• Journal of Korean Society on Water Environment
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• v.18 no.3
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• pp.237-243
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• 2002

The effect of a salinity on the performance of a biological nutrient removal system was investigated using a model SBR(Sequencing Bach Reactor) system. The system was operated at a 12hr, 18hr, 24hr, and 36hr HRT with a salinity level of 20,000mg/L and compared with a system similarly operated with fresh water. The influent salinity level of 8,000 mg/L does not have a significant effect on BOD removal efficiency, there is a noticeable decrease in BOD removal rate from 10,000 mg Cl-/L. The Nitrogen could be removed from the saline wastewater with the same efficiency as for the fresh water because of low C/N ratio in anoxic period. The excess biological phosphorous removal is highly affected by the increase in the influent salinity. The efficiency is decreased from 96.6% to 43.4% when the influent salinity is increased from 0 to 20,000mg/L.

• Journal of Industrial and Engineering Chemistry
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• v.68
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• pp.355-363
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• 2018

There are serious issues with the application of surfactant flooding as a third recovery method, such as surfactant slug losses. In this study,the impact of the salinity gradient on the remobilization of oiltrapped in Berea sandstone was investigated by emphasizing the surfactant adsorption gradient and phase behavior to determine the optimal salinity of the chosen surfactant concentration for investigating the salinity gradient. Three salinity-gradient schemes were applied to six cores saturated with light and heavy oils. The positive salinity gradient provided the best recovery results with an in situ microemulsion formation that could be observed in the fluid collector.

• Journal of the Korean earth science society
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• v.26 no.7
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• pp.714-724
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• 2005

The East Sea, a semi-enclosed marginal sea with shallow straits in the northwest Pacific, is marked by the nearly geographic isolation and the low sea surface salinity during the last glacial maximum (LGM). The East Sea might have the only connection to the open ocean through the Korea Strait with a sill depth of 130 m, allowing the paleo-Tsushima Water to enter the sea during the LGM. The low paleosalinity associated with abnormally light $\delta^{18}O$ values of planktonic foraminifera is interpreted to have resulted from river discharge and precipitation. Nevertheless, two LGM features in the East Sea are disputable. This study attempts to estimate volume transport of the paleo-Tsushima Water via the Korea Strait and further examines its effect on the low sea surface salinity (SSS) during the lowest sea level of the LGM. The East Sea was not completely isolated, but partially linked to the northern East China Sea through the Korea Strait during the LGM. The volume transport of the paleo-Tsushima Water during the LGM is calculated approximately$(0.5\~2.1)\times10^{12}m^3/yr$ on the basis of the selected seismic reflection profiles along with bathymetry and current data. The annual influx of the paleo-Tsushima Water is low, compared to the 100 m-thick surface water volume $(about\;79.75\times10^{12}m^3)$ in the East Sea. The paleo-Tsushima Water influx might have changed the surface water properties within a geologically short time, potentially decreasing sea surface salinity. However, the effect of volume transport on the low sea surface salinity essentially depends on freshwater amounts within the paleo-Tsushima Water and excessive evaporation during the glacial lowstands of sea level. Even though the paleo-Tsushima Water is assumed to have been entirely freshwater at that time period, it would annually reduce only about 1‰ of salinity in the surface water of the East Sea. Thus, the paleo-Tsushima Water influx itself might not be large enough to significantly reduce the paleosalinity of about 100 m-thick surface layer during the LGM. This further suggests contribution of additional river discharges from nearby fluvial systems (e.g. the Amur River) to freshen the surface water.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.49 no.5
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• pp.612-619
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• 2016

In this study, we crossbred Epinephelus akaara and E. lanceolatus to produce a hybrid grouper with faster growth and adaptation to domestic aquaculture environments. The plasma cortisol and glucose levels and osmoregulation (stress response indicators) of the hybrid grouper, E. akaara ♀ × E. lanceolatus ♂, were investigated under several salinity levels (32, 24, 16, and 8 psu). The body lengths and weights of E. akaara (8.2 ± 0.1 cm, 8.3 ± 0.4 g) and the hybrid (8.6 ± 0.1 cm, 10.0 ± 0.4 g) were similar at the start of the experiment, but were significantly different at the end of the experiment. Juveniles of both E. akaara and the hybrid showed greater weight gain, specific growth, and feed conversion rate (FCR) under low salinity of 16 psu. Under the 8 psu treatment, the juvenile E. akaara all died, while the hybrid juveniles survived. Plasma cortisol levels were not affected by lower salinity in both species. The above results indicate that the hybrid is more tolerant of low salinity than is E. akaara, although both species exhibited higher growth and FCR at 16 psu, lower than the salinity of natural seawater. Thus, juveniles of both E. akaara and the hybrid can be more effectively cultured in brackish areas or waters with salinity lower than that of seawater.

• The Journal of the Acoustical Society of Korea
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• v.42 no.1
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• pp.16-24
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• 2023

The salinity of sea water is known as a less influencing variable in the calculation of the sound speed of the sea water. This study investigated how the low salinity of sea water affects the vertical structure of the sound speed near the mouth of the Yangtze (Changjiang) River when the diluted fresh water extends toward the East China Sea in the summer. As a result of comparing two types of sound speeds considered measured and fixed salinity, sound speeds appeared distinguishable when the halocline formed steeper than the thermocline due to Yangtze-River Diluted Water (YRDW). In addition, unlikely with fixed salinity conditions, when measured salinity was considered, an underwater sound channel appeared in the middle of the thermocline of which the source depth is located. Accordingly, considering the salinity, this study suggests using Expendable Conductivity Temperature Depth (XCTD) and Expendable Sound Velocimeter (XSV) rather than Expandable Bathy Thermograph (XBT) when calculating sound speed because of the strong halocline due to YRDW in the summer.

• Korean Journal of Microbiology
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• v.29 no.5
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• pp.339-343
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• 1991

Heterotrophic activity, total bacteria and salinity were determined seasonally in the estuary of Naktong River over half tidal cycle. Heterotrophic activity was determined by the uptake of [U- $^{14}$ C]glucose. Heterotrophic activity fluctuated with the tides and was decreased as salinity increased. Teh great activity occurred near low ebb tide at all seasons except summer. The main environmental factor affecting hetreotrophic activity was the salinity rather than water temperature in the estuary of Naktong River. In order to estimate the effect of salt, salt was added to estuarine water. Vmax for glucose of salt-added water was 17% and 77% of original estuarine water at station 1 and 2 respectively and slight increase was observed at station 3. Respiration rate and Kt+Sn for glucose of salt-added sample increased at all 3 stations. The increase of the Kt value implies the reduced affinity of bacterial population for glucose. The effects of salinity on the heterotrophic activity were more extensive in the upper region of estuary than at the mouth.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.33 no.4
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• pp.266-274
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• 1997

To understand seawater exchange are important to analyze the formation of watermass, material circulation and transfer of pollutant material etc. The purpose of this study is to review the previous studies and to propose new exchange ratio. where,$C_1$ ; average salinity of the water at low water$C_2$ ; average salinity of the water at the next low water$C_0$ ; average salinity of the water passing the bay mouth on the flood tide$V_2$ ; total water volume of the bay on the low water$V_0$ ; the volume of the remaining outer bay water entering during the flood tideSeawater exchange ratio of Dongho Bay calculated by new method are 26.1%, 23.8% respectevely.The average fresh water residence ratio calculated by equation (12) is 2.2 days, that is corresponding 23.5 % of exchange ratio. Thus, it appears similar result as proposed exchange ratio.

• Journal of Aquaculture
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• v.22 no.1
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• pp.122-125
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• 2009

Salinity tolerance on survival rate of 2, 4 and 6-week-old larvae and juvenile of black porgy Acanthopagrus schlegeli was investigated at 0, 7.5, 15, 22.5 and 30 psu for 21 days. In the 2 and 4-week-old larvae and juvenile (TL: 1.23 and 1.72 cm) were all died within 12 and 26 hours after to the 0 psu transfer, respectively. However, survival rate of other experimental group (7.5, 15, 22.5 and 30 psu) was significantly difference in the range between 27.3% and 95% (P<0.05). However survival rate of 6-weeks-old juvenile (TL: 2.83 cm) were over 99.0% during experimental periods and they appeared in good health. There was no significant difference in survival those reared to the salinities of all experimental groups (P>0.05). The present study suggests that the freshwater and saline groundwater of low salinity could be used to grow early juveniles of black porgy and it may be possible to culture in freshwater.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.2
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• pp.296-300
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• 2005

Human-induced soil salinity is becoming a major threat to agriculture across the world. This salinisation occurs in both irrigated and rain-fed agricultural zones with the highest proportions in the arid and semi-arid environments. Livestock can play an important role in the management and rehabilitation of this land. There are a range of plants that grow in saline soils and these have been used as animal feed. In many situations, animal production has been poor as a result of low edible biomass production, low nutritive value, depressed appetite, or a reduction in efficiency of energy use. Feeding systems are proposed that maximise the feeding value of plants growing on saline land and integrate their use with other feed resources available within mixed livestock and crop farming systems. Salt-tolerant pastures, particularly the chenopod shrubs, have moderate digestible energy and high crude protein. For this reason they represent a good supplement for poor quality pastures and crop residues. The use of salt-tolerant pasture systems not only provides feed for livestock but also may act as a bio-drain to lower saline water tables and improve the soil for growth of alternative less salt tolerant plants. In the longer term there are opportunities to identify and select more appropriate plants and animals for saline agriculture.

• Journal of the Korean Society of Marine Environment & Safety
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• v.9 no.2
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• pp.53-57
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• 2003

Low salinity water appears by outflow of fresh water from the Yangtze River in southwestern sea of the Korean peninsula. The water volume discharged form the Yangtze River is not constant with year, according to the time series data recorded in the past, the maximum value of the discharged volume is two times as high asr minimum value. Therefore, the distribution of low salinity water over study area with different discharged fresh water volume is studied using numerical model, Princeton Ocean Model (POM). POM is three dimensional circulation model selecting a $\sigma$­coordinate. According to the result of numerical simulation by the Model, current velocity on the continental slope is faster than those in other regions, current which flows toward the central part of the Yellow Sea through western part of Jeju exists, and also, southward flow along the coastal region exists. the greater discharged volume from the Yangrze River is. the lower salinity water appears closer to Jeju.