• Korean Journal of Environmental Agriculture
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• v.18 no.4
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• pp.310-315
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• 1999

The feasibility of an absorbent biofilter system was examined for rural wastewater treatment. Hydraulic loading rates varied from 50 to 250 cm/day. Effluent of the septic tank was fed into the absorbent biofilter, and small ventilation fan was provided to supply air at the rate of 250 L/min to aerate the biofilter. The biofilter system demonstrated high removal rates for $BOD_5$ and TSS at the loading rate of 150 cm/day, generally meeting the Korean effluent water quality standard of 20 mg/L applicable to both. The nutrient removal was less satisfactory than the results of $BOD_5$ and TSS, but it was within the expected range of biological treatment processes. Considering the abnormally high influent concentration of nutrients during the experiment, better performance results could have been obtained if ordinary domestic wastewater was used. The system performance was not significantly affected by the hydraulic loading up to 150 cm/day, which is far more than the loading limit of the sand filter systems. Maintenance requirement was minimal, and no problems with noise, odor, flies or sludge arose. Since the biofilter system can be operated at a distance, operation in remote rural area and multi-system connected to one control office might be advantageous to the rural area. Overall, considering the cost-effectiveness, stable performance, and minimum maintenance, the biofilter system was thought to be a competitive alternative to treat wastewater in Korean rural communities.

• Journal of Wetlands Research
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• v.10 no.2
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• pp.105-114
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• 2008

Growth in population and urbanization has progressively increased the loadings of pollutants from non-point sources as well as point sources. Separated sewer overflows(SSO) have been considered as a major cause of water-quality deterioration of natural water-courses in the vicinity of the heavily urbanized areas. The factors defining the magnitude and occurrence of SSO are site-specific. It is important to know exact properties of pollutants contained in SSO to address water quality impacts that are caused by SSO inputs to the receiving waters. Site and event parameters found to have significant influences on urban runoff pollutant EMCs include total event rainfall, antecedent dry period, rainfall intensity. In this study, a field survey was carried out in some selected areas of Cheongju city. Literature from previous similar studies was consulted and some important factors affecting the runoff characteristics of urban drainage areas were analyzed for some selected survey points. It was found that the factors most affecting BOD are the number of dry days prior to rainfall and the intensity of the rainfall. The factor most affecting CODcr is the number of dry days prior to rainfall. The factors most affecting SS are the amount of rainfall and the number of dry days prior to rainfall. The factor most affecting TN is the amount of rainfall. The factor most affecting TP is the amount of rainfall and the number of dry days prior to rainfall.

• Proceedings of the Korean Society of Rural Planning Conference
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• 1996.03a
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• pp.17-20
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• 1996

지난 20여년 동안 급격한 도시화, 산업화를 추진하는 과정에서 대기와 물의 오염, 쓰레기 공해 등 자연환경의 훼손과 피폐화가 심각한 상태에 이르렀다. 또한, 과다한 농약. 비료의 투입과 농사료에 의한 축산으로 높은 농업 생산성을 이룩하였으나, 이로 인하여 토양오염과 하천과 지하수 수질오염, 식생, 곤충 등 생태계 파괴 등의 문제가 대두되고 있다. 최근, 수자원 함양, 수질 정화 등의 순기능으로 농업의 환경 기여 효과가 큰 것으로 발표되었다. 논으로 부터의 오염부하는 생활 오수나 공장폐수 등에 비하여 정성적으로는 미미한 것이 사실이며, 실제로 관개수로 유입되는 영양물질이 작물에 의하여 흡수되므로 물질 수지적 측면에서 수질정화 효과를 나타낸다는 개념이다. 그러나, 오염된 관개수와 함께 유입되는 물질과 영농 목적으로 투입되는 다량의 비료와 농약, 제초제 등의 독성 물질 등에 의한 생태 환경의 변화 등에 대한 영향 등에 관한 종합적 관점에서의 효과는 불분명한 것이 현실이다. 특히, 폭우시 농경지로부터 유출에 의한 토사유실과 영양 물질이 손실 등에 대한 정량적 평가가 부족하며, 이로 인한 유역에서의 수문, 수질, 생태환경 등을 정량적 분석이 부족한 것이 현실이다. 따라서, 농업유역에서의 수문과 물질순환과정을 정량적으로 분석하고, 이를 통하여 주요 오염원을 파악하고, 효과적인 조절방법 등을 위한 유역수질관리 기술개발과 함께, 경지와 주변 생태계에 미치는 영향 등을 극소화할 수 있는 종합적인 연구가 필요하다. 특히, 관개시설 등 농업기반조성사업에 따른 인위적인 수문환경으로 인한 농경지내에서의 수문.물질순환 기작의 변화 등을 고려한 수질 및 생태환경에 판한 종합적인 모니터링, 모델링 등의 접근이 필요한 것이다. 본 논문에서는 $.$95 농림수산특정연구 중 첨단연구과제로 추진 중인 농업생태환경 및 종합적 환경관리 시스템 개발연구의 목표와 내용, 범위 등을 소개하고, 농촌지역에서의 건전한 환경관리를 위한 유역관리기술 개발의 방향 등을 정리하도록 한다.

• Proceedings of the Korea Water Resources Association Conference
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• 2005.05b
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• pp.1528-1532
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• 2005

본 연구는 유역통합관리를 위한 사전 단계로 유역의 물순환에 대해 구체적이고 정량적으로 문제점을 파악하는데 그 목적이 있다. 중유역별로 현장답사 및 다양한 지수를 이용하여 치수, 이수, 수질 등의 측면에서 제시될 수 있는 문제점을 파악하였다. 홍수피해잠재능(PFD)을 이용하여 수문요소뿐만 아니라 사회경제적인 요소까지 포괄하여 홍수에 대한 잠재적인 피해 취약도를 조사하였고, 건천화 지수(SDI)를 이용한 하천의 건천 정도를 도출하였으며, 중유역별 불투수 면적 비율(IAR)을 이용하여 수질관리 방안을 분류하였다. 또한, 복개하천 현황, 단순하게 운영되고 있는 저수지 현황, 하천수의 취수, 지하수의 이용, 하천수가 하천바닥으로 손실되는 여부, 오수의 하천 유입 등을 조사하여 치수 이수, 수질관리 측면에서 문제가 되는 중유역을 도출하였다. 이렇게 중유역별로 정량적 또는 정성적으로(qualitatively) 제시하는 방법은 유역통합관리를 위한 조사사업 등에 도움이 될 것이며 향후 유역통합관리 방안을 올바르게 수립하는데 기초 자료로 활용될 수 있다.

• Journal of Environmental Health Sciences
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• v.32 no.5 s.92
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• pp.451-461
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• 2006

Laboratory scale experiments were conducted to study the conversion of sludge from conventional activated sludge to nitrogen-phosphorus removal sludge using two types of sequencing batch reactor (SBR) systems, a conventional SBR and sequencing batch biofilm reactor (SBBR). The nitrogen and phosphorus removal characteristics were similar between SBR and SBBR and the removal efficiencies were very low when the influent TOC concentrations were low. The nitrogen and phosphorus removal efficiencies in SBR were 96% and 77.5%, respectively, which were higher than those in SBBR (88% and 42.5%) at the high influent TOC concentration. In SBBR, the simultaneous nitrification-denitrification was occurred because of the biofilm process. The variations of pH, DO concentration and ORP were changed as the variation of influent TOC concentration both in SBR and SBBR and their periodical characteristics were cleary shown at the high influent TOC concentration. Especially, the pH, DO concentration and ORP inflections, were cleary occurred in SBR compared with SBBR.

• Proceedings of the KAIS Fall Conference
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• 2006.05a
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• pp.585-586
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• 2006

본 연구에서는 고도처리를 위한 BNR 공정에 사용되는 MBR (Membrane Bioreactor)의 막 오염(membrane fouling)을 저감시키기 위해 분리막을 침지시킨 침전조를 상하로 나누어 상부는 폭기조로, 하부는 침전조의 역할을 수행하게 하는 새로운 형태의 막분리 침전조 (aerated settler)의 성능을 평가 하였다. 막분리 침전조는 상하로 구분하기 위해서 baffle을 설치하였다. 파일럿 규모 ($Q=50m^3/d$)의 MBR 공정은 실제 오수를 유입수로 사용하였으며 약 6개월간 운전하였다. 탈질을 위하여 막분리 침전조 하부에서 무산소조로 반송되는 반송수의 DO를 크게 줄어들게 함으로써 무산조에서의 탈질효율이 증가되었다. 처리수의 총 TN 제거율은 75%이었다. 또한 막분리침전조 상 하부의 MLSS 농도 차에 의해 상부에 침지된 막 모듈은 기존의 MBR 공정보다 막 오염 저감 효과가 있어서 세정주기가 증가하였다. 운전 개시 후 4개월째 되는 시점에 TMP가 40cmHg에 도달하여 1회 화학적 약품세정만이 필요하였다.

• Korean Journal of Environmental Agriculture
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• v.16 no.2
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• pp.170-174
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• 1997

Constructed wetland system was studied to treat wastewater from industrial complex in rural area. Pilot plant at the Baeksuk Nongkong Danzi in Chunahn-City was used for field study. For the DO, the effluent concentration was higher than the influent concentration and it implies that natural reaeration supplies enough oxygen to the system. For the SS, the effluent concentration was consistently lower than the water quality standard even though the influent concentration varied significantly, which showed that SS was removed by the system effectively which is consist of soil and plants. For the BOD and COD, the average removal rate of them were 56% and 43%, respectively, therefore, the effluent concentration could not meet water quality standards when influent concentration was high. The removal rate of BOD and COD can be improved by supplemental treatment in addition to this system if necessary. For the T-N and T-P, the influent concentration of them were lower than the water quality standards than no further treatment was needed. Overall, the result showed that constructed wetland system is a feasible alternative for the treatment of wastewater from industrial complex in rural area. For actual application of this system, further study on design factors including loading rate, removal mechanism, and temperature effects is required to meet water quality standard consistently. Compared to existing systems, this system is quite competitive because it requires low capital cost, almost no energy and maintenance, and therefore, very cost effective.

• Journal of Animal Environmental Science
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• v.11 no.2
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• pp.89-96
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• 2005

To investigate the influence of livestock farm's wastewater on the near stream, the water quality of 3 different streams are analysed after seasons. In summer, the minimum T-N in the upper stream was 0.005 ppm and the maximum T-N in the down stream was 5.005 ppm. The phosphate was detected only in down stream of S2 point and was 0.5 ppm. COD was varied from 8 ppm in upper stream to 20 ppm in down stream. In fall, the T-N and the phosphate had shown similar results as that of in summer, however COD was varied from 3 ppm in upper stream to 6 ppm in down stream. In winter, the minimum T-N in the upper stream was 0.053 ppm and the maximum T-N in the down stream was 0.51 ppm. The phosphate was detected only in down stream of S2 point and was 0.5 ppm. COD was varied from 3 ppm in upper stream to 6 ppm in down stream. To be becoming fall and winter, the water quality of streams showed better than that of summer, and the wastewater from the livestock farms had little influence on the near streams.

• Journal of the Korean Society for Marine Environment & Energy
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• v.2 no.2
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• pp.20-30
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• 1999

To improve water quality particularly for sea bathers along the Fylde coastal zone near Blackpool, North West England, waste water from a sewage outfall is studied using a mathematical model. The explicit second order accurate central scheme and the third order accurate QUICKEST scheme are used to represent the diffusion terms and the advection terms of the advective-diffusion equation, respectively. Hydrodynamic model is run for a coarse and fine grid, of 1km and 200m, respectively, obtaining good agreement with measured data. Water quality model is then used to predict faecal coliform levels in the region for four different scenarios, including discharges from: - (i) Fleetwood outfall, (ii)River Ribble for summer condition, (iii)River Ribble for winter condition, and (iv)combined sewer overflows for the Blackpool and Fleetwood communities. Main findings from the simulations are:- (i) Fleetwood outfall has a negligible impact on the beaches with respect to pathogen levels; (ii) Discharge from River Ribble for both summer and winter conditions is predicted in the range of coliform levels 10 -500 counts/100ml along the beach at Lytham St. Annes; and (iii) The CSO effluent discharges are predicted not to advect out into offshore by stronger tidal currents.

• Journal of Soil and Groundwater Environment
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• v.14 no.2
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• pp.1-9
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• 2009

This study was objected to identify the effect on water quality and contamination by non-agricultural facilities in 'A' reservoir watershed located in OO city, Kyounggi-do, Korea. Ground- and stream water samples showed (Na+K)-Cl, Ca(Cl, SO$_4$) and Ca-Cl type in an illegally discharging area of sewage and a densely industrial area indicating water contamination. Stream water of an illegally discharging area of sewage had high COD, T-N and T-P. In this area, direct incoming of sewage into stream water was induced ground water system by well pumping, and it made a progress of ground water contaminations with those components. Groundwater of a densely industrial area showed high concentrations of T-N, NO$_3$N. From a nitrogen isotope analysis, stream water of an illegally discharging area of sewage has ${\delta}^{15}N-NO_3$values of 0.7%0 was strongly affected by nitrogen originated from agrochemicals, and a densely industrial area of 19.7%0 from septic system. Ground- and stream water of a livestock fanning area were contaminated with NH$_3$-N and Mn, which was affected by intensive livestock facilities. SAR-conductivity plot indicates the water does not pose either alkalinity or salinity hazard for irrigation. COD, T-N, T-P, NO$3$-N, NH$_3$N and Mn concentrations from contaminated areas were diminished by mixing with 'A' reservoir water. There were no water contaminations in silver towns, vacationlands around reservoir and golf links. Consequently, it should be made a plan of systematic managements for past and- present possible contaminants and sewage systems in preventing water contamination by non-agricultural facilities.