• 한국환경농학회지
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• 제23권4호
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• pp.228-233
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• 2004

Nitrate removal was examined from May to October 2003 of a surface flow treatment wetland cell, which was a part of a treatment wetland system composed of four wetland cells and a distribution pond The system was established on rice paddy near the Kohung Estuarine Lake located in the southern part of the Korean Peninsula. Effluent from a secondary-level night soil treatment plant was funneled into the system. The investigated cell, 87 m in length and 14 m in width, was created in April 2003. An open water was designed at its center, which was equivalent to 10 percent of its total area. Cattails (Typha angustifolia) were transplanted from natural wetlands into the cell and their stems were cut at about 40cm height from their bottom ends. Average $25.0\;m^3/day$ of effluent from the treatment plant was funneled into the cell by gravity flow and average $24.1\;m^3/day$ of its treated effluent was discharged into the Sinyang Stream flowing into the lake. Its water depth was maintained about 0.2 m and its hydraulic detention time averaged 5.2 days. Average height of the cattail stems was 42.5 cm in May 2M3 and 117.7 cm in September 2003. The number of stems averaged $9.5\;stems/m^2$ in May 2003 and $16.4\;stems/m^2$ in September 2003. The growth of cattails was good. Temperature of influent and effluent averaged 25.9 and $26.7^{\circ}C$, respectively. $NO_3$-N loading rate of influent and effluent averaged 176.67 and $88.09\;mg/m^2\;day$, respectively. Removal of rf03-N averaged $89.58\;mg/m^2\;day$ and its removal rate by mass was about 50%. Considering its initial operating stage in which cattail rhizomes and litter layer on the bottom were not Idly established, the $NO_3$-N removal rate of the cell was rather good.

• 한국물환경학회지
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• 제23권3호
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• pp.367-370
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• 2007

Numerous sets of simulation were conducted in order to find out the optimum operational conditions of the existing BNR process using GPS-X program. The model of ASM3 and modified Bio-P module were applied for simulations. From the result of this study, effluent quality was closely related with the step feeding rate and influent C/N ratio. The effluent TN concentration seemed to be significantly affected by step feeding rate at the low C/N condition. But at the high C/N condition, the effluent concentration of TP rather than that of TN was affected by the control of step feeding rate.

• 한국농공학회:학술대회논문집
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• 한국농공학회 2005년도 학술발표논문집
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• pp.479-484
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• 2005

A GIS-based integrated system for reuse of effluent from wastewater treatment plants was developed in this study. The GIS-supported program classified attribute data which the effluent's quantity and quality and agricultural thematic map data according to the 5 big river basin area. From the database, showing the spatial variation of the water quality of the effluent, thereby proposing proper mitigation strategies over the watershed. Also, this system enables the users who is going to reuse the reclaimed water for their paddies to provide of all the wastewater treatment plant data and agricultural structures and thematic map data.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2006년도 학술발표회 논문집
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• pp.535-539
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• 2006

GIS-based integrated management system was developed for the treated wastewater to be reused as agricultural water. The major scopes of this research includes developing different types of system such as connecting data of wastewater treatment plants to data of hydraulic structures and paddy field ; separating spatial data into the watershed boundary and the agricultural water boundary ; and estimating applicable site for reuse. This system can enable to provide more scientific support to manage information of effluent and agricultural data utilizing GIS techniques.

• 상하수도학회지
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• 제19권4호
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• pp.446-454
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• 2005

An economic treatment method to remove oxidized nitrogen from wastewater is biological denitrification with organic matters. Several organics can be used, however, methanol is commonly used. When methanol is provided, M:N (Methanol to Nitrogen) ratio is used to define methanol demand for denitrification. In this study, two artificial wastewaters were provided to a biological system to evaluate denitrification performance. Differences of influent total CODcr from effluent soluble CODcr were converted to methanol equivalent and oxidized nitrogen difference between influent and effluent were converted to nitrate equivalent to define M:N ratios. Modes I, II, III, I-1 and IV showed 5.1, 2.7, 3.3, 2.3 and 2.6 of M:N ratios, respectively. Since denitrifying microorganisms had to build a new metabolic system for methanol and influent organics, initial operation mode, Mode I, required more methanol and this resulted in high M:N ratios compared with later operation mode, Mode I-1. Salt in influent did not show inhibitory effects on denitrfication, although this was believed to increase effluent SS and soluble CODcr concentrations in Mode III, I-1 and IV, respectively. The concentrations of effluent soluble $COD_{Mn}$ did not changed much with influent salt.

• 한국해안해양공학회지
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• 제6권1호
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• pp.34-39
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• 1994

흐름수역으로 방류되는 측면부력젵이 연안으로 귀환하는 현상과 희석경향에 대해 실험을 통하여 조사하였다. 실험에서 저흐름의 가로흐름 수역에 warm-water를 등수심으로 측면방류하여 횡방향으로 퍼짐과 수면으로 상승하는 열-plume이 발생하는 부력젵(buoyant jet)이 귀환현상을 얻었다. 실험에서 발생하는 귀환현상과 오염정체지역인 순환영역의 기하학적 구조 및 희석경향을 Froude수(F), 밀도 Froude수(F$_{o}$ ), 부력 특성길이(l$_{b}$)를 이용하여 멱법칙(Power law)으로 표현하였다. 보험결과 귀환현상은 R(U$_{o}$ /U$_{a}$ )<4, F/F$_{o}$ >0.22 일 때 발생하며, 희석은 x/l$_{b}$에 따라 변화하고 순환영역은 속도비(R)에 따라 변화함을 알 수 있었다.

• 상하수도학회지
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• 제19권5호
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• pp.537-546
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• 2005

This study was carried out to evaluate EPS and SMP variation of sludge and effluent in nitrification and denitrification process with zeolite addition, a possible reduction of effluent DOC by URC(Ultra Rapid Coagulation) process. As a biological wastewater treatment result, EPS formation of both aeration and anoxic sludges are not affect by SRT variation. However, EPS concentration of sludges is higher in aeration tank than in anoxic tank by 6~8 mg EPS/ g VSS. Linear relationship between SMP to DOC indicates that SMP of bulk solution contributes to most of the biological treatment effluent DOC. DOC and turbidity removal efficiency was more improved with URC process than in a conventional coagulation. For pretreatment of UF filtration DOC removal was advanced by URC process than only UF filtration.

• 상하수도학회지
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• 제19권1호
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• pp.16-24
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• 2005

Mathematical model was developed to verify a sequential particle removal taking place in a granular media gravity filter. Consequential multi-layer filtration cycle model was applied to verify the fraction of filter effluent particles that are filter influent particles that were never removed as well as the fraction of filter effluent particles that were detached after deposition were performed through laboratory experiments. Three sizes of marker particles were injected ahead of the filter column as a pulse in the presence of four sizes of polystyrene particles that were used as a primary source of particles in the raw suspension to investigate particle attachment alone in contrast to net removal from attachment and detachment. Microscopic counting of filter effluent particles was assumed to reflect attachment. Experimental results indicated that particle detachment is significant beginning from the early phase of filtration. For each size of fluorescent microspheres at one filter depth, fluorescent microsphere removal increased with filter runtime to a maximum due to ripening. The detached fraction of effluent particles increased with particle size and filter depth. The presence of detached particles and the increasing fraction of detached particles in deeper bed were confirmed.

• 상하수도학회지
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• 제19권1호
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• pp.3-7
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• 2005

In the present study a feasibility of a novel filtration process using synthetic for secondary effluent reclamation was investigated. Polyurethane was chosen as a filter medium among tested three media. Compressibility and up-flow velocity were changed to determine the optimum operation for the system. An equation was introduced to express the relationship between the removal efficiency and up-flow velocity. In pilot study, the synthetic medium filtration with compression showed very stable effluent quality without clogging trouble, though the system operated with 3 times higher filtration rate and much longer backwashing interval than conventional systems.

• 한국물환경학회지
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• 제24권3호
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• pp.306-310
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• 2008

Characteristics of microalgal growth was investigated using anaerobic effluent from two-phase animal waste digestor as substrate. Batch experiments were carried out to investigate the effect of the initial nitrogen and phosphorus concentrations on growth of Microcystis aeruginosa, Chlorella sp. and Euglena gracilis. In 400 times diluted anaerobic effluent (TN 3 mg/L), single cell growth of the Euglena gracilis population increased twice without delay, although Chlorella sp. and Microcystis aerugenos take over 144 hours. Similar appearance with single cell growth was observed in mixed cultures. However, microalgae population did not increase under condition of 10 times diluted influent (TP 3 mg/L) in both pure and mixed cultures, which was affected by high organic and nitrogen concentration. Logistic growth model successfully fitted to determine biokinetic parameters such as ${\lambda}$: lag time, ${\mu}m$: maximal specific growth rate, A: asymptote of growth.