• Title/Summary/Keyword: oxalic acid

Search Result 628, Processing Time 0.033 seconds

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

  • Koo, Bon-Jun;Chung, Doug-Y.;Yang, Jae-E.
    • Korean Journal of Environmental Agriculture
    • /
    • v.21 no.4
    • /
    • pp.291-296
    • /
    • 2002
  • 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 $g/cm^3$ 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 (> $10^3M$) and linear (> $10^3M$) curves where the solution of oxalic acid was not adiustet 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 $10^3M$ 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 $10^4M$, showing a linear increase. Therefore, we may conclude that the rate-limited desorption was involved as the concentration of oxalic acid decreased.

Oxalic Acid Metabolism and Decay Characteristics of Tyromyces palustris (갈색부후균 Tyromyces palustris의 수산대사와 목질분해 특성)

  • Son, Dong-Weon;Lee, Dong-Heub;Oh, Jung-Soo
    • Journal of the Korean Wood Science and Technology
    • /
    • v.23 no.4
    • /
    • pp.54-59
    • /
    • 1995
  • This experiment was carried out to evaluate the role of oxalic acid metabolism in the incipient decay of brown rotting, and to investigate the effects of various compositions of culture medium. Until 5days incubation, the amount of oxalic acid produced by Tyromyces palustris was increased, while pH was gradually decreased. The difference in oxalic acid production depending on carbon sources was not significant and the pH adjustment of media did not stimulate the production of oxalic acid. In this experiment, hemicellulose was hydrolyzed with 1% oxalic acid, so it is suggested that nonenzymatic acid hydrolysis of hemicelluloses might be involved in the process of incipient decay of brown-rot fungi.

  • PDF

Degradation Characteristics of Oxalic Acid and Citric Acid by UV/H2O2 Oxidation (Oxalic Acid와 Citric Acid UV/H2O2에 의한 분해특성 조사)

  • Ha, Dong-Yun;Cho, Soon-Haing;Choi, Young-Soo;Kyung, Gyu-Seok;Kim, Dong-Hyun
    • Journal of Korean Society of Environmental Engineers
    • /
    • v.22 no.7
    • /
    • pp.1307-1318
    • /
    • 2000
  • The purpose of this study is to investigate the degradation characteristics of oxalic acid and citric acid by $UV/H_2O_2$ oxidation. For this purpose, the effects of pH, $H_2O_2$ dosage and the concentration of each compounds on the degradation of oxalic acid and citric acid by $UV/H_2O_2$ were investigated. Oxalic acid was effectively degraded at the wavelength of 254 nm, while the degradation efficiency of citric acid was very low at the same wavelength. It was also found that both organic substances were not degraded by the injection of $H_2O_2$ only. The optimum pH of degradation of oxalic acid and citric acid was 4 and 4 to 6, respectively. In the case of $UV/H_2O_2$ oxidation, the degradation efficiency was increased by increasing $H_2O_2$ dosage. The degradation efficiency decreased when the dose of $H_2O_2$ exceeds 200 mg/L. From these results, it can be concluded that the optimum reaction conditions for the degradation of oxalic acid and citric acid by $UV/H_2O_2$ oxidation were pH 4 and 200mg/L of $H_2O_2$.

  • PDF

The Spectrophotometric Determination of Oxalic Acid with Zr(IV)-XO Complex (분광광도법에 의한 옥살산의 정량)

  • Woo-Tae Chung;Myon-Yong Park;Byong-Cho Lee;Kee-Chae Park
    • Journal of the Korean Chemical Society
    • /
    • v.20 no.1
    • /
    • pp.43-47
    • /
    • 1976
  • The determination of oxalic acid is carried out with Zr(IV)-XO complex by spectrophotometry. The Mechanism of this method in 1∼4N HCl solution is shown below (XO = xylenol orange); Zr(IV)+XO=Zr(IV)-XO+ excess XO, Zr(IV) - XO + oxalate = Zr(IV)-oxalate + XO When oxalic acid is added to Zr(IV)-XO complex(red color), the absorbance of Zr(IV) - XO complex is decreased in proportional to the amount of oxalic acid. The malic, malonic, maleic, fumaric, succinic, folic and glutamic acid did not interfere even if they are present in hundred times of oxalic acid. If they are present in the same amount as oxalic acid, citric and tartaric acid did not interfere but they are interfere when they are present in much more than that of oxalic acid.

  • PDF

A STUDY ON THE MICROSCOPIC CHANGE OF THE ENAMEL SURFACE AFTER ACID ETCHING (법랑질(琺瑯質)의 산탈회(酸脱灰)에 관(關)한 실험적(實驗的) 연구(硏究))

  • Min, Byoung-Duck
    • Restorative Dentistry and Endodontics
    • /
    • v.6 no.1
    • /
    • pp.37-50
    • /
    • 1980
  • Scanning Electron Microscopic (SEM) examination on the labial surface of 91 permanent upper incisors were made after etching procedure with phosphoric acid, sulfuric acid, nitric acid, hydro chloric acid, oxalic acid, formic acid, citric acid and zinc phosphate liquid for 2 minutes. Following results were obtained. 1. In the surfaces etched by 10%. 50% phosphoric acid, 50% sulfuric acid, 10%. 30% nitric acid, 10%. 50% oxalic acid, 10%. 30%. 50% formic acid, 30%. 50% citric acid and zinc phosphate liquid, there appeared to be a preferential removal of prism cores, but in the surfaces etched by 10% phosphoric acid, 50% nitric acid, 10%. 30% hydrochloric acid and 30% oxalic acid, the prism peripheries were removed preferentially. 2. According to Silverstone classification on enamel etching pattern the surface treated by zinc phosphate liquid, 30. 50% citric acid, 10%. 30%. 50% formic acid, 10%. 50% oxalic acid, 10%. 30% nitric acid, 50% sulfuric acid and 10%. 50%. phosphoric acid showed Type 1, and etched by 30% oxalic acid, 10%. 30% hydrochloric acid, 50% nitric acid and 10% phosphoric acid showed Type II. Etching of prism cores was by far the most common occurence. The changes produced could be related to intrinsic differences in histology and / or solubility of enamel.

  • PDF

Effect of Potassium Formate, Glycine and Oxalic Acid in Sulfate Bath on Trivalent Chromium Deposition Composition and Current Efficiency (Potassium formate, Glycine, Oxalic acid가 황화물계 3가 크롬도금층의 조성과 전류효율에 미치는 영향)

  • Kim, Man;Kim, Dae-Young;Park, Sang-Eon;Kwon, Sik-Chul;Choi, Yong
    • Journal of the Korean institute of surface engineering
    • /
    • v.37 no.2
    • /
    • pp.86-91
    • /
    • 2004
  • Effect of potassium formate, glycine and oxalic acid in a sulfate solution on the deposit composition and current efficiency of trivalent chromium plating was studied. The trivalent chromium layers prepared by solutions with potassium formate, glycine and oxalic acid contain a few carbon inside. The solutions containing potassium formate, glycine and oxalic acid are relatively stable with pH change. The solution with the potassium formate shows 6-30% current efficiency with current density, whereas, the solutions with oxalic acid and glycine show about 5% current efficiency, respectively. The improved current efficiency is related to enough supply of chromium ions to the electrode due to the increase of pH at the front of electrode.

A Study on Oxalic Acid and Calcium Content in Korean Foods (한국 상용식품중 칼슘과 수산함량에 관한연구)

  • Kim, Eul-Sang;Im, Kyeoung-Ja
    • Journal of Nutrition and Health
    • /
    • v.10 no.4
    • /
    • pp.104-110
    • /
    • 1977
  • Vegetables are liberally taken to enhance the mineral, vitamin, and rouphage value of the diet. And calcium is an essential mineral at all ages, although the daily requirement varies with physiological status of the individual. On the other hand, oxalic acid is an unwanted constituent of several clinical disorders. It is therefore necessary to take into account the calcium as well as the oxalic acid content of the various calcium, foods. Oxalic acid, calcium, calcium/oxalic acid ratio and available calcium have been determined in 31 kinds of the Korean common vegetables. The results are summarized as follows; 1. The highest content of oxalic acid has been recorded in Amaranth. spinach and beet. It is respectively 1,100mg%, 619mg%, 550mg% in fresh sample. It is comparatively high in Leek, leavels of perilla, Mugwort, Chyi-leaves, green red pepper, Burdock. 2. Many vegetables have been calculated as below 2.0 in the calcium/oxalic acid ratio. 3. Avaiable calciumis much in Malaolitoria, Lettuce, Green onion whole, Green garlic, Wild onion, Cabbage and Radish root. 4. A food calendar is suggested as a guide to the proper selection of food items for normal individuals and for those suffering from urolithiasis, cardiovascular disease or calcium deficiency status.

  • PDF

Hard Anodizing Treatment in Malic Acid Bath mixed with Oxalic Acid (말릭산과 수산혼합욕에서 경질양극 산화처리)

  • Jeong, Yong-Soo;Chang, Do-Yon;Kwon, Sik-Chol
    • Journal of the Korean institute of surface engineering
    • /
    • v.17 no.3
    • /
    • pp.78-86
    • /
    • 1984
  • Hard anodic oxide film was investigated formed on pure aluminium with various temperature (30$^{\circ}-60^{\circ}C$), current densities (1.5-3.0A/$dm^2$) and concentrations(3-15g/l) of oxalic acid in 0.5M malic acid bath. The resulting characteristic of the anodic oxide film obtained were summarized as follows in the view point of physical and mechanical properties in relation with the above process variables. 1. The film thickness increased with oxalic acid concentration and bath temperature, while the reversed phenomena were obtained at a high concentration of oxalic acid and high temperature due to the severe dissolution of the anodic oxide film. 2. The hardness and the abrasion resistance were improved by lowering the addition of oxalic acid and the bath temperature. This feature was directly dependent on the porosity formed on the anodic oxide film. 3. The maximum hardness of anodic oxide film showed Hv 579 in the temperature of 30$^{\circ}C$ with the current density, 2.5A/$dm^2$ in the 0.5M malic acid bath mixed with 5g/l oxalic acid.

  • PDF

Ex-situ Remediation of a Contaminated Soil of Fe Abandoned Mine using Organic Acid Extractants (유기산 추출에 의한 철 폐광산 오염토양의 복원)

  • 정의덕;강신원;백우현
    • Journal of Environmental Science International
    • /
    • v.9 no.1
    • /
    • pp.43-47
    • /
    • 2000
  • A study on the remediation of heavily for ion contaminated soils from abandoned iron mine was carried out, using ex-situ extraction process. Also, oxalic acid as a complex agent was evaluated as a function of concentration, reaction time and mixing ratio of washing agent in order to evaluate Fe removability of the soil contaminated from the abandoned iron mine. Oxalic acid showed a better extraction performance than 0.1N-HCl, i.e., the concentrations of Fe ion extracted from the abandoned mine for the former at uncontrolled pH and the latter were 1,750 ppm and 1,079 ppm, respectively. The optimum washing condition of oxalic acid was in the ratio of 1:5 and 1:10 between soil and acid solution during l hr reaction. The total concentrations of Fe ion by oxalic acid and EDTA at three repeated extraction, were 4,554 ppm and 864 ppm, respectively. The recovery of Fe ions from washing solution was achieved, forming hydroxide precipitation and metal sulfide under excess of calcium hydroxide and sodium sulfide. In addition, the amounted of sodium sulfide and calcium hydroxide for the optimal revovery of Fe were 15g/$\ell$ and 5g/$\ell$ from the oxalic acid complexes, respectively.

  • PDF

New Bleaching Method for KP with Permanganate(III) -Evaluation of Role of Oxalic Acid as a Acid Catalyst and a Reductant on the Permanganate Oxidation with Phenolic Model Compounds- (과망간산칼륨을 이용한 KP의 새로운 표백법(제3보) -모델화합물 실험에서 Oxalic acid 첨가의 평가-)

  • Yasuo Kojima
    • Journal of Korea Technical Association of The Pulp and Paper Industry
    • /
    • v.33 no.1
    • /
    • pp.73-79
    • /
    • 2001
  • Stricter environmental demands have increased the need to replace conventional C/D bleaching sequence by chlorine-free sequence. Permanganate is well known as a powerful oxidant and have been used industrially in variable fields. However, it has considered to be difficult to use permanganate as a bleaching reagent because of its strong oxidative effect decreasing the viscosity of pulps extremely. We have tried to use permanganate as a bleaching reagent for KP under the mild condition and it was clear that pernanganate oxidized lignin remained in pulps selectively and increased pulp brightness decreasing K number of pulps with small degradation of cellulose. We have employed the neutral condition in the permanganate bleaching process in this study. In this case, permanganate was converted to manganese dioxide after bleaching reaction. The manganese dioxide is remained in the treated pulp fibers because of its insolublity in water. So it was required to reduction the manganese oxide to manganese ion by using reductants with acid. In this paper, we proposed to use oxalic acid as a reducing reagent converting manganese oxide to manganese ion after bleaching reaction. Oxalic acid plays the role as a reductant and a acid, so post-treatment after bleaching became to be easy by using oxalic acid. On the study using lignin model compounds, it was clear that permaganate react with phenols firstly, after that oxalic acid reduce the manganese oxide to manganese ion in the mixture of permanganate, phenols and oxalic acid. Several lignin model compounds ($\textit{p}$-hydroxybenzaldehyde, vanillin, syringaldehyde, veratraldehyde) are selected to elucidate the effect of substituents on reaction rate and its mechanism with permanganate including oxalic acid in this study. Except for veratraldehyde, the rate of oxidative degradation of phenolic compounds by permanganate with oxalic acid are higher than neutral condition. Especially, the degradation rate of $\textit{p}$-hydroxybenzaldehyde are strongly dependent on pH of reaction mixture. On the other hand, the degradation rate of veratraldehyde are decreased with decreasing pH and main degradation product is veratric acid. This result indicate that pH of bleaching liquor should be kept over 2 to degrade of non-phenolic lignin in the pulps effectively in permanganate bleaching.

  • PDF