• Journal of Korean Society on Water Environment
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• v.26 no.6
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• pp.919-925
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• 2010

The features of precipitating reaction of fluoride have been examined by employing waste gypsum as a precipitant. The major component of waste gypsum was examined to be CaO with minor components of $SO_3$, $SiO_2$. In the experimental condition, the precipitating reaction of fluoride progressed rapidly within a few minutes after the reaction started and reached its equilibrium in 10 minutes. Kinetic analysis showed that the precipitating reaction of fluoride generally followed a first Oder and second Oder with decreasing rate constant with the initial dosage of precipitant. XRD analysis showed that the crystalline structure of precipitate was mainly $CaF_2$ with partly $Ca_5(PO_4)_3(OH)$.

• The Korean Journal of Rheology
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• v.5 no.2
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• pp.161-169
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• 1993

Glucomannan(G.M.)은 Amorphophallus Konjac C. Koch의 tuber로부터 분리되었고. 이 G.M.은 다시 침전제로 메탄올을 사용하여 4단계로 분별되었다.(F.1, F.2, F.3, F.4,). 각분 별물에 비하여 직선으로부터 벗어남을 보였다. Low shear viscometer로 G.M. 용액의 viscosity를 측정하였고 농도와 zero shear specific viscosity의 logarithm을 도시한 결과 inflection point를 나타내었다. 이것은 G.M. 분자들의 coil overlap의 시작에서 기인한 것이 고 묽은 용액에서 진한 용액으로의 전이행동은 임계농도. C＊=4/[η]에서 일어났고 이때의 zero shear specific viscosity는 10을 나타내었다. 또한 specific viscosity는 묽은 용액에대해 서는 C14로써 변화하였고 진한 요액에서는 C3.0으로변화하였다. G.M.의 고체상태에 대한 유 전성($\varepsilon$＇,$\varepsilon$＂)과 점탄성(C＇,C＂)계수들을 액체질소 온도에서부터 15$0^{\circ}C$ 온도범위에 걸쳐 4단계로 film을 건조시키면서 10Hz에서 측정하였다. G.M. film의 유전성과 점탄성의 허수부 분은 ($\varepsilon$＂, C＂), -10$0^{\circ}C$에서 peak를 나타내었고 이 peak는 hydroxy methyl 기들의 회전 운동에서 생겨난 것이다. 건조시키지 않은 상태의 G.M. film의 유전성과 점탄성의 허수부분 의 값들은 -5$0^{\circ}C$에서 물 분자의 운동에 의하여 생긴 peak를 보였다.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 1979.10a
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• pp.236-238
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• 1979

자연계에 배출되는 유기물함유폐수는 Figl 에 나타난 바와 같이 미생물의 생태적변동에 의해 정화된다. (표 1참조)이 자연현상을 인공장치에 의해 효율좋게 정화시키는 연구를 20수년전부터 개시하여 Test plant 및 Pilot plant을 작제하여, 검토하여 현재는 Fig. 2.에 나타난 바와 같은 실용화 plant가 다수, 가동하게 되었다. Fig. 2의 flow pheet를 개약설명한다. 먼저 폐수원액은 vibrating filter를 통과시키므로서 고형물은 제거된다. 이 용액을 구기조(Aeration tank)에 투입하여, 맹렬히 통기하면서, 호기분해를 행한다. 1 일간, 포기후, 호기성균체를 포함한 용액을 다음의 광합성세균배양조에 이행시켜, 4 일간 체류시키므로서 광합성세균등을 증식시킨다. 그후 응집침전제를 첨가하여, 광합성세균등의 Bacterial mass는 회수된다. 그 상맥부는 최종적으로 포기되고, (동기, 한랭에 있어서는 산포여상 Contact oxidation tower를 통과시킨다.) 소량의 침전제을 분리한 후 방류한다, 광합성세균이용에 의한 수처리기술의 특징은 1) 농후유기폐수를 희석하지 않고 정화처리할 수 있다. 2) 표3에 나타난 바와같이 적용할 수 있는 폐수의 종류는 많다. 3) 부산물로서 회수한 균체는 축산사료나 수산사료로서 이용할 수 있다. 표4 및 표5는 산난계 및 부화직후의 치어의 첨가사료 로서 이용한 일예이다.

• Applied Biological Chemistry
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• v.9
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• pp.71-81
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• 1968

Defatted rice bran is mixed with diluted acid solution, the mixture is agitated some hrs. at constant temparature. After the mixture is filtered, thus filtrate is obtained. This filtrate is phytin extract solution. (Test-1) The alkali is added to this filtrate and filtered out, then the precipitation of phytin is obtained. (Test-2) At the test-1, the effect of kind of acid, conc. of acid, amount of extract sol'n., time of extraction, temp. of extraction, to the extract amount of phytin is tested. Consequently, the following facts are known. 1. Amount of phytin extract is greater HCI extraction than $H_{2}SO_4$ extraction. 2. At 0.3% HCI, the amount of phytin extract is greatest of all HCl extraction. 3. The sufficient amount of acid solution is 8-10 times of amount of defatted rice bran. 4. The time of extraction at room temperature is sufficient 8-12 hrs. 5. When extract temperature is $20-30^{\circ}C$, the amount of phytin extraction is greater of all temp. 6, When defatted rice bran 20 g is shanken with 160 ml of 0.3% HCl for 10 hr. at room temp., in this case the amount of phytin extract is 11.34% of defatted rice bran, it is 93% of theoretical yield. At the test-2 the effect of kind of precipitation agent, degree of nutralization to the amount of phytin prcipitation is tested. 1. Degree of nut. is best at pH 6.8-7.0. 2. When use of $Ca(OH)_2$ the amount of phytin precipitation is more than use of KOH, NaOH, or $NH_{4}OH$. 3. At pH 6.0-7.2, the solubility of phytin is followed. K-phytate > $NH_{4}-phytate$ > Na-phytate > Ca-phytate 4. When phytin extract solution is nutralized with $Ca(OH)_2$ to pH 7.0, the amount of phytin precipitation is 94.78% of theoretical yield.

• Journal of Forest and Environmental Science
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• v.17 no.1
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• pp.29-36
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• 2001

Compared to other industries, pulp and paper industry use a lot of water. As a result, a large amount of the waste water is discharged in the pulp and paper industry. This study was investigated to prevent the environmental pollution terribly faced with our society nowadays. In the waste water of pulp and paper, there are so many things in the waste water, like fiber, filler, and other organic solvent etc. so we must remove them from our environment. This study was investigated to experiment on test of impressed filtration with the kind and quantity of coagulant and the variance of pressure. In this study, we used feds, alums. $CaCl_2$, polymer as a coagulant and these pressure was 49, 98, 147, 196kpa. According to this study, we measured the speed of filtration and turbidity, measuring filtrated water. According to the values, we know the fact that as the consistency of coagulant and pressure were high, the filtration was good.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2004.10a
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• pp.223-226
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• 2004

본 논문은 정수장에서 사용하는 응집제의 종류와 주입량을 결정하기 위한 시스템 개발에 관한 내용이다. 정수장은 여러 단위 처리장으로 구성되며, 탁도와 색도를 제거하기 위하여 혼화지에서 응집제를 주입하여 침전을 시킨다. 현재까지 응집제 결정을 위해 Jar-test를 이용하였는데, 이 방법은 사람의 주관적인 판단에 의존하므로 실험 오차가 발생할 수 있다. 특히 정수장의 자동화를 위한 시스템 개발에서 가장 큰 걸림돌로 작용하고 있다. 본 논문은 이러한 문제점을 해결하기 위하여 데이터 마이닝 기법 등을 이용한 응집제 종류와 양을 결정하는 제어기를 개발하였다.

• Analytical Science and Technology
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• v.11 no.1
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• pp.13-19
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• 1998

In the dye sensitization for the solar energy conversion with a photoelectrochemical cell containing allylthiourea, the time profile of the sensitized photocurrent showed a rise and fall with the irradiation time. The dye solution before and after irradiation was analyzed by means of spectroscopic methods. A new precipitation reaction between sensitizer and supersensitizer and photobleaching of the dye appeared to be involved in the decreased photocurrent.

• Korean Chemical Engineering Research
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• v.51 no.2
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• pp.257-262
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• 2013

As the regulation of total phosphorus (T-P) concentration in biologically treated sewage effluent is reduced to 0.2~2 mg/L, flocculation process is recommended to remove T-P. In this study, the performance of Ti-salt coagulant was investigated in terms of dosage and pH in removing phosphorus and the collected sludge after Ti-salt flocculation was calcined to produce titania for effective sludge recycling. The flocculation performance was carried out using two methods: sedimentation and air floatation. Both methods were feasible to apply for Ti-salt flocculation. Ti-salt flocculation was effective in reducing phosphorus concentration in sewage effluent, which showed similar performance of alum ($Al_2(SO_4)_3$). The calcined sludge was recycled to titania which is the widely used metal oxide. Titania produed from Ti-salt sludge indicated similar characteristics of commercially-available P-25 in regard to photocatalytic activity and surface area. Therefore, this can be easily adopted to titania application by replacing P-25.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.3
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• pp.368-373
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• 2017

Comparative fining trials were conducted in a laboratory to study the effects of fining treatments including polyvinylpolypyrrolidone (PVPP) and bentonite on the color and clearness of apple wine. The wines were subjected to three different fining treatments: PVPP, PVPP+bentonite (applied at the same time), and PVPP+bentonite (24 h later). Based on the results, all treatments induced noticeable decreases in wine color (APHA value) and turbidity. The treatment including PVPP and bentonite at the same time provided the best results in relation to wine color and clearness. PVPP was the most effective in the reduction of phenolic compounds, which means it helped wine obtain a paler color. Organic acids and aromatic profile were not altered by the fining treatments.

• Journal of the Korean Applied Science and Technology
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• v.33 no.4
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• pp.795-801
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• 2016

This study is on the denitrification process using the sodium alginate and $CaCl_2$ as a flocculant. Removal techniques of nitrate nitrogen from waste water are reverse osmosis, ion exchange, electro dialysis and biological method etc. We tried to remove nitrate nitrogen with flocculation and sedimentation method in the present study. Calcium alginate is expected to form a chelate bond with nitrate nitrogen in the solution. So the effects of flocculantt component, flocculation reaction time, molar ratio of the flocculant, flocculant injection rate are studied to determine the best removal rate of nitrate nitrogen. In addition, we tried to determine the nitrate nitrogen removal mechanism by analyzing the structure and component ratio of the configuration after the agglutination precipitate by FE-SEM and EDS. As a result, the nitrate nitrogen removal mechanism is turned out to form calcium-nitro-alginate, and the best mole ratio of flocculating agent is 1 : 1, the injection rate of the flocculant was up to 2%, the removal rate of the nitrate nitrogen to be 56.7% in the synthetic wastewater.