• 한국염색가공학회지
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• 제23권1호
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• pp.51-59
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• 2011

Calcium alginate fiber were prepared by wet spinning of various conditions, including different concentrations of sodium alginate solution and $CaCl_2$ concentrations for coagulating the fiber through an absorption of calcium ion. The absorption of calcium ion during the coagulating step lead to solidify the fibers by the replacement of sodium ion with calcium ion to produce some crosslinking. The concentration of calcium ion in the calcium alginate fiber seems to be well related to the mechanical and physical property of the fiber, such as fiber strength moisture regain, and degree of swelling. The tensile strength of calcium alginate fiber was increased along with the increasing amount of sodium alginate solution. According to EDS analysis, 7 wt% $CaCl_2$ coagulation bath resulted in more calcium ion in the fiber compared to 3 wt% $CaCl_2$ coagulation bath. The decomposition temperature of calcium alginate fiber was $199^{\circ}C$, which $14^{\circ}C$ higher than that of sodium alginate.

• 한국수산과학회지
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• 제36권2호
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• pp.74-79
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• 2003

The functional properties such as a firming maintenance capacity for fermented vegetables, protein coagulation capacity antibacterial activity, calcium and peroxide absorption capacity of calcium powder of cuttle bone treated with acetic acid (ATC) were examined. In the Korean pickled cucumbers (20 days), the calcium content of ethanol insoluble solids was 5,264.9 mg/100 g and this value was higher than that of control (2,036.4 mg/100 g). Protein coagulation capacity of ATC was $0.9\%$ and its calcium absorption capacity was $49.3\%.$ The peroxide absorption capacity of ATC was shown $0-1.1\%$ range. Antibacterial activity was detected above $0.2\%.$ The ATC was effective in a firming maintenance of fermented vegetables (cucumber), coagulation capacities for soybean milk and antibacterial activity. The ATC was not effective in clarifying wastewater. Peroxide absorption capacity toward linoleic acid could not be checked by ATC, but its calcium absorption ratio was high compared to that of commercial calcium powder.

• 한국환경과학회지
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• 제8권6호
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• pp.717-724
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• 1999

This experiment was performed on three parts with prepared coagulants. (1) The characterization of coagulation for PACI coagulants. (2) Comparison of the characterization of coagulation with PAS and PACI coagulants. And (3) Comparison of the characterization of coagulation for the addition of calcium with PACI. Coagulation experiments were conducted with several dosages and pH for each coagulants. For the characterization of coagulation with PACI coagulants, coagulation of Nakdong river waters with three PACls (r=2.0, 2.2, 2.35) showed that the effectiveness of the three coagulants can be considered as r=2.2 > 2.0 > 2.35 which are also the order of higher polymeric aluminum contents. For the comparison of the characterization of coagulation for PAS and PACI coagulants, PAS (r=0.75) coagulants was more effective than other coagulant for the removal of organic matters by sweep floc mechanism with $A;(OH)_{3(S)}$. For comparison of the characterization of coagulation for the addition of calcium with PACI, the presence of divalent cation like $Ca^{2+}$ was supposed to influence the complex formation of organic anions. From the result of test on coagulation at various pH ranges, the PACI was least affected by the coagulation pH, and the addition of calcium to PACI was very effective for the removal of turbidity and organic materials over broader pH range (pH 4-9).

• 대한환경공학회지
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• 제33권4호
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• pp.231-236
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• 2011

본 연구는 알루미늄 응집에 의한 인 제거 공정에 마그네슘 및 칼슘과 같은 2가의 금속이온을 첨가하였을 경우 인의 응집특성에 미치는 영향을 조사하였다. 인을 제거하기 위한 최적 알루미늄 응집 pH는 약 5~6 사이이며, 그 이상 pH에서는 TP 제거효율이 감소하였다. 마그네슘이나 칼슘과 같은 2가의 금속이온을 알루미늄 응집공정에 함께 사용할 경우 pH 6 이상 에서도 TP 및 $H_nPO_4^{n-3}$ 제거효율은 안정적으로 95% 이상을 유지하였다. 응집초기 $Al^{3+}/H_nPO_4^{n-3}$ (Al/P) 몰비가 3 이상에서 TP 제거효율이 80% 이상 높게 유지되었으며, 응집 후 잔류 TP 농도를 0.2 mg/L 이하로 제어하기 위해서는 Al/P 몰비는 약 6 이상 이었다. 마그네슘이나 칼슘 이온을 알루미늄 응집공정에 함께 사용할 경우 TP 제거를 위한 최적의 알루미늄 대비 마그네슘 및 칼슘 이온의 몰비($Al^{3+}/Mg^{2+}$ or $Ca^{2+}$)는 모두 2이었다. 알루미늄 응집공정에 마그네슘이나 칼슘 이온을 함께 사용하면, 동일한 양의 TP를 제거하기 위한 알루미늄 응집제 주입량이 감소하였고, 결과적으로 최종 슬러지 발생량도 감소하였다.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2005년도 INTERNATIONAL SYMPOSIUM ON SOIL & GROUNDWATER ENVIRONMENT
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• pp.105-106
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• 2005

• Advances in environmental research
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• 제7권1호
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• pp.1-11
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• 2018

Textile factories are one of the industries which its wastewater treatment is a challenging issue, especially in developing countries and a conventional treatment cannot treat all its pollutants properly. Using chemical coagulants is a technique for physical and chemical primary treatment of the wastewater. We applied jar test for selection of suitable coagulant among the five coagulants including alum, calcium hydroxide, ferrous sulfate, ferrous chloride and barium chloride for the effluent of wastewater in Mazandran textile factory located in Mazandran Province, Iran. In addition, jar test, we also used analytic hierarchy process (AHP) method considering criteria which included coagulation cost, sensitivity to pH change, the amount of sludge generation and side effects for coagulation. The results of the jar test indicated that calcium hydroxide was proper among the coagulants which it removed 92.9% total suspended solid (TSS), 70% dye and 30% chemical oxygen demand. The AHP analysis presented that calcium hydroxide is more suitable than other coagulants considering five criteria.

• 한국식품영양학회지
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• 제1권2호
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• pp.102-107
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• 1988

Production of calcium lactate very useful for medical supplies of Ca-therapy was obtained by lactic acid fermentation of lactobacillus sporogenes, a spore forming lactic acid bacterium. Corn steep liquor 1%, soybean enzyme hydrolysate 3%, yeast extract powder 2% can substitute for yeast extract and peptone as nutrient sort traces in fermentation medium using 10% glucose concentration. In the calcium lactate production medium containing yeast extract powder 2%, glucose 18%, CaCO3 12%, the lactic acid fermentation was carried out at 45$^{\circ}C$ for 4days with continuous agitation of 100 rpm. As results, fermentation yield was 97.5%. The five steps such as protein coagulation, decolorizing evaporating, crystallizing, and drying were carried out to harvest calcium lactate from 10l of supernatant of fermented medium to be removed cell and CaCO3. As results, 2065.0g of white crystal calcium lactate dihyrate was recovered and a yield of 84.9% was obtained.

• 대한수의학회지
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• 제44권3호
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• pp.469-473
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• 2004

This study was performed to investigate the effects of calcium administration on the blood coagulation mechanism through APTT in the calf. Five male calves (70~90 kg) were used in this experiment. In the control group, heparinized normal saline (1 IU/kg/min) had been infusing into the jugular vein for 100 minutes. For the analysis of calcium effects on the APTT, the same solutions had been infusing during the first 40 minutes, subsequently the solution including calcium gluconate (3.3 mg/ml/min) had been infusing for 60 minutes. Blood samples were serially collected every 10 minutes for the APTT and platelets count and every 20 minutes for the calicum level during the infusion. In the calcium-treated group, after 70 minutes the APTT ratio (APTT heparin/APTT baseline) was higher than the therapeutic range. APTT was significantly increased at 50, 60 and 70 minutes in the calcium-treated group as compared to the control group (p<0.01). In the control group, calcium level was decreased significantly after heparin infusion (p<0.01). The platelet count was gradually decreased without significant variation in the both control and calcium-treated groups. These results suggested that APTT is slightly increased in combined heparin and calcium administration.

• 자원환경지질
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• 제38권3호
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• pp.273-284
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• 2005

소석회$(Ca(OH)_2)$사 탄산칼슘$(CaCO_3)$을 응집제로 이용한 화학적 응집/침전법으로 지하수로부터 중금속을 제거하는 실내실험을 실시하였다. 비소(As), 카드뮴(Cd), 망간(Mn), 납(Pb), 아연(Zn)으로 오염시킨 인공오염수로부터 중금속을 제거하는 배치 실험 결과, 소석회를 이용한 경우, As과 Mn의 제거 효율은 $0.3\;wt.\%$소석회 첨가만으로 $90\%$ 이상을 나타내었으며, Cd와 Zn의 경우 $0.5\;wt.\%$ 첨가 시 약 $75-85\%$온의 제거 효율을 나타내었다. 탄산칼슘을 첨가한 경우 소석회 첨가에서 제거율이 비교적 낮았던 Pb의 제거율이 매우 높게 나타나 $0.1\;wt.\%$의 첨가만으로 거의 $100\%$를 제거할 수 있었으며, Cd의 제거율도 소석회보다 높게 나타나 $1.0\;wt.\%$ 첨가시 $93\%$이상의 제거율을 나타내었다. 그러나 As, U, Zn의 제거율은 약 30- $50\%$정도로 낮게 나타났다. 대형 칼럼 반응조를 이용한 중금속 제거 실험에서는, 응집제를 오염지하수에 첨가한 후 응집제의 확산 유도와 응집제와 응집할 입자간의 접촉을 위해 급속 교반하였으며, 교반으로 인해 성장된 플럭(floc)의 침전을 유도하여 상등액과 침전입자를 분리함으로써 오염지하수로부터 중금속을 제거하였다. 소석회를 첨가한 칼럼실험의 경우, 앞서의 배치실험 결과와 같이 As는 $1wt.\%$의 소석회 첨가에 의해서 침전 30분 이후에 $99\%$이상의 제거 효율을 나타내었다. Cd, Mn, Zn도 $80-85\%$의 제거효과를 나타내어 높은 제거 효율을 나타내었으나, Pb의 제거 효율은 배치 실험의 결과와 같이 낮아 약 $40\%$내외를 유지하였다. 소석회 침전 슬러지를 재활용하여 중금속 제거 실험을 반복 실시한 결과도 As, Mn, Cd에 대해서는 침전 슬러지 재활용 2회까지 평균 $90\%$이상의 높은 제거율을 나타내었으며, Zn에 대해서는 $70\%$내외의 제거율을 나타내었다. 탄산칼슘을 이용한 칼럼실험에서는 Cd와 Pb의 경우 제거 효율이 높아, 침전 후 30분 이내 에 $95\%$이상이 제거되었다. Zn은 $57\%$의 제거율을 나타내었으며, As와 Mn은 제거율이 낮아 약 $40\%$정도가 제거되었다. Fe와 Mn의 농도가 매우 높은 울산지역의 실제 매립장의 오염지하수를 대상으로 $1wt.\%$의 소석회를 이용한 칼럼실험 결과, 두 원소 모두 $96\%$이상의 제거율을 나타내어 소석회를 이용한 응집/침전법의 중금속 오염지하수 정화 효율이 매우 뛰어난 것으로 나타났다

• 한국산업융합학회 논문집
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• 제16권2호
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• pp.35-39
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• 2013

This paper synthesized the new copper removal agent(PW-2001) and investigated removal efficiency of copper, COD, calcium, SS and sludge amounts. Removal efficiency of copper were 96.1% and 99.1% with the lime and PW-2001, respectively while COD removals reached up to 38% and 69.6% with the use of lime and PW-2001. The concentrations of calcium and SS with PW-2001 were decreased 2.68 and 4.95 times lower than those with lime. Amount of sludge with PW-2001 was 60% smaller than lime. Quantity of PW-2001 needed for coagulation only reached 58.7, compared to lime standard quantity(100), and total cost of copper removal with PW-2001 was saved 25% more than lime.