• Journal of Korean Society of Environmental Engineers
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• v.34 no.3
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• pp.162-167
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• 2012

The removal of orthophosphate ions from aqueous solutions by the anion exchange resin in the form of $Cl^-$ ion was investigated to elucidate the ion exchange mechanism which depends on the forms of orhthophoshate ions. In addition, the effects of alkalinity and other common anions were studied. The results showed that the orhthophosphate ions with the oxidation state of 2 and 3 ($HPO{_4}^{2-}$ and $PO{_4}^{3-}$) were effectively removed by the anion exchange resin, whereas the part of the $H_2PO_4{^-}$ ion passed through the ion exchange column. This suggested that the affinity of $H_2PO_4{^-}$ to the ion exchange resin was comparable with that of $Cl^-$ ion. In all cases, the effluent pHs have shown to be much lower than the calculated values, indicating that more $Cl^-$ ions than the orthophosphate equivalents in the influent were eluded. As the alkalinity increases, the decrease in pH was minimized. When the alkalinity was 100 mg/L ($CaCO_3$) or greater, 100 mg/L orthophosphate ions including $H_2PO_4{^-}$ were completely removed. The common anions such as $SO{_4}^{2-}$ and $NO_3{^-}$ were also removed by the anion exchange resin, and thus decreased the ion exchange capacity for the removal of orthophosphate.

• Journal of the Korean Wood Science and Technology
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• v.44 no.5
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• pp.743-749
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• 2016

The concentration control of wood preservatives is necessary to produce a preservative treated wood having a uniform quality. Concentration measurement method of wood preservatives to be easily used in the field has not been developed yet. This study examined the way to estimate the concentration from turbidity of ACQ wood preservative that can be relatively easily measured by using a portable turbidity meter. The addition of phosphoric acid solution in an alkaline ACQ solution having a very low turbidity is created a suspension of the white substance and the turbidity suddenly increased. The optimum amount of addition of the phosphoric acid solution is until the pH of ACQ solution reaches 7, the turbidity of the ACQ solution reaches maximum value. Excessive addition of the phosphoric acid solution results in a turbidity decrease with acidification of the ACQ solution. Also ACQ solution becomes transparent. The high significance was recognized with positive correlation between the concentration and the turbidity of the ACQ solution. From the t-test, The significant difference between the actually measured concentrations and the concentrations predicted by the regression equation for industrial ACQ solutions was not recognized. Thus, it was possible to know that concentration prediction and control of industrial ACQ solution using the turbidity and a regression equation. Therefore, using the regression equation and turbidity is expected to be able to management the concentration of ACQ solution in the industrial field.

• Korean Journal of Soil Science and Fertilizer
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• v.15 no.3
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• pp.162-165
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• 1982

As an approach to the explanation of increased availability of phosphate in reduced wetland soils, the interrelationships among pH, pe, $Fe^{+{+}}$ and water soluble phosphate in reduced soil-water suspension was studied. 1. p.e value of soil incubated for 8 weeks at $30^{\circ}C$ under waterlogged condition was sufficiently low to allow the conversion of strengite to vivianite. 2. The concentration of water soluble $Fe^{+{+}}$ in this system was higher than that is allowable by the solubility of vivianite. 3. From the relationship between pH and the concentration of water soluble $Fe^{+{+}}$, the concentration of water soluble $Fe^{+{+}}$ could be determined with the solubility of $FeCO_3$. 4. No definite relationship between pH and water soluble P was recognized which implied that the concentration of water soluble P in this system could not determined with the solubility of vivianite.

• Korean Journal of Environmental Agriculture
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• v.17 no.1
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• pp.34-38
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• 1998

To test a potential salt tolerance in phosphorus (P) efficient plants (T9 and T8), tomato seedlings were hydroponically grown in saline media. The tolerance was evaluated by comparing growth and metabolism against T5, non-P-efficient variety, at different salt concentrations: 0, 1, 5, 10 g/L. Fresh weights (FW) were measured weekly. Dry weight (DW), mineral contents, and stomatal resistance (Rs) were measured at the termination of experiment. At the lower two salt concentrations (0, 1 g/L), no significant difference was observed in terms of FW, DW, and Rs. At 5, 10 g/L of salt concentration, however, significant variation is evident: T9 and T8 outperformed T5. On the other hand, no difference was also in N, P, K, and Na contents at the corresponding salt concentration. These observations together indicate that P-efficient strain can better tolerate to salinity.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.27 no.1
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• pp.97-105
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• 1994

To investigate the characteristic and the cause of the yellow water zones in the estuary of keum River, physico-chemical measurement and analyses were made on seawater samples collected from 18 stations in May, July, august, October in 1992, and February in 1993 respectively. The yellow water zones were recorded as grade 9 on the forel water color meter and appeared consistently at the stations 1, 2, 3, 4, 5, 7, 8, 9, 13, 14, 15 and 17 through out the year. The organically polluted matter gradually increased in the study area. The nutrient concentrations of inner waters of water zones were higher than that of the surrounding waters and were over red tide criteria levels. But abnormal aggregation of phytoplanktons could not occur because of lack of light and high current velocity. In Conclusion, this yellowish colored water zone was caused not by abnormal aggregation of phytoplanktons but by inorganic matters such as sand or soil particles, $85\%$ of which consisted of suspended solids.

• Applied Biological Chemistry
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• v.50 no.1
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• pp.77-81
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• 2007

In order to minimize the mycelial pellet size of a high phosphate-solubilizing fungus, Aspergillus sp. PS-104 in liquid media, one of the critical obstacles during the submerged culture of filamentous fungi, an investigation was focused on the culture conditions (media and inoculum size) and additives (different soils, surfactants and polyethylene glycol 200). When the fungus was cultured in PDB, SDB and YPD media. their pellet sizes decreased in the order of SDB=YPD>PDB. At the higher concentrations of initial inoculum ranging from $1{\times}10^3$ to $1{\times}10^7$ conidia/ml, the smaller size of pellet was formed in the PDB medium. In addition, the pellet size was effectively reduced by 1/6${\sim}$1/4 by the addition of 0.1% soil containing zeolite, diatomite, loess, kaoline and talc, excluding bentonite. The addition of 0.1% Tween 80, Triton X-100 and PEG 200 also decreased the pellet size, but SDS completely inhibited the fungal growth.

• Korean Journal of Microbiology
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• v.30 no.2
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• pp.113-118
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• 1992

To elucidate a part of phosphorus cycle an'd the nutritional status of phosphorus. the degradation rates of organic phosphate by phosphatase activity (PA). were studied at the water column of Lake Soyang. from March 1900 to April 1991. Phosphatase activity showed the range of 1-2220 nMillhr. Its maximum value was recortled on August and minimum during October and November. The PA and chlorophyll u v~luess howed high correlation coefficent (0.69). and the values of specific astivity was highest during Winter, 45-12\ulcorner nMihripg chl. a, and lowest on October. 2 nMl hripg chl. 11. The values of PA and bioavailable dissolved inorganic phosphate (DIP) showed negative correlation in surface water. During destratification period (Oct. and Nov. 1990). the values of PA were about 11240 times lower than those during August albeit high concentration of chlorophyll a (1.7- 7.2 mglm'). Such results seem to be cause'd by DIP supply from the metalimnion. hypolimnion ant1 sediment. With these results. phosphate was sufficient to sustain the biomass in Autumn. and internal loading of phosphate shoultl accelerate the eutrophication in Lake Soyang.

• Microbiology and Biotechnology Letters
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• v.10 no.4
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• pp.253-258
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• 1982

Lactobacillus casei YIT 9018 was infected with phage J1 and subjected to grow in $Ca^{＋＋}$ -free MRT (spell out) medium under the presence of four different types of phosphates, sodium-metaphosphate,-pyrophos-phate,-dibasic phosphate, and potassium-phosphate. Among the phosphates tested, sodium pyrophosphate showed sufficient inhibition on the lytic activity of the phage at 0.1% level whereas other phosphate needed more than 0.2% for the same effect. When the concentration of sodium pyrophosphate increased to 0.17%, the bacteria could be protected from lysis until the second succeeding transfer.

• Journal of the korean academy of Pediatric Dentistry
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• v.32 no.1
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• pp.152-157
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• 2005

Hypophosphatemia rickets, also known as Vitamin D-resistant rickets(VDRR) and refractory rickets, is a form of rickets which is resistant to the usual doses of vitamin D. VDRR is characterized by decreased renal tubular reabsorption of inorganic phosphate and is easily diagnosed by a normal blood calcium, hypophosphatemia, and slightly elevated alkaline phosphatase. Clinical features of Hypophosphatemia rickets included lateral bowing deformities of the legs, short stature, scoliosis, and enlargement of wrist and ankles. Dental finding in patient with VDRR were spontaneous dental abscesses in caries free teeth and other dental findings included delayed eruption, delayed apical closure, thin and hypoplastic enamel, absent or poorly defined lamina dura, enlarged pulp chambers, and numerous accessory canals and pulp horns that extend up and into the dentinoenamel junction. we reported the clinical feature and treatment of VDRR child who was referred from the department of pediatrics for early loss of primary teeth and its treatment.

• Applied Chemistry for Engineering
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• v.19 no.6
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• pp.690-692
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• 2008

Pure glycerol could be obtained from a biodiesel byproduct by separation processes including neutralization, precipitation, and distillation. The contents of distilled glycerol through the above separation processes were measured and the results were compared according to experimental conditions such as acid concentration and precipitation temperature. Neutralization processes were carried out in the concentration range of 5~37 wt% hydrochloric acid, 5~95 wt% sulfuric acid, and 5~85 wt% phosphoric acid, respectively. Precipitation temperatures in neutralization were controlled in the range of 293~333 K. Higher values of the distilled glycerol content were obtained due to the salt removal in the pretreatment case of neutralization with 10 wt% sulfuric acid and precipitation of 313 K with 85 wt% phosphoric acid, respectively. The variations of acid concentration and precipitation temperature in pretreatment steps affected to some extent glycerol recovery from the biodiesel byproduct.