• 한국물환경학회지
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• 제20권3호
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• pp.281-289
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• 2004

Optimal analytical conditions have been established for mixing and reaction coil length, concentrations of ECR, CTAB, and acetate, reaction temperature and pH in the determination of aluminum by using flow injection analysis(FIA). Detection limit and repeatability for this system were $3{\mu}g/L$ and better than 1% of relative standard deviation, respectively. The interference from iron(III) was suppressed up to 6mg/L of iron(III) by $0.1{\mu}M$ ascorbic acid, and the interference from fluoride could be tolerated in absorption of Al/ECR/CTAB derivative by 10mM boric acid at pH 3.5 adjusted with nitric acid. This FIA system was applied to the determination of aluminum leached from cooking utensils by distilled and tap water containing fluoride ranged from 0.5 to 2mg/L by measurement of absorbance for Al/ECR/CTAB at 585nm. The leached aluminum content was increased with increasing concentration of fluoride. The aluminum contents leached from aluminum utensils by tap water were about 9 fold higher than those leached by distilled water, whereas aluminum contents leached by distilled water containing fluoride were about 2 fold higher compared to those leached by distilled water. That represented that other dissolved substances as well as fluoride in tap water contributed to liberation of aluminum from aluminum utensils. A comparison between FIA data and ICP-AES data by correlation and paired t test showed that the FIA system could be accepted as a good alternative method for the determination of aluminum in tap water.

• 대한환경공학회지
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• 제35권4호
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• pp.257-262
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• 2013

불산(HF)을 함유한 폐수는 주로 불소이온($F^-$)과 불화붕산염($BF{_4}{^-}$)을 포함하고 있으며, 불산 폐수처리는 보편적으로 칼슘을 이용한 응집 침전 공정을 사용하고 있다. 불소이온은 칼슘이온에 의해 높은 제거효율을 나타내지만 불화붕산염($BF{_4}{^-}$)의 경우 반응성이 낮아 총 불소 제거에 많은 어려움이 있다. 본 연구의 목적은 알루미늄을 이용하여 불화붕산염을 분해하여 총 불소 제거 효율을 향상 시키는데 있다. 불소처리공정 모사 반응기를 이용하여 pH, 알루미늄 주입량, 수온에 따른 불화붕산염의 분해 실험을 실시하였다. 실험결과 알루미늄을 이용한 불화붕산염 분해는 낮은 pH와 높은 수온 그리고 Al/T-F (Aluminum/Total Fluoride) mole ratio가 증가할수록 분해속도도 증가하였으며 반응시간 120분 후에는 큰 농도변화가 없는 것으로 나타났다. 연구결과 알루미늄을 이용한 처리를 통하여 불화붕산염을 포함한 폐수의 처리효율을 향상시킬 수 있을 것으로 판단된다.

• Toxicological Research
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• 제14권2호
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• pp.163-169
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• 1998

Fluoride (F), over a narrow concentration range, increases bone formation. Aluminum (Ai) too is biphasic in its action on bone, being mitogenic at very low levels and inhibitory at higher levels. Both F and Al are present in finished drinking water where the chemical interaction of these two agents is well characterized. F and AI, given individually, accumulate preferentially in bone. In addition. in vivo studies have shown that F causes the co-accumulation of Al in bone. Thus, it was necessary to determine the interactive effect of these two agents on bone mitogenesis. Calvaria were obtained from neonatal CD-1 mice and cultured with various concentrations of F (0.05~19 ppm) as NaF, Al (2 ppb~2 ppm) as $AlCl_3$ , or F and Al for 3 days at $37^{\circ}C$ on a rotating roller drum. Alkaline phosphatase activity in calvaria and $\beta$-glucuronidase activity in culture medium were determined as a measures of bone turnover. Alkaline phosphatase activity in calvaria was significantly increased by F (0.05~2 ppm) treatment and $\beta$-glucuronidase activity was slightly increased in the culture medium of calvaria treated with 0.3 ppm Al. The combination of 19 ppm F and 0.3 ppm Al increased alkaline phosphatase activity in calvaria, but did not affect $\beta$-glucuronidase activity, suggesting the interactive effect of fluoride and aluminum on bone turnover.

• 상하수도학회지
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• 제25권5호
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• pp.767-775
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• 2011

In this study we verified if the electro-coagulation process can treat properly the nitrate and fluoride that are not removed well in the conventional small water treatment plants which usually employ chlorination and filtration only. As we gave a change of electrode material and gap-distance between electrodes, removal efficiency of the nitrate and fluoride was determined by electro-coagulation process which were equipped with aluminum and stainless steel (SUS304) electrodes. In addition, electrode durability was investigated by determination of electrodes mass change during the repetitive experiments. Removal efficiency was great when aluminum was used as an anode material. Nitrate removals increased as electric density and number of electrodes increased, but fluoride removal was less sensitive to both parameters than nitrate. After 10 minutes of contact time with the current density from $1{\times}10^{-3}$ to $3{\times}10^{-3}A/cm^{2}$, nitrate and fluoride concentration ranged from 9.2 to 1.2mg/L and from 0.02 to 0.01mg/L, which satisfied the regulation limits. Regardless of the repeating number of experiments, removal efficiency of both ions were almost similar and the change of electrode mass ranged within ${\pm}$0.5%, indicating that the loss of the electrode mass is not so much great under the limited circumstances.

• 전기화학회지
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• 제11권2호
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• pp.125-129
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• 2008

리튬이온폴리머전지는 휴대용 전자기기와 전기자동차 등의 차세대 동력원으로 주목을 받고 있다. 본 연구에서는 폴리에틸렌 분리막에 소량의 부기 화합물과 고분자를 코팅하여 제조된 표면 개질 분리막을 리튬이온폴리머전지에 적용함으로써 전지 특성을 향상시키고자 하였다. 불화 알루미늄과 아크릴로니트릴-메틸 메타크릴레이트 공중합체를 폴리에틸렌 지지체에 코팅하여 얻어진 표면 개질 분리막을 이용하여 제조된 리튬이온폴리머전지는 충 방전 싸이클 과정 중에 균일한 전도성 고체 전해질 계면이 전극 표면에 형성되어 낮은 계면 저항값을 보였으며, 이에 따라 불화 알루미늄을 포함하고 있지 않는 리튬이온폴리머전지와 비교하여 싸이클 특성과 고율 방전 특성이 크게 향상되었다. 표면 개질된 분리막을 이용하여 제조된 리튬이온폴리머전지를 0.5 C rate로 충 방전한 결과, 초기 방전용량 150 mAh/g을 나타내었으며, 300싸이클에서 133 mAh/g의 방전 용량을 유지하여 우수한 용량 보존특성을 나타내었다.

• 청정기술
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• 제20권1호
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• pp.51-56
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• 2014

본 연구에서는 폴리술폰(polysulfone, PSf)으로 알루미늄 수산화물(aluminum hydroxide, $Al(OH)_3$)을 고정화한 PSf-$Al(OH)_3$ 비드를 제조하였다. 제조한 PSf-$Al(OH)_3$ 비드에 의한 불소 이온 제거실험은 회분식으로 수행하였으며, pH, 초기농도, 공존이온과 같은 변수들의 영향을 살펴보았다. Langmuir 등온식으로 구한 불소 이온의 최대 제거량은 52.4 mg/g이었으며, 최적 pH 범위는 4~10이었다. PSf-$Al(OH)_3$ 비드에 의한 불소 이온의 제거과정은 전 단계에서 외부물질전달이 나중 단계에서 내부확산이 지배인 것을 알 수 있었다. 또한 PSf-$Al(OH)_3$에 의한 불소 이온의 제거에서 $HCO_3{^-}$, $SO{_4}^{2-}$, $NO_3{^-}$, $Cl^-$와 같은 공존 음이온들은 불소 이온의 제거에 방해를 하는 것으로 나타났다.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
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• pp.276-277
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• 2006

In order to accelerate the sintering of Al-Bronze powder covered with passive oxide film, we focused on the way to add Al-Ca fluoride consisting of $AlF_3$ and $CaF_2$, examined the effect of the $CaF_2$ mixing rate in Al-Ca fluoride, the amount of the added Al-Ca fluoride and the sintering temperature on sintering properties of Al-Bronze powder and considered the mechanism of the sintering acceleration. Al-Bronze powder was sintered most effectively by adding Al-Ca fluoride with the $CaF_2$ mixing rate of 20mass%. If the amount of added fluoride was over 0.05mass% and the sintering temperature was over 1123K, the sintering acceleration of the Al-Bronze powder appears. Regarding the mechanism of the sintering acceleration, it was presumed that $Al_2O_3$ film on the surface of the Al-Bronze particles was removed in the process of the formation of gaseous AlOF by the reaction with $AlF_3$, and the reaction was accelerated further by the presence of the liquid phase which is formed in Al-Ca fluoride.

• 한국환경과학회지
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• 제23권5호
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• pp.887-893
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• 2014

In order to remove fluoride ions from aqueous solution, PVC-$Al(OH)_3$ beads were prepared by immobilizing $Al(OH)_3$ with polyvinyl chloride (PVC). The prepared PVC-$Al(OH)_3$ bead was characterized by using SEM, EDS and Zeta potential. Dependences of pH, contact time and initial fluoride concentration on the adsorption of fluoride ions were studied. The optimal pH was in the range of 4~10. The adsorption was rapid during the initial 12 hr, and equilibrium was attained within 72 hr. The adsorption rate of fluoride ions by PVC-$Al(OH)_3$ beads obeyed the pseudo-second-order kinetic model. The maximum adsorption capacity obtained from Langmuir isotherm model was found to be 62.68 mg/g.

• Environmental Analysis Health and Toxicology
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• 제13권1_2호
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• pp.19-26
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• 1998

In Korea, fluoride was first introduced into the drinking water of residents of Jinhae, KyungNam in 1981 for the prevention of dental caries. Ever since, growing numbers of communities favor fluoridation. The mechanism of F prevention of tooth decay is well known: fluoride ions substitute for hydroxyl ions in hydroxyapatite of hard tissues, which result in crystal perfection, with consequent reduction in dental caries. Soluble fluorides such as sodium fluoride are almost completely absorbed from the gastrointestinal tract. However, the presence of divalent or trivalent cations such as aluminum, magnesium, and calcium that can complex with F can reduce the degree of absorption. In U.S.A., over 7000 communities are now adding F to their drinking water. However, some portion of population oppose fluoridation, voicing both concern about the safety of fluoridation as well as for personal choice. Thus, This paper reviews the interaction of fluoride and cations as well as fluoride and suggests possible problems associated with fluoridation, a controversial issue.

• 자원리싸이클링
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• 제6권1호
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• pp.5-10
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• 1997

알루미늄 드로스로부터 알루미늄 회수에 관한 연구를 행하였다. 알루미늄 드로스의 발생량이 가장 많은 중립(1.0~12.0mm)의 드로스를 시료로 하여 $850^{\circ}C$의 용해온도와 용해 2시간에서 염화나트륨과 염화칼륨의 첨가 영향은 40% 첨가시 약 76.9%로 최대 회수율을 얻었으며, 그 이상 첨가는 점성의 증가로 회수율에 별 영향을 미치지 않았다. 한편, 40%의 기본염용제에 NaF, $CaF_2$, $AlF_3$ 및 ${Na}_{3}{AlF}_{6}$ 첨가시 5%에서 최대 회수율을 나타내었으며, 특히 5%의 빙정석 첨가시 약 83.5%의 최대 회수율을 얻을 수 있었다. 그러나 불화물을 5% 이상 첨가시에는 점성이 증가하여 알루미늄 회수율에 큰 영향을 미치지 않았다.