Ethylenediaminetetraacetic Acid Disodium Salt Research Articles

Batch and Column Extraction of Lead from Al-Doura Oil Refinery Soil

The aim of this research is to investigate the extraction of lead (Pb) from soil of Al-Doura oil refinery in Baghdad/Iraq. Ethylenediaminetetraacetic acid disodium salt (Na2EDTA) and Hydrochloric acid (HCl) solution were used as extractants. Soil washing method was practiced in two ways, batch extraction and column extraction experiments. A set of batch experiments were carried out at different conditions of extractant (Na2EDTA, HCl) concentration, contact time, pH and agitation speed. From the batch experiments, the maximum removal percentages of Pb that have been obtained were 70 % using Na2EDTA (0.1M) at pH 4 , agitation speed 200 and at equilibrium time 4 hours and 65 % using HCl (1M) at pH 1.08 , agitation speed 200 at equilibrium time 5 hours. 
 Column experiments were conducted at different conditions of extractant (Na2EDTA, HCl) concentration, contact time and flow rate. The maximum removal percentages of Pb were 78% using Na2EDTA (0.1M) at pH 4 , flow rate 30 ml/hr and equilibrium time 8 hours and 75% using HCl (1M) at pH 1.08, flow rate 20 ml/hr and equilibrium time 10 hours. 
 The column extraction proved that the extractant volume required to achieve high removal efficiency is less than that of the batch extraction, but requires a longer contact time.
 The experimental data of batch and column extraction were applied in four kinetic models; first order, parabolic diffusion, two constant and Elovich model to find best fit model for extraction system. For batch extraction, the parabolic diffusion and two-constant models gave the best correlation {coefficient of determination (R2)} with experimental data using HCl and Na2EDTA respectively. While for column extraction, Elovich model gave good correlation with experimental data.

Insoluble π‐Conjugated Polyimine as an Organic Adsorbent for Group 10 Metal Ions

AbstractMetal ion adsorbents are indispensable materials for the recovery of noble metal ions in a sustainable society. Herein, we report that poly(isopyrazole‐3,5‐diyl‐trans‐vinylene) (1) effectively adsorbed group 10 metal ions from solution in acetonitrile. Owing to its fully π‐conjugated and rigid structure, polyimine 1 was virtually insoluble in common organic solvents and water, making it advantageous for metal ion adsorption via a solid/liquid interface. Inductively coupled plasma (ICP) analysis showed that ≥90 % of Ni2+, Pd2+, and Pt2+ ions were adsorbed at a concentration of 10 μM (order of ≤2 ppm) after stirring suspensions at room temperature. Metal ion desorption was achieved by treatment with ethylenediaminetetraacetic acid disodium salt (EDTA ⋅ 2Na), and the adsorbent was reused. Theoretical calculations supported that the desolvation energy was an important factor for effective adsorption in acetonitrile.

Modification of Ag8SnS6 Photoanodes with Incorporation of Zn Ions for Photo-Driven Hydrogen Production

In this study, Zn ions were incorporated into Ag8SnS6 thin films on glass and indium–tin–oxide-coated glass substrates using chemical bath deposition. Detailed procedures for the growth of Ag–Zn–Sn–S semiconductor films and their optical, physical and photoelectrochemical performances were investigated. X-ray diffraction patterns of samples revealed that kesterite Ag2ZnSnS4 phase with a certain amount of Ag8SnS6 phase can be obtained using ethylenediaminetetraacetic acid disodium salt and trisodium citrate as the chelating agent couples. Images of field-emission scanning electron microscope showed that plate-like microstructures with some spherical aggregates were observed for the sample at low Zn content. It changed to irregular spherical grains with the [Zn]/[Sn] ratios being higher than 0.95 in samples. The energy band gaps of the samples were in the range of 1.57–2.61 eV, depending on the [Zn]/[Sn] molar ratio in sample. From the Hall measurements, the carrier concentrations and mobilities of samples were in the ranges of 6.57 × 1012–1.76 × 1014 cm−3 and 7.14–39.22 cm2/V·s, respectively. All samples were n-type semiconductors. The maximum photoelectrochemical performance of sample was 1.38 mA/cm2 in aqueous 0.25 M K2SO3 and 0.35 M Na2S solutions.

Synthesis of Ethylenediaminetetraacetic Acid Disodium Salt Functionalized Magnetite/Chitosan Nanospheres for the Highly Efficient Removal of Methylene Blue.

In this paper, novel Ethylenediaminetetraacetic acid disodium salt (EDTA) functionalized magnetite/ chitosan nanospheres (Fe₃O₄/CS-EDTA) are synthesized by combining solvothermal method and chemical modification, and they are further applied as a kind of adsorbent to eliminate dye of methylene blue (MB) from wastewater. The properties as well as structure exhibited by the fabricated adsorbent are characterized through FTIR, XRD, TG and TEM, together with VSM. The impact exerted by sorption parameters (time of contact, initial dye concentration, temperature, etc.) on the adsorptions were evaluated in batch system. These results demonstrated that our magnetic materials held the adsorption capacity for MB of 256 mg g-1 (pH = 11), and the kinetic model of pseudo-second-order and the Langmuir model could make an effective simulation regarding the adsorption kinetics and isotherm, respectively. Besides, the external magnetic field can assist in easily separating dye adsorbed Fe₃O₄/CS-EDTA from solution for regeneration. The removal efficiency of recycled adsorbents remained above 92% in the 5th adsorption/desorption cycle. These superioritiesmake Fe₃O₄/CS-EDTA a high-efficientmultifunctional adsorbent for removing dyes from wastewater.

An Exceptional Broad-Spectrum Nanobiocide for Multimodal and Synergistic Inactivation of Drug-Resistant Bacteria

An Exceptional Broad-Spectrum Nanobiocide for Multimodal and Synergistic Inactivation of Drug-Resistant Bacteria

Amino acid derivative reactivity assay-organic solvent reaction system: A novel alternative test for skin sensitization capable of assessing highly hydrophobic substances.

The amino acid derivative reactivity assay (ADRA) is an in chemico alternative to animal testing that focuses on protein binding. The ADRA is a skin sensitization test that solves problems associated with the direct peptide reactivity assay. However, when utilizing the ADRA to evaluate highly hydrophobic substances with octanol/water partition coefficients (logKow) of >6, the test substances may not dissolve in the reaction solution, which can prevent the accurate assessment of skin sensitization. Therefore, we developed the ADRA-organic solvent (ADRA-OS) reaction system, which is a novel skin sensitization test that enables the assessment of highly hydrophobic substances with a logKow of >6. We discovered that the organic solvent ratio, the triethylamine concentration, and the ethylenediaminetetraacetic acid disodium salt dihydrate concentration participate in reactions with the nucleophile N-(2-(1-naphthyl)acetyl)-l-cysteine (NAC) and sensitizers that are used in ADRA and in stabilizing NAC. Thus, we determined the optimal reaction composition of the ADRA-OS according to L9 (33 ) orthogonal array experiments. Using this test, we assessed 14 types of highly hydrophobic substances. When we compared the results with ADRA, we found that ADRA-OS reaction system has high solubility for highly hydrophobic substances and that it has a high predictive capacity (sensitivity: 63%, specificity: 100%, accuracy: 79%). The implication of the results is that the novel ADRA-OS reaction system should provide a useful method for assessing the skin sensitization of highly hydrophobic substances with a logKow of >6.

Sustainable Biosynthesis of Antioxidants from Koji Rice Fermented with Aspergillus flavus Using Microwave-Assisted Extraction

The present study proposes microwave-assisted extraction as a sustainable technique for the biosynthesis of bioactive compounds from rice fermented with Aspergillus flavus (koji). First, fermentation conditions (i.e., pH from 3–12, five temperatures from 20–40 °C, and four culture-fermentation media viz. wheat, wheat bran, malt and rice) were optimized for producing microbial bioactive compounds. Microwave extraction was performed at 2450 MHz and 500 W for 20, 30, and 40 s with seven solvents (distilled water, ethyl acetate, hexane, ethanol, chloroform, diethyl ether, and methanol). The obtained results revealed that ethyl acetate is the most appropriate solvent for extraction. Effects of this ethyl acetate extract were compared with a commercial synthetic antioxidant. Antioxidant properties were enhanced by preventing the oxidation of the linoleic acid (C18H32O2) with an inhibition rate (antioxidant efficacy) of 73.13%. Notably, the ferrous ion binding ability was marginally lower when compared to the disodium salt of ethylenediaminetetraacetic acid (EDTA). Additionally, the obtained total content of phenolic compounds in the ethyl acetate extract of fermented rice (koji) by Aspergillus flavus was 232.11 mg based on gallic acid/mL. Antioxidant compounds in the ethyl acetate extract of fermented rice showed stability under neutral conditions, as well as at high temperatures reaching 185 °C during 2 h, but were unstable under acidic and alkaline conditions. The results demonstrate the efficacy of novel microwave-assisted extraction technique for accelerating antioxidant production during rice fermentation.

Growth, ultraviolet‐visible, vibrational, photoluminescence and second harmonic generation studies of Amaranth and EDTA co‐doped KDP crystals

KDP (Potassium dihydrogen phosphate) single crystals were grown from Amaranth dye and EDTA (Ethylenediaminetetraacetic acid disodium salt) mixed KDP solutions by the temperature lowering method and Sankaranarayanan-Ramasamy technique. The molar concentration of EDTA in the solutions was 1 mol%. The Amaranth concentrations were 0.001, 0.005, 0.01, 0.03 and 0.05 mol%. The growth of KDP crystals was oriented in type I and type II phase-matching directions which bring maximum second harmonic generation (SHG) efficiency to the crystals. Optical properties of Amaranth and EDTA co-doped KDP crystals (KAE) were investigated by Ultraviolet-Visible (UV-Vis) spectroscopy, FT-Raman spectroscopy, and photoluminescence. SHG efficiency of the crystals was measured by shining 1064 nm Nd:YAG laser directly into them and receiving output signals. The most important result in the study showed that KAE crystals had SHG efficiency of 1.7 and 2.4 times higher than EDTA doped KDP crystal (KE) and pure KDP crystal respectively. Then second-order nonlinear optical coefficients of these crystals were calculated. The simultaneous doping of two organic substances into KDP crystals has further enhanced their nonlinear optical characteristics.

Controlled preparation of micro–nano hierarchical hollow calcium carbonate microspheres by pressurized-CO2 carbonization and their CaCO3:Eu3+ photoluminescence properties

Herein, calcium carbonate hollow microspheres with a micro–nano hierarchical structure were successfully synthesized using disodium salt of ethylenediaminetetraacetic acid (EDTA-2Na) as an additive, by bubbling pressurized carbon dioxide and calcium hydroxide at 120 °C.

A low-temperature hydrothermal synthesis of submicron spherical BaF2.

The sub-micron spherical barium fluoride (BaF2) was successfully synthesized via a low-temperature hydrothermal method using ethylenediamine tetraacetic acid disodium salt (EDTA-2Na) as the chelating agent. The effect of pH, the molar ratio of EDTA to Ba2+, barium hydroxide octahydrate (Ba(OH)2·8H2O) concentration, hydrofluoric acid (HF) concentration, hydrothermal temperature and time, on the formation of spherical BaF2 were investigated. The formation mechanism of spherical BaF2 has been proposed based on the experimental results. The results show that the spherical BaF2, with an average size of 346.9 nm, is formed by the self-assembly of nanocubes. The optimized synthesis conditions are: pH = 14, EDTA-2Na : Ba2+ = 1 : 1, Ba(OH)2 concentration is 0.1 mol L−1, HF concentration is 2.0 mol L−1, hydrothermal temperature is 80 °C and hydrothermal time is 2.0 h. The self-assembly mechanism of the spherical secondary structure was revealed from the perspective of crystal nucleation and growth, and the important role of EDTA in the spherical BaF2 formation is explained.

Ethylenediaminetetraacetic Acid Disodium Salt Acts as an Antifungal Candidate Molecule against Fusarium graminearum by Inhibiting DON Biosynthesis and Chitin Synthase Activity.

Fusarium fungi are the cause of an array of devastating diseases affecting yield losses and accumulating mycotoxins. Fungicides can be exploited against Fusarium and deoxynivalenol (DON) production. However, Fusarium resistance to common chemicals has become a therapeutic challenge worldwide, which indicates that new control agents carrying different mechanisms of action are desperately needed. Here, we found that a nonantibiotic drug, ethylenediaminetetraacetic acid disodium salt (EDTANa2), exhibited various antifungal activities against Fusarium species and DON biosynthesis. The infection of wheat seeding caused by F. graminearum was suppressed over 90% at 4 mM EDTANa2. A similar control effect was observed in field tests. Mycotoxin production assays showed DON production was significantly inhibited, 47% lower than the control, by 0.4 mM EDTANa2. In vitro experiments revealed a timely inhibition of H2O2 production as quickly as 4 h after amending cultures with EDTANa2 and the expression of several TRI genes significantly decreased. Chitin synthases of Fusarium were Mn2+-containing enzymes that were strongly inhibited by Mn2+ deficiency. EDTANa2 inhibited chitin synthesis and destroyed the cell wall and cytomembrane integrity of Fusarium, mainly via the chelation of Mn2+ by EDTANa2, and thus led to Mn deficiency in Fusarium cells. Taken together, these findings uncover the potential of EDTANa2 as a fungicide candidate to manage Fusarium head blight (FHB) and DON in agricultural production.

Electrodialysis enhanced with disodium EDTA as an innovative method for separating Cu(II) ions from zinc salts in wastewater

In recent years, interest in developing methods for hazardous metal recovery from wastewater has grown steadily within the scientific community. This report describes a method based on electrodialysis enhanced with metal-complex formation to separate cupric ions from zinc sulfate present in a model zinc plating bath. The investigated method can be applied for resource (zinc sulfate) recovery, or to reduce the amount of hazardous galvanic wastes. In this work, the disodium salt of ethylenediaminetetraacetic acid (Na2EDTA) is employed as a complexing agent. The effects of the membrane and current density on the separation efficiency are evaluated and discussed. Finally, the optimal conditions for selective removal of Cu(II) ions from a zinc salt bath are identified, and the effectiveness of the examined method is demonstrated in a batch test. It was determined that, by using thick heterogeneous AM(H)-CM(H) ion-exchange membranes an approximately 13-fold reduction in Cu(II) content, relative to Zn(II), can be achieved at high Zn(II) recovery (94.6%) and current density (220 A/m2). The possibility of applying the described method for concentration of zinc salts in the plating bath was also evaluated. It was shown that Zn(II) content can be increased of up to 1.5 times.

EFFECT OF MODIFYING ADDITIVES ON CHEMOSORPTION OF SULFUR (IV) OXIDE BY FIBROUS MATERIAL IMPREGNATED WITH POLYETHYLENEPOLYAMINE

The principal possibility of increasing of the absorption capacity of impregnated fibrous chemisorbents (IFCS) acid gases based on nitrogen-containing organic bases by introducing into impregnating solutions of some additives such as sodium chloride, potassium iodide, ethylenediaminetetraacetic acid disodium salt (EDTA), glycine, sodium and potassium carbonates was investigated. Under static conditions using a vacuum sorption unit with McBen-Bakr quartz spring scales the hydrophilicity of fibrous chemisorbents of acid gases based on polyester synthetic fibers impregnated with polyethylenepolyamine containing as modifiers of potassium, such as potassium modifiers, such as promoters sodium and potassium carbonates, glycine and the disodium salt of ethylenediaminetetraacetic acid was studied. It is shown that the introduction of these additives leads to a sharp increase in the hydrophilicity of the samples, which creates the preconditions for further more efficient chemisorption of sulfur(IV) oxide. Within the framework of the Brunauer-Emmett-Teller theory of polymolecular sorption, water vapor sorption isotherms are analyzed, the values of the monolayer capacity and the values of the sorption heat of water molecules in the first layer are determined. Under static and dynamic conditions, chemisorption of sulfur oxide (IV) by dry and moistened samples of chemisorbents was studied. It is established that the process of SO2 chemisorption can occur only in the presence of «free» water formed after the formation of the monolayer. It is shown that the introduction of hydrophilized additives leads to a significant increase in the absorption capacity of sulfur(IV) oxide in both static and dynamic conditions. The obtained results are planned to use in the development of theoretical bases for the creation of functional sorption filtering materials for respiratory purposes.

Effect of EDTA-2Na modification on Fe-Co/Al2O3 for hydrogenation of carbon dioxide to lower olefins and gasoline

Capturing and utilization of carbon dioxide (CO2) not only leads to effective use of carbon resources, but also alleviates environmental pollution caused by increasing concentration of CO2, thus making it a hot research topic in recent years. In this study, a series of highly dispersed iron-cobalt (Fe-Co) catalysts was prepared by ethylenediaminetetraacetic acid disodium salt (EDTA-2Na) modification, which could efficiently convert CO2 into high value-added chemicals (C2-C4= and C5-C11). X-ray diffraction (XRD) analysis showed that the addition of a small amount of Co and EDTA-2Na contributed to enhance the sintering resistance of Fe species. During the calcination process, EDTA4− can be decomposed into small organic molecules with reducibility, thus promoting the reduction of iron species. The CO temperature-programmed desorption (CO-TPD) results showed that cobalt enhanced the adsorption and activation of intermediate CO on NaxFe-Co catalyst, thereby promoting the catalytic conversion of CO2. The complexation of EDTA promotes the synergistic effect of Fe-Co bimetals, enhances the chemical adsorption of CO2. Sodium in EDTA-2Na promotes the surface basicity of the catalysts, which is favored for improving the product distribution of hydrocarbons. At lower H2/CO2 (1/1) ratio, the EDTA-2Na modified Fe-Co/Al2O3 catalyst exhibited high conversion of CO2 (32.8 %) and excellent selectivity toward high value-added chemicals. The selectivity of by-product CO was only 8.1 %; and C2-C4= (32.5 %) and C5-C11 (46.3 %) accounted for ∼79 % selectivity among the hydrocarbons generated.

Superwettable membrane with hierarchical porosity for simultaneous separation of emulsions and removal of nanoparticles

The burgeoning severity of water pollution calls for new developments in membrane design, particularly those that can separate oil from water while simultaneously removing nanoparticulates. In this study, a poly(vinyl alcohol-co-ethylene) nanofiber membrane possessing a hierarchically porous structure was fabricated. Subsequent modification with ethylenediamine tetraacetic acid disodium salt induced special properties, such as superamphiphilicity in air, superoleophobicity in water and superhydrophobicity in oil. This superwetting property endows the membrane with high oil/water emulsion separation efficiency (> 96 %) while its porous nature also makes it ideal for pigment microfiltration, achieving > 99.8 % separation efficiency. This membrane also displays a stable underoil hydrophobicity, and underwater oleophobicity over a wide pH range. The stable surface property and simultaneous removal efficiency of oil (96 %) and nanoparticles (99.5 %) from water indicate that this novel membrane possesses great potential in water purifying applications.

Pre-protection strategy performed in processable aqueous dispersions of TiS2 nanosheets to fabricate laminar films with improved electric properties

Processable aqueous dispersions of two-dimensional (2D) transition metal dichalcogenides (TMDs) nanosheets show extraordinary promise in assembling laminar films for a variety of applications but are usually limited by the oxidation of adsorbed water molecular on the edge and defect regions, which damage the stability of the colloidal solution and electric properties of the resulted films. In this work, we developed a pre-protection strategy by adding ethylenediaminetetraacetic acid disodium salt (EDTA-2Na) as the protective agent into TiS2 nanosheets aqueous dispersions. The introduction of EDTA-2Na can effectively slow down the adsorption and decomposition of confined water molecules and enhance the oxidation resistance of TiS2 nanosheets in the colloidal solution. Compared with the untreated TiS2 nanosheets, the storage time of the pre-protected nanosheets in aqueous dispersions can be significantly improved, and the electrical conductivity of prepared laminar films as thermoelectric materials also increased from 2.43 × 103 S m−1 to 1.51 × 104 S m−1. Our exploration provides a new concept performed in aqueous solution for the protection of TMDs nanosheets, which can be adopted to fabricate TMDs films with stable electric properties by controlling the assembly process of colloidal chemistry

Enhancement of Cu(II) removal by carbon disulfide modified black wattle tannin gel

Xanthated black wattle tannin gel (XBTG) was prepared by modifying black wattle tannin gel (BTG) with carbon disulfide to improve the performance of Cu(II) removal. Structure characterization demonstrated that xanthate groups were successfully introduced onto BTG and surface morphology of BTG was maintained after CS2-modification. Zeta potential measurement showed that XBTG was negative charged at a pH range from 1 to 5. Compared to the BTG, the thermal stability and the surface area of XBTG decreased, but the Cu(II) adsorption rate and adsorption capacity increased. The adsorption kinetics of BTG and XBTG followed pseudo-second-order model. The adsorption isotherms fitted well with Langmuir model, and the calculated maximum adsorption capacity for the XBTG increased to 149.25 mg/g at 298 K, which was 228.95 % higher than BTG. Moreover, the Cu(II) loaded XBTG could be regenerated using 0.1 M ethylenediaminetetraacetic acid disodium salt solution. The adsorption capacity of the regenerated XBTG after five cycles decreased to 58 % compared with the fresh adsorbent, which was equivalent to that of BTG. The adsorption mechanism was attributed to the surface complexation of Cu(II) by adjacent phenolic hydroxyl groups and xanthate groups or to the ion exchange between Na(I) and Cu(II).

Recycling alginate composites for thermal insulation

We present a new method for the total functional recycling of alginate-based composite materials made via ionotropic gelation. The original material, an alginate/fiberglass foam with thermal insulation characteristics, was produced following a patented process in which fiberglass waste is embedded into the polyanionic gel matrix, and the resulting compound is then freeze-dried. The functional recycling is carried out by disassembling the ionic matrix – which is initially formed by the interaction between a cation (e.g. calcium) and the negatively charged alginate backbone – with the use of a chelator (Ethylenediaminetetraacetic acid disodium salt) with a high affinity for the cations, thus obtaining a homogeneous solution. An ionotropic gel can then be re-formed upon deactivation of the chelating activity under mild acid conditions. We managed to maintain or improve the thermal, mechanical and acoustic performances of the original material and we successfully tested the possibility of multiple recycling cycles.

Potential of TiO2 with Various Au Nanoparticles for Catalyzing Mesotrione Removal from Wastewaters under Sunlight.

Nowadays, great focus is given to the contamination of surface and groundwater because of the extensive usage of pesticides in agriculture. The improvements of commercial catalyst TiO2 activity using different Au nanoparticles were investigated for mesotrione photocatalytic degradation under simulated sunlight. The selected system was 2.43 × 10−3% Au–S–CH2–CH2–OH/TiO2 (0.5 g/L) that was studied by transmission electron microscopy and ultraviolet-visible (UV-Vis) spectroscopy. It was found that TiO2 particles size was ~20 nm and ~50 nm, respectively. The Au nanoparticles were below 10 nm and were well distributed within the framework of TiO2. For 2.43 × 10−3% Au–S–CH2–CH2–OH/TiO2 (0.5 g/L), band gap energy was 2.45 eV. In comparison to the pure TiO2, addition of Au nanoparticles generally enhanced photocatalytic removal of mesotrione. By examining the degree of mineralization, it was found that 2.43 × 10−3% Au–S–CH2–CH2–OH/TiO2 (0.5 g/L) system was the most efficient for the removal of the mesotrione and intermediates. The effect of tert-butanol, NaF and ethylenediaminetetraacetic acid disodium salt on the transformation rate suggested that the relative contribution of various reactive species changed in following order: h+ > ●OHads > ●OHbulk. Finally, several intermediates that were formed during the photocatalytic treatment of mesotrione were identified.

Recovery of iodide as triiodide from thin-film transistor liquid crystal display wastewater by forward osmosis

Triiodide, a larger charged molecule compared to iodide, is thermodynamically favored with the presence of both iodide and iodine, and is easier to be retained by membrane processes. For the first time, iodide was recovered in the form of triiodide by forward osmosis (FO) for thin-film transistor liquid crystal display industries by preoxidation of iodide to triiodide. Partial oxidation by NaOCl was used to convert the iodide to iodine and then to form triiodide. Ethylenediaminetetraacetic acid disodium salt (EDTA-2Na), a commonly used chelating agent in the industry, was used as the draw solute because of its low reverse salt flux. The results revealed that the ideal efficiency of iodide recovery was at pH 3 with a preoxidation (adding 0.0150 M NaClO) for the 0.048 M iodide wastewater with a recovery of 98.5%. Additionally, the Pourbaix diagram and starch indicator were used to verify the formation of triiodide. Membrane distillation was demonstrated to recover the EDTA-2Na draw solute, and more than 99% of recoveries for the draw solutes with initial water flux of 12.0 L/m2 h were achieved, indicating that simultaneous recovery of the EDTA-2Na draw solute and water is feasible.