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Subject: search.filters.subject.Oxalic acid

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    Photocatalytic degradation of Irgalite violet dye using nickel ferrite nanoparticles
    (IWA Publishing, 2020) Vijay, S.; Mohan Balakrishnan, R.M.; Rene, E.R.; Priyanka, U.
    Nanotechnologies have prominent applications in the field of science and technology owing to their size-tunable properties providing a promising approach for degradation of various pollutants. In this scenario, the present work aims to study the effect of nickel ferrite nanoparticles on the degradation of Irgalite violet dye by Fenton’s reaction using oxalic acid as an oxidizing agent in the presence of sunlight. The effect of pH and adsorbent dosage on the rate of dye degradation was monitored. Based on these studies it was observed that 99% dye degradation was achieved for catalyst dosage of 0.2 g, 400 ppm dye concentration and 2.0 mM oxalic acid at pH 3.0 within 60 min. The studies reveal that the degradation follows pseudo-first-order kinetics and the catalyst reusability remained constant almost for five cycles. Further, nickel ferrite nanoparticles are proven to be an efficient alternative for the removal of dyes from coloured solutions. © 2020 IWA Publishing.
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    Advancing Carbon Neutrality: Formulation and Microstructural Analysis of Iron Carbonate Binder with Normal and Saline Water
    (Springer Science and Business Media Deutschland GmbH, 2024) M, M.; Jagati, D.P.; Palanisamy, T.
    The Iron carbonate binder emerges as a promising eco-friendly alternative to traditional cement, addressing the substantial carbon footprint of concrete production. Composed of iron dust, a byproduct of the iron industry, alongside limestone, fly ash, and metakaolin, this innovative binder not only utilizes diverse waste materials but also boasts a carbon-negative profile. This experiment investigates the impact of optimizing oxalic acid dosage, curing regimes, and water types on mechanical properties, notably compressive strength, and microstructural characterization. Saline water-treated iron carbonate binder exhibits superior performance, achieving a maximum compressive strength at 0.18 water binder ratio compared to normal water treatment. By minimizing environmental impact and efficiently repurposing industrial waste, the Iron carbonate binder aligns with the imperative to reshape construction practices towards a more sustainable future, embodying a pivotal step in fostering eco-friendly and efficient construction industries globally. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2024.
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    Crafting Sustainability: Optimizing Oxalic Acid in Iron Carbonate Binder Formulation with Waste Iron Powder for a Carbon-Negative Impact
    (Springer Science and Business Media Deutschland GmbH, 2024) M, M.; Chouksey, A.; Palanisamy, T.
    The construction industry, while facing challenges related to pollution and global warming, is largely dependent on cement, intensifying environmental concerns. This study aims to alleviate this impact by diminishing cement reliance in construction, focusing on the development of green concrete through the utilization of alternative, renewable materials. Among these, the Iron Carbonate binder emerges as an innovative solution, blending iron dust, fly ash, lime powder, and metakaolin. To enhance the utilization of iron waste, oxalic acid, a chelating agent, is incorporated into the binding formulation. This binder undergoes a unique strengthening process, relying on carbon dioxide curing followed by ambient curing for moisture removal. The research is dedicated to exploring the mechanical properties of the Iron Carbonate binder, with a specific focus on compressive strength. To optimize its composition, the study evaluates the ideal content of oxalic acid and the water-binder ratio with casting methodology such as wet mix method, specifically considering the method of addition of oxalic acid in conjunction with other raw materials. The casting methodology involves addition of the diluted oxalic acid to a proportionally dry mixed raw material which is then compacted, compressed and ejected mechanically and placed in carbon dioxide environment with immediate demolding followed by defined curing regime. The study is limited to specific water-binder ratio and oxalic acid concentrations based on experimental constraints and challenges. Microstructural characterization is also an important aspect of this research, aiming to understand the behavior of varying dosages of oxalic acid and water-binder ratios concerning strength. By investigating into these mechanical and microstructural intricacies, the study contributes valuable insights towards the sustainable evolution of construction practices, offering an eco-friendly alternative to conventional concrete. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2024.
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    The measurement of electrical conductivity for the investigation of the number of water molecules present in the mixed crystals of barium copper oxalate and barium ammonium oxalate lattice have been carried out in the temperature range 30 to 450 °C. The dehydration temperature and the number of water molecules removed out of the structure at a particular temperature is estimated from the sharp increase in conductivity at these points. The almost steep increase of conductivity is attributed to the increase in the number of mobile charge carriers H+ and OH– ions generated from the escaping water molecules. The study of electrical conductivity in association with the thermal behaviour has been used to understand the mechanism of conduction. Copyright © 1995 WILEY?VCH Verlag GmbH & Co. KGaA
    (Electrical Conductivity and Thermal Dehydration Studies of Mixed Single Crystals of BaCu(C2O4)2 · 6 H2O, Ba1–xCuxC2O4 · 4 H2O and Ba1–2x(NH4)2xC2O4 · 4 H2O) Kasthuri, V.B.; Mohan Rao, P.
    1995
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    Large scale synthesis of carbon nanofibres on sodium chloride support
    (InTech Europe info@sagepub.co.uk, 2012) Rajarao, R.; Badekai Ramachandra, B.R.
    Large scale synthesis of carbon nanofibres (CNFs) on a sodium chloride support has been achieved. CNFs have been synthesized using metal oxalate (Ni, Co and Fe) as catalyst precursors at 680 °C by chemical vapour deposition method. Upon pyrolysis, this catalyst precursors yield catalyst nanoparticles directly. The sodium chloride was used as a catalyst support, it was chosen because of its non-toxic and water soluble nature. Problems, such as the detrimental effect of CNFs, the detrimental effects on the environment and even cost, have been avoided by using a water soluble support. The structure of products was characterized by scanning electron microscopy, transmission electron microscopy and Raman spectroscopy. The purity of the grown products and purified products were determined by the thermal analysis and X-ray diffraction method. Here we report the 7600, 7000 and 6500 wt% yield of CNFs synthesized over nickel, cobalt and iron oxalate. The long, curved and worm shaped CNFs were obtained on Ni, Co and Fe catalysts respectively. The lengthy process of calcination and reduction for the preparation of catalysts is avoided in this method. This synthesis route is simple and economical, hence, it can be used for CNF synthesis in industries. © 2012 Rajarao and Bhat.
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    Morphological analysis and photoluminescence properties of hydrophilic porous anodic alumina formed in oxalic acid
    (Springer New York LLC barbara.b.bertram@gsk.com, 2016) Ramana Reddy, P.R.; Ajith, K.M.; Udayashankar, N.K.
    Porous anodic alumina (PAA) templates were prepared via two-step anodization process in 0.3 M oxalic acid for different anodization durations (2–10 h with a step of 2 h). In this article, we report our studies on the morphological analysis and photoluminescence (PL) properties of hydrophilic PAA templates prepared at 8 and 18 °C. Two-dimensional fast Fourier transform was used to study the regularity ratio of PAA. It was found that for a longer anodization time (6, 8 and 10 h) the better array of pores observed with anodization potential of 40 V. The effect of anodization duration on the structural aspects including pore diameter, interpore distance, porosity and pore density were investigated in detail. It was observed that increase in anodization duration led to an increase in pore diameter and porosity. Contact angle measurement of PAA templates was carried out to confirm the hydrophilic nature. The relationship between morphology of PAA and PL emission bands was studied. The PL spectra of PAA templates show two emission sub-bands, which can be ascribed to two luminescence centers, F+ (band-1) and F (band-2), respectively. © 2016, Springer Science+Business Media New York.
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    Micro and nanoindentation analysis of porous anodic alumina prepared in oxalic and sulphuric acid
    (Elsevier Ltd, 2016) Ramana Reddy, P.R.; Ajith, K.M.; Udayashankar, N.K.
    In this article, the mechanical behavior of porous anodic alumina (PAA) structures obtained from two different electrolytes (oxalic and sulphuric acids) was investigated using micro and nanoindentation techniques. Regularity ratio (RR) of PAA structures was calculated using WSxM software and it was found that strength of the PAA structures varies with the RR of the pores. Micro hardness of the PAA structures was studied using 0.98, 9.8 N loads and it was observed that surface ring cracks were generated for 9.8 N load in oxalic acid. PAA structures formed in sulphuric acid exhibits an extremely high hardness of 7.5 GPa and Young's modulus as 146.5 GPa compared with oxalic acid due to low porosity. Results indicate that the indentation modulus and hardness of the PAA structures decrease with increasing pore size. Further the effect of porosity and regularity ratio of pores on mechanical properties of PAA structures was studied in detail. © 2016 Elsevier Ltd and Techna Group S.r.l.
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    Exploring the fungal protein cadre in the biosynthesis of PbSe quantum dots
    (Elsevier B.V., 2017) Jacob, J.M.; Sharma, S.; Mohan Balakrishnan, R.M.
    While a large number of microbial sources have recently emerged as potent sources for biosynthesis of chalcogenide quantum dots (QDs), studies regarding their biomimetic strategies that initiate QD biosynthesis are scarce. The present study describes several mechanistic aspects of PbSe QD biosynthesis using marine Aspergillus terreus. Scanning electron microscopic (SEM) studies indicated distinctive morphological features such as abrasion and agglomeration on the fungal biomass after the biosynthesis reaction. Further, the biomass subsequent to the heavy metal/metalloid precursor was characterized with spectral signatures typical to primary and secondary stress factors such as thiol compounds and oxalic acid using Fourier Transform Infra-Red Spectroscopic (FTIR) analysis. An increase in the total protein content in the reaction mixture after biosynthesis was another noteworthy observation. Further, metal-phytochelatins were identified as the prominent metal-ion trafficking components in the reaction mixture using Liquid Chromatography Mass Spectroscopic analysis (LCMS). Subsequent assays confirmed the involvement of metal binding peptides namely metallothioneins and other anti-oxidant enzymes that might have played a prominent role in the microbial metal detoxification system for the biosynthesis of PbSe QDs. Based on these findings a possible mechanism for the biosynthesis of PbSe QDs by marine A. terreus has been elucidated. © 2016 Elsevier B.V.
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    Optimization of Fenton’s oxidation of herbicide dicamba in water using response surface methodology
    (Springer Verlag, 2017) Sangami, S.; Manu, B.
    In this study Fenton’s oxidation of dicamba in aqueous medium was investigated by using the response surface methodology. The influence of H2O2/COD (A), H2O2/Fe2+ (B), pH (C) and reaction time (D) as independent variables were studied on two responses (COD and dicamba removal efficiency). The dosage of H2O2 (5.35–17.4 mM) and Fe2+ (0.09–2.13 mM) were varied and optimum percentage removal of dicamba of 84.01% with H2O2 and Fe2+ dosage of 11.38 and 0.33 mM respectively. The whole oxidation process was monitored by high performance liquid chromatography (HPLC) along with liquid chromatography/mass spectrometry (LC/MS). It was found that 82% of dicamba was mineralized to oxalic acid, chloride ion, CO2 and H2O, which was confirmed with COD removal of 81.53%. The regression analysis was performed, in which standard deviation (<4%), coefficient of variation (<8), F value (Fisher’s Test) (>2.74), coefficient of correlation (R2 = Radj2) and adequate precision (>12) were in good agreement with model values. Finally, the treatment process was validated by performing the additional experiments. © 2017, The Author(s).
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    All that Glitters Is Not Gold: A Probe into Photocatalytic Nitrate Reduction Mechanism over Noble Metal Doped and Undoped TiO2
    (American Chemical Society service@acs.org, 2017) Challagulla, S.; Tarafder, K.; Ganesan, R.; Roy, S.
    Photocatalytic reduction of aqueous nitrate has been thoroughly studied over noble metals doped and pristine TiO2 synthesized by a customized single step microwave assisted hydrothermal method. The synthesized catalysts are systematically characterized using XRD, Raman spectroscopy, FE-SEM, HR-TEM, XPS, diffuse reflectance spectroscopy, and PL measurements. The characterization reveals the successful synthesis of highly crystalline doped and undoped nano-TiO2. The photocatalytic rate of aqueous nitrate reduction over undoped TiO2 is found to be higher than that of noble metal doped TiO2. Mechanistic studies of the photocatalytic reduction are carried out with the help of different hole (oxalic acid, and methanol) and electron (sodium persulfate) scavengers, which reveal that the photogenerated electrons are the primary agents toward efficient nitrate photoreduction. Detailed studies have revealed that the noble metal doping in TiO2 helps in efficient photogeneration of H2 compared to the undoped analogue, however, the in situ produced H2 is found to be inefficient in reducing NO3-. The conduction band position from first principle calculations with respect to the nitrate and hydrogen reduction potentials derived from cyclic voltammetry provide insights to the electron transfer process in determining the reaction pathway. © 2017 American Chemical Society.