• Journal of Korean Society of Environmental Engineers
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• v.30 no.1
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• pp.69-78
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• 2008

An integration study of watershed model(HSPF, Hydological Simulation program-Fortran) and reservoir water quality model (CE-QUAL-W2) was performed for the evaluation of turbid water management in Yongdam reservoir. The watershed model was calibrated and analyzed for flow and suspended solid concentration variation during rainy period, their results were inputted for reservoir water quality model as time-variable water temperature and turbidity. Results of the watershed model showed a good agreement with the field measurements of flow and suspended solid. Also, results of the reservoir water quality model showed a good agreement with the filed measurements of water balance, water temperature and turbidity using linkage of the watershed model results. Integration of watershed and reservoir model is an important in turbid water management because flow and turbidity in stream and high turbidity layer in reservoir could be predicted and analyzed. In this study, the integration of HSPF and CE-QUAL-W2 was applied for the turbid water management in Yongdam reservoir, where it is evaluated to be appliable and important.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.12
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• pp.1273-1280
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• 2008

This study sought to establish the optimum operating condition for the recovery of caustic (NaOH) solution from mercerization in textile process. As main factors, the silt density index (SDI) evaluation of ceramic membrane for the application of nanofiltration/reverse osmosis (NF/RO) membrane, the recovery yield measurement of caustic solution for the application of polymeric membrane, the optimum condition of chemical cleaning for the membrane regeneration, the optimum removal condition of total organic carbon (TOC), turbidity, color, and the permeate flux of ceramic membrane/polymeric membrane combined process were investigated. As results, ceramic ultrafiltration (UF) in the first step and nanofiltration (NF) in the second step were found to be suitable for the removal of total suspended solid (TSS), residual organics, turbidity including color, and the recovery of caustic solution from caustic wastewater stream in mercerization process. When only the ceramic UF membrane was used, the rejection efficiency of both of TSS and turbidity was more than 99.0%, and the color and TOC were rejected about 74.7% and 49.2%, respectively. Meanwhile, the combined membrane precess of UF and NF membranes showed even more efficient removal abilities and thus more than 99.9% of TSS and turbidity, 87.7% of color, and 78.2% of TOC were removed. In particular, 91.3% of NaOH was successfully recovered with 83.7% of total volume in the combined membrane process. With this regard, a clean caustic solution was obtained in a high purity, which can be reused for mercerization process, expecting to offer economical benefits.

• Journal of Life Science
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• v.18 no.12
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• pp.1671-1678
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• 2008

We investigated the effect of the turbid water on the phytoplankton community in the 4 sites of Imha reservoir. The turbidity of water was proportional to the concentrations of $SiO_2$-Si. Therefore, as the turbidity of water grow, the concentration of $SiO_2$-Si increased. And the both the turbidity of water and the concentrations of $SiO_2$-Si were increased as the water run deep. The concentration of chlorophyll-a decreased as the depth of water increased. Seventy phytoplankton taxa were identified and the most abundant group was Chlorophyceae consisting of 32 taxa (46%), and Cyanophyceae and Bacillariophyceae consisted of 12 taxa (17%). And Euglenophyceae, Synulophyceae, Cryptophyceae and Dinophyceae consisted of 6 taxa (9%), 4 taxa (6%), 3 taxa (4%) and 1 taxon (1%), respectively in Imha reservoir. The concentrations of phytoplankton were increased according to the turbidity of water because of the high amount of organic nutrition which is presented with turbid water. And especially, the concentrations of nitrogen increased easily because of the weak binding to the soil particle. In conclusion, total nitrogen and $SiO_2$-Si flowed into the Imha reservoir with soil particle, and these inorganic nutritions affect the growth of algae.

• Proceedings of the Membrane Society of Korea Conference
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• 2005.05a
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• pp.71-74
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• 2005

• Journal of Korean Society of Water and Wastewater
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• v.13 no.3
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• pp.36-41
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• 1999

High quality drinking water can be produced by membrane separation process. A major problem in the current system is a membrane fouling control. In order to investigate membrane fouling due to E.coll removal, lab scale experiment using MF and UF and semi pilot plant experiment using UV radiation or not was performed. AS a result, the possibility of membrane fouling control by repressing of micro-organism on the membrane surface was clearly verified. But it was not clearly verified in this experiment the combined effect with other factors such as Turbidity, organic and inorganic matters.

• Journal of Korean Society of Water and Wastewater
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• v.22 no.6
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• pp.665-672
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• 2008

It is necessary to implement the management plan for the production of safe and high quality drinking water from lake Paldang. To set up the plan, the water quality items such as BOD, T-P, SS and coliform were monitored for ten years, 1997~2006, and the influence of raw water quality on the drinking water treatment process and the treated water quality was also evaluated from 2004 to 2006. In conclusion, water quality items such as turbidity(SS), T-P(eutrophication), pathogens(fecal coliforms, enterovirus, reovirus, giardia, cryptosporidium), DOC(precursor of disinfection by-products), and micro-pollutants(phthalates, VOCs, heavy metals) are should be managed to get safe and high quality drinking water from lake Paldang.

• Journal of Korean Society on Water Environment
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• v.31 no.5
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• pp.523-532
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• 2015

Hydrocyclone is widely used in industry, for its simple design, high capacity, low maintenance and low operational cost. The objective of this study is to develop hydrocyclone coagulation and filtration system. The system is made of hydrocyclone ballasted coagulation with polyaluminium chloride silicate (PACS) and upflow filter to treat micro particles in urban storm runoff. Roadside sediment particles (< $200{\mu}m$) was mixed with tap water to make various turbid suspensions to simulate urban storm runoff. The filter cartridge was filled with polyethylene media system and ran 1hr per everyday and total operation time were 8.19hrs and backwashing everyday after end of operation. The operation condition of flowrate was $8.2{\sim}11.9m^3/day$ (mean $10.1m^3/day$) and surface overflow rate (SOR) based on filter surface area was $45.5{\sim}65.9m^3/m^2/day$ (mean $55.7m^3/m^2/day$). The range of PACS dosage concentration was 14.0~31.5 mg/L. As the results of operation, the range of removal efficiency of turbidity, SS were 81.0~95.8% (mean 89.5%) 81.8~99.0% (mean 91.4%), respectively. An increase of filtration basin retention time brought on increased of removal efficiency of turbidity and SS, and increase of SOR brought on decreased of removal efficiency. During the first flush in urban area, storm runoff have an high concentration of SS (200~600 mg/L) and the filtration bed becomes clogged and decreased of removal efficiency. Backwashing begins when the drainage pipe valve at the filtration tank bottom is completely open (backwashing stage 1). Backwashing stage 2 was using air bubbles and water jet washing the media for 5 mins and open the drainage valve. After backwashing stage 1, 2, 61.83~64.04%, 18.53~27.51% of SS loading was discharged from filtration tank, respectively. Discharged SS loading from effluent was 7.12~14.79% and the range of residual SS loading in fliter was 2.26~5.00%. The backwashing effects for turbidity, SS were 89.5%, 91.4%, respectively. The hydrocyclone coagulation and filtration with backwashing system, which came out to solve the problems of the costly exchange filter media, and low efficiency of removing micro particles of filter type nonpoint treatment devices, is considered as an alternative system.

• Food Science and Preservation
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• v.21 no.4
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• pp.506-511
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• 2014

In Gyeongsangbuk-do seongju area, hundreds of tons of spoiled oriental melon are harvested annually. Therefore, ways to prevent such spoilage are needed. This study was conducted to investigate the quality characteristics of spoiled oriental melon juice after enzyme treatment for the production of oriental melon concentrate. The treatment of the oriental melon juice with three kinds of enzymes with variable concentrations showed the following results. PECE(1), which was compounded pectinase and cellulase at 0.01% (v/v), gave the melon a 0.16 brown color and 0.01 turbidity, and the highest L value of 97.00. The detected free sugar contents were fructose, glucose and sucrose, with the amount of sucrose the highest at roughly 4,000 mg%. The mixture of different enzyme treatments resulted in a 0.15 brown color and 0.01 turbidity at 60 minutes, and the L value was high at 97.25. The enzyme treatment temperatures of $50^{\circ}C$ and $60^{\circ}C$ yielded a low-level brown color and low turbidity, but the L values were high at $60^{\circ}C$ and $70^{\circ}C$. These results showed that 0.01% (v/v) mixing enzyme, i.e., pectinase and cellulose compounded at $60^{\circ}C$ for 60 min, must be used for the production of oriental melon concentrate.

• Journal of Korean Society of Forest Science
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• v.108 no.3
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• pp.329-340
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• 2019

Water pollution in erosion control dams is a major issue for forest watershed management, but the effects of erosion control dams on water quality remain poorly understood. In this study, water quality data from streams and dam reservoirs were collected over the Nakdong river basin. Monitored data were further analyzed to examine the relationship between watershed characteristics and water quality. Of the total 43 erosion control dams, less than 10% had lower water quality that was not suitable for agricultural use. TOC and oxygen demand, SS and turbidity, SS and Chl-a, and Chl-a and turbidity showed high correlations (p < 0.01) both in stream water and in detained water. BOD and SS, BOD and Chl-a, BOD and turbidity, and TOC and Chl-a showed high correlations only in stream water. Overall, the results demonstrated that for most erosion control dams the water quality was relatively good. In addition, the quality of downstream water is somewhat affected by the water detained by erosion control dams, in limited ways.

• Journal of Korean Society of Water Science and Technology
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• v.26 no.6
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• pp.99-107
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• 2018

This research has developed a high temperature steam cleaning technology using a ceramic membrane with durability against temperature and pressure conditions. In steam cleaning, steam of $120^{\circ}C$ is injected into the ceramic membrane to induce pyrolysis by the endothermic reaction to remove fouling from the membrane. The water quality of raw water was adjusted to turbidity 10, 25 NTU and DOC 2.5 mg/L, and the membrane was uniformly fouled by constant pressure operation at 100, 200, and 300 kPa. Physical backwashing was performed with water and air at a pressure of 500 kPa and steam at $120^{\circ}C$ was injected for 0 to 5 minutes. As the turbidity concentration and the operating pressure increased, the flux decreased by 0.7 to 14.4%. It is confirmed that 10.7 to 53.8% recovery is possible than physical cleaning at the injection of steam for 3 minutes, so it is considered that the steam cleaning of the ceramic membrane is effective. Compared with CEB after NaOCl (300 mg/L) filtration at 25 NTU and 300 kPa of turbidity, the steam cleaning result for 3 minutes was similar to 46.7% of CEB for 3 hours. It has been confirmed that steam cleaning is suitable for a ceramic membrane having excellent heat resistance against high temperature. It was considered to have better cleaning efficiency as compared with general physical backwashing.