Showing papers on "Oxalic acid published in 2020"
TL;DR: In this article, a green, cheap and safe approach is proposed by using a choline chloride-citric acid deep-eutectic solvent (DES) as lixiviant.
114 citations
TL;DR: In this paper, an AgBr nanoparticles and g-C3N4 nanosheets were synthesized and coupled to obtain the AgBr-g-C 3N4 catalyst, which showed a boosted activity in the photodegradation of methyl orange (MO) in aqueous solution.
86 citations
TL;DR: Ce-AlOOH were investigated to develop as an adsorbent for removing fluoride and modification of oxalic acid exhibited a new easier way to quickly increase M-OH content, which contributed to the dominated adsorption sites.
78 citations
TL;DR: A ZnO/PEG (polyethylene glycol) -Co(II)-PbO2 nanocomposite electrode was constructed by using the anodic electrodeposition method and used for the electrocatalytic degradation phenol, and HPLC results showed that the degradation pathway is as follows: firstly, phenol is gradually decomposed into o-diphenol, p-d Diphenol and benzoquinone under hydroxyl radicals attack.
60 citations
TL;DR: In this paper, organic acids commonly associated with microbial P solubilization (citric, gluconic, itaconic, malic, and oxalic) were applied at increasing doses to solve RPs with distinct reactivity grades.
59 citations
TL;DR: In this paper, a novel water-stable Tb-based metal-organic framework (Tb-MOF) was studied for its highly sensitive detection towards nitrite, which is a hazardous chemical in water and food.
Abstract: A novel water-stable Tb-based metal–organic framework (Tb-MOF), namely {[Tb(CA)(OA)0.5(H2O)2]·H2O}n (H2CA = chelidonic acid; H2OA = oxalic acid), was synthesized via a solvothermal method. Tb-MOF was studied for its highly sensitive detection towards nitrite, which is a hazardous chemical in water and food. As a luminescent sensor, Tb-MOF displays a linear detection range between 0 and 15.6 μM, with a limit of detection of 28.25 nM. Dynamic quenching process was observed in this system and was studied in detail. A mechanism study revealed that the fluorescence response of Tb-MOF towards nitrite was due to the energy transfer from the sensitized Tb3+ ion to the nitrite.
56 citations
TL;DR: In this paper, the results of soil washing experiments showed that mixing an equal volume of 0.05 m EDTA and 0.2 m organic acids (citric acid, oxalic acid, and tartaric acid) could remove more than 80% heavy metals from soil under the optimal conditions.
52 citations
TL;DR: In this article, copper oxide (CuO) modified graphitic carbon nitride (g-C3N4) denoted as CuO-CNx composites were successfully fabricated via a reflux condensation method and used as efficient ozonation catalysts for oxalic acid (OA) degradation in aqueous solution.
51 citations
TL;DR: Four deep eutectic solvents (DESs) were synthesized and their performance in the dissolution of cellulose was studied, showing that the melting point of the DESs varied with the proportion of the hydrogen bond donor material.
Abstract: Four deep eutectic solvents (DESs), namely, glycerol/chlorocholine (glycerol/ChCl), urea/ChCl, citric acid/ChCl, and oxalic acid/ChCl, were synthesized and their performance in the dissolution of cellulose was studied. The results showed that the melting point of the DESs varied with the proportion of the hydrogen bond donor material. The viscosity of the DESs changed considerably with the change in temperature; as the temperature increased, the viscosity decreased and the electrical conductivity increased. Oxalic acid/ChCl exhibited the best dissolution effects on cellulose. The microscopic morphology of cellulose was observed with a microscope. The solvent system effectively dissolved the cellulose, and the dissolution method of the oxalic acid/ChCl solvent on cellulose was preliminarily analyzed. The ChCl solvent formed new hydrogen bonds with the hydroxyl groups of the cellulose through its oxygen atom in the hydroxyl group and its nitrogen atom in the amino group. That is to say, after the deep eutectic melt formed an internal hydrogen bond, a large number of remaining ions formed a hydrogen bond with the hydroxyl groups of the cellulose, resulting in a great dissolution of the cellulose. Although the cellulose and regenerated cellulose had similar structures, the crystal form of cellulose changed from type I to type II.
49 citations
TL;DR: In this paper, the results indicated that 99.06% of vanadium was extracted and only 7.95% of aluminum was co-extracted in a counter-current extraction comprising five stages under the optimal conditions.
49 citations
TL;DR: In this article, a hierarchical Fe biochar (Fe/CBC) derived from cellulose was fabricated via a hydrothermal carbonization coupled with microwave irradiation and NH3 activation.
TL;DR: Ion-exclusion HPLC analysis of electrolyzed solutions revealed the formation of maleic and oxalic acid as final short-chain linear carboxylic acids in the degradation of Acid Red 1 azo dye by solar photoelectro-Fenton-like (SPEF-like) process.
TL;DR: The results provided a better understanding for the influence of organic acids on the micro-ecological environment in Cd contaminated soil, based on physicochemical and biological analysis.
TL;DR: In this paper, the authors used organic acids such as acetic acid, citric acid, tartaric acid, oxalic acid and malic acid to improve surface functional groups on biochars.
TL;DR: The remarkable improvement of adsorption capacity and reduced chemical consumption demonstrate that Zr-ACF prepared by drop-coating is a promising adsorbent for fluoride removal.
TL;DR: 10 mmol L-1 oxalic acid application could be considered suitable to delay post-cut browning of lotus root slices.
TL;DR: An efficient Ti/TiO 2-RNTs/Sb-SnO2/PbO2-ND electrode with electrochemically reduced TiO2 nanotubes as the interlayer and nano-diamond as the dopant is fabricated to design an efficient electrode material for the wastewater treatment.
TL;DR: In this article, the regeneration of LiNi1/3Co/3Mn/O2O2 battery was studied. But the regenerative capability of the battery was not evaluated.
Abstract: One of the emerging issues in solving the electronic waste problem is to address the growing amount of end-of-life Li-ion battery (LIB) waste. In this work, the regeneration of LiNi1/3Co1/3Mn1/3O2 ...
TL;DR: In this article, the phase formation has been confirmed by XRD patterns, which is a characteristic of spinel ferrite with most intense (311) peak, the crystallization of the material in the cubic spinel structure, the lattice parameter is approximately 8.38
TL;DR: In this article, cross-linked oxalic acid/chitosan hydrogels (ChOxb) were synthesized, characterized and tested for the adsorption of azo-dyes (Reactive Red 195 RR195) in contaminated wastewater; this novel biodegradable material was highly efficient.
Abstract: Cross-linked oxalic acid/chitosan hydrogels (ChOxb) were synthesized, characterized and tested for the adsorption of azo-dyes (Reactive Red 195 RR195) in contaminated wastewater; this novel biodegradable material was highly efficient. SEM-EDS and N2 adsorption/desorption were used to analyze specific area; FTIR-ATR spectra evidenced electrostatic interactions between protonated amino groups of chitosan and oxalate ions (intensity decrease and shift of amide-II band). Adsorption performance in batch assays showed a maximum percentage of removal of 90.6%, at pH = 4 (initial dye concentration of 300 mg.L−1). The maximum adsorption capacity (Qm) at pH = 4 was 110.7 mg.g−1, positioning ChOxb as one of the most efficient adsorption materials. Oxalic acid (natural organic acid) is an eco-friendly cross-linking agent that reduced swelling and improved chemical stability of ChOxb at low pH = 2.5. Redlich-Peterson adsorption isotherm presented the best fit; adsorption thermodynamic parameters were evaluated. Mixed surface reaction and diffusion-controlled kinetic model was the equation that best fitted kinetic data. FTIR-ATR, SEM-EDS and Z-potential showed electrostatic interactions between dye and amino groups of ChOxb; ChOxd can be reused without losing adsorption capacity and competitive electrostatic interactions between ChOxb-nitrate were observed. This new bio-material is an excellent alternative for the removal of RR195, improving Qm with better structural and functional properties.
TL;DR: The findings not only reveal the activation process of PFOA in soils by root exudates, particularly oxalic acid at rhizospheric concentrations, but also give an insight into the mechanism of enhancing PFOB accumulation in lettuce varieties.
Abstract: Perfluorooctanoic acid (PFOA) is bioaccumulative in crops. PFOA bioaccumulation potential varies largely among crop varieties. Root exudates are found to be associated with such variations. Concentrations of low-molecular-weight organic acids (LMWOAs) in root exudates from a PFOA-high-accumulation lettuce variety are observed significantly higher than those from PFOA-low-accumulation lettuce variety (p 80% attribution. Oxalic acid at rhizospheric concentrations (0.02-0.5 mM) can effectively inhibit PFOA sorption to soils by decreasing hydrophobic force, electrostatic attraction, ligand exchange, and cation-bridge effect. Oxalic acid enhances dissolution of metallic ions, iron/aluminum oxides, and organic matters from soils and forms oxalate-metal complexes, based on nuclear magnetic resonance spectra, ultraviolet spectra, and analyses of metal ions, iron/aluminum organometallic complexes, and dissolved organic carbon. The findings not only reveal the activation process of PFOA in soils by root exudates, particularly oxalic acid at rhizospheric concentrations, but also give an insight into the mechanism of enhancing PFOA accumulation in lettuce varieties.
TL;DR: In this article, USY zeolites obtained by hydrothermal pretreatment were leached by nitric acid (HNO3), hydrochloric acid and oxalic acid, respectively, and used as catalysts to upgrade in-situ lignite tar into light aromatics.
TL;DR: In this paper, the authors compared the process kinetics considering fructose dehydration to HMF as the objective reaction and condensation of fructose and HMF to humin and rehydration of HMF, as the main side reactions.
TL;DR: In this paper, the authors synthesized novel magnesium oxide-based adsorbents and utilized them for CO2 capture at ambient conditions (1 atm, 30 °C).
Abstract: In this study, we synthesized novel magnesium oxide-based adsorbents and utilized them for CO2 capture at ambient conditions (1 atm, 30 °C). Magnesium oxide (MgO) was synthesized using a facile sol-gel technique starting from magnesium nitrate and ammonium hydroxide, sodium hydroxide or oxalic acid. MgO adsorbent synthesized in the presence of ammonium hydroxide (labeled as MgO-A) showed the highest surface area (350 m2/g), which has been correlated with the highest CO2 adsorption capacity (30 mg/g) relative to those synthesized in the presence of sodium hydroxide (MgO-N) or oxalic acid (MgO-O). The characterization of the MgO samples (MgO-A, MgO-N and MgO-O) using XRD, FTIR, SEM, BET, and elemental analysis revealed that the synthesis route has a significant impact not only on surface area but also on the crystallinity, morphology, and textural properties (surface area, porosity and pore size distribution) of these MgO adsorbents. Nonetheless, the key novelty of the work reported herein is the functionalization of MgO with 3-aminopropyl-triethoxysilane (APTES), diethylenetriamine (DETA) and polyethylenimine (PEI) and their utilization for CO2 capture at ambient conditions. The functionalization of MgO-A with the three amines significantly altered its characteristics (i.e., crystallinity, morphology, and textural properties). More importantly, the functionalization of MgO-A with APTES and DETA resulted in an increase in CO2 adsorption from 30 (in the case of the unmodified MgO-A) to 65 and 47.6 mg/g, respectively. These values correspond, respectively, to 0.81 and 1.13 mol CO2 captured/mol amine loaded on MgO-A. However, the functionalization of MgO-A with the polymeric amine (PEI) caused a significant reduction in the adsorbent surface area, leading to a decrease in CO2 adsorption. Regeneration studies (using APTES-MgO-A as an example) demonstrated that contacting the spent adsorbent with N2 gas at 120 °C for a short time can fully restore its original adsorption capacity, suggesting the potential commercial use of APTES-MgO-A for CO2 capture with a minimal energy requirement.
TL;DR: The synthesized composite was considered as a low cost, high efficiency, super selectivity and easy to mass production material for Pb(Ⅱ) adsorption from solution.
TL;DR: Nitrate adsorption onto the MSP700 biochar in the presence of all three-LMWOAs followed first order and second order kinetics, suggesting that the immobilization of nitrate involved complex interplay of physisorption and chemis orption.
TL;DR: In this article, the utilization of glucose, oxalic acid and urea to derive carbonaceous materials for chemical fixation of CO2 with an epoxide into cyclic carbonate without the aid of solvent was presented.
TL;DR: In this paper, microcosm experiments were conducted to examine the chemical behavior of selected heavy metals in the co-presence of biochar and low-molecular-weight organic acids.
TL;DR: In this paper, a solution equilibrium calculation was performed to understand the impact of contaminant metal ions on the precipitation efficiency of selected rare earth elements (Ce3+, Nd3+, and Y3+) using oxalic acid as precipitant.
TL;DR: In this article, the authors investigated the leaching of copper with Phanerochaete chrysosporium from waste printed circuit boards (WPCBs) and found that after 14 days of treatment with fungi, the copper clad laminates of printed circuit board were seriously corroded without any metallic luster with the corresponding color change from yellow to reddish-brown.