apartments is inevitable in treating their foodwaste having a water content of more than 80%. Also we have to ensure that this extra disposer-foodwaste BOD loadings be treated properly by installing/operating a pre-treatment system before this wastewater enters public sewer system. However, the degree of BOD removal should not be excessive since a BOD/N ratio higher than 5 is required for removing N/P at a municipal wastewater treatment plant. The removal of BOD/N in the pretreatment system rather than BOD alone can be an alternative solution in solving this problem. The particles separated by sedimentation, screen or packed-bed can be anaerobically digested at apartment sites to generate biogas that can be used for simple digester heating and to generate volatile fatty acids (VFAs) for nitrogen removal. We suggest that Korean government grants a temporary license (say for 5 years) to foodwaste treatment companies in collaboration with apartment construction companies which may do business and develop various kinds of disposer-foodwaste treatment systems in diverse wastewater discharge systems of Korean apartments.

• Journal of Korean Society of Water and Wastewater
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• v.21 no.5
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• pp.589-599
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• 2007

This study was conducted to investigated the removal efficiency of BOD and nutrient for the treatment of low strength municipal wastewater by a biological nutrient removal system. In this experiment, the effect of operating parameter including HRT of 7.0hr, BOD/TN ratios of 2.62~4.08, internal recycle of 50~300%, and return sludge of 50~100%, were studied during winter season. Efficiencies of organic matter and T-P removal and denitrification were not significantly affected by the change of temperature in winter season. However, the specific nitrification rate and nitrification efficiency decreased at low temperature. Besides, denitrification efficiencies increased with increasing BOD/TN ratios. It was also found that the internal recycle and return sludge ratio below 50% is required for the effective denitrification of low strength municipal wastewater. With operating mode 4 of the optimum, the effluent BOD, T-N and T-P concentration were obtained to average 5.8, 14.6, and 0.84 mg/L, respectively. The temperature-activity coefficient (${\theta}$) of specific nitrification rate, specific denitrification rate and specific phosphorus uptake rate were obtained 1.044, 1.017, 1.028, respectively.

• Korean Journal of Environmental Agriculture
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• v.27 no.2
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• pp.111-119
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• 2008

This study was conducted to evaluate water quality and pollutant loads on small agricultural watershed in Jeonbuk province. The EC level of investigated watershed ranged from 0.07 to 0.52 dS/m, BOD level ranged from 0.1 to 5.0 mg/L, and $COD_{Cr}$ level ranged from 0.6 to 17.7 mg/L. As above, contents of water quality indicators covered wide range, but each indicator was alike in mean content every other year. The contents of EC, $Ca^{2+},\;Mg^{2+},\;K^+\;and\;Na^+$ were decreased in rainy season, but the contents of BOD, $COD_{Cr},\;COD_{Mn}$, T-N and T-P were not greatly different as compared to dry season. And high content of SS showed substantial sediments near the surface flow out and influence on water system in rainy season. The pollutant loads measured in terminal of watershed were $9.6{\sim}757.9$ kg/day for BOD, $51.2{\sim}1418.5$ kg/day for T-N and $0.3{\sim}44.7$ kg/day for T-P. The pollutant loads of BOD, T-N and T-P in rainy season increased several times as compared to dry season. In rainy season, watershed with more than 30% in the proportion of paddy field to land showed relatively low discharge and pollutant loads in comparison to watershed with less than 30%. The discharge of watershed in rainy season increased 5.7times compared with the dry season in watershed with less than 30% in the proportion of paddy field to land, whereas was only 2.3times in watershed with more than 30%. The correlation coefficient($R^2$) of regression between discharge and pollutant loads of T-N were higher than those of BOD and T-P.

• Proceedings of the Korea Water Resources Association Conference
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• 2016.05a
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• pp.524-524
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• 2016

본 연구에서는 홍천 자운지구 고랭지 농업지역을 대상으로 장기간의 유역조사와 하천 모니터링을 통해 관측된 축척 데이터를 이용하여 비점오염저감 효과를 정량화하고 추후 모니터링 자료로서 탁수와 비점오염원 저감시설의 저감효과와 비점오염원의 효율적인 관리를 위한 기초자료를 제공하고자 하였다. 모니터링 결과 소양호 유역의 오염부하(1차 강우사상) 중 홍천군 자운지구의 유역단위 비점오염 저감효과의 분석에는 강우량과 단위면적당 오염부하를 이용하였으며, 자운천은 SS 5,396,761 kg, COD 82,261 kg, BOD 57,329 kg, T-N 68,711 kg, T-P 3,091 kg이었으며, 오염부하(2차 강우사상)는 SS 320,293 kg, COD 34,588 kg, BOD 22,350 kg, T-N 48,954 kg, T-P 640 kg으로 나타났다. 또한 소양호 유역의 EMC(1차 강우사상) 중 자운천은 SS 829.9 mg/L, COD 12.7 mg/L, BOD 8.8 mg/L, T-N 10.567 mg/L, T-P 0.475 mg/L 이었으며, EMC(2차 강우사상)는 SS 68.6 mg/L, COD 7.4 mg/L, BOD 4.8 mg/L, T-N 10.487 mg/L, T-P 0.137 mg/L로 나타났다. 소양호 유역의 단위면적당 오염부하(1차 강우사상) 중 자운천은 SS 402.0 kg/ha/event, COD 6.1 kg/ha/event, BOD 4.3 kg/ha/event, T-N 5.118 kg/ha/event, T-P 0.230 kg/ha/event 이었으며, 오염부하(2차 강우사상)는 SS 23.9 kg/ha/event, COD 2.6 kg/ha/event, BOD 1.7 kg/ha/event, T-N 3.646 kg/ha/event, T-P 0.048 kg/ha/event로 나타났다. 오염부하에서는 1차 강우에 비해 2차 강우에서는 SS 5,076,468 mg/L, COD 47,673 mg/L, BOD 34,979 mg/L, T-N 19,757 mg/L, T-P 2451 mg/L로 1차 강우사상에 비해 오염부하가 낮은 것으로 나타났다. 또한 EMC에서는 1차 강우에 비해 2차 강우에서는 SS 761.3 mg/L, COD 5.3 mg/L, BOD 4.0 mg/L, T-N 0.080 mg/L, T-P 0.338 mg/L로 1차 강우사상에 비해 EMC가 저감되었다. 단위면적당 오염부하는 1차 강우에 비해 2차 강우에서는 SS 378.1 mg/L, COD 3.5 mg/L, BOD 2.6 mg/L, T-N 1.472 mg/L, T-P 0.182 mg/L로 1차 강우사상에 비해 EMC가 저감되었다. 강우량과 강우강도 그리고 영농활동의 시기에 따른 EMC와 단위면적당 오염부하는 큰 차이를 보였으며, 예년에 비해 적은 강수량으로 인해 탁수와 비점오염부하의 배출이 상대적으로 적었던 것으로 판단된다. 소양호 유역과 같은 넓은 유역에서 시행되는 비점오염원의 저감연구는 오랜 시간 동안 자료를 축적해야 유의미한 평가가 이루어질 수 있으므로 장기적이고 지속적인 모니터링을 통한 유량 데이터 자료구축과 수질분석뿐만 아니라, 발생되는 비점오염 물질의 관리를 위한 체계적인 연구가 지속되어야하며, 아울러 농민의 인식도 변화 등을 포함하는 많은 인자들을 정밀히 조사하고 다각도로 분석하여 저감효과에 대한 지속적인 연구가 필요하다.

• Journal of Environmental Health Sciences
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• v.11 no.2
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• pp.17-27
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• 1985

The objectives of this study is to examine efficiency of swinery wastewater treatment by trickling filters' pilot plant. The results of this study are as follows: 1. The characteristics of sample. The BOD$_5$ was from 2,450 to 2,880mg/l, COD(KMnO$_4$ acid method) was from 910 to 1,064mg/l, and SS was from 920 to 990mg/l. The pH of influent was from 7.3 to 7.6, and the temperature of water was from 17.0$\circ$C to 22.5$\circ$C. 2. For experiment by recirculation, the BODs removal efficiency is 65.2% at recirculation ratio (r)=0, and 70.7% at r=1. The ramoval efficiency of this study is higher than NRC formula of U.S.A.. The recirculation is not significant effect on removal efficiency. 3. For experiment by hydraulic load, the BOD$_5$ removal rate decreased from 73.1% at $3.1m^3/m^2\cdot d$ to 65.3% at $9.2m^3/m^2\cdot d$. The design formula of this study which shows the removal rate of soluble BOD is $Le/Li =10^{-0.24} D/Q^{0.24}$ (Q: hydraulic load, D: depth of filter). 4. For experiment by organic load, the BOD$_5$ removal rate is increased from 70.2% at $0.77kg/m^3\cdot d$ to 75.4% at $4.28kg/m^3\cdot d$. We can obtain the straight line y=0.749 x (y: removed BOD, x :applied BOD) by the least squares method. 5. We can know that trickling filters is strong with the hydraulic load and the organic matter shock load. Here, we can judge that trickling filters is a good method for the treatment of swinery wastewater which containing high concentrated organic matter.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.8 no.3
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• pp.129-138
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• 1988

In order to develop the design and operational criteria in sewage treatment by indirect aerating submerged biofilter, experimental investigations were performed for the reasonable oxygen supply and effecting factors of treatment efficiency. The experiments were executed for the up-flowing synthetic wastewater and aerated water in the submerged biofilter at $20^{\circ}C$. The obtained results are as follows: 1) Appropriate mean diameter of gravels was about 11mm. 2) $BOD_5$ loading rate based on biofilter volume was more reasonable than that on surface area of gravel for operational criteria. 3) To remove the influent $BOD_5$ more than 90%, $BOD_5$ loading rate must be less than $1.0kg-BOD_5/m^3{\cdot}d$ and circulating flowrate must be more than $189m^3/m^3{\cdot}d$. 4) Reaction rate coefficient $K_1$ is related to diameter of gravel and circulating flow rate based on biofilter volume.

• Journal of Marine Life Science
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• v.2 no.2
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• pp.49-55
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• 2017

Four chemical treatments with hydrogen peroxide (H₂O₂), copper sulfate (CuSO₄), potassium permanganate (KMnO₄) and chlorine (Cl₂) were applied to the effluent pond water of a hybrid striped bass saltwater recirculating aquaculture system to compare their oxidation power. Four chemicals were applied at concentrations of 0 (control), 1, 5, 10 and 20 mg/l. An additional concentration of 40 mg/l was included in the chlorine treatment. Water samples from four hybrid striped bass ponds were tested with KMnO₄ and Cl₂. H₂O₂ did not reduce any of BOD, COD and chlorophyll-a, and copper sulfate was only effective on chlorophyll-a for the effluent pond. Removal efficiencies for chlorophyll-a by copper sulfate were 19.2%, 37.5%, 54.2% and 74.1% dose-dependently. Potassium permanganate effectively removed the BOD, COD and chlorophyll-a. The COD removal rates in four fish ponds varied from 15.9% to 31.6% at the concentration of 10 mg/l. Interestingly, Cl₂ did not reduce the BOD and COD at all, but the BOD and COD instead increased drastically with increasing the Cl₂ concentration. The pond water with the highest initial BOD and COD values among the fish ponds tested increased by 350% in the BOD and 150% in the COD at 20 mg/l. Furthermore, Cl₂ did not significantly reduce any types of solid matter in this study, while KMnO₄ seemed to reduce some extent volatile dissolved solid in the fish pond.