Effect Of Oxalic Acid Research Articles

Effect of oxalic acid as a catalyst and dry control chemical additive (DCCA) for hydrophilic aerogel base sodium silicate by ambient pressure drying

Ultra-light pours hydrophilic silica were prepared by sol gel neutralization chemical method under the ambient temperature under the effect different molar ratio of oxalic acid (1, 2, and 3), to study its effect on the structure of silica aerogel based on water glass (Na2SiO3. 5H2O) used as the precursors. The gel was washed with deionized distilled water four times for 24 hours. The pH of the gel has a constant value of about 8. Time gelation occurs during (10-25) minutes depending on the acidic molar ratio. The diagnostic analysis is taken by Fourier transition infrared (FTIR), field emission scanning electron microscope (FESEM), and X-ray diffraction (XRD). The material products have a lightweight with low density (0.35 – 0.27) gm/cm 3, It was floating in the water by its low weight despite its hydrophilic characteristic property. All the diagnostic results matching conformity to most published research results which will also be explained in the present study

The Effect of Oxalic Acid on Corrosion Resistance of Hydroxyapatite Sol-Gel Coated Ti6Al4V Alloys

Bu çalışmada biyomalzeme uygulamalarında kullanılmak üzere etkili bir biyomalzeme geliştirilmesi amaçlanmış ve sol-jel yöntemi kullanılarak Ti6Al4V altlık malzemeler üzerine hidroksiapatit kaplamalar yapılmıştır. Sol-jel yöntemi ile biyoaktifliği ve korozyon dayanımı yüksek, çatlaksız bir kaplama tabakası elde etmek amaçlanmıştır. Bu amaçla, hazırlanan hidroksiapatit çözeltilerine farklı oranlarda oksalik asit (OA, C2H2O4) eklenmiş ve OA’nın kaplama morfolojisinde oluşturduğu değişimler incelenmiştir. Analizlerde, enerji dispersif spektrumlu taramalı elektron mikroskobu (SEM-EDS) ve X-Işını kırınımı (XRD) kullanılmıştır. Kaplama yapılmış numunelerin korozyon özelliklerinde meydana gelen değişimler ise hazırlanan yapay vücut sıvısı içinde üç elektrotlu sistem kullanılarak gerçekleştirilen elektrokimyasal-potansiyodinamik korozyon testleri ile incelenmiştir. Çalışmanın sonucunda OA katkı oranının artması ile kaplama adacıkları arasındaki mesafelerin kapandığı, morfolojide gözlemlenen çatlakların azaldığı ve büyük ölçüde engellendiği gözlemlenmiştir. Korozyon hızları kıyaslandığında ise OA miktarının ağırlıkça % 0,001 olduğu ve 0,015 olduğu numunelerde korozyon hızının diğer katkılı numunelere göre 10 kat ve katkısız numuneye göre ise 5 kat daha az olduğu gözlemlenmiştir.

Study of the Efficacy of Oxalic Acid and Thymovar (Thymol) against the Parasitic Mite of the Honey Bee, Varroa destrutor

Varroasis is a dangerous pathogen of the honey bee caused by the mite Varroa destructor, the aim of this work is to assess the effectiveness of two natural products (oxalic acid and thymol) in the fight against varroasis. The experiment covered 40 colonies in the central region of Algeria. Two doses of oxalic acid were used: 30 and 45 grams per liter of sugar syrup. For thymol (Thymovar), two treatments were carried out: ½ strip with one and two applications for each group of colonies. The 1/2 strip formulation in two applications at an interval of two weeks apart seems the most effective; the 45 gm solution of oxalic acid has a higher efficacy compared to that of 30 gm, that the effectiveness of oxalic acid is directly linked to the presence of brood at the time of the intervention. these two treatments are of control measure to be integrated by beekeepers as part of an alternative control strategy.

Oxalate-Induced Photoreduction Dissolution and Transformation of Schwertmannite: Change of Mineral Phase and Elemental Fate

Schwertmannite (Sch), a common metastable ferric sulfate secondary mineral in acidic mine drainage (AMD) matrix, can be transformed under solar irradiation, thus playing a significant role in elemental redistribution. However, the effects of oxalic acid on the converted mineral products and the fate of S and C during the dynamic process of Sch photoreduction transformation remain unclear. In this study, we investigated the transformation process and the elemental fate of Sch under the synergistic effect of oxalate and light radiation. Characterizations with X-ray diffraction (XRD), scanning transmission electron microscopy (SEM), Fourier transform infrared (FTIR), and Raman spectra at different concentrations of oxalate indicated that solar irradiation and oxalate resulted in the formation of goethite and/or humboldtine. Upon treatment with lower oxalate concentrations of 0.5 and 1.0 mM, Sch could be dissolved and recrystallized to goethite by Fe(II) generated from iron-oxalate complex under ultraviolet radiation (365 nm) at pH 3.0. However, on increasing the oxalate concentration to 5 and 10 mM, goethite proportion decreased and new mineral humboldtine appeared. Therefore, the change of oxalate dosage altered the oxalate-induced Sch dissolution and photoreduction transformation pathway and end product. To sum up, these results provide critical information for understanding the environmental behavior of S and C during the conversion process of secondary minerals under complex natural influencing factors in AMD environments.

Reductive release of Fe mineral-associated organic matter accelerated by oxalic acid

The properties and composition of soil dissolved organic matter (DOM) are highly affected by the adsorption and desorption of organic matter (OM) on soil minerals and heterotrophic microbial respiration. Organic acids (e.g., oxalic acid), components of root exudates, have been revealed to liberate organic matter (OM) by the dissolution of protective mineral phases and stimulate microbial degradation of OM. However, the effects of organic acids on the properties and composition of soil DOM molecules and the related mechanisms are still poorly understood. In this study, we conducted microcosm incubation experiments with and without oxalic acid addition, and aimed to elucidate the variations of DOM properties and composition, employing a combination of Fourier transform ion cyclotron resonance mass spectrometry, optical spectroscopy, and bacterial community composition analysis. Our results indicated that the released OM from the direct dissolution of protective mineral phases by oxalic acid further stimulated the microbial reductive release of Fe mineral-associated OM under anoxic conditions. Furthermore, the addition of oxalic acid enhanced the degradation of aliphatic compounds and lignins with low O/C ratios, and increased the accumulation of lignins with high O/C ratios, tannins, and condensed aromatics. Linking the bacterial community composition to DOM molecular properties and composition further suggested that the enhanced reductive release of Fe mineral-associated OM was highly related to the increased abundances of Proteobacteria and Actinobacteria. Overall, oxalic acid induced long-lasting impacts on soil DOM properties and composition under anoxic soil conditions in our study. We expect that our results will contribute to understanding the dynamics of soil DOM molecules in the environment.

Preharvest Application of Oxalic Acid Improved Pomegranate Fruit Yield, Quality, and Bioactive Compounds at Harvest in a Concentration-Dependent Manner

The effects of oxalic acid (OA) applied in preharvest on pomegranate crop yield and quality properties have not yet been investigated. Pomegranate trees were treated with OA at 1, 5, and 10 mM along the developmental growth cycle during 2016, from full blossom until harvest, and the fruit diameter was recorded monthly. The yield was significantly higher in OA-treated pomegranate trees, the on-tree ripening process being promoted in a concentration-dependent manner. With respect to quality traits, OA at 10 mM showed better results in terms of firmness, external color due to a red color enhancement, and respiration rate and sensory attributes. Then, a second-year experiment was performed with OA at 10 mM, and crop yield and fruit quality results were confirmed. In addition, an increase in glucose and total acidity, specifically malic and ascorbic acids, was observed in OA 10 mM-treated pomegranate fruit. Bioactive compounds were also higher in OA-treated fruit than control, the 10 mM concentration being the most effective in increasing total phenolics, total anthocyanins, and total antioxidant activity. Overall, results suggest that OA applied at 10 mM as preharvest treatment could be an effective tool to enhance pomegranate crop and quality and to improve the content of health-related compounds.

Mobility and transformation of Cr(VI) on the surface of goethite in the presence of oxalic acid and Mn(II)

Goethite is an effective adsorbent for hexavalent chromium (Cr(VI)). Oxalic acid and other organic acids will affect the release, immobilization, and bioavailability of Cr(VI) in nature on the mineral surface. Mn(II) can accelerate the reduction of Cr(VI) with oxalic acid. Herein, the effects of oxalic acid and Mn(II) on the mobilization and transformation of adsorbed Cr(VI) on the surface of goethite were investigated in this study. The results revealed that Mn(II) could increase the adsorption of Cr(VI) by increasing the positive charge on the surface of goethite. The complexation of oxalic acid with the surface of goethite caused the adsorbed Cr(VI) to be released into the solution. Moreover, oxalic acid could undergo redox with adsorbed Cr(VI) through electron conduction on the surface of goethite, thereby resulting in the transformation of adsorbed Cr(VI) to Cr(III). During the reaction in the presence of oxalic acid, the concentration of Cr(III) increased from 0 to 13.9mg/L. In addition, Mn(II), oxalic acid, and Cr(VI) could form unstable ester-like species in the solution, which accelerated the reduction of Cr(VI) to Cr(III). These findings of this study may enrich our understanding of the behaviors of Cr(VI) in the coexistence of goethite, oxalic acid, and Mn(II).

Phanerochaete chrysosporium-driven quinone redox cycling promotes degradation of imidacloprid

This study systematically investigated the advanced oxidation processes driven by the white-rot fungus (WRF) Phanerochaete chrysosporium in the removal of the neonicotinoid pesticide imidacloprid (IMI). The quinone redox cycling driven by P. chrysosporium promotes the degradation of IMI in presence of Mn2+ and Fe (III)-oxalate. Results showed that the degradation efficiency varied with the type of quinine mediator, and gallic acid (GA) was a more effective mediator than 1,4-benzoquinone (BQ). The removal rate of IMI was increased by 1.8-fold in the presence of 100 μM of Mn2+ compared with that of the system without Mn2+. The addition of oxalic acid and EDTA promoted the degradation of IMI, and the effect of oxalic acid was more pronounced at the later stage (day 5 and day 6); the optimal Fe3+/oxalate ratio was 1:3. Time-course experiments revealed the maximum removal rates of IMI were 97.37%, 82.0% and 73.52% at the initial IMI concentration of 10, 20, and 30 mg/L, respectively, in the presence of 100 μM Mn2+, 100 μM Fe3+-300 μM of oxalate and 500 μM gallic acid. Under quinone redox cycling conditions, the good correlation between ·OH production rates and the enzymes activity was concluded, the quinines redox cycles promote enzyme activity, as well as the rate of ·OH production. Results from this study indicated the GA mediator-based system using P. chrysosporium offers a new method to advance the bio-oxidation process owing to its simple culture system, low-cost precursors, unique fungi, and degradation stability.

Management of soft rot disease, caused by Erwinia carotovora subsp. carotovora in potato tubers

Six isolates of Erwinia carotovora were isolated from naturally infected potato tubers in different localities in Egypt. All isolates gave the same results in the pathological, morphological, physiological and biochemical tests and identified as E. carotovorasubsp. carotovora. The isolates showed variation in their virulence. The isolate ET was selected because this isolate was the nearest isolate to E. carotovora and also it was the most severe isolate on potato tubers. The effects of oxalic acid and biological control agents, Penicillium simplicissmum GP17-2, Pseudomonas putida T15, Pseudomonas vranovensi A30, Pseudomonas resinovorans A5 and Pseudomonas brassicacearum N32 on disease progress were evaluated. Oxalic acid at concentrations of 5, 10 and 20 mM and biological control agents significantly reduced soft rot development in wounded entire potato tubers cv. Kara as compared with the control. Disease development was significantly decreased by the tested treatments with increasing soaking time. Data obtained in this study showed that the tested concentrations of oxalic acid proved to be superior to biological control agents in reduction of soft rot disease except for GP 17-2 and T15 isolates.

Oxalic Acid From Sesbania rostrata Seed Exudates Mediates the Chemotactic Response of Azorhizobium caulinodans ORS571 Using Multiple Strategies.

Chemotaxis toward seed exudates is important in the establishment of microbe–plant associations. The objective of this work was to explore whether organic acids from the seed exudates of Sesbania rostrata play a role in recruiting Azorhizobium caulinodans ORS571 in the plant rhizosphere. High-performance liquid chromatography (HPLC) was used to analyze the organic acid content in seed exudates of S. rostrata and to further determine their roles in A. caulinodans growth and chemotactic response. Succinic, acetic, citric, oxalic, and lactic acids were the most abundant, and, except for oxalic acid, they could support A. caulinodans growth as the sole carbon source. TlpA1, a transmembrane chemoreceptor, was found to be involved in the chemotactic response to these organic acids. Oxalic acid played a direct role in the chemotactic response, but it also played an indirect role by promoting or inhibiting the chemotactic response toward other chemoeffectors. Furthermore, the indirect role of oxalic acid on other chemoeffectors was concentration-dependent. The effect of oxalic acid at different concentrations on host root colonization was also determined. By using different strategies, oxalic acid appears to play a major role in the early steps of the association of A. caulinodans and its host plant.

Effects of oxalic acid on Cr(VI) reduction by phenols in ice.

Since Cr(VI) is highly toxic, the environmental reduction of Cr(VI) to Cr(III) has attracted significant attention. Oxalic acid, a primary component of dissolved organic matter (DOM), is widely distributed throughout the natural environment but the reduction of Cr(VI) by oxalic acid is insignificant at the low concentrations present in the environment; however, the reduction of Cr(VI) is accelerated significantly in ice. In terms of combined pollution, Cr(VI) can coexist with other organic pollutants in the environment but the impact of organic pollutants on the reduction of Cr(VI), changes to the organic pollutants themselves, and the role of oxalic acid in these reactions are unknown. In this study, we investigated redox reactions between Cr(VI) and phenolic compounds in ice (- 15 °C) in the presence of oxalic acid and compared these to room temperature redox reactions in aqueous solutions (20 °C). While these redox reactions were negligible in aqueous solution, they were significantly accelerated in ice under acidic conditions, which was primarily attributed to the freeze concentration effect. Oxalic acid has two functions in these redox reactions; the first is to provide the H+ required for the reaction and the second is to serve as a reducing agent. When oxalic acid and phenolic pollutants coexist, Cr(VI) preferentially reacts with the phenolic compounds. Phenol, 4-chlorophenol (4-CP), and 2,4-dichlorophenol (2,4-DCP) were each demonstrated to reduce Cr(VI) in ice, but the reaction rate and overall reactivity of these three phenolic compounds are different.

A scientific note on the effect of oxalic acid on honey bee larvae

The approval of oxalic acid as a treatment for Varroa destructor infestation of honey bee hives gives beekeepers an additional option for controlling this devastating parasite and disease vector, but the effects of oxalic acid on developing bees are not completely understood. In this study, we find that doses of oxalic acid not reported to be toxic to adult bees are toxic to larval bees. While it has been recommended that oxalic acid only be used during broodless periods because it does not penetrate cappings and is only effective in killing phoretic mites, it is tempting to use it at other times of the year because of the dearth of effective treatment options. Knowing whether oxalic acid is toxic to larvae and at what doses is important for beekeepers as they manage their colony population throughout the year.

Effect of oxalic acid on edible quality of bamboo shoots (Phyllostachys prominens) without sheaths during cold storage

The effect of oxalic acid on the edible quality of postharvest bamboo shoots during storage at 6 ± 1 °C for 20 days was investigated to better understand the mechanism of quality improvement. Shoots were placed in cold storage after being removed from their sheaths and soaked in a 10 mmol/L oxalic acid solution for 10 min. The results showed that oxalic acid treatment enhanced membrane integrity, reduced respiration along with decreasing losses of total sugar content and weight, decreased disease incidence, inhibited enzymatic browning, and retarded the lignification process in bamboo shoots during cold storage. These characteristics collectively contribute to maintenance of the edible quality of bamboo shoots. It was suggested that application of oxalic acid might also be a promising method for quality control of bamboo shoots postharvest.

Investigation on the effect of oxalic acid, succinic acid and aspartic acid on the gas hydrate formation kinetics

Gas hydrate reserves are potential source of clean energy having low molecular weight hydrocarbons trapped in water cages. In this work, we report how organic compounds of different chain lengths and hydrophilicities when used in small concentration may modify hydrate growth and either act as hydrate inhibitors or promoters. Hydrate promoters foster the hydrate growth kinetics and are used in novel applications such as methane storage as solidified natural gas, desalination of sea water and gas separation. On the other hand, gas hydrate inhibitors are used in oil and gas pipelines to alter the rate at which gas hydrate nucleates and grows. Inhibitors such as methanol and ethanol which form strong hydrogen bond with water have been traditionally used as hydrate inhibitors. However, due to relatively high volatility a significant portion of these inhibitors ends up in gas stream and brings further complexity to the safe transportation of natural gas. In this study, organic additives such as oxalic acid, succinic acid and L-aspartic acid (all three) having COOH group(s) with aspartic acid having an additional NH2 group, are investigated for gas hydrate promotion/inhibition behavior. These compounds are polar in nature and thus have significant solubility in liquid water; the presence of weak acidic and water loving (carboxylic/amine groups) moieties makes these organic acids an excellent candidate for further study. This study would pave ways to identify a novel(read better) promoter/inhibitor for gas hydrate formation. Suitable thermodynamic conditions were generated in a stirred tank reactor coupled with cooling system; comparison of gas hydrate formation kinetics with and without additives were carried out to identify the effect of these acids on the formation and growth of hydrates. The possible mechanisms by which these additives inhibit or promote the hydrate growth are also discussed.

Effects of root exudates on the sorption of polycyclic aromatic hydrocarbons onto biochar

ABSTRACTThe effect of oxalic acid on phenanthrene sorption was varied from that on pyrene sorption. 1.0 mg L-1 of oxalic acid inhibited phenanthrene sorption, whereas 20, 50 and 100 mg L-1 of oxalic acid enhanced the sorption. However, pyrene sorption onto biochar was all inhibited among different concentrations of oxalic acid. New functional groups and increased polarity were observed in the biochar coexisted with oxalic acid, moreover, a high concentration of oxalic acid led to an increased specific surface area of the biochar. These changed factors contributed to biochar sorption to phenanthrene, which was dominated by surface adsorption. Weakened aromaticity and increased release of dissolved organic carbon from biochar may have been the main reason for inhibited pyrene sorption onto biochar by oxalic acid. Therefore, this study suggested that root exudates could greatly influence the sorption behavior of biochar towards PAHs in soil rhizosphere, which deserves attention in agricultural systems.

Postharvest application of oxalic acid to preserve overall appearance and nutritional quality of fresh-cut green and purple asparagus during cold storage: a combined electrochemical and mass-spectrometry analysis approach

The effect of oxalic acid (OA) treatment on visual properties and bioactive compounds of two green and one purple cultivars of fresh asparagus was investigated during twelve storage days at 5 °C. Cold storage and OA treatment positively affected the overall appearance of the investigated cultivars. Cut-end dehydration increased, all along the storage period, in all cultivars but, the negative effect of the storage, clear on control samples, was mitigated by OA. The most represented compounds in Grande and Vegalim cultivars were: quercetin rutinoside, feruloyl quinic acid and cumaroyl quinic acid. Cyanidin glucosyl rutinoside, cyaniding rutinoside and peonidin rutinoside were identified in Purple Passion cultivar. The bioactive compounds seemed to be affected by storage but not by OA treatment. The sensor-biosensor system indicated that the antioxidant activity is negatively affected by storage but not by OA. The decrease of antioxidant activity coincided with the reduction of ascorbic acid levels in all the cultivars.

Influence of recurrent rainfall and oxalic acid on phosphorus releasing from rocks phosphate in the Chaohu watershed, China

In order to understand the spatial distribution characteristics, loss risk and leaching behaviors of phosphorous from exposed rocks in typical small-area of Chaohu watershed, phosphorus-rich rock was selected for conducting a series of column leaching experiments to investigate the phosphorus leaching. By simulating the intermittent cycle of acid rainfall, effects of oxalic acid on the weathering of phosphate rocks were studied. Total phosphorus contents, pH and phosphate leaching capacity from phosphorus rocks were tested in the presence of oxalic acid at different dry-wet intervals. The results indicated that the cumulative release of phosphorus increased first and then decreased with the duration of dry-wet intervals increasing. Four typical kinetic equations can describe phosphorus release from phosphate rocks with the action of oxalic acid. The best fitting models were the weight function and parabolic equation, with a mean correlation coefficient R2 of 0.9727 and 0.9941, respectively, which reached significance level. Total phosphorus (TP) leaching distribution in each column showed a tendency of gradually decreasing from top to bottom except for time interval of 5 d and 7 d. Occluded-bound P (Oc-P) is the dominant form in rocks. The change point value of rocks phosphorus is 4.11 mg kg−1 after intermittent leaching, and the phosphorus loss risk is relatively large in some rocks formations.

Effect of oxalic acid on visual appearance and quality of ‘Long’ longan fruit during low temperature storage

Effect of oxalic acid on visual appearance and quality of ‘Long’ longan fruit during low temperature storage

Effects of Oxalic Acid on UV-C Sensing Property of Tomato Thin-Film Based Photodetector

New concept of UV photodetector with self-powered and biodegradable features are needed to solve energy and environment. In this work, tomato thin-film was used as an active organic layer in UV photodetector. The effect of oxalic acid in the extraction of tomato juice on the formation of a solid thin film that dried at 120°C for 30 min has been investigated. The purpose of adding oxalic acid is to extract ascrobic acid from tomato. A comparison between tomato juice extracted with and without oxalic acid on the structural, chemical, optical, electrical and UV sensing properties of tomato thin-film have been investigated. The UV photodetector was consisted of a sandwich structure of glass substrate/tomato thin-film/interdigitated aluminium electrode. The photodetector operated at 5 V with tomato thin-film extracted from tomato juice with oxalic acid revealed the highest responsivity percentage difference (89.60%) in UV-C with quantum efficiency (η) of 1.0335x10-5 %, responsivity (R) of 2.1178x10-6 A/W, and detectivity (D*) of 1.1649x1021 Jones. While without oxalic acid, the highest responsivity percentage difference (70.6%) in UV-C was operated at 0 V.

The Effect of Oxalic Acid, the Pathogenicity Factor of Sclerotinia Sclerotiorum on the Two Susceptible and Moderately Resistant Lines of Sunflower.

BackgroundOne of the main sunflower diseases is the white mold Sclerotinia sclerotiorum. The oxalic acid (OA), which is one of the main pathogenicity factors of this fungus, beside the direct toxicity on the host, has other functions such as the disruption of the cell wall and chelating out the calcium ions.ObjectivesRegarding the importance of this disease, it is important to study the reactions of the plant against OA which is a nonspecific toxin of many other necrotrophic fungi.Materials and MethodsIn this study, two susceptible and moderately resistant sunflower lines were inoculated with OA and samples at the first leaf stage were collected within the intervals of 2, 6, 12 and 24 hours post inoculation. The expression of five genes related to tricarboxylic acid cycle, including citrate synthase, fumarase, iso-citrate lyase, malate synthase and malate dehydrogenase was studied under OA treatment.ResultsTwo hours after the inoculation, no significant change was observed in the expression of the five studied genes in the moderately resistant line. The iso-citrate lyase gene, which is related to glyoxylate cycle (a variation of the tricarboxylic acid cycle), showed no change in the moderately resistant line; however, it showed an increase in the susceptible line. The increase in fumarase gene expression in moderately resistant line was higher than the susceptible line. The result showed the activation of glyoxylate cycle and destruction of fatty acids in the susceptible line.ConclusionsActivation of glyoxylate cycle indicated induction of senescent symptoms by OA in susceptible line. Increasing in H2O2 leads to oxidative burst and cell death. Cell death has an apparent benefit for development and growth of necrotrophic pathogens in the plant cells. The study of resistance mechanisms in response to the pathogen is useful for breeding programs to provide lines with higher resistance to this pathogen.