• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.41 no.5
• /
• pp.485-492
• /
• 2021

This study focused on safety aspects surrounding energy consumption in the seawater desalination process in the Daesan Industrial Complex located on the West Sea coast. The safety index for energy consumption was evaluated under different salinities and temperatures of the incoming seawater. Temperature and salinity input data for the 1997-2018 period were obtained from the Marine Environment Information System, and the power required for reverse osmosis (RO) was applied to the program as per the data provided by the RO membrane manufacturer (Q-Plus v3.0). Notably, reasonable energy consumption guidelines were proposed during the design of the desalination facilities; in this regard, the desalination process required approximately 2.10-2.90 kWh/m³ electrical power. Moreover, the energy safety based on 95 % was estimated to be 2.80 kWh/m³ when the desalination facility was operated.

• Journal of Korean Society of Environmental Engineers
• /
• v.38 no.1
• /
• pp.8-13
• /
• 2016

This study investigated the removal of a radioactive cesium ($Cs^+$) in the water at the water treatment processes. Since cesium is mostly present as the $Cs^+$ ion state in water, it is not removed by sand filtration, and coagulation with polyaluminum chloride (PACl), powdered activated carbon (PAC) and mixture of PACl and PAC. However, it is known that the removal rate of cesium increases as the turbidity increases in raw water. As the turbidity was adjusted by 74 NTU and 103 NTU using the surrounding solids near G-water intake and yellow soils, removal rate of cesium was about 56% and 51%, respectively. In case of a GAC filtration with supernatants after jar-mixing/setting was conducted, 80% of cesium is approximately eliminated. The experimental results show that it is efficient to get rid of cesium when the turbidity of the raw water is more than 80 NTU. In case of a GAC filtration, about 60% of cesium is removed and it is considered by the effect of adsorption. Cesium is not eliminated by microfiltration membrane while about 75% of cesium is removed by reverse osmosis.

• Applied Chemistry for Engineering
• /
• v.24 no.5
• /
• pp.456-470
• /
• 2013

Hollow-fiber membranes, is one of the new technologies that is growing rapidly in the past few decades. In addition, separation membranes using polymer materials, have attracted attentions in various fields including gas separation, fuel cells, water treatment, wastewater treatment, and organic separation. Nanofiltration (NF) membranes having the separation characteristics in the intermediate range between ultrafiltration and reverse osmosis (RO) membranes for liquid separation, with relatively low investment cost and operating pressure lower than that of RO membranes, have high permeance and rejection performance of multivalent ions as well as organic compounds of molecular weight between $200{\sim}1000gmol^{-1}$. In this paper, we would like to review the research trends on the various structure control and characterization of NF hollow fiber membranes with respect to materials and the methods of preparation (phase inversion method and interfacial polymerization method). Currently, most of NF membranes have been manufactured by plate and frame types or spiral wound types. But hollow fiber types have delayed in commercial products, because of the weak strength when to produce on the basis of the existing materials, therefore the development of new materials or improvement of existing materials will be needed. If improving manufacturing technology is available, hollow fiber types will replace spiral wound types and gradually show a higher market share.

• The Korean Journal of Physiology
• /
• v.1 no.1
• /
• pp.57-66
• /
• 1967

Cold $(0^{\circ}C)$ or warm $(25^{\circ}C)$ fresh and sea water were flooded into the lungs of rabbits through tracheal canule. Respiratory arrest ensued in 19.5 minutes in the warm fresh water flooded rabbits and was the longest survival time among the experimental groups. The survival times in the other groups were: 2.32 minutes in cold fresh water group, 2.75 minutes in .warm sea water group, and 4.57 minutes in cold sea water group. Cardiac output was measured by means of T-1824 dilution technique after 2 or 3 minutes of flooding in 27 rabbits. Blood pressure was observed by mercury manometer throughout the survival time in 40 rabbits. The following results were obtained. 1. Cardiac output in the warm fresh water flooded and sea water flooded animal was smaller than that of control rabbits. In the cold fresh water flooded animal cardiac output was greater than that of the control animal. 2. Time constants of T-1824 dilution curve of experimental group were elongated than the normal curve. 3. Central blood volume showed an increase in the fresh water group, a decrease in cold sea water group and no change in warm sea water group. 4. In all of the experimental groups arterial blood Pressure showed an abrupt and great variations after flooding of lungs and lasted about 30 seconds. Thereafter, arterial pressure remained at a plateau level until the sudden fall to zero and this was almost coincided with the time of respiratory arrest. The Plateau level of arterial Pressure in fresh water group was about 10 mmHg higher than the control value, and it was lower than the control value in warm sea water group. In cold sea water group the plateau was made up by fluctuations around the control value. 5. Osmosis of water through the lung alveolar membrane occured in all animals. Fresh water caused hemodilution and sea water caused hemoconcentration. 6. In sea water flooded animal more volume of water was recovered through the tracheal canule than the volume injected into trachea. This was interpreted as the consequence of the shift of water from plasma to alveolar sac. 7. Relative freight of lung was greater in fresh water group than sea water group. In all animal lung edema ensued. 8. The mechanisms of cardiac output variations were discussed.

• Journal of Animal Environmental Science
• /
• v.14 no.2
• /
• pp.119-128
• /
• 2008

This experiment was conducted to investigate the effects of concentrated pig slurry using membrane filter on growth of tomato in nutriculture. Pig slurry was filtered by ultra filtration and concentrated by reverse osmosis process. Filtration of pig slurry was necessary to prevent the hose clogging in nutriculture. The concentrated pig slurry (CS) and nutrient solution (NS) were mixed by six different mixing ratios of 0:100, 20:80, 40:60, 60:40%, 80: 20 and 100%:0% based on nitrogen content. The chemical nutrient solution was the solution of National Horticulture Research Station for the growth of tomato. The concentration of nutrient solution was adjusted a range of $1.6{\sim}2.0mS/cm$ in EC. The plant height of tomato treated with CS 20+NS 80% was similar with NS 100% control plot. Plant height was highest in the plot of CS 20+NS 80%. The treatment of 100% concentrated pig slurry was lowest in the gowth characteristics of tomato. Number of cluster was very lower in 100% concentrated pig slurry compared with plot of chemical nutrient solution. In the beginning of growth stage, SPAD reading value was reduced in plot treated with CS 100%, but CS 20+NS 80% plot was higher compared to 100% concentrated pig slurry. SPAD value of tomato leaves was decreased as the amount of CS was increased. The SPAD value also in treatment of concentrated pig slurry was lower in the middle growth stage compared to control plot. The dry weight of stem and leaf were 107.4, 104.2g in plot of NS 100% and CS 20%+NS 80%, respectively. The fruit number and weight were decreased at high application plots of concentrated pig slurry, The fruit setting of tomato showed lowest in the plot treated with 100% concentrated pig slurry, and the growth of tomato severely decreased after application of 100% CS treatment. In conclusion, the growth characteristics such as plant height and fruit weight of tomato were not significantly different between the plots treated with mixture of 20% CS +80%NS and 100% nutrient solution treatment. In conclusion, the mixture solution of 20% of concentrated pig slurry and 80% of nutrient solution could be used as a nutrition solution of tomato nuticulture.