Originals : Distribution Patterns of Native Sulfate Displaced by Respective Pore Volumes of Oxalic Acid in Cecil Bt Soil

( Bon Jun Koo ),( Doug Y,Chung ),( Jae E. Yang ) 한국환경농학회 2002 한국환경농학회지 Vol.21 No.4

In this investigation we tried to investigate the effect of oxalic acid on the fate of native sulfate in Bt soil that contained a high kaolinitic clay by observing the distribution of two anions using soil column under the given competitive adsorption between displaced and displacing anions. To do this, the soil columns uniformly packed to a bulk density of 1.25 g/㎤ with Cecil Bt soil were disected and analyzed the amounts of sulfate and oxalic acid both in solution and solid phases after flowing the designated pore volumes of oxalic acid. The results showed that two sets of curves-nonlinear (> 10^-3 M) and linear (< 10^-3 M) curves where the solution of oxalic acid was not adjusted, while the approaches to the plateau were slow when pH of oxalic acid was adjusted to 5. The cumulative amount of sulfate desorbed by successive addition of oxalic acid was nonlinearly approached to the plateau at the concentration of 10^-3 M or greater, indicating that the number of addition of oxalic acid increased with decreasing order of oxalic acid. However, the plateau did not obtain where the concentration of oxalic acid were less than 10^-4 M, showing a linear increase. Therefore, we may conclude that the rate-limited desorption was involved as the concentration of oxalic acid decreased. The rate of desorption of SO₄ from soil surface may be determined by the exchange with oxalic acid entering to each location, resulted in the dominant factor on the distribution of SO₄ in solution and solid phase. And the relative distribution of SO₄ in solid phase at each location was influenced riot only by the partition of displaced 904 between solid and solution phase, but by the competitive adsorption dependent upon the concentration of oxalic acid simultaneously present in solution On the other hand, the results indicate that the presence of increasing amount of oxalic acid in solution enhance the competition for sorption sites with the displaced SO4, resulting in the reduction of SO₄ adsorption. Therefore, the depth of penetration of the displacing anion, oxalic acid, might occur behind the depth of displaced anions, SO₄ since the effectiveness of competitive adsorption capacity of oxalic acid was greater than that of SO₄ in this study. Thus, the transport behavior of displaced anion, SO₄, and displacing anion, oxalic acid, in this investigation could be much governed by the competitive adsorption characteristics and the relevant factors such as hydrodynamic dispersion coefficient and velocity in the system

ZnC2O4의 Oxalate로의 효과적 분리 및 이의 전기화학적 환원을 통한 글리콜산으로의 전환

임선미,박이슬 한국청정기술학회 2023 청정기술 Vol.29 No.1

Oxalic acid has been traditionally obtained via the oxidation of carbohydrates using nitric acid and catalysts. However, this process produces a variety of nitrogen oxides during oxidation and requires a separation process due to its various intermediates. These products and additional steps increase the harmfulness and complexity of the process. Recently, the electrochemical reduction of carbon dioxide into oxalic acid has been suggested as an environmentally friendly and efficient technology for the production of oxalic acid. In this electrochemical conversion system, zinc oxalate (ZnC2O4) is obtained by the reaction of Zn2+ ions produced by Zn oxidation and oxalate ions produced by CO2 reduction. ZnC2O4 can then be converted to form oxalic acid, but this requires the use of a strong acid and heat. In this study, a system was proposed that can easily convert ZnC2O4 to oxalic acid without the use of a strong acid while also allowing for easy separation. In addition, this proposed system can also further convert the products into glycolic acid which is a high-value-added chemical. ZnC2O4 was effectively separated into Zn(OH)2 powder and oxalate solution through a chemical treatment and a vacuum filtration process. Then the Zn(OH)2 and oxalate were electrochemically converted to zinc and glycolic acid, respectively. 옥살산(oxalic acid)은 기존에 질산을 사용한 carbohydrates의 산화 공정에 의해 얻어질 수 있으며 여러 분야에서 사용되고 있다. 하지만 이 반응은 다양한 질소 산화물을 형성하고 많은 증간 생산물의 분리를 필요로 하기에 복잡하고 환경에 유해하다. 한편, 이산화탄소로부터 전기화학적 방법에 의해 옥살산을 높은 효율로 얻을 수 있는 방법이 제안되었다. 아연 전극 산화에 의해 생성된 Zn2+이온과 CO2 환원에 의한 oxalate이온의 반응으로 zinc oxalate(ZnC2O4)가 얻어진다. 이후 산처리에 의해 옥살산이 생성될 수 있으나 강산과 열을 필요로 한다. 본 연구에서는 CO2의 전기화학적 전환으로 형성된 ZnC2O4을 강산을 사용하지 않고, 간단하고 분리가 쉬운 방법을 적용하여 옥살산으로 전환하고자 한다. 또한, 고부가 물질인 글리콜산으로 더 전환시킴으로써 이산화탄소에 서 고부가 물질로의 전환 가치를 높이고자 하였다. ZnC2O4를 상온, 상압에서 화학적 방법 및 여과 과정을 통해 효과적으로 Zn(OH)2 입자와 oxalate 용액으로 분리하였으며 얻어진 Zn(OH)2와 oxalate는 전기화학적 방법을 사용하여 각각 Zn, 글리콜산으로 전환되었다

THE STUDIES ON THE QUANTITY OF OXALIC ACID FROM LOCAL GARNISH VEGETABLES OF SOUTHERN THAILAND

Naim Laeni,Anat Chenea,Rosalee Romaeyah,Hameedah Musa 국제과학영재학회 2010 APEC Youth Scientist Journal Vol.2 No.-

Eating local vegetables is considered a habit in the life style of the people in the southern part of Thailand for a long time. Vegetables which can be found easily in the local. These vegetables are commonly eating raw or it could be served as garnish along with the food and sauce like spicy sauce or local preserved fish sauce (Boodoo). From the studied, some garnish vegetables contained oxalic acid that would precipitate to calcium oxalate which makes a significant contribution to urinary oxalate, and caused Kidney Stones disease and Gouty Arthritis. There are 5 parts of experiment: The first part is the study on the quantity of Calcium oxalate dregs from the reaction between calcium compounds with oxalic acid. We found that calcium hydroxide solution precipitated calcium oxalate with highest quantity. The second part is the study on quantity of oxalic acid from 33 kinds of garnish vegetables from southern Thailand. According to the experiment, the 6 kinds of vegetables which contain the most quantity of oxalic acid are Parkia javanica Merr. , Archidendron jiringa Nielson , Amaranthus lividus Linn. , Archidendron jiring , Parkia speciosa Hassk.,and Anacardium occidental L. respectively .In the third part is the study on the result of temperatures toward the reduced quantity of oxalic acid from 6 kinds of the ferment garnish vegetables. The result show that the higher temperatures the lower oxalic acid. The forth part and the last part of the experiment is the study on the effect of the Local preserved fish sauce (Boodoo) and Shrimp paste toward the quantity of oxalic acid in the 6 kinds of garnish vegetables above. The reduction of oxalic acid are 0.9938 %w/w, 0.9300 %w/w. respectively.

옥살산을 이용한 꿀벌 안전성과 꿀벌응애류 방제 효율 평가

오대근,김길원,김경문,피터 아콩테,김주경,이창훈,박보선,김수배,조유영,최용수,김동원 한국양봉학회 2023 韓國養蜂學會誌 Vol.38 No.1

This study investigated the safety of oxalic acid (natural acaricide), on honeybee ( Apis mellifera) colonies and its acaricidal effects on honeybee pest mites (Varroa destructor and Tropilaelaps mercedesae). To determine the safety and acaricidal effects of oxalic acid, the impacts of oxalic acid was examined using different treatment methods (i) fumigation and (ii) dripping (trickling), and concentrations (0.7, 3, and 6%). For the fumigation, 1 g of oxalic acid was treated inside the beehive, and the experimental groups were divided by blocking the entrance of the beehive for different durations (1, 5, 10, and 15 min.). For the dripping, oxalic acid-sugar solutions with different concentrations (0.7, 3, and 6%) were prepared and applied to the beehive to measure safety and efficacy of oxalic acid. The safety of honeybees with oxalic acid treatment showed no significant differences between the experimental and control groups for both the fumigation and dripping methods, and had no significant impact on the honeybee colonies. The acaricidal effect of oxalic acid treatment was higher against V. destructor in all experimental groups compared to the control group in the fumigation method. In the dripping method, only the experimental groups with 3 and 6% concentrations showed significant differences and demonstrated acaricidal effects compared to the control group. For T. mercedesae , the low number of detected individuals resulted in no significant effects. Both treatment methods did not show any significant acaricidal effects on V. destructor and T. mercedesae, which exist inside the capped brood cells.

열 피로에 미치는 알루미늄 양극산화 제조방법의 융합연구

강수영 한국융합학회 2016 한국융합학회논문지 Vol.7 No.5

알루미늄의 양극산화는 황산법, 수산법과 황산과 수산을 활용한 혼산법 등이 있다. 산업체에서 만들어 지는 양극산화는 황산법으로 전해액속의 황산농도가 15 ∼ 20 wt %이다. 연질 양극산화피막을 생성할 경우는 전해 액의 온도가 20∼30℃ 범위에서 생산되고 있으며, 생산 전압은 직류전압으로 13∼15 V 이내가 가장 많이 사용된다. 경질 양극산화피막을 생성할 경우는 전해액의 온도가 0 ∼ -5 ℃에서 생산되어지고 있다. 본 연구에서는 황산법과 수산법을 이용하여 50㎛ 두께의 양극산화피막(알루미나)를 제작하였다. 황산법과 수산법에 의해 시편을 제조하여 열 피로시험을 수행하였다. 황산법과 수산법의 균열발생온도는 500℃와 600℃이었다. 황산법의 균열발생온도는 수 산법의 균열발생온도보다 낮았다. 시험결과 수산법의 열 피로는 황산법의 열 피로 특성보다 좋았다. 그 이유를 알루 미늄과 알루미나의 열팽창계수와 제조온도로 설명하였다. 고온에서 사용되는 양극산화제품의 제조방법을 여기서의 융합 연구를 통해 제안 가능하게 되었다. Anodic oxidation of aluminum has a sulfuric acid method and a oxalic acid method. Sulfuric acid concentration of the sulfuric acid method is 15∼20 wt%. In the case of soft anodizing used in the 20 ∼30 ℃ range, and voltage is the most used within a DC voltage 13∼15V. In the case of hard anodizing used in the 0 ∼ -5 ℃ range. An aluminum oxide layer is made using sulfuric acid and oxalic acid. In this study, thermal fatigue of aluminum oxide layer which is made using sulfuric acid and oxalic acid is compared. Crack generating temperature of a sulfuric acid method and a oxalic acid method is 500℃ and 600℃. Thermal fatigue of aluminum oxide layer which is made using oxalic acid is better than thermal fatigue of aluminum oxide layer which is made using sulfuric acid. The characteristic of thermal fatigue can be explained by using thermal expansion coefficient of Al and Al2O3 and manufacturing temperature on Al anodizing. It was made possible through the convergent study to propose the manufacturing method of the anodic oxidation product used at a high temperature.

An Oxalic Acid Sensor Based on Platinum/Carbon Black-Nickel-Reduced Graphene Oxide Nanocomposites Modified Screen-Printed Carbon Electrode

Income, Kamolwich,Ratnarathorn, Nalin,Themsirimongkon, Suwaphid,Dungchai, Wijitar The Korean Electrochemical Society 2019 Journal of electrochemical science and technology Vol.10 No.4

A novel non-enzymatic oxalic acid (OA) sensor based on the platinum/carbon black-nickel-reduced graphene oxide (Pt/CBNi-rGO) nanocomposite is reported. The nanocomposites were prepared by the ethylene glycol reduction method. Their morphology and chemical composition were characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and transmission electron microscopy (TEM). The results clearly demonstrated the formation of the Pt/CB-Ni-rGO nanocomposite. The electrocatalytic activity of the Pt/CB-Ni-rGO electrode was investigated by cyclic voltammetry. It was determined that the appropriate amount of Pt enhanced the catalytic activity of Pt for oxalic acid electro-oxidation. Moreover, the modified electrode was determined to be highly selective for oxalic acid without interference from compounds commonly found in urine including uric acid and ascorbic acid. The chronoamperometric signal gave a wide linearity range of 20 μM-60 mM and the detection limit (3σ) was found to be 2.35 μM. The proposed method showed high selectivity, stability, and good reproducibility and could be used with micro-volumes of sample for the detection of oxalic acid. Finally, the oxalic acid content in artificial and control urine samples were successfully determined by our proposed electrode.

젖산과 옥살산을 이용한 폐 이차 리튬이온 전지 양극 활물질로부터 희유금속들의 회수

김연정,한지선,최식영,오인경,홍용표,유건상 대한화학회 2019 대한화학회지 Vol.63 No.6

We have developed a method that can leach Co, Mn, and Ni in the cathode active material safely using lactic acid. When cathode active material was leached by lactic acid, lactic acid showed the highest efficiency at 2 N than 1 N and above 4 N concentration. When the cathode active material was added incrementally into the solution of lactic acid, the maximum solubility was 30 g/L at 2 N concentration. Oxalic acid was added in the solution of lactic acid and it showed that rare metals represent the most economical recovery efficiency at 4 g/L. Based on this study, it was found that the optimal condition for recovery of rare metals from cathode active material is oxalic acid : cathode active material = 7 : 1 as a ratio of weight. In addition, it was observed that the precipitate produced by oxalic acid is a polynuclear crystalline material bonded with 3 components of Co, Ni, and Mn. 젖산을 이용하여 안전하게 양극활물질에 있는 Co, Mn, Ni을 침출할 수 있는 방법을 개발하였다. 양극활물질을 젖산으 로 침출 시켰을 때, 젖산의 농도는 1N과 4 N 이상에서 보다는 2 N에서 가장 높은 효율을 보였다. 양극활물질을 단계적으로 젖 산 용액에 첨가 하였을 때, 최대 용해도는 2 N의 젖산 용액에서 1 L 당 30 g이었다. 젖산 용액에 옥살산을 첨가하였고 희유금속 들은 1 L 당 4 g에서 가장 경제적인 회수율을 보였다. 본 연구를 바탕으로 해서, 양극활물질로부터 희유금속들을 회수하기 위한 최적의 조건은 무게비로 옥살산과 양극활물질이 7 : 1이라는 것을 확인할 수 있었다. 첨가하여, 옥살산에 의해서 생성된 침전물 은 Co, Ni, Mn 3성분이 결합되어 있는 다핵 결정성 물질이었다.

Preparation of Cellulose Nanocrystals via a Mild Mixed Acid Hydrolysis with High Yield and High Thermal Stability

Zhufan Zou,Xianghao Yang,Hongxiang Xie,Hongyan Lan,Yang Cheng,Jiahui Shen,Youngsoo Bae,Chuanling Si 강원대학교 산림과학연구소 2018 강원대학교 산림과학연구소 학술대회 Vol.2018 No.09

Cellulose nanocrystals (CNCs) are mainly produced by traditional mineral acid hydrolysis, such as sulfuric acid, hydrochloric acid, nitric acid, phosphoric acid, etc., which usually causes some problems such as corrosion of equipment, inability of acid recovery, large amounts of water usage, and over-degradation of cellulose. In this work, a green and sustainable approach for the preparation of CNCs was developed by using a mixed acid hydrolysis of oxalic acid and sulfuric acid. The acid ratio, reaction temperature, and reaction time were investigated in detail. It was discovered that a high yield up to 85 % was achieved by this mixed acid with a ratio of 5:1:4 for sulfuric acid: oxalic acid: H2O respectively at 95 oC for 2 h. Results showed that the resultant CNCs have a narrow particle size of 416±35 nm (based on dynamic light scattering). TEM characterization showed the CNCs was perfect whisker morphology. Also, the obtained CNCs exhibited superior dispersion stability in water due to the introduction of carboxyl group on the surface of CNCs by oxalate esterification. Thermogravimetric analyses revealed that the resultant CNCs showed a much higher thermal stability (315 °C) than the traditional sulfuric acid hydrolyzed CNCs. In addition, over 90% of oxalic acid could be recovered by a simple recrystallization step. Thus, the present work demonstrated an efficient and green preparation method of CNCs with high yield and high thermal stability.

화학세척제를 이용한 도자기의 철산화물 제거 특성 연구

박대우,장성윤,남병직,함철희,임성태 한국문화재보존과학회 2011 보존과학회지 Vol.27 No.4

금속산화물에 오염된 도자기 유물을 보존처리 하기 위해서는 경우에 따라 화학적 세척과정이 필요하다. 본 연구에서는 화학적 세척과정을 침적법과 습포법으로 구분하여, 침적법에서는 옥살산과 구연산의 농도에 따른 철산화물 제거특성을 확인하고자 하였다. 나아가 앞선 침적법의 결과를 토대로 spot 테스트를 거친 후, 태안 마도에서 출토된 도자기유물에 습포법을 적용하여 철산화물을 제거하였다. 옥살산에 60시간 침적시 도자기 빙렬 내의 철산화물은 제거되었지만, 육안관찰에서 침적 3시간 이후부터 철산화물이 관찰되지 않기 때문에 보존처리현장에서는 유물의 안정성을 고려하여 0.25M 이하의 옥살산에 1~3시간동안 침적하는 것이 적당할 것으로 판단된다. 구연산에서는 60시간 침적시 철산화물은 제거되지 않았다. 이는 옥살산과의 분자량 차이 및 산도(acidity) 등에 의한 것으로, 빙렬 내에 침투한 철산화물을 제거할 때에는 구연산보다 옥살산이 좀 더 효과적이었다. 옥살산을 용제로 제작한 습포팩(벤토나이트, 세피올라이트, 활성탄소섬유, 셀라이트)을 오염된 백자태토에 10시간동안 도포 처리하여 철산화물은 제거되었지만, 유물적용성은 벤토나이트와 세피올라이트가 뛰어났다. 그래서 앞선 침적법의 결과를 토대로, 0.25M의 옥살산과 세피올라이트를 습포팩으로 제조하여 태안 마도 출토 청자 및 백자에 적용하였다. 습포팩 1회 처리로 유물표면의 철산화물은 대부분 제거되었으나 오염물의 형태에 따라 적용횟수는 달라질 수 있을 것으로 판단되며, 세피올라이트에 의한 2차 오염을 방지하기 위한 세척도 함께 병행되어야 할 것이다. To remove metal stains of the ceramics, chemical cleaning is essential case by case. This study investigated the removal characteristics of iron stains by oxalic acid and citric acid including their application methods of soaking and poultice. The soaking method in cleaning agents showed removal process by color difference and released iron contents from iron stains on ceramics. Iron stains were removed successfully from ceramics, which soaked in oxalic acid for 60 hours. However, it is recommendable to soak in 0.25M oxalic acid for one to three hours because most iron stains were disappeared in 3 hours soaking. Citric acid is less effective than oxalic acid in removing iron stains because of heavy molecular weight and low acidity. Poultices (bentonite, sepiolite, activated carbon fiber and celite) with oxalic acid were applied on contaminated ceramics. After ten hours, iron stains on ceramics were removed successfully by poultice. Among them, bentonite and sepiolite have better application. Therefore, sepiolite with 0.25M oxalic acid was applied on the iron stains of whiteware and celadon from Ma Island, and then stains were removed. However, it is judged that the application methods can be varied according to the form and depth of contaminant. In addition, the residues of poultice on the ceramics will be considered for preventing contamination.

식품중의 수산분석법에 관한 연구

김복성,이영자,홍기형,이창희,류시생,진희숙,송성실,김용철,이명환 국립보건연구원 1992 국립보건원보 Vol.29 No.2