• Journal of Environmental Health Sciences
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• 제19권3호
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• pp.36-40
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• 1993

The objective of this research was to retrofit an on-site sewage treatment system suitable to current situation of Korea to reduce the pollution loading and preserve the invaluable water resources. Operation at the F/M ratio of 0.1 kg. BOD/kg MLSS day showed 87.1% BOD removal efficiency and 84.5% COD removal efficiency, and its effluent concentration was 6.4 mg/l as BOD and 21.7 mg/l as COD. Average removal of total nitrogen showed high removal efficiency of 80%.

• Proceedings of the Korea Concrete Institute Conference
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• 한국콘크리트학회 2006년도 춘계 학술발표회 논문집(II)
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• pp.117-120
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• 2006

The purpose of this study is to efficiently treat the sewage sludge discharged from sewage treatment plants and evaluate the feasibility of the manufacture of lightweight aggregates(LWA) using a large quantity of sewage sludge. Sintered lightweight aggregate from sewage sludge is experimentally manufactured with various mass ratios of clay to sewage sludge by a pilot plant, and is tested for density, water absorption and crushing value. Their physical properties are compared to those of a commercial sintered lightweight aggregate. As a result, an experimentally manufactured lightweight aggregate is similar or superior in physical properties to the commercial lightweight aggregate. The manufactured lightweight aggregate could be used for structural concrete and non-structural concrete.

• Journal of Korean Society on Water Environment
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• 제25권3호
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• pp.452-458
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• 2009

This study was carried out to assess the effect of discharge loading at sewage treatment plants (STP) on water quality in Kyoungan stream. The seasonal variations of water quality (BOD, COD, SS, TN, and chl.a) at site 1(Mesanribo) were similar with those at site 2(Sehabo). BOD, COD, SS, and chl.a concentration were also similar except for TN and TP concentration which were lower than those at site 1. The BOD, COD, TN, TP and chl.a concentration at site 2 in dry period were higher than that of wet period. The ratios of BOD, TP, COD, SS discharge loading at all STP in Kyoungan stream watershed to delivery loading at site 2 were 0.69, 0.54, 0.48, 0.31, and 0.26 on average, respectively. Both site 1 and site 2, the seasonal variations of discharge loading at STP did not showed any relationship with those of water quality. The mean ratios of inflow loading at site 1 to delivery loading at site 2 were relatively high that ranged from 0.43 to 0.61. In dry period, the ratios of discharge loading at STP in Sehabo watershed to delivery loading at site 2 were below 0.2 except for BOD (0.24), and decreased <0.1 in wet period. While, SS loading from watershed between site 1 and site 2 to delivery loading at site 2 ratios increased in wet period.

• Journal of Korean Society of Environmental Engineers
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• 제36권8호
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• pp.549-553
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• 2014

Variation of sewage sludge interface height and flow rate by rainfall were applied to the actual public sewage treatment plant, and the efficiency of sewage treatment was evaluated by measuring $BOD_5$, $COD_{Mn}$, SS, T-N, and T-P. When both flow and interfacial height are increased, the treatment efficiencies in terms of the five water pollutants are decreased. Among them SS is the most critical pollutant in rainfall. When 0.5 Q inflow was applied, the efficiencies were 74.2% at the sludge interface height of 0.5 m, 76.4% at 1.0 m, 70.2% at 1.5 m, and 60.7% at 2.0 m. When 1.0 Q inflow was applied, the efficiencies were 71.7% at the sludge interface height of 0.5 m, 71.9% at 1.0 m, 46.4% at 1.5 m, and -38.0% at 2.0 m. Operation at 2.0 Q~2.0 m and 3.0 Q~1.0 m above the sludge rising phenomenon occurred causing adverse effects on the public bodies. If the flow rate increases, the processing efficiency is reduced from 74.2% to 17.3%, even though the sludge interface height was maintained at 0.5 m, so that the inflow adjustment was most important during rainfall, and the interface height of 1.0 m should be maintained to minimize the adverse effect on public water system.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 한국항해항만학회 2006년도 International Symposium on GPS/GNSS Vol.1
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• pp.387-392
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• 2006

There have been several problems in treating shipboard sewage due to special environmental conditions of ship, such as limited space, rolling and pitching, change of temperature and so on. It was suggested that Sequence Batch Reactor (SBR) might be suitable process for overcome these problems in terms of small size, high capacity of treating wastewater and full automation. In this study a SBR process was employed for biological treatment of organic wastes in the shipboard sewage. This process was able to remove nitrogen and phosphorus as well as organic matter efficiently. More than 95% of chemical oxygen demand(COD) were removed. In addition, about 97% of total nitrogen (T-N) was reduced. The total phosphorus(T-P) reduction averaged 93%. A disturbance operation caused by the treatment of Methylene Blue Active Substances(MBAS) was not observed.

• 수도
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• 제23권5호통권80호
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• pp.31-45
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• 1996

• 수도
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• 통권69호
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• pp.104-119
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• 1994

• Journal of Korean Society on Water Environment
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• 제29권6호
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• pp.808-812
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• 2013

A new type of microbial fuel cell (MFC) with anaerobic membrane filter was designed to produce bioelectricity and to treat domestic sewage at relatively high organic loading rate (OLR) of $6.25kgCOD/m^3/day$ and short hydraulic retention time (HRT) of 1.9 h. A following aeration system was applied to ensure effluent water quality in continuous operation. Glucose was supplemented to increase the influent concentration of domestic sewage. Influent substrate of 95% was removed via the MFC and following aeration system and the corresponding maximum power density was $25.6mW/m^3$. External resistor of $200{\Omega}$ and air-cathode system contributed better MFC performance comparing to $2000{\Omega}$ and dissolved oxygen as a catholyte.

• Journal of environmental and Sanitary engineering
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• 제20권3호
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• pp.36-43
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• 2005

Prior to the study of the sewage treatment methods, water quality for Gwangju sewage of fluent was investigated from January to December, 2004 for sewage water reuse. Monthly mean values of BOD, SS, turbidity, total phosphorus and color were 4.1 mg/L, 2.9 mg/L, 0.8 NTU, 1.3 mg/L, and 27 unit, respectively. Jar-test was performed to investigate the removal efficiency of pollutants under the coagulation conditions of fast mixing for 5 min, slow mixing for 15 min and precipitation for 1hr. Here, alum and polyaluminium chloride (PAC) were used as coagulants to reduce color, turbidity, total phosphorus (TP) and total organic carbon (TOC) in sewage effluents. The results showed that PAC gave better efficiency in removing turbidity and dissolved phosphorus than alum. It was also found from the relative molecular weight (RMW) distribution analysis that organic matter over 1,000 Dalton (Da) was easily removed by coagulation and subsequently MF treatment, while it was not effective for less than 500 Da. Based on tis result, Natural organic matter (NOM) with lower molecular weight (< 500 Da) may cause harmful disinfectant by-product (DBP) after chlorine treatment. Thus, activated carbon adsorption seems to be required for the complete removal of DBP in the hybrid system.

• Korean Journal of Environmental Agriculture
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• 제19권5호
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• pp.426-432
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• 2000

Field experiment was performed from August 1996 to December 1999 to examine the feasibility of constructed wetland system for sewage treatment in rural areas. A pilot system was installed in Konkuk University and the effluent of septic tank for school building was used as an influent to the wetland treatment basin. The system was composed of sand and reed, and operated continuously including winter time. Average removal rate of about 70% was observed for BOD, COD, and SS, about 50% for T-P, and about 25% for T-N. The reason for poor T-N removal might be due to high loading rate and short retention time. The system demonstrated satisfactory effluent concentration and stable performance in growing season. And it also worked adequately in wintertime even below $10^{\circ}C$ without freezing, and removal was still significant. The amount removed in BOD, COD, and SS was almost the same as in the growing season, and the amount removed in nutrients was about half of the one in growing season. Overall performance of the experimental system was compared with existing data base (NADB, 1994), and it was within the range of general system performance. As study period increased, removal rates for BOD, COD, SS, and T-P were consistently maintained and even enhanced, but removal rate for T-N decreased slightly. Wetland system was thought to be a feasible alternative for sewage treatment in rural area considering its low cost and low maintenance requirement. However, the effluent of the experimental wetland system often exceeded current effluent water quality standards, therefore, further treatment could be required if the effluent should be discharged to public waters. Wetland system of interest locates in rural area and is a part of rural ecosystem, therefore, ultimate disposal of reclaimed sewage for agricultural purpose or subsequent land treatment might be available and further research in this matter is recommended.