• Korean Journal of Environmental Agriculture
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• v.26 no.1
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• pp.25-35
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• 2007

Excess runoff contaminated with N and P can impact the quality of downstream water. It has been known that aquatic plants improve the water quality through their intake of organic or inorganic nutrients. This study was conducted to select aquatic plants having high purification ability for nutrient N and P, and mineral nutrients related to EC such as K, Ca, Na, Cl, and $SO_4$ in raw sewage water in greenhouse. We assessed nutrient phytoremediation potential of alien hydrophyte and hydro-crop as well as native landscape hydrophyte to select suitable aquatic plant applied to artificial wetland and buffering site of stream-side. The amount of irrigation water during whole growing period of aquatic plane ranged from 225 L $m^{-2}$ to 444 L $m^{-2}$. Oryza sativa, Typha orientalis, Zizania latifolia, Aster subulatus, Coix lachryma-jobi var. mayuen, Paspalum disdichum var. indutum which had high biomass consumed the large amount of irrigation water over 350 L $m^{-2}$. As a result of analysis of water purification effect N and P content of shoot biomass, and media soil after experiment, Oryza sativa, Zizania latifolia, Aster subulatus, Coix lachryma-jobi var. mayuen, Paspalum distichum var. indutum showed high purification ability about eutrophication elements such as T-N and T-P. It is presented that Pistia stratiotes, Eichhornia crassipes, and Paspalum distichum var. indutum had excellent purification ability about K, Ca, Na, and Cl. Moreover, Paspalum distichum var. indutum greatly removed $SO_4$ in row sewage water.

• Journal of Environmental Science International
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• v.7 no.1
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• pp.57-61
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• 1998

The biosorption of heavy metals has received a lot of attraction for application of metal ions treatment. In this work, we studied with Arthrobactor sp., screening from a wastewater containing heavy metals. The Pb uptake capacity of Arthrobactor sp. was nearly 146.9 mg Pb/g dry biomass(initial concentration, 500 may L), whereas the Pb uptake capacity of Sacchuomyces cerevisiae and Sacchuomyces uvuum were only around 39.40 and 35.65 mg Pb yg dry biomass, respectively. The Pb and Cr were removed from metal solution much more effeciently than were the other metals(Cd and Cu). The Pb uptake capacity of Aythrobactor sp. increased with increasing in pH(1.8, 3.0 and 4.0) and decreased with Increaslng of biomass concentration. At pH 4.0, the Pb uptake capacity reached 244 mg Pb/g dry biomass in Pb initial concentration of 1000 mg/L. The Pb uptake capacity of Ayhol)actor sp. treated by KOH and $CaCl_2$ were increased above values obtained with untreated Ayurobactor sp. However, the Pb uptake capacity fore the breakthrough points were reached.

• The Journal of Natural Sciences
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• v.11 no.1
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• pp.113-117
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• 1999

Treatments with increased amount of nitrogen fertilizer had less calcium content than those of conventional fertilization in 'Starkrimson' apple fruits. When $CaCl_2$ solution was applied as tree spray, treatment of conventional fertilization had increased fruit calcium content and decreased occurrence of spotted disorders. Better in increasing fruit calcium content was secured in treatment of conventional nirtogen fertilization. The irrigation effect to sandy loam soil where 'Fuji' apple fruits were planted were observed in fruit enlargement and increase of calcium content in leaves and fruits.

• Fisheries and Aquatic Sciences
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• v.2 no.2
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• pp.149-154
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• 1999

Response Surface Methodology was applied for optimizing the processing parameters of ultrasound treatment in order to produce low-molecular alginate. The use of ultrasound significantly reduced viscosity of alginate solutions. Suggested parameters of ultrasound treatment for maximum reduction of alginate molecular weight were: specific intensity, 115.81 $W/cm^2$ at 20kHz frequency; treatment time, 35.55 min; temperature, $20.08^{\circ}C$; alginate concentration, $2.5\%$. Low-molecular alginate obtained by ultrasound had two peaks on Sepharose CL-6B gel filtration. The viscosities of control, fraction I, and fraction II at $0.1\%$ concentration and $25^{\circ}C$ were 3.07, 1.23, and 0.82cps, respectively. Molecular weights of control, fraction I, and fraction II alginates were 336,500, 70,400, and 52,800 daltons, and their solubilities were 3, 6, and $14\%$, respectively. The lower molecular weight of alginate, the lower the alcohol precipitation and the higher $Ca^{2+}$ ion binding capacities. Heavy metal ion binding capacities of alginates were high in the following order of Pb, Cd, Zn, and Co.

• Membrane and Water Treatment
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• v.1 no.2
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• pp.139-158
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• 2010

This work focuses on the application of nanofiltration (NF) to the concentration of a pharmaceutical product, Clavulanate ($CA^-$), from clarified fermentation broths, which show a complex composition with six main identified ions ($K^+$, $Cl^-$, ${NH_4}^+$, $H_2{PO_4}^-$, ${SO_4}^{2-}$ and $CA^-$), glucose and glycerol. The solutes transport through the NF membrane pores was investigated using the SEDE (Steric, Electric and Dielectric Exclusion) model. This model was applied to predict the rejection rates of the initial feed solution and the final concentrated solution (10-fold concentrated solution). The best results were achieved with a single fitted parameter, ${\varepsilon}_p$ (the dielectric constant of the solution inside pores) and considering that the membrane selectivity is governed by steric, electric (Donnan) and Born dielectric exclusion mechanisms. While the predicted intrinsic rejections of solutions comprising up to six ions and uncharged solutes were in good agreement with the experimental values, the deviations were much larger for the 10-fold concentrated solution.

• Journal of Plant Biology
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• v.38 no.2
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• pp.195-201
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• 1995

The present study was made of the effects of abscisic acid(ABA) and calcium ions on dark respiration in protoplasts isolated from the basal intercalary meristematic tissues of oat (Avena sativa L.) seedlings. The influences of calcium channel blockers diitiazem(DTZ), verapamil(VPM), and $LaCl_2$ and the calmodulin antagonist trifluoperazine(TFP) on protoplast respiration activities were also investigated in order to evaluate the possible involvement of calcium channels and calmodulin during the dark respiration. The ABA only caused an 21% inhibition of protoplast respiration at $10^{-6}\;M$, but the extent of inhibition was very low by calcium treatments in the absence of ABA. In the presence of $10^{-6}\;M$ ABA, however, this inhibition of respiration increased by the increment of calcium ions concentrations. Treatments of DTZ and VPM were all found to restore the calcium-dependent inhibition of protoplast respiration by ABA and it was the same in thc $LaCl_2$ treatment except at $10^{-4}\;M$. At concentration from $10^{-6}\;M\;to\;10^{-4}\;M$, TFP also restored an inhibition of respiration. These results support the possibility that ABA increases plasmalemma permeability to calcium ions which might then bind to calmodulin to regulate oat protoplast dark respiration.ration.

• Journal of Animal Science and Technology
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• v.45 no.5
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• pp.875-884
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• 2003

Operational parameters for struvite crystallization, as a process to recover nitrogen and phosphorus resources from animal wastewater, were studied in this research. Crystallization distinctive of NH$_4$-N and PO$_4$$^{3-}$ in accordance to chemical sources, influent pH, aeration and stirring was examined using 2L of working volume of struvite reactor. Also, to find an effective treatment process combining with electrolysis method, removal characteristics of NH$_4$-N and PO$_4$$^{3-}$ in 6 different processes was tested. As chemical sources for the derivation of struvite formation, MgSO$_4$ and MgCl$_2$ were superior to CaCO$_3$ and CaCl$_2$. From experiment which was conducted to know the effects of aeration and stirring on struvite formation, it was revealed that aeration stimulated the crystallization reaction by inducing faster pH increase. While 90% of P removal was achieved within 1 hour under aeration, 14 hours was consumed under stirring condition. Struvite formation under aeration was affected by influent pH. No crystallization was observed at pH 5 level, but active crystallization reaction was induced over pH 6.0. 95% of P removal by struvite formation at pH 6, 7 and 9 was achieved within 3h, 2h and 10 min., respectively. However, over pH 10, operational problem due to excessive foam formation occurred, and blunting of crystallization reaction was observed at pH 11. When consider the pH range of animal wastewater, pH 7 to 9, efficient struvite formation could be achieved by simple aeration, without any chemical usage for pH adjustment. Among tested processes, the treatment process which electrolyzing the supernatant from struvite reactor, providing air to both reactors, showed best pollutant removal efficiencies. In this combined process, the removal efficiencies of NH$_4$-N and PO$_4$$^{3-}$ was 86% and 98%, respectively, and 92.4% of color removal was obtained.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.23 no.5
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• pp.394-400
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• 1990

In the previous paper, we reported that the bacteriostatic effect of condensed phosphate. The present study was intended to observe influence of various environmental factors on the bacteriostatic effect of condensed phosphates in the laboratory media, in order to get the information on the possibility to use the phosphate as food preservative. Bacteriostatic effect of sodium polyphosphate was not reduced by the heating at 100 for 1 hour, but it was considerably decreased by heating at $121^{\circ}C$ for 15 min and the phosphate sensitivity of bacteria was increased by freezing and heating. On the other hand, the strong bacteriostatic activity of condensed phosphate was observed below pH 6.5 in nutrient broth culture, and the activity was decreased by the addition of $CaCl_2$, KCl and $MgSO_4$.

• Journal of Environmental Science International
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• v.30 no.10
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• pp.803-809
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• 2021

This study aimed to investigate the effects of soil amendment (heat-expanded clay and active carbon) and planting of Dendranthema zawadskii var. latilobum on the remediation of salt-affected soil and the plant growth under high calcium chloride (CaCl₂) concentration. The experimental group comprised treatments including Non treatment (Cont.), heat-expanded clay (H), active carbon (AC), planting (P), heat-expanded clay+planting (H+P), active carbon+planting (AC+P). A 200 mL solution of CaCl₂ at a concentration of 10 g·L^-1 was applied as irrigation once every 2 weeks. Compared to the Cont., the incorporation of the 'heat-expanded clay' amendment decreased electrical conductivity of the soil leachate and cation exchange capacity, whereas the growth of Dendranthema zawadskii var. latilobum was relatively increased. These results suggest that the combination of 'heat-expanded clay' amendment and planting will mitigate negative effect of de-icing salts and improve plant growth in salt-contaminated roadside soils.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.51 no.6
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• pp.682-687
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• 2018

We investigated the effects of a highly saline solution (HS) containing hypochlorous acid, calcium chloride ($CaCl_2$), and phosphoric acid ($H_3PO_4$) on cell death and growth rate of laver Porphyra yezoensis and green laver Ulva intestinalis. Cell death rates of laver treated with HS and HS plus hypochlorous acid (HS + HOCl) in the harvesting stage were less than 0.5%, and there were no significant differences between the HS and HS + HOCl treatments. However, cell death of green laver treated with HS + HOCl in the harvesting stage was greater than 81.2%. These results indicate that the addition of HOCl is highly effective to eradicate noxious green laver without causing damage to laver. The addition of HOCl and $H_3PO_4$ to HS did not increase the area or weight of laver blades. A combination treatment of $CaCl_2$ and HS, however, significantly increased the area and weight of laver lades compared to controls (P<0.05).