• Title/Summary/Keyword: high salt concentration

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Optimization of chemical cleaning of discarded reverse osmosis membranes for reuse

  • Jung, Minsu;Yaqub, Muhammad;Lee, Wontae
    • Membrane and Water Treatment
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    • v.12 no.1
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    • pp.1-9
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    • 2021
  • This study optimized the chemical cleaning process of discarded RO membranes for reuse in less demanding separation processes. The effect of physicochemical parameters, including the temperature, cleaning time, pH of the cleaning solution, and addition of additives, on the cleaning process was investigated. The membrane performance was evaluated by testing the flux recovery rate and salt rejection before and after the cleaning process. High temperatures (45-50 ℃) resulted in a better flux recovery rate of 71% with more than 80% salt rejection. Equal time for acid and base cleaning 3-3 h presented a 72.43% flux recovery rate with salt rejection above 85%. During acid and base cleaning, the best results were achieved at pH values of 3.0 and 12.0, respectively. Moreover, 0.05% concentration of ethylenediaminetetraacetic acid presented 72.3% flux recovery, while 69.2% flux was achieved using sodium dodecyl sulfate with a concentration of 0.5%; both showed >80% salt rejection, indicating no damage to the active layer of the membrane. Conversely, 0.5% concentration of sodium percarbonate showed 83.1% flux recovery and 0.005% concentration of sodium hypochlorite presented 85.2% flux recovery, while a high concentration of these chemicals resulted in oxidation of the membrane that caused a reduction in salt rejection.

Efficacy of Blanket Vegetation Mats on Soil and Native Groundcover Plants under Treatment of High Concentration Deicing Salt (고농도 제설제 처리에서 토양 및 자생 초화류에 미치는 Blanket 식생매트의 효용성)

  • Ju, Jin Hee;Lee, Je Man;Kim, Won Tae;Lim, Byung Ok;Seo, Nam Kyu;Yoon, Yong Han
    • Journal of Environmental Science International
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    • v.31 no.3
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    • pp.247-254
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    • 2022
  • This study investigated the effect of vegetation mat on plant growth and salt reduction in the soil treated with high concentration deicing salt. In order to measure soil chemical characteristics and plant growth, three native groundcover plants (Dendranthema zawadskii var. latilobum, Dendranthema boreale, and Kalimeris yomena) were grown in each of the three plastic containers (50.0 cm width × 35.0 cm length × 8.5 cm deep) with a high concentration treatment of calcium chloride deicing salt. There were two treatments: control, and BVM that combines B (blanket) and VM (vegetation mat). 1,600 g of soil was placed on the top of the drainage layer with 290 g of perlite, 100 seeds each of the three native plants with three repetitions were sowed, and 10 g/L of calcium chloride deicing salt was added in the treatment. As a result of the chemical properties of soil, soil in control treatment was acidic and soil electrical conductivity in BVM was the lowest. Also, exchangeable cations (K+, Ca2+, Na+, and Mg2+) in soil and all the three plants were significantly decreased in the BVM treatment. Meanwhile, the germination rate of Dendranthema zawadskii var. latilobum was the highest under high concentration deicing salt in compared to the two plants. Overall, three native groundcover plant growth was higher in the BVM than control treatment significantly. These results suggest that the treatment of blanket vegetation mat has a positive effect on soil and plant growth in soil damaged by deicing salt.

Effect of Salt Contents on High Pressure Inactivation of Microorganism in Doenjang (염 함량이 된장의 초고압 살균에 미치는 영향)

  • Mok, Chulkyoon
    • Food Engineering Progress
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    • v.15 no.4
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    • pp.318-323
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    • 2011
  • High pressure processing (HPP) technology was applied to inactivate the microorganisms in Doenjang (soybean paste) and the effects of salt concentration on the HPP inactivation of microorganisms were analyzed. The microorganisms in Doenjang containing low salt content showed greater sensitivity to HPP than those with high salt content. HPP inactivation effects decreased as salt concentration of Doenjang increased. The HPP sensitivity decreased in the order of fungi, yeasts, bacteria in terms of microorganism type. The HPP of Doenjang at 6,500 atm for 40 min inactivated most yeasts and fungi, indicating that the HPP technology was applicable to control the microorganisms in Doenjang, especially with a low level of salt.

Effects of Pre-salting on the Components Changes in the Preparation of Salted Anchovy (Engraulis japonica)

  • Cho Young-Je;Shim Kil-Bo;Kim Tae-Jin;Ju Jung-Mi;Choi Yeung-Joon
    • Fisheries and Aquatic Sciences
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    • v.3 no.3_4
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    • pp.200-204
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    • 2000
  • To investigate pre-salting conditions in the preparation of salted anchovy from large anchovy, anchovy were salted with various salt concentration and stored at $5^{\circ}C$ and $20^{\circ}C$ for 10 days. Moisture content decreased with the increase of salt and the salinity increased in proportion to salt concentration at $20^{\circ}C$. Total nitrogen decreased slightly as the increase of salt concentration during pre-salting at $20^{\circ}C$. The nitrogenous components such as amino nitrogen and extractable nitrogen were invariable or decreased until 7 days in salt concentration over $25\%$ during pre-salting at $5^{\circ}C$. These results imply that soluble nitrogen with moisture run out of anchovy body in high salt concentration and the hydrolysis was inhibited by salt over $25\%$ at $5^{\circ}C$. VBN content were constant in salt concentration over $25\%$ until 7 days, regardless of curing temperature. The POV were under the influence of salt concentration and temperatures. We concluded that the optimal condition for preparation of salted anchovy were pre-salting with salt over $25\%$ at $5^{\circ}C$ for 7 days.

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Salt Injury and Overcoming Strategy of Rice (수도의 염해와 대책)

  • 이승택
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.34 no.s02
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    • pp.66-80
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    • 1989
  • Salt injury in rice is caused mainly by the salinity in soil and in the irrigated water, and occasionaly by salinity delivered through typhoon from the sea. The salt concentration of rice plants increased with higher salinity in the soil of the rice growing. The climatic conditions, high temperature and solar radiation and dry conditions promote the salt absorption of rice plant in saline soil. The higher salt accumulation in the rice plant generally reduces the root activity and inhibits the absorption of minerals of rice plant, resulting the reduction of photosynthesis. The salt damages of rice plant, however, are different from different growth stage of rice plants as follows: 1. Germination of rice seed was slightly delayed up to 1.0% of salt concentration and remarkably at 1. 5%, but none of rice seeds were germinated at 2.5%. This may be due to the delayed water uptake of rice seeds and the inhibition of enzyme activity, 2. It was enable to establish rice seedlings at seed bed by 0.2% of salt concentration with some reduction of leaf elongation. The increasing of 0.3% salt concentration caused to the seedling death with varietal differences, but most of seedlings were death at 0.4% with no varietal differences. 3. Seedlings grown at the nursery over 0.1% salt, gradually reduced in rooting activity after transplanting according to increasing the salt concentration from 0.1% up to 0.3% of paddy field. However, the seedlings grown in normal seed bed showed no difference in rooting between varieties up to 0.1% but significantly different at 0.3% between varieties, but greatly reduced at 0.5% and died at last in paddy after transplanting. 4. At panicle initiation stage, rice plant delayed in heading by salt damage, at meiotic stage reduced in grains and its filling rate due to inhibition of glume and pollen developing, and salt damage at heading stage and till 3 weeks after heading caused to reduction of fertilization and ripening rate. In viewpoint of agricultural policy the overcoming strategy for salt injury is to secure sufficient water source. Irrigation and drainage systems as well as underground drainage is necessary to desalinize more effectively. This must be the most effective and positive way except cost. By cultural practice, growing the salt tolerant variety with high population could increase yield. The intermittent irrigation and fresh water flooding especially at transplanting and from panicle initiation to heading stage, the most sensitive to salt injury, is important to reduce the salt content in saline soil. During the off-cropping season, plough and rotavation with flooding followed by drainage, or submersion and drainage with groove could improve the desalinization. Increase of nitrogen fertilizer with more split application, and soil improvement by lime, organic matter and forign soil addition, could increase the rice yield. Shift of trans-planting is one of the way to escape from the salt injury.

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Contribution of Counterion Entropy to the Salt-Induced Transition Between B-DNA and Z-DNA

  • Lee, Youn-Kyoung;Lee, Juyong;Choi, Jung Hyun;Seok, Chaok
    • Bulletin of the Korean Chemical Society
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    • v.33 no.11
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    • pp.3719-3726
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    • 2012
  • Formation of Z-DNA, a left-handed double helix, from B-DNA, the canonical right-handed double helix, occurs during important biological processes such as gene expression and DNA transcription. Such B-Z transitions can also be induced by high salt concentration in vitro, but the changes in the relative stability of B-DNA and Z-DNA with salt concentration have not been fully explained despite numerous attempts. For example, electrostatic effects alone could not account for salt-induced B-Z transitions in previous studies. In this paper, we propose that the B-Z transition can be explained if counterion entropy is considered along with the electrostatic interactions. This can be achieved by conducting all-atom, explicit-solvent MD simulations followed by MM-PBSA and molecular DFT calculations. Our MD simulations show that counterions tend to bind at specific sites in B-DNA and Z-DNA, and that more ions cluster near Z-DNA than near B-DNA. Moreover, the difference in counterion ordering near B-DNA and Z-DNA is larger at a low salt concentration than at a high concentration. The results imply that the exclusion of counterions by Z-DNA-binding proteins may facilitate Z-DNA formation under physiological conditions.

A Cross-Cultural Study of the Awareness and the Preference on Salinity among the Northeast Asians (동북아 아시아인의 짠맛에 대한 인지도 및 기호도 비교 연구)

  • Park, Hyun-Jung;Kwak, Eun-Jung;Cho, Mee-Hee;Lee, Kyung-Hee
    • Journal of the East Asian Society of Dietary Life
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    • v.19 no.4
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    • pp.525-532
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    • 2009
  • The purpose of this study was to compare the ability of Northeast Asians to discriminate the salinity in salt solution and foods, and to compare their preference of salinity. Panels of Korean, Japanese and Chinese evaluated three kinds of samples that contained different level of salt such as salt solutions, julienned radish salad, Bulgogi. The salt levels had been manipulated to produce five samples of each one. The salt solutions were prepared by adding 0.3%, 0.7%, 1.1%, 1.5%, 1.9% salt into water. Different levels of salt in Julienned radish salad and Bulgogi were prepared by adding 0.5%, 1.5%, 2.5%, 3.5%, 4.5% salt to the recipe. The results of this study showed that the three ethnic groups had significant differences in their ability to distinguish the intensity of salinity in solutions containing a high contents of salt(1.5~1.9%). According to the regression analysis, Koreans(a=1.050) turned out to be the most able to detect the intensity of salinity, compared to the Japanese (a=0.988) and Chinese (a=0.807). All ethnic groups preferred a salt concentration of 0.3%, and the preference for this concentration was lower in Japanese than in Koreans and Chinese. There were significant differences in the perception of salinity in the julienned radish salad containing more than 3.5% salt between Koreans and Chinese. Koreans (a=1.168) appeared to be the most able to detect the intensity of salinity, compared to the Japanese (a=0.908) and Chinese (a=0.793). Both Koreans and Japanese had the strongest preference for the julienned radish salad containing a 1.5% salt concentration, while the Chinese preferred a salt concentraion of 2.5%. The ability of ethnic groups to detect the salinity in Bulgogi were significantly different at high salt -concentrations (more than 3.5%), and the awareness of salinity was as fallows : Koreans(a=0.161) > Japanese (a=0.896) > Chinese (a= 0.845). Koreans and Japanese had a higher preference or the Bulgogi containing a salt concentration of 1.5%, and the Chinese had higher preference at a salt concentration of 2.5%.

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Effects of Salting Methods on the Physicochemical Properties of Kakdugi Fermentation (깍두기의 절임방법이 발효숙성 중 이화학적 특성에 미치는 영향)

  • 장명숙;김나영
    • Korean journal of food and cookery science
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    • v.15 no.1
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    • pp.61-67
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    • 1999
  • The effects of salting methods on Kakdugi (cubed radish kimchi) fermentation were evaluated. Kakdugi was prepared with various salting methods, salt concentrations, and settling times, and fermented at 10$^{\circ}C$ for up to 52 days. Radish (Raphanus sativus L.) cubes (2 cm size) were salted by using the following methods salt concentration of about 1.5% which was known appropriate for the organoleptic quality of Kakdugi: 1) Treatment S-1: applying dry salt uniformly onto the radish cubes, with a salt concentration of about 1.5% (w/w) and cured for 1 hr, 2) Treatment S-5: applying dry salt uniformly onto the radish cubes, with a salt concentration of about 1.2% (w/w) and cured for 5 hr, 3) Treatment B-1: brining radish cubes in a 8.5% (w/v) salt solution for 1 hr, 4) Treatment B-5: brining radish cubes in a 4.0% (w/v) salt solution for 5 hr. As the fermentation continued, the initial high decrease in pH has been retarded in all the treatments, of which the delaying extent was more significantly noted from B-1 and B-5 than S-1 and S-5. The pH of the Kakdugi which showed a good eating quality dropped to 4.3∼4.8 with the accumulation of total acids. Total vitamin C increased sharply at the palatable period of Kakdugi during the initial fermentation and then decreased gradually following a sigmoidal changing pattern. The reducing sugar levels were also influenced by salting methods and fermentation as sugars are converted into acids. High initial contents of reducing sugars and their subsequent rapid decrease were observed in “S” group than “B” group during fermentation. For nonvolatile organic acids, lactic acid increased consistently throughout the fermentation while malic acid, which was high at the initiation of fermentation, decreased rapidly afterwards at the palatable period of Kakdugi.

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Fermentative Bio-Hydrogen Production of Food Waste in the Presence of Different Concentrations of Salt (Na+) and Nitrogen

  • Lee, Pul-eip;Hwang, Yuhoon;Lee, Tae-jin
    • Journal of Microbiology and Biotechnology
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    • v.29 no.2
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    • pp.283-291
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    • 2019
  • Fermentation of food waste in the presence of different concentrations of salt ($Na^+$) and ammonia was conducted to investigate the interrelation of $Na^+$ and ammonia content in bio-hydrogen production. Analysis of the experimental results showed that peak hydrogen production differed according to the ammonia and $Na^+$ concentration. The peak hydrogen production levels achieved were (97.60, 91.94, and 49.31) ml/g COD at (291.41, 768.75, and 1,037.89) mg-N/L of ammonia and (600, 1,000, and 4,000) $mg-Na^+/L$ of salt concentration, respectively. At peak hydrogen production, the ammonia concentration increased along with increasing salt concentration in the medium. This means that for peak hydrogen production, the C/N ratio decreased with increasing salt content in the medium. The butyrate/acetate (B/A) ratio was higher in proportion to the bio-hydrogen production (r-square: 0.71, p-value: 0.0006). Different concentrations of $Na^+$ and ammonia in the medium also produced diverse microbial communities. Klebsiella sp., Enterobacter sp., and Clostridium sp. were predominant with high bio-hydrogen production, while Lactococcus sp. was found with low bio-hydrogen production.

Effect of Soil Salinity on Growth, Yield and Nutrients Uptake of Whole Crop Barley in Newly Reclaimed Land (신간척지에서 토양 염농도가 청보리 생육, 수량 및 양분 흡수에 미치는 영향)

  • Lee, Sang-Bok;Cho, Kwang-Min;Shin, Pyung;Yang, Chang-Hyu;Back, Nam-Hyun;Lee, Kyeong-Bo;Baek, Seung-Hwa;Chung, Doug-Young
    • Korean Journal of Environmental Agriculture
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    • v.32 no.4
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    • pp.332-337
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    • 2013
  • BACKGROUND: Newly reclaimed land has poor soil environment for crop growth since it is high in salt concentration but low in organic content compared with ordinary soil. It is known that whole-crop-barley can grow better in the soil of relatively high salt concentration than other crops but, the growth is poor at the concentration if higher than certain amount and it is a difficulty to secure productivity. Hence, the level of soil salt concentration suitable for the production of bulky feed in newly reclaimed land has been investigated. METHODS AND RESULTS: At Saemanguem reclaimed land, the land for the soil salt concentration electrical conductivity (EC) 0.8, 3.1, 6.5, 11.0 dS/m was selected; and chemical fertilizer $N-P_2O_5-K_2O$ (150-100-100kg/ha) was tested; and forage barley 220kg/ha were sown. The soil salt concentration during the cultivation period decreased in the order of harvest season>earing season>sowing season>wintering season, and the salt concentration in harvest season is 1.4-4.2 times higher than that of the sowing season. The higher the salt concentration, the poorer the over ground growth due to poor rooting; especially at EC 11.0 ds/m there was emergence but, it blighted after wintering. The Yield from the soil salt concentration 3.1dS/m and 6.5 dS/m was 68% and 35% from that of the soil salt concentration 0.8 dS/m (8.8 MT/ha) respectively. The proline content in early life stage was more than that of the harvest season, and it increased with salt concentration. The higher salt concentration, the more $Na_2O$ and MgO content in harvest season; but the higher the salt concentration, the less the content of N, $P_2O_5$, $K_2O$ and CaO. CONCLUSION(S): When the soil salt concentration becomes higher than 3.1 dS/m, the yield becomes poor because there is serious growth inhibition of forage barley both in root part and above aerial part that results in unbalanced absorption of nutrients. Therefore, it is recommended that the salt concentration should be lowered below 3.1 dS/m by underground drainage facilities or irrigating water for the stable production of whole-crop-barley.