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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of Korean Society of Water and Wastewater
Journal Basic Information
Journal DOI :
The Korean Society of Water and Wastewater
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Volume & Issues
Volume 21, Issue 6 - Dec 2007
Volume 21, Issue 5 - Oct 2007
Volume 21, Issue 4 - Aug 2007
Volume 21, Issue 3 - Jun 2007
Volume 21, Issue 2 - Apr 2007
Volume 21, Issue 1 - Feb 2007
Selecting the target year
Assessment of Structural Safety of Buried Water Mains
Bae, Chul-Ho ; Kim, Ju-Hwan ; Kim, Jung-Hyun ; Hong, Sung-Ho ; Lee, Kyung-Jae ;
Journal of Korean Society of Water and Wastewater, volume 21, issue 2, 2007, Pages 151~164
Criteria for rehabilitation priority are discussed to evaluate structural stability of deteriorated water transport and transmission pipes, in this study.For the purposes, safety factor is introduced and estimated by measuring tensile strength and by analyzing stress caused by the internal-external loads working on buried pipe body. Related informations are surveyed and collected under various conditions in the fields by digging out and the structural stability is assessed.In the evaluation results of structural safety, it is shown that steel pipe is more affected by external load than internal load.The average external load is estimated as 53.7 ㎏/㎠ and total hoop stress is estimated by 2676.5 ㎏/㎠. Also, Poisson effect into longitudinal direction due to internal and external loads is most influential on hoop stress.The calculated safety factors of hoop stress are ranged from 0.7 to 5.2 with average value of 2.1, considering a bending stress to longitudinal direction.The decision of rehabilitation priority by safety factors show that structural safety of CIP sample 1(S1) was assessed at the lowest order with safety factor value, 0.7 and that of DI sample 15(S15) was evaluated as the most stable in structural aspect.
The Assessment of Wastewater Treatment and Management Using Performance Indicators and Cluster Analysis
Kim, Shin-Geol ; Choi, Tae-Yong ; Koo, Ja-Yong ;
Journal of Korean Society of Water and Wastewater, volume 21, issue 2, 2007, Pages 165~175
The Effect of Dead Zone on Hydraulic Efficiency in Clearwell
Lee, Seung-Jae ; Shin, Eun-Her ; Kim, Sung-Hoon ; Park, Hee-Kyung ;
Journal of Korean Society of Water and Wastewater, volume 21, issue 2, 2007, Pages 177~185
Hydraulic efficiency(T10/T) in clearwell is often estimated by L/W ratio. However, this estimation is not accurate because other factors which give an effect on hydraulic efficiency such as shape of basin, diffuser wall and intra-basin is ignored. Therefore, in this research, hydraulic efficiency is predicted by the quantitative analysis of dead zone using CFD simulation in a pilot scale clearwell. The results show that the reason why higher L/W ratio increase the hydraulic efficiency is to decrease the dead zone of linear region which is located between baffles. Diffuser wall or intra-basin also affects on hydraulic efficiency with this process. Also, we conclude that hydraulic efficiency can not be reached to 0.8 or higher.
Application of Dispersion Number for Analysis of Tracer test in Sedimentation Basin
Kim, Young-Il ; Park, No-Suk ; Jung, Nam-Jung ; Kim, Seong-Su ; Bae, Byung-Uk ;
Journal of Korean Society of Water and Wastewater, volume 21, issue 2, 2007, Pages 187~193
Reynolds and Froude numbers, along with tracer tests, have been widely used to estimate hydrodynamics in full-scale horizontal sedimentation basin in water treatment plants (WTPs). In spite of this, the former numbers do not reflect actual operating conditions, instead most often being based on the dimensions of the structures. The index and graphic analyses most often used were found to be too subjective to accurately analyze tracer test results. In order to overcome these limitations, dispersion number was applied for analysis of tracer test results. Tracer tests were conducted in eight full-scale sedimentation basins in six WTPs, and then analyzed by index and graphic analyses as well as by dispersion number. The dispersion number was more useful as an indicator of the hydrodynamic behavior in the basin. It was also found that as dispersion number decreased, flow approached the ideal for plug flow in which case, higher sedimentation efficiency could be expected.
The Effects of PAC (Powdered Activated Carbon) on Water Treatment Performance of an Immersed Membrane System Using Flat-sheet Membrane Module
Gai, Xiang-Juan ; Kim, Han-Seung ;
Journal of Korean Society of Water and Wastewater, volume 21, issue 2, 2007, Pages 195~201
A submerged flat-sheet membrane separation system integrated with PAC (powdered activated carbon) was used in this research in order to investigate the effects of PAC on the efficiencies of operation and treatment and to evaluate the performance of the system. The experiments were carried out under operating conditions of a filtration rate of 0.38 m/d, water temperature of 2028C, and PAC dose of 0 g/L (Run-A) and 20 g/L (Run-B). The influent concentrations of TOC (total organic carbon), NH4+-N (ammonia nitrogen) and UV254 (UV absorbance at 254 nm) were 2.48 mg/L, 1.4 mg/L and 2.53 1/m, respectively. TOC removal of 43.2 and 73.6%, ammonia nitrogen removal of 4.9 and 15.9%, and UV254 removal of 20.6 and 31.6% were obtained for Run-A and Run-B, respectively. During an experimental period of 33 days, no change was found in TMP (Run-B), but the TMP in Run-A increased by 5 kPa after 29 days. This research showed that the filtrate quality and the performance efficiency were enhanced when PAC was introduced into the filtration system.
A Study on the Process Selection for Two-stage and Dual Media Filtration System for Improving Filtration Performance
Song, Si-Bum ; Jo, Min ; Nam, Sang-Ho ; Woo, Dal-Sik ;
Journal of Korean Society of Water and Wastewater, volume 21, issue 2, 2007, Pages 203~214
This study aimed at researching the process selection for two-stage and dual media filtration system, as a technology substituting the existing sand filter without expanding the site when retrofitting an old filter bed or designing a new one. In order to select the process for optimum complex filtration system, three running conditions have been tested. Test results demonstrated that Run 3 in which the 1st stage was filled with anthracite and coarse sand, and the 2nd stage was filled up with activated carbon and fine sand reduced the head loss and the load of turbidity substances. Also, Run 3 showed better performance in removing TOC, particle counts, THMFP and HAAFP, compared to other two conditions. 99 % of Cryptosporidium was removed. Bisphenol-A was rarely removed from the 1st stage of coarse sand and 2nd stage of fine sand, but 99 % of it was removed from the 2nd stage of activated carbon. In conclusion, when it is required to retrofit an old rapid filter bed or design a new one for the purpose of improving filtration performance, the following two-stage and dual media filtration system is suggested: the 1st stage of filter bed needs to be filled up with coarse sand to remove turbidity as the pretreatment for extending duration of filtering, the top part of 2nd stage needs to be filled up with granular activated caron to remove dissolved organic matters and others as the main process, and finally the bottom part of 2nd stage needs to be filled up with fine sand as the finishing process.
The Capability Analysis of Water Supply for the Parallel Reservoir System by Allocation Rules
Park, Ki-Bum ; Jee, Hong-Kee ; Lee, Soon-Tak ;
Journal of Korean Society of Water and Wastewater, volume 21, issue 2, 2007, Pages 215~224
The purpose of this study was to estimates water supply reliability indices of the water supply by Allocation Rules(AR) for parallel reservoirs. Rule (A) can be considered it as only current storage, Rule(B) can be considered it as current storage and inflow and Rule(C) can be considered it as current storage, inflow and water supply capacity. First, conditions of water supply are divided by Condition Ⅰ for the monthly constant water supply and Condition Ⅱ for the monthly varied water supply. Second, results of allocation coefficients are revealed the smallest different at Rule(C). The analysis of water supply showed that the capability of water supply is superior to the Rule(B), it is superior to the Rule(C) on the base of the balance of water supply. The reliability analysis was highly showed at the Rule(B) and Rule(C). A methodology for the analysis of water supply was developed and applied to the parallel reservoir system from this research, The operation rule for the parallel reservoir can be slightly modified and successfully applied to the different kinds of the parallel reservoir system.
Characteristics of Non-point Pollutants from the Road Runoff (1): Water Quality
Park, Sang-Woo ; Oh, Jei-Il ; Choi, Young-Hwa ; Seo , Jeong-Woo ;
Journal of Korean Society of Water and Wastewater, volume 21, issue 2, 2007, Pages 225~233
Road runoff water is one of the non-point sources (NPSs) of pollution negatively influencing drinking water source. Numerous road runoff NPS waters have been studied for over the last decade. However, the sources of pollution can be conditional, seasonal, or accidental. Therefore, measurement of pollutant loadings in different site is necessary to estimate the effect of road runoff water. The objective of this study was to examine the quality of road runoff water from a city bridge in Seoul, Korea. This study was conducted for two years to assess annual discharge pollution loads. In this study, key water quality parameters including chemical oxygen demand (CODCr), biochemcial oxygen demand (BOD5), total nitrogen (T-N), total phosphorus (T-P), and suspended solid (SS) were measured at 18 different events. The results showed that typically the pollutant concentrations are higher at the beginning of each event and decrease afterwards. The first 20% of the volume of the runoff from each event is transporting 46% (CODCr), 48% (BOD5), 50% (T-N), 34% (T-P), 30% (SS), respectively. The event mean concentrations (EMCs) were CODCr (199 mg/L), BOD5 (41.2 mg/L), T-N (7.97 mg/L), T-P (0.42 mg/L) and SS (113 mg/L). Although the results were consistent with the previous study (Barbosa and Hvitved-Jacobsen, 1999), CODCr, BOD5, T-N exhibit a stronger first flush effect compared to the other contaminants.
Characteristics of Non-point Pollutants from the Road Runoff (2): Heave Metals and Pathogens
Park, Sang-Woo ; Oh, Jei-Il ; Choi, Young-Hwa ; Kim, Jong-Hwa ; Ha, Jae-Won ;
Journal of Korean Society of Water and Wastewater, volume 21, issue 2, 2007, Pages 235~242
Road runoff water includes various heavy metals (zinc, Zn; lead, Pb; copper, Cu; chrome, Cr; cadmium, Cd; etc.) and pathogens (E-coli and coliform). Since these pollutants are significantly harmful to human beings and have negative impact on water streams, numerous studies have been conducted to determine the characterization of these non-point pollutants from road runoff water. However, since these non-point pollutant concentrations vary depending on road traffic, road construction, and road maintenance, measurement of pollutant loadings in different site is necessary to estimate the effect of road runoff water on drinking water source. The objective of this study was to examine the quality of road runoff water from a city bridge in Seoul, Korea. This study was conducted for two years to assess annual discharge pollution loads. In this study, five key heavy metals (Zn, Pb, Cu, Cr, and Cd) and two pathogens (E-coli and coliform) were measured at 18 different events. The pollutant load mass transported was always higher than the corresponding runoff volume for Zn, Cu, and Cd, while Pb and Cr showed similar values between the load mass transported and the corresponding runoff volume. The event mean concentrations were Zn (0.908 mg/L), Pb (0.092 mg/L), Cu (0.141 mg/L), Cr (0.023 mg/L), and Cd (0.006 mg/L). Like Zn, Cu, and Cd, E-coli and coliform values (relatively high in Summer and Fall) are higher at the beginning of each event and decrease afterwards.
Characteristics of Micro Floc in a Rapid Mixing Step at Different Coagulant Dose
Jun, Hang-Bae ; Park, Sang-Min ; Park, Noh-Back ; Jung, Kyung-Su ;
Journal of Korean Society of Water and Wastewater, volume 21, issue 2, 2007, Pages 243~252
Effects of alum dosage on the particle growth were investigated by monitoring particle counts in a rapid mixing process. Kaolin was used for turbid water sample and several other chemicals were added to adjust pH and ionic strength. The range of velocity gradient and mixing time applied for rapid mixing were 200～300sec-1 and 30～180 sec, respectively. Particle distribution in the synthetic water sample was close to the natural water where their turbidity was same. The number of particles in the range of 10.0～12.0㎛ increased rapidly with rapid mixing time at alum dose of 20mg/L, however, the number of 8.0-9.0㎛ particles increased at alum dose of 50mg/L. The number of 14.0～25.0㎛ particles at alum dose of 20mg/L was 10 times higher than them at alum dose of 50mg/L. Dominant particle growth was monitored at the lower alum dose than the optimum dose from a jar test at an extended rapid mixing time(about 120 sec). The number of 8.0～14.0㎛ particles was lower both at a higher alum doses and higher G values. At G value of 200 sec-1 and at alum dose of 10-20mg/L, residual turbidity was lower as the mixing time increased. But at alum dose above 40mg/L and at same G value, lower residual turbidity occurred in a short rapid mixing time. Low residual turbidity at G value of 300sec-1 occurred both at lower alum doses and at shorter mixing time comparing to the results at G value of 200sec-1.
A Study on Heavy Metal Removal Characteristics Using Bone Char
Kim, Jae-Young ; Kim, Hwan-Gi ;
Journal of Korean Society of Water and Wastewater, volume 21, issue 2, 2007, Pages 253~258
Abstract The adsorption capacity of bone char for lead, cadmium and zinc was studied in both single and binary multiple component systems. Equilibrium experimental studies have been performed to determine the sorption capacity of bone char for each metal ion. These have been analysed using single and multi-component equilibrum models. The results show that the sorption of metal ions for multi-component systems can be predicted reasonably well from the IAS theory with the Langmuir equation, the Freundlich and the Slip equation for metal ions.