• Membrane and Water Treatment
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• v.8 no.5
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• pp.423-435
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• 2017

Settling Basins are one of the most important and popular methods for removal of suspended sediments irrigation and drainage networks or power canals taking off from an alluvial river and wastewater treatment plant. Improving the performance and so increasing sediment removal efficiency of settling basins by an alternative method is necessary. In the present work, the effect of baffle and its angle of attack with the flow (${\theta}$) on the sediment removal efficiency is investigated by conducting a series of experiments on a straight canal with 8 m length, 0.3 m width and 0.5 m height and 3 m length of basin equipped with an adjustable glass baffle. A numerical analysis has been carried out using ANSYS Fluent 3D software (a general purpose computational fluid dynamics simulation tool) for three Froude numbers from the experiments. The numerical and experimental results were found to match reasonably well.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.5 no.2
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• pp.174-185
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• 2004

Organic pollutants (Phenol, 2-Chlorophenol, Nitrobenzene) were separated from wastewater by nondispersive membrane solvent extraction, using a microporous hydrophobic hollow fiber module. The system was operated countercurrently and cocurrently with the aqueous phase flowing through the fiber lumens and the solvent flowing through the shell side. The distribution coefficients of several solvents (MIBK, IPAc, Hexane) were examined and MIBK was selected as an extracting solvent. Separation efficiency of countercurrent flow method was better than that of cocurrent flow method. Also, the overall mass transfer coefficients were determined.

• Journal of Korean Society of Water and Wastewater
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• v.24 no.5
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• pp.519-525
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• 2010

From the results of tracer test for the existing chlorine contactor in Y water treatment plant, $T_{10}$ and $T_{10}$/T were calculated as 130 min and 0.16, respectively. Therefore it required the modification schemes for improving hydraulic efficiency, surrogated by T10 and $T_{10}$/T, and disinfection performance. In this study, in order to reduce dead zone within contactor, the installation of porous baffles in the near of each corner was suggested and verified using transient CFD(Computational Fluid Dynamics) simulation technique and tracer tests on dynamic condition. From the results of simulation and tracer tests, it was revealed that porous baffles installed have been effective to reduce dead zone within contactor, and increase plug flow fraction.

• Journal of Korean Society of Water and Wastewater
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• v.25 no.5
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• pp.759-765
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• 2011

In this study, in order to investigate the effects of wall roughness on the hydraulic characteristics of chlorine contactor, CFD simulation and tracer tests were conducted for both of reactors whose walls are made of concrete and lined with PE(Poly Ethylene). In the case of walls contacted with water being lined with PE (relatively lower roughness), the flow within reactor is closer to plug flow than that in the case of concrete walls (relatively higher roughness). Especially, the longer tail of C-curve from the results of transient CFD simulation can tell that Morill index in the case concrete walls is much higher than that in the case of walls be lined with lower roughness material.

• Journal of Korean Society of Water and Wastewater
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• v.20 no.2
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• pp.207-214
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• 2006

The current paper focuses the analysis of leakage detection in water pipeline systems by means of the transient method. In order to obtain essential data for evaluation the existing methodology, an extensive experimental process has been carried out in a single pipeline system, Several experimental tests were performed with and without a leakage in the system. Using the unsteady friction and improved unsteady friction factors gives reasonable match between the computed and measured results on the condition of the flow situations presented in the paper. The transient method attempts to estimate the leakage in water pipelines using observed pressure data collected during transient events on the system.

• Journal of Korean Society of Water and Wastewater
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• v.24 no.1
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• pp.103-108
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• 2010

Until now, research reports that it is difficult for brokenup floc after coagulation to reaggregate and settling efficiency of reaggregated floc is relatively low have dominated in water treatment process. In contrast, from recent study conducted by the French researcher, because the density of the reaggregated floc was higher than the previous floc, the settling efficiency of reaggregated floc increased. In this study, 15 times wet test were carried out and the removal efficiency of reagrregated floc was considerably increased. Moreover, this result was explained using the turbulent model for the flow occurred around the floc. Consequently, in the case of suitable hydrodynamic condition for the reaggregation, the characteristics of the reaggregated floc was changed into the favorable condition for improvement of settling efficiency. Also, the most important factor for reaggregation of floc was governed by hydrodynamic shear stress.

• 수도
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• v.23 no.1_2 s.76_77
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• pp.61-70
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• 1996

• Resources Recycling
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• v.15 no.3 s.71
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• pp.66-73
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• 2006

Continuous column adsorption experiments have been conducted fur artificial and actual wastewater which containing $Ni^{2+}$ by using manganese nodule as an adsorbent for the purpose of wastewater treatment along with an increased $Ni^{2+}$ recovery in the refining of manganese nodule. The adsorption features of $Ni^{2+}$ artificial wastewater were examined by taking the height of fixed bed, influent flow rate, and the initial concentration of adsorbate as the influential parameters. The adsorption capacity of manganese nodule and the rate constant for $Ni^{2+}$ adsorption were estimated employing Bohart-Adams equation. In addition, the variation of the adsorbed amount of adsorbate for each column according to the influent flow rate and the initial concentration of adsorbate was investigated based on the breakthrough curves fur each column. For serially connected columns, the adsorbed amount of $Ni^{2+}$ for each column was observed to increase gradually as the adsorption proceeded from the initial column to the final column. The variation of the breakthrough curve for actual wastewater with the height of fixed bed was not so significant as that for artificial wastewater, which was considered to be due to the high concentration of $Ni^{2+}$ in actual wastewater. Regarding the effect of the particle size of manganese nodule on adsorption, the adsorbed amount of adsorbate was found to somewhat increase as the particle size became smaller.

• Journal of Wetlands Research
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• v.9 no.1
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• pp.69-78
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• 2007

Constructed wetlands and other aquatic systems have been successfully used for waste and wastewater treatment in either temperate or tropical regions. To treat waste or wastewater in a sustainable manner, the integrated eco-engineering designs are explained in this paper with 2 case studies: (i) a combination of vertical-flow constructed wetland (CW) with plant irrigation systemfor fecal sludge management and (ii) integrated CW units with landscaping at full-scale application for domestic wastewater treatment. The pilot-scale study of fecal sludge management employed 3 vertical-flow CW units, each with a dimension of $5{\times}5{\times}0.65m$ (width ${\times}$ length ${\times}$ media depth) and planted with cattails (Typha augustifolia). At the solid loading rate of 250 kg total solids (TS)/$m^2.yr$ and a 6-day percolate impoundment, the CW system could achieve chemical oxygen demand (COD), TS and total Kjeldahl nitrogen (TKN) removal efficiencies in the range of 80 - 96%. The accumulated sludge layers of about 80 - 90 cm was found at the CW bed surface after operating the CW units for 7 years, but no clogging problem has been observed. The CW percolate was applied to 16 irrigation Sunflower plant (Helianthus annuus) plots, each with a dimension of $4.5{\times}4.5m$ ($width{\times}length$). In the study, the CW percolate were fed to the treatment plots at the application rate of 7.5 mm/day but the percolate was mixed with tap water at different ratio of 20%, 80% and 100%. Based on a 1-year data of 3-crop plantation were experimented, the contents of Zn, Mn and Cu in soil of the experimental plots were found to increase with increasing in CW percolate ratios. The highest plant biomass yield and oil content of 1,000 kg/ha and 35%, respectively, were obtained from the plots fed with 20% or 50% of the CW percolate, whereas no accumulation of heavy metals in the plant tissues (i.e. leaves, stems and flowers) of the sunflower is found. In addition to the pilot-scale and field experiments, a case study of the integrated CW systems for wastewater treatment at Phi Phi Island (a Tsunami-hit area), Krabi province, Thailand is illustrated. The $5,200-m^2$ CW systems on Phi Phi Island are not only for treatment of $400m^3/day$ wastewater from hotels, households or other domestic activities, but also incorporating public consultation in the design processes, resulting in introducing the aesthetic landscaping as well as reusing of the treated effluent for irrigating green areas on the Island.

• Journal of Wetlands Research
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• v.3 no.1
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• pp.75-89
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• 2001

Constructed wetlands were typically cost less to build and operate, and require less energy than standard mechanical treatment technology but they have similar performance to centralized wastewater treatment plants. Therefore, they were constructed especially many in rural areas, where are small villages but not industries. Accordingly, plantless column tests were performed to investigate the possibility on using zeolite as a filter medium of constructed wetland for the wastewater treatment. $COD_{cr}$ removal efficiency was 94.63% at hydraulic load $314L/m^2{\cdot}d$ and filtering hight 100cm filled with a zeolite mixture. This zeolite mixture consisted of 1 : 1 by volume of a zeolite in the diameter range of 0.5 to 1mm to a zeolite in the diameter range of 1 to 3mm. According, hydraulic load $314L/m^2{\cdot}d$ was considered as optimal. Three zeolite mixture were used to determine the optimal mixing ratio by volume of a zeolite(A) in the diameter range of 0.5 to 1mm to a zeolite(B) in the diameter range of 1 to 3mm diameter. 1 : 3, 1 : 1 and only B in A to B by volume were tested at hydraulic load $314L/m^2{\cdot}d$ and filtering hight 100cm. $COD_{cr}$ removal efficiency was more than 89% at mixing ratios of 1 : 3 and 1 : 1 in A to B. Removal efficiency was lower at the column filled with only B. Removal efficiency was better at filter medium filled with mixing ratio 1 : 1 in A to B than with the other mixing ratios. Thus, it was found that the mixture of mixing ratio 1 : 1 in A to B was appropriate for filter medium of constructed wetland. Removal efficiency was higher in down-flow than in up-flow, and $COD_{cr}$ and BOD were removed best in 20cm filter height near feeding area.