• Journal of Korean Society of Water and Wastewater
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• v.38 no.4
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• pp.233-242
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• 2024

This study evaluates the potential of various coagulants to enhance the efficiency of total phosphorus removal facilities in a sewage treatment plant. After analyzing the existing water quality conditions of the sewage treatment plant, the coagulant of poly aluminium chloride was experimentally applied to measure its effectiveness. In this process, the use of poly aluminium chloride and polymers in various ratios was explored to identify the optimal combination of coagulants. The experimental results showed that the a coagulants combination demonstrated higher treatment efficiency compared to exclusive use of large amounts of poly aluminium chloride methods. Particularly, the appropriate combination of poly aluminium chloride and polymers played a significant role. The optimal coagulant combination derived from the experiments was applied in a micro flotation method of real sewage treatment plant to evaluate its effectiveness. This study presents a new methodology that can contribute to enhancing the efficiency of sewage treatment processes and reducing environmental pollution. This research is expected to make an important contribution to improving to phosphorus remove efficiency of similar wastewater treatment plant and reducing the ecological impact from using coagulants in the future.

• Proceedings of the Korea Concrete Institute Conference
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• 2002.10a
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• pp.299-304
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• 2002

This research was to investigate the invasion and diffusion properties of chloride ion on the concrete containing mineral admixtures by the electrically accelerated test. Mineral admixtures selected in mixes were fly-ash, ground granulated blast-furnace slag, silica fume, and meta-kaolin with 3 degrees of replacement ratios. Tang and Nilsson's test method was used to estimate chloride diffusion coefficients of that mixes. As a result, the total current passing charge and the diffusion coefficient of chloride ion were reduced with the use of mineral admixtures and the increase of replacement ratios. In addition, compressive strength was related with diffusion coefficient of chloride ion. Diffusion coefficients of concrete mixed with ground granulated blast-furnace slag showed relatively low value under the range of compressive strength of 400㎏f/㎠.

• Proceedings of the Korea Concrete Institute Conference
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• 1999.10a
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• pp.787-790
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• 1999

To estimate durability of reinforced concrete structures located in or nearby seawater, many different kinds of accelerated tests for evaluation of chloride ion permeation in concrete were proposed. At present the only standardized test is the ASTM C 1202(RCP test). This test method is used to estimate the concrete's resistivity of the chloride penetration in concrete by using the total charges passed and sometimes used to calculate the chloride diffusion coefficients. However, this test may lead to an erroneous chloride diffusion coefficient. So this test method was compared with the modified Dhir's test and the traditional concentration diffusion test. Experimental results showed that the diffusion coefficients determined the RCP test and the PD Index gave wrongous values, but the diffusion coefficient acquired by considering a migration term was nearly the same to the CD Test.

• Computers and Concrete
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• v.17 no.5
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• pp.655-672
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• 2016

A predictive model for chloride binding isotherms of blended cements with various supplementary cementitious materials (SCMs) was established in this work. Totally 560 data points regarding the chloride binding isotherms of 106 various cements were collected from literature. The total amount of bound chloride for each mixture was expressed a combinational function of the predicted phase assemblage and binding isotherms of various hydrated phases. New quantitative expressions regarding the chloride binding isotherms of calcium-silicate-hydrate (C-S-H), AFm, and hydrotalcite phases were provided. New insights about the roles of SCMs on binding capabilities of ordinary portland cements (OPC) were discussed. The proposed model was verified using separate data from different sources and was shown to be reasonably accurate.

• Proceedings of the Korea Concrete Institute Conference
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• 2003.05a
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• pp.681-686
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• 2003

One of the major degradation processes of reinforced concrete (RC) structure is corrosion of reinforced steel due to chloride attack. Severe environments, such as marine environment and exposure to de-icing salts, could accelerate the steel corrosion of RC structures through the chloride ion intrusion into concrete. In order to delay this degradation process, several kinds of admixtures have been used in concrete mix. In this study, effective diffusion coefficient of chloride ion ($D_{eff}$) and total passed charge of concrete with and without fly ash were measured using electrical method. It is found that fly ash concrete has much less chloride ion coefficient than ordinary concrete at later age. By analyzing the test results, $D_{eff}$ at 28 and 90 days was obtained as a function of water-binder ratio (W/B) and an equation for predicting $D_{eff}$ with age was proposed considering the decreasing rate of $D_{eff}$.

• Proceedings of the Korea Concrete Institute Conference
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• 2003.05a
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• pp.711-714
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• 2003

Factors causing deterioration of concrete structures under marine environment are various, especially penetration and diffusion of chloride ion, carbon dioxide, and water through pore effects on the durability of concrete as well as mechanical properties of concrete. Pore of porous materials like concrete can be classified as micro-, meso-, and macro-pore. And pore of cement matrix is classified as pore which occupied by water, air void, and ITZ between cement paste and aggregates. In this study, to verify the relationship between pore of cement matrix and the property of chloride ion diffusivity, the regression analysis is producted. From the result of regression analysis, the average pore diameter more than total pore volume effects on the diffusivity of chloride ion.

• Journal of Environmental Science International
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• v.27 no.2
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• pp.143-146
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• 2018

This study was conducted to evaluate the effect of chemical blend additives (a combination of ferrous sulfate and aluminum chloride) on decreasing pathogens in poultry litter. A total of 240 broiler chickens were assigned to 4 chemical treatments with 4 replicates of 15 chickens per pen. The four chemical blend additives were a control (no treatment), 25 g ferrous sulfate + 75 g aluminum chloride/kg poultry litter, 50 g ferrous sulfate + 100 g aluminum chloride/kg poultry litter and 100 g ferrous sulfate + 150 aluminum chloride/kg poultry litter. During the 6-wk experimental period, there were significant differences in both E.coli and Salmonella enterica for weeks 4 through 6, but not at weeks 1 and 3, respectively. Consequently, using chemical blend additives that serve as methods to control strict environmental regulations reduced pathogens in poultry litter.

• Journal of Korean Society for Atmospheric Environment
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• v.2 no.3
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• pp.27-33
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• 1986

Atmospheric particulate matter (A. P. M.) was collected and size-fractionated by an Andersen high-volume air sampler over 15 month period from Jan. 1985 to Feb. 1986 in Seoul. The concentration of chloride, nitrate and sulfate were extracted in an ultrasonic bath and were analyzed by ion chromatography. The annual arithmetical mean of A. P. M. was 128.54 $\mug/m^3$. The concentration of anions were 2.88 $\mug/m^3$ for chloride, 3.86$\mug/m^3$ for nitrate, and 25.44$\mug/m^3$ for sulfate. The content of A. P. M. was lowest in the particle size range 1.1 $\sim 3.3\mum$ and increased as the particle size increased or decreased. And the anions exhibited a seasonal variation in the isize distribution. The contents of anions were higher in winter than summer. Ther ratio of fine particles to the total particles defined by F/T for chloride, nitrate and sulfate. The F\ulcornerT of these anion generally decrease with increasing air temperature. This tendency was prevalent in the chloride and nitrate.

• Food Science and Preservation
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• v.18 no.5
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• pp.678-683
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• 2011

The effects of coagulant types (magnesium chloride, calcium chloride, calcium sulfate, glucono-${\delta}$-lactone) on yield, quality properties and storability of astringent persimmon powder added tofu were investigated. Yield, hardness, chewness, crispness, and overall acceptability of tofu coagulated by glucono-${\delta}$-lactone were higher than those coagulated by the others. L value, a value, pH, soaking-solution turbidity, and total aerobic bacteria of glucono-${\delta}$-lactone coagulated tofu were lower than those coagulated by the others. Calcium sulfate and calcium chloride coagulated tofu showed relatively high L and b values. Magnesium chloride coagulated tofu had higher sensory score for firmness, taste, overall acceptability than calcium chloride and calcium sulfate coagulated tofu, but there was no significant difference between magnesium chloride and glucono-${\delta}$-lactone. The results suggested that glucono-${\delta}$-lactone and magnesium chloride were found to be the suitable coagulants for processing of the persimmon powder added tofu.

• Journal of Sasang Constitutional Medicine
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• v.9 no.2
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• pp.227-243
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• 1997

The experimental study used in this paper was done to examine the clinical effects of Taeumchowetang for the gastric ulcer and the function of gastrointestinal tract using rats and mice which were administered orally the water extraction from Taeumchowetang. Then, the counter-action of the water extraction on the isolated ileum and gastric fundus, the inhibitory effects of pylorus-ligated ulcer and indomethacin-induced ulcer, the associations with gastric juice secretion, total acidity, pepsin output, the transportability in the small and large intestine, were studied with administering acetylcholine chloride and barium chloride. In addition, it was investigated whether the central nervous system related to pain control and sleeping time was influenced by Taeumchowetang. The following results have been obtained; 1. As resulting from injection of acetylcholine chloride and barium chloride into the isolated ileum of rats and mice, Taeumchowetang led to have an inhibitory effect on the muscle contraction of the ileum. Then, acetylcholine chloride was measured as lower effect than barium chloride 2. For the inhibitory effect on contraction for the gastric fundus strip in rats by either acetylcholine chloride or barium chloride, the one showed low inhibitory effect, on the other hand the other showed density-dependent effect. 3. The water extraction was given on the pylorus ligated ulcer with using two different administration groups of 1,300mg/kg and 2,600mg/kg, each result was measured as 22.9% and 36.5% for an ulcerous inhibitory effect (p<0.05). 4. According to the two administration groups, the preventive effect was tabulated 18.1% and 29.3% for indomethacin-induced ulcer (p<0.05, P<0.01). 5. For associations with gastric juice secretion, total acidity, pepsin output in the administration group 2,600mg/kg, Taeumchowetang was recognized as having an inhibitory effects related to suppressive actions involving gastric juice secretion(p<0.05), and free acidity(p<0.01), but there was no significant association with total acidity and pepsin output. 6. To know the transportability in the intestine, BaSO4 solution was used. The transportability of the small intestine in the administration group 2,600mg/kg was 22.2% which was statistically significant compared with the large intestine's transportability(P<0.01). 7. In the administration group 1,300mg/kg and 2,600mg/kg, analgesic effect with against acetic acid was measured as being 16.8% and 24.4% which was shown as statistically siginificant(p<0.01). 8. No statistically significant association between Taeumchowetang and sleeping time was found in both 1,300mg/kg and 2,600mg/kg by administering phenobarbital-Na. According to the results of this study, Taeumchowetang has agreed with the effects of literature review. Further more in this study, Taeumchowetang also has preventive effects on pylorus-ligated ulcer. Hence, Teaumchowetang can be significant effect such as both anti ulcer agent and increasing gastric activity for the patients who suffer from gastric ulcer.