• 한국수자원학회:학술대회논문집
• /
• 한국수자원학회 2000년도 학술발표회 논문집
• /
• pp.779-783
• /
• 2000

• 한국수자원학회논문집
• /
• 제33권S1호
• /
• pp.779-783
• /
• 2000

• 한국물환경학회지
• /
• 제31권4호
• /
• pp.351-359
• /
• 2015

The study on the improvement of discharge water quality from domestic wastewater treatment plant (DWTP) was performed in a filter type bioelectrochemical system. The COD removal efficiency for a synthetic discharge water was about 88%, and the effluent COD was less than 5mg/L. The nitrification efficiency of the bioelectrochemical system was over 97%, but a considerable amount of the nitrogen was remained as nitrate form in the effluent. The total nitrogen removal efficiency was only around 30%. There are no significant differences in the removal of COD and nitrogen at 0.6 and 0.8V of the applied voltages between anode and cathode. The removal of COD and nitrogen in the system were quite stable when the HRT ranged from 60 to 15 minutes, and at 10 minutes of HRT, the nitrification efficiency was slightly decreased. The performance of the bioelectrochemical system has quickly recovered from the shocks in the influent due to high concentration of COD and nitrogen. For the effluent that discharged from the DWTP, the removal efficiencies of COD and total nitrogen from the bioelectrochemical system were 50 and 30%, respectively. Thus the bioelectrochemical system was a feasible process for further polishing the effluent quality from DWTP.

• 상하수도학회지
• /
• 제20권6호
• /
• pp.789-797
• /
• 2006

This study was conducted to establish the refined model for prediction of flocculation/sedimentation efficiency in factual drinking water treatment plants using model tree technique. In order to carry out machine leaning for determining each linear model, five parameters; time, coagulant dose, raw water turbidity, SCD and conductivity, which were measured and collected from the field (K_DWTP), were selected and used. The existing analytical models developed by previous researchers were used only to examine closely the mechanism of flocculation rather than to apply it for practical purpose. The refined model established using model tree technique in this study could predict the factual sedimentation efficiency accurately (below 9% of average absolute error). Also, in aspect of engineering convenience, without any additional manipulation of parameters, it can be applied to practical works.

• 상하수도학회지
• /
• 제14권3호
• /
• pp.240-250
• /
• 2000

In this study, DWTP Advisor developed from U.S. EPA was adapted for performance assessment in small water treatment plant and studied for improvement advice about the problem. From results of performance assessment, the ability of each major unit process meets to Peak Instantaneous Flow(PIF) as Type I (above 95% of PIF) in N WTP. But, outlet condition in the sedimentation basin are permitting the loss of solids from the basin and the lack of proper solids removal is degrading the performance in N WTP. From results of the hydraulic analysis using fluoride tracer, flow rate in sedimentation basin is rapidly more lower than upper. The Reynolds number, Re, and Froude number, Fr which are used to predict flow condition in sedimentation basin is calculated to be 3159.98 and $2.06{\times}10^{-7}$, respectively. There is possibility of occurrence of short-circuiting and turbulence. Also, the different type of effluent trough makes unstable flow in sedimentation basin and increases carry-overing of sedimented solids.

• 상하수도학회지
• /
• 제20권5호
• /
• pp.691-700
• /
• 2006

This study conducted to optimize the design and operation of orifice typed distribution channels which were generally constructed to link the rapid mixing process and flocculation/sedimentation basin. To accomplish the goal of this study, programming step method using FORTRAN 90, was applied it to simulate the performance of existing distribution channel in the selected S DWTP (Drinking Water Treatment Plant). The proposed step method program was validated in terms of the feasibility with comparison between the measurement and prediction value in each orifice. From the evaluation results of the current conditions with the design and operation, it was revealed that the existing gradient of the tapered channel is not appropriate. Also, we suggested that in the case of the inlet width being 3.5m, reducing the downstream width by about 0.5m would make more equitable distribution flow in the channel. Consequently, dealing with various conditions of the design and operation with distribution channel, we could conclude that for the parallel typed channel, as the width is wider and the diameter of orifice is smaller, the more equitable distribution occur. In addition, the inlet flowrate and the number of orifice can affect the flow velocity in the channel.

• 상하수도학회지
• /
• 제32권5호
• /
• pp.389-398
• /
• 2018

A nationwide survey of 8 N-nitrosamines in finished water samples from drinking water treatment plants (DWTPs) in Korea was conducted. The samples were pre-treated by solid-phase extraction (SPE) and analyzed using a gas chromatography coupled with tandem mass spectrometry (GC-MS/MS). According to the study results, four N-nitrosamines (NDMA, NDEA, NMOR, NDBA) were detected for three consecutive years, NMEA and NPYR were only found in samples collected in 2013. Two of these N-nitrosamines, N-nitrosodimethylamine (NDMA) and N-nitrosodiethylamine (NDEA), have received attention and were the most commonly detected. The concentration of NDMA and NDEA in this study ranged from $0.002{\mu}g/L$ to $0.013{\mu}g/L$ and in $0.001{\mu}g/L$ to $0.008{\mu}g/L$, respectively. In comparison to studies performed in EPA(UCMR2), the concentrations of NDMA (from $0.002{\mu}g/L$ to $0.630{\mu}g/L$) and NDEA (from $0.005{\mu}g/L$ to $0.100{\mu}g/L$) observed in the this study were low.

• 분석과학
• /
• 제17권5호
• /
• pp.423-433
• /
• 2004

본 연구는 서울시 상수도 계통에서 내분비계장애물질인 BPA 및 NP의 실태조사를 위해 2002년 9월부터 2003년 12월까지 수행되었다. 상수원 유역의 한강 및 지류천중의 BPA 및 NP의 수준은 다음과 같았다: 팔당댐, $ND{\sim}0.033{\mu}g/L$ 및 $ND{\sim}0.823{\mu}g/L$ ; 경안천, $ND{\sim}0.659{\mu}g/L$ 및 N$D{\sim}3.827{\mu}g/L$ ; 왕숙천, $ND{\sim}0.528{\mu}g/L$ 및 $ND{\sim}12.724{\mu}g/L$. 서울시 6개 취수장 원수중의 BPA 수준은 $ND{\sim}0.260{\mu}g/L$, NP의 농도는 $0.122{\sim}2.724{\mu}g/L$의 범위에 있었다. 그리고 왕숙천 수역을 중심으로 한 3개 정수장의 여과수와 그 수돗물에서 BPA는 모두 불검출된 반면에, NP는 전지점에서 ppt 수준으로 검출되었다. 또한, 먹는물의 정수처리공정에서 NP의 제거율은 정수장별 차이가 없이 80{\sim}95%로 높게 나타났다. 따라서 본 연구결과는 상수도 계통에서 BPA 및 NP의 농도는 한강유역에 존재하는 점오염원 및 하수처리장 방류량에 의존된다는 것을 시사하고 있다.