• Ocean and Polar Research
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• v.22 no.1
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• pp.45-56
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• 2000

Hydrodynamic mixing characteristics of submerged effluent discharges into Masan Bay were investigated by both field observations and numerical model simulations. CORMIX model, a length-scale mixing model, was adopted to obtain the near-field dilution and wastefield characteristics of the effluent discharges into Masan Bay. Model predictions of the near-field dilution rates were in a good agreement with field observations in summer and winter seasons. Seasonal variations in the dilution rates showed that the highest dilution rate was obtained in winter while the lowest dilution rate was in summer. As the effluent discharges are increased with the treatment capacity expansion to be completed by 2011, the dilution rates are expected to be much reduced and the near-field stability of the wastefields will become unstable due to the increased effluent discharges.

• Journal of the Korean Society for Marine Environment & Energy
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• v.3 no.1
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• pp.35-44
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• 2000

The winter case of the near-field dilution at the Masan outfalls has been studied by field measurements and CORMIX model simulations. Dilution rates of the wastewater discharge in winter were obtained by a salinity deficit method using the field data observed in the neap tidal period of February, 1999. The observed dilution rates in winter season were found to be very high in the range of 90～130 due to the isopycnal mixing of ambient density compared with the summer range of 30～40 under weak neap tidal currents. The results of CORMIX model simulations also show that the winter dilution rates under a weak ambient current(Ua=6.0ms/s) were increased by 3-fold of the summer dilution rates. However, the difference between two seasons becomes small by 30% under a strong current(Ua=15.5cm/s). This result indicates that the dilution and hydrodynamic mixing process of the effluents are more influenced by ambient crossflow condition than by ambient density stratification at the outfalls site.

• Journal of Radiation Protection and Research
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• v.23 no.1
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• pp.1-6
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• 1998

A diffusion model of radioactive liquid effluents is developed and applied for YGN NPP's site, based on the Gaussian plume type model. Due to the complexity of oceanic diffusion characteristics of YGN site, a simple and reliable statistical model based on Reg. Guide 1.113 is developed. Also, a computer code package to calculate dilution factors as a function of plant operation conditions and pathway of radioactive materials. A liquid effluents diffusion model is developed by dividing the diffusion range into two categories, i. e, a near field mixing region and a far field mixing region. In the near field, the initial mixing is affected by a buoyance force, a high initial turbulence and momentum which is characterized by a plant operation condition and environmental conditions. The far field mixing is similar to gaseous effluents diffusion. So, beyond the near field region, wellknown Gaussian plume model was adopted. A different area averages of Gaussian plume equation was taken for each radioactive exposure pathway. As a result, we can get different dilution factors for different pathways. Results shows that present dilution factors used for YGN ODCM is too much overestimated compared with dilution factors calculated with the developed model.

• Journal of the Korean Society for Marine Environment & Energy
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• v.2 no.2
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• pp.60-69
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• 1999

In this paper, we have obtained the initial and near-field dilution rates of wastewaters discharged from the ocean outfall of Masan-Changwon municipal wastewater treatment plant from both of field measurements and CORMIX model simulations. In the summer of 1998, water temperature and salinity profiles was measured at 16 stations in the vicinity of the Masan outfall and the dilution rates were analyzed by salinity deficit method. The transport of the wastefields and their initial dilution rates were calculated by CORMIX model using field data as model input. Both of observed and predicted results are shown In very low dilutions with the range of 32～48 from the field data analysis and 29～43 from the model prediction, respectively. This indicates that the water quality in the Masan outfall area can be worsening due to the low dilution rates of diswastewaters, especially, when the ambient currents are very weak in a neap tide and ambient water density is highly stratified in summer.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.11 no.2
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• pp.116-126
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• 1999

In this paper, we have studied the seasonal vanatIons of near-field dilutions of wastewater discharged from the submerged mutiport-diffuser in Masan Bay. Seasonal changes of temperature and salinity, and tidal currents were measured at 16 stations in Masan Bay. Based on the observed ambient field data, the seasonal changes of near-field dilutions due to ambient current and density fields were calculated by CORMIX model. Because of the shallow ambient water depth of 15 m, the density profiles are isopycnal in autumn and winter seasons, in which the dilution factors were the highest, 168 with the strong spring-tidal current and 110-120 with the weak neap-tidal current. As the season changes from spring to summer, the dilution factors are considerably reduced by the factor of 2 as the thermocline is getting deepened up to Sm in depth in summer. In the case of a weak ambient current, the dilution factor in summer was reduced to 1/4 of the dilution in winter. However, with strong ambient current the difference between summer and winter dilutions becomes relatively small by 30%. The results indicate that the seasonal variation of near-field dilution is very large up to 4 times with a weak neap-tidal current, but its variations become small under a strong ambient current of spring tide in MasanBay.

• Journal of Korean Port Research
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• v.14 no.2
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• pp.241-249
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• 2000

The amount of municipal water has been increased rapidly up to now and it is necessary to treat and dispose the wastewater effectively. The recent trend of the effluent disposal system, after treatment, show a nearshore discharge which has an outfall with length somewhere between the shoreline discharge and an extended deepwater outfall. There is no universal solution to municipal water treatment and disposal and each case must be examined on its merits and on economic, technical and environmental bases. In this study we focused mostly on the scientific and engineering aspects of ocean disposal through the outfall. For this purpose, we made an investigation to the near-field characteristics of discharged water and made some comparison with the existing experimental results. We also applied it to the Pusan Jungang Effluent Outfall System, which is planned to build in the Gamchun harbour and will be completed in 2011. The model output showed the trajectoral variation of dilution and mixing behavior for three cases of outfall system. Dilution differences have been simulated and found the highest dilution condition under the different displacement of outfall system. On the basis of these outputs it will be proposed the optimum outfall system type and location.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.12 no.2
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• pp.53-69
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• 2000

For the case of the capacity increase of Masan-Changwon wastewater treatment plant, the changes of near-field dilution rates due to the increased discharges into Masan Bay from the submerged multipart-diffuser were predicted by using CORMIX model. As the increase of wastewater discharges from currently 280,000 m3f day to 720,000 m3fday by 2011, the dilution rates become much lower than the present rates. To enhance the reduced dilution rates, the engineering design changes of diffuser length and alignment were considered as an optimal engineering option. According to the results of the model simulations for these changes, the dilution rates were increased in the strong ambient current of spring tide, but they were not affected by these changes in the weak current of neap tide in Masan Bay. From the analysis of oceanographic survey data, new outfalls sites have been searched. A promising outfalls site is selected and proposed on the basis of maximum obtainable dilution rates predicted by the model simulations.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 1999.10a
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• pp.243-252
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• 1999

Recently several research groups using CORMIX, approved by EPA, have been working on the hydrodynamic mixing processes due to the ocean discharges. It provides a useful tool for analyzing near field mixing characteristics through the outfall system. This paper applies CORMIX 1 & 2 to the Pusan Jungang Effluent Outfall System, which is planned to be in the Gamchun harbour and will be completed in 2011. This model output shows the trajectoral variation of dilution and concentration for three cases of outfall system. Dilution differences have been simulated and found the highest dilution condition under the different displacement of outfall system. On the basis of these outputs it will be proposed the optimum outfall system type and location. This approach might contribute on protecting the serious water quality problem due to the ocean discharge.

• Proceedings of the KSME Conference
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• 2002.08a
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• pp.455-458
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• 2002

Mixing zone characteristics of the wastewater effluents discharged from an ocean outfall have been investigated using an outfall mixing zone analysis method. This analysis was applied to Sokcho ocean outfall case and was used to simulate the concentration distribution of wastewater effluents. Hourly concentration distributions of outfall effluent discharges were averaged for the period of 15 days. The results show that near-field dilution was relatively high with the dilution of 130 for the winter season.

• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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• 2001.06a
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• pp.1171-1171
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• 2001

Quantitative analysis is an important requirement in exploration, mining and processing of minerals. There is an increasing need for the use of quantitative mineralogical data to assist with bore hole logging, deposit delineation, grade control, feed to processing plants and monitoring of solid process residues. Quantitative analysis using X-Ray Powder Diffraction (XRD) requires fine grinding and the addition of a reference material, or the application of Rietveld analysis to XRD patterns to provide accurate analysis of the suite of minerals present. Whilst accurate quantitative data can be obtained in this manner, the method is time consuming and limited to the laboratory. Mid infrared when combined with multivariant analysis has also been used for quantitative analysis. However, factors such as the absorption coefficients and refractive index of the minerals requires special sample preparation and dilution in a dispersive medium, such as KBr to minimize distortion of spectral features. In contrast, the lower intensity of the overtones and combinations of the fundamental vibrations in the near infrared allow direct measurement of virtually any solid without special sample preparation or dilution. Thus Near Infrared Spectroscopy (NIR) has found application for quantitative on-line/in line analysis and control in a range of processing applications which include, moisture control in clay and textile processing, fermentation processes, wheat analysis, gasoline analysis and chemicals and polymers. It is developing rapidly in the mineral exploration industry and has been underpinned by the development of portable NIR spectrometers and spectral libraries of a wide range of minerals. For example, iron ores have been identified and characterized in terms of the individual mineral components using field spectrometers. Data acquisition time of NIR field instruments is of the order of seconds and sample preparation is minimal. Consequently these types of spectrometers have great potential for in-line or on-line application in the minerals industry. To demonstrate the applicability of NIR field spectroscopy for quantitative analysis of minerals, a specific example on the quantification of lateritic bauxites will be presented. It has been shown that the application of Partial Least Squares regression analysis (PLS) to the NIR spectra can be used to quantify chemistry and mineralogy in a range of lateritic bauxites. Important, issues such as sampling, precision, repeatability, and replication which influence the results will be discussed.