Ethylenediaminetetraacetic Disodium Research Articles

Fabrication of mango-leaf biowaste mediated green magnetite (Fe3O4@MBE NPs) and modified EDTA/Fe3O4@MBE NCs for enhanced heavy metals sequestration: Characterisation, simulation modelling, mechanism, cost-effectiveness and electroplating wastewater performance

This work reports biogenic green fabricated novel magnetite nanoparticles (Fe3O4@MBE NPs) coated with mango-leaf biowaste extract and modified disodium ethylenediamine tetra-acetate (EDTA) functionalised nanocomposite (EDTA/Fe3O4@MBE NCs). Several approaches were used to characterise them, and their applicability as nanoadsorbents was exhaustively investigated in batch mode sequestration of Cd(II), Ni(II), and Zn(II) from synthetic solutions. The Brunauer Emmett and Teller’s surface areas of Fe3O4@MBE and EDTA/Fe3O4@MBE was determined to be 47.73 and 43.95 m2/g, respectively, with average porous diameters of 10.36 and 7.44 nm, revealing mesoporosity. EDTA/Fe3O4@MBE NCs exhibit soft ferromagnetism with a saturation magnetisation of 40.67 emu/g. Further, EDTA modification creates carboxyl and amino sites, improving adsorption performance. Adsorption was pH dependent, with optimal sequestration at 40 mg/L divalent metal ions, 0.5 g/L nanoadsorbent dosage, and 75 min of reaction duration at 27 °C. Among the simulation models employed, the Langmuir isotherm, pseudo second order kinetic, and Elovich kinetic were the best fitted and offered the highest capability to explain the adsorption process. The Langmuir monolayer adsorption capacity (qmax) of 147.06, 129.87, and 117.65 mg/g for Cd(II), Ni(II), and Zn(II) by EDTA/Fe3O4@MBE, respectively, were significantly higher than Fe3O4@MBE (120.48, 102.04, and 95.24 mg/g). The best-suited kinetics precisely describe chemisorption as the primary rate-limiting phase in divalent metal ions adsorption. Thermodynamics approved the endothermic nature and feasibility of divalent metals adsorption, with modest improvement in efficacy at higher temperatures. The ability of EDTA/Fe3O4@MBE to form stable surface complexes with divalent metals enhances adsorption even in the presence of other co-existing ionic species. EDTA/Fe3O4@MBE NCs magnetic separability, improved sequestration upto five recycles, and regenerability of ≥89.07 % demonstrate its cost-effectiveness in heavy metals sequestration. Finally, practicality study confirmed that EDTA/Fe3O4@MBE nanoadsorbent provides a practical and economically efficient option for heavy metals sequestration from electroplating wastewater; thus, it contributed towards UN-2030, SDG No-6.

Hemp (Cannabis sativa L.) Tolerates Chelator Stress Showing Varietal Differences and Concentration Dependence

The world’s arable land has been contaminated by heavy metals to a large extent, which has led to the decreasing availability of farmland. Thus, the remediation of heavy metal pollution deserves due attention, and phytoremediation is preferred. Hemp has been proposed as an ideal alternative crop for remediating heavy-metal-contaminated soil, owing to its well-developed roots, large biomass, and tolerance to heavy metals. Chelators can activate heavy metals to enhance plant absorption, but they may cause stress to plant growth. Therefore, it is very important to optimize the combination of chelator and plant (cultivar) for efficacious phytoremediation. The effects of different concentrations (2, 5, 10, 15, and 25 mmol·L−1) of the chelators disodium ethylene diamine tetra-acetate (EDTA) and citric acid (CA) on the seed germination and plant growth of hemp cultivars were investigated. Triple application of increasing concentrations of EDTA or CA two days apart gradually reduced the germination potential, germination rate, radicle length, and embryonic shoot length of hemp seed, although 2 mmol·L−1 of CA could even promote seed germination. Distinct varietal differences were found in the response of hemp to chelator stress. Under the scheme of four-time uses one week apart, both chelators caused a concentration-dependent linear decrease in the plant height, stem diameter, and biomass of hemp plants, but the growth inhibition due to CA was relatively milder. This could be partially explained by the change in tested physiological indices in hemp leaf. In conclusion, 2 mmol·L−1 of CA helped with seed germination and was almost nontoxic to plant growth; cultivar BM was more tolerant to the chelators than cultivar Y1.

Uji Kadar Zat Besi (Fe) Sediaan Obat Tablet Tambah Darah (Ferro Fumarat) dengan Metode Kompleksometri

Iron is a very important element to form hemoglobin (Hb). Blood supplement tablets which are often consumed in the process of g iron are ferro fumarate. The aims is determine the levels of iron (Fe) contained in blood supplement drugs (ferro fumarate). This type of research was a laboratory experiment using the complexometric method and a complex forming substance, namely disodium ethylene diamine tetra acetate (Na2EDTA). A sample of blood supplement tablets (ferro fumarate) which was prepared in 10 tablets was made into powder and then 150 mg was taken and titrated with Na2EDTA as the titrant and using the Erichrome Black T (EBT) indicator resulting in a purple titration end point turning blue. The results showed that the level of iron (Fe) in the blood supplement sample (ferro fumarate) was 200%.

Uji Kadar Zat Besi (Fe) Dalam Sediaan Obat Tambah Darah (Ferro Fumarat) Dengan Metode Kompleksometri

Iron is a very important element to form hemoglobin (Hb). Blood supplement tablets which are often consumed in the process of adding iron are ferro fumarate, so this study aims to determine the levels of iron (Fe) contained in blood supplement drugs (ferro fumarate). This type of research was a laboratory experiment using the complexometric method and a complex forming substance, namely disodium ethylene diamine tetra acetate (Na2EDTA). A sample of blood supplement tablets (ferro fumarate) which was prepared in 10 tablets was made into powder and then 150 mg was taken and titrated with Na2EDTA as the titrant and using the Erichrome Black T (EBT) indicator resulting in a purple titration end point turning blue. The results showed that the level of iron (Fe) in the blood supplement sample (ferro fumarate) was 200%.

Mechanism and controlling factors on rapid methylmercury degradation by ligand-enhanced Fenton-like reaction at circumneutral pH

Methylmercury (MeHg), derived from industrial processes and microbial methylation, is still a worldwide environmental concern. A rapid and efficient strategy is necessary for MeHg degradation in waste and environmental waters. Here, we provide a new method with ligand-enhanced Fenton-like reaction to rapidly degrade MeHg under neutral pH. Three common chelating ligands were selected (nitriloacetic acid (NTA), citrate, and ethylenediaminetetraacetic disodium (EDTA)) to promote the Fenton-like reaction and degradation of MeHg. Results showed that MeHg can be rapidly degraded, with the following efficiency sequence: EDTA > NTA > citrate. Scavenger addition demonstrated that hydroxyl radical (▪OH), superoxide radical (O2▪–), and ferryl (FeⅣO2+) were involved in MeHg degradation, and their relative contributions highly depended on ligand type. Degradation product and total Hg analysis suggested that Hg(Ⅱ) and Hg0 were generated with the demethylation of MeHg. Further, environmental factors, including initial pH, organic complexation (natural organic matter and cysteine), and inorganic ions (chloride and bicarbonate) on MeHg degradation, were investigated in NTA-enhanced system. Finally, rapid MeHg degradation was validated for MeHg-spiked waste and environmental waters. This study provided a simple and efficient strategy for MeHg remediation in contaminated waters, which is also helpful for understanding its degradation in the natural environment.

A facile complexing chemical reduction for the preparation of Sn/graphene nanocomposites and their high performance for lithium-ion batteries

The pursuit of simpler and more efficient methods for the preparation of high-performing lithium-storage materials is always considered to be an important job for researchers interested in lithium-ion batteries. Herein, a facile complexing chemical reduction strategy is successfully developed for the preparation of newly advanced Sn/graphene (Sn/G) nanocomposite as anode material LIBs. The complexing reagent of ethylenediamine tetraacetate disodium (EDTA-2Na) and reducing agent of NaBH4 added in the preparation process are both found to play pivotal roles in the controllable reduction of Sn2+ and formation of highly conductive graphene matrix. The Sn/G nanocomposite exhibits a loosely stacked structure with ultrafine Sn nanoparticles (20–40 nm) uniformly dispersing on graphene nanosheets. This specially designed morphology is proved to be beneficial for electrolyte infiltrating and highly efficient transport of Li-ions. The Sn/G nanocomposite displays outstanding lithium storage up to 1032 mAh g−1 after 150 cycles and a high rate performance of 535 mAh g−1 at 1 A g−1. The highly conductive and flexible network of graphene effectively alleviates the small absolute volume expansion of ultrafine Sn nanoparticles and maintains the structure stability. In addition, a fair low-temperature performance of 322 mAh g−1 at − 20 °C was also achieved due to the excellent structural features of the Sn/G nanocomposite. The work has managed to provide a simple and reliable method for the synthesis of Sn/C material as well as a potential candidate for low-temperature lithium storage applications.

Effect of polyacid on crude oil emulsifying properties of amphiphilic polymer supramolecular system

Amphiphilic polymers can emulsify with crude oil to form and stabilize oil in water emulsion due to existence of hydrophobic groups, so as to improve the dispersion effect of crude oil. Supramolecular system is constructed by electrostatic interaction between amphiphilic polymer and polybasic acid, which may affect the interaction between hydrophobic groups and crude oil. Whether stable emulsion can be formed, and effect of polybasic acid structure on the stability of crude oil emulsion needs to be further studied. The effect of polybasic acid on the stability of the emulsion was studied by bottle test and stability analyzer. Furthermore, particle size analysis, interfacial tension analysis, interfacial rheological analysis, dynamic rheological characteristics analysis and visual rheology test were used to study the emulsification law of supramolecular crude oil and the action mechanism of stable emulsion. The results show that emulsion stability of different amphiphilic polymer supramolecular systems is mainly affected by interfacial tension, external phase structure strength and droplet migration rate. The higher the external phase viscosity, the smaller the interfacial tension and droplet size, the more conducive to the stability of the emulsion. From high to low, the order of stability of supramolecular system emulsion with different polybasic acids is citric acid > heptanedioic acid > disodium ethylenediamine tetraacetate > sodium polyacrylate. After the supramolecular system is constructed by electrostatic interaction between amphiphilic polymer and polyacid, the system has considerable crude oil dispersion characteristics and oil in water emulsion was easily formed, which laid a foundation for its application in enhanced oil recovery.

Carboxylated chitosan modified alkalization of 2D MXene Ti3C2 and its Cr(VI) removal performance in aqueous solution

In this work, a novel adsorbent for the removal of hexavalent chromium (Cr(VI)) in aqueous solution was successfully prepared by altering the 2D Ti3C2/chitosan composite with disodium ethylenediaminetetraacetate (EDTA·2Na) agent. The successful surface loading of chitosan on Ti3C2 was demonstrated by various characterization methods, including scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FT-IR). The adsorption of Cr(VI) by Ti3C2-based composite under various circumstances was evaluated using batch adsorption experiments. The adsorption performance of the optimal sample for Cr(VI) was investigated in detail through different influencing factors, and the adsorption process was analyzed by adsorption kinetics and isotherm model. In addition, XPS analysis of adsorbents before and after adsorption showed that some Cr(VI) was reduced to Cr(III) during the whole process, which was conducive to reducing the biological toxicity of Cr(VI). The mechanism analysis showed that the adsorption was mainly electrostatic physical adsorption, supplemented by chemical reduction adsorption. Finally, through the regeneration cycle experiment, it was found that the adsorption rate of Cr(VI) remained above 80% after six repeated adsorptions, indicating that the composite material had good stability and might have certain practical application value in the treatment of Cr(VI)-containing wastewater.

Flocculation performance and evaluation of a sulfur-containing tannin flocculant for Cu2+ removal

To introduce sulfur compounds into tannin-based flocculants, thiosemicarbazide (TC) was selected as a raw material to react with black wattle bark tannin and formaldehyde through the Mannich reaction in order to synthesize a sulfur-containing tannin flocculant (TFA) with the functions of chelation, flocculation and precipitation. The physicochemical characteristics of TFA were characterized by elemental analysis (EA), Fourier transform infrared spectroscopy (FT-IR), 13C solid-state nuclear magnetic resonance (13C NMR) and zeta potential to identify the successful synthesis. The flocculation performance of TFA was evaluated by measuring the Cu2+ removal rate. The effects of pH, initial Cu2+ concentration, TFA dosage, coexisting inorganic compounds and organic complexing agents on the Cu2+ removal rate were investigated through flocculation experiments. The results showed that the Cu2+ removal rate increased with increasing pH and the maximum Cu2+ removal rate for 5, 10 and 25 mg/L initial Cu2+ reached 100 % by raising the TFA dosage. Coexisting inorganic compounds, such as KCl, NaCl, CaCl2, MgCl2, NaNO3, and Na2SO4, had a negligible impact on Cu2+ removal, while the presence of organic complexing agents (humic acid, disodium ethylenediamine tetraacetate, citric acid and aminoacetic acid) had a significant influence on Cu2+ removal. The flocculation mechanisms of Cu2+ by TFA mainly involved a combination of bridge-aggregation and chelating precipitation, accompanied by a sweeping effect.

Synthesis and Photocatalytic Activity of Pt-Deposited TiO2 Nanotubes (TNT) for Rhodamine B Degradation.

Dye wastewater has attracted more and more attention because of its high environmental risk. In this study, a novel TiO2 nanotube (TNT) catalyst was prepared and its morphology and structure were characterized. The synthetic catalyst was used to degrade Rhodamine B (RhB) under UV light and evaluated for the application performance. According to the characterization results and degradation properties, the optimum synthetic conditions were selected as 400°C calcination temperature and 10 wt% Pt deposition. As a result, the degradation efficacies were sequenced as TNT-400-Pt > TNT-500-Pt > TNT-400 > TNT-300-Pt. In addition, the effect of pH and initial concentration of RhB were explored, and their values were both increased with the decreased degradation efficacy. While the moderate volume of 11 mm of H2O2 addition owned better performance than that of 0, 6, and 15 mm. Scavengers such as tertbutanol (t-BuOH), disodium ethylenediaminetetraacetate (EDTA-Na2), and nitroblue tetrazolium (NBT) were added during the catalytic process and it proved that superoxide radical anions , photogenerated hole (h+) and hydroxyl radical (OH•) were the main active species contributing for RhB removal. For the application, TNT-Pt could deal with almost 100% RhB, Orange G (OG), Methylene blue (MB), and Congo red (CR) within 70 min and still kept more than 50% RhB removal in the fifth recycling use. Therefore, TNT-Pt synthesized in this study is potential to be applied to the dye wastewater treatment.

Monoclinic Bimetallic Prussian Blue Analog Cathode with High Capacity and Long Life for Advanced Sodium Storage.

Prussian blue analogs (PBAs) are regarded as promising cathode materials for sodium-ion batteries (SIBs), but most of them suffer from an incompatibility between capacity and structural stability. Herein, an innovative disodium ethylenediaminetetraacetate (Na2EDTA)-assisted hydrothermal method is proposed to synthesize monoclinic Fe-substituted Ni-rich PBA (H-PBA) cathodes for Na-ion storage. The as-designed H-PBA cathode combines the merits of the low strain of a Ni-based PBA framework and the enhanced capacity of N-Fe3+/Fe2+ redox sites. It can achieve superior sodium-storage performance in terms of capacity, rate capability, and cycle stability. Moreover, ex situ measurements reveal that solid solution (2.0-3.0 V) and phase-transition (3.0-4.0 V) reactions occur during the charge/discharge process to allow almost 1.5 Na+ storage in the H-PBA lattice. Meanwhile, the H-PBA//NaTi2(PO4)3@C full cell also delivers remarkable electrochemical properties. Prospectively, this work would promote the practical application of SIBs in grid-scale electric energy storage.

Effect of some hydroxyl additives on the growth and optical properties of KDP crystals

Potassium dihydrogen phosphate (KDP) single crystal was doped with disodium tetraborate decahydrate (or borax), L-alanine, and disodium ethylenediaminetetraacetate (or disodium EDTA) with 0.05 mol%, 9 mol%, and 2 mol% concentration in the aqueous solution, respectively. These crystals were fabricated by the temperature reduction method incorporating the Sankaranarayanan-Ramasamy technique and were grown onto seed crystals that were inclined at the type I phase-matching angle to the vertical. Each doped KDP single crystal rod was cut into three parts: the bottom, the middle, and the top, which were related to the fabrication temperature range of 50–40 °C, 40–30 °C, and 30–20 °C, respectively. The effect of the additives on the growth and optical properties of KDP crystals was evaluated through Ultraviolet–Visible spectroscopy, Raman spectroscopy, X-Ray Diffraction analysis, Energy-Dispersive X-ray spectroscopy, and Second Harmonic Generation measurement. The hydroxyl impurities have improved the optical properties of KDP crystals by contributing more hydrogen bonds to the KDP lattice. The doped KDP crystals increased SHG efficiency by 1.19 to 2.36 times compared with pure KDP crystals.

Micro-/mesoporous copper-containing zeolite Y applied in NH3-SCR, DeNO

Zeolite Y was prepared by a dense-gel method and subsequently modified either by treatment with diethylamine (DEA), sodium hydroxide (NaOH) or disodium ethylenediaminetetraacetate (Na 2 H 2 EDTA), or by sequential treatment (H 4 EDTA-NaOH or H 4 EDTA-NaOH-Na 2 H 2 EDTA). Individual treatment did not succeed in introducing mesoporosity in the parent zeolite Y, while the sequential treatment lead to formation of mesopores. After introduction of Cu 2+ ions, the obtained materials were studied as catalysts for the selective catalytic reduction of NO x by NH 3 (NH 3 -SCR, DeNO x ). The catalytic investigations reveal a similar NO conversion for all Cu-containing catalysts up to 450 °C, independent of the introduced mesoporosity. Insights into the dynamics of NH 3 -SCR intermediates through rapid scan FT-IR show that for Cu–Y, the rate-determining step is the formation of the mixed [Cu(O − )(NH 3 ) n -1 (NO)] 2+ complexes, which initiate the NH 3 -SCR reaction. • Formation of mesopores in zeolite Y by sequential treatment. • NO conversion for Cu–Y independent of the introduced mesoporosity. • Formation of the mixed [Cu(O − )(NH 3 ) n -1 (NO)] 2+ complexes, initiating NH 3 -SCR.

Nickel recovery from precipitate of NCA lithium-ion battery leach liquor by using disodium ethylene diamine tetraacetate

The nickel cobalt aluminium oxides (NCA) type Li-ion battery is a type of battery currently used in electric vehicles. The UGM battery team has recycled this type of battery to obtain high purity lithium metal. Aside from lithium, the NCA battery contains high-value metals, nickel is one of them. This experiment aims to test the ease of nickel to chelate with disodium ethylene diamine tetraacetate (EDTA). The experiment was carried out by means of a triple neck flask for 4 hours. The samples were taken at certain minutes and then fitted using a pseudo homogeneous first-order reaction equation. The chelate formed was further processed through multilevel precipitation or electrodialysis to separate nickel. Based on the experiment, nickel formed chelates optimally at 60°C using 0.086 M EDTA with the reaction constant for nickel being 1.4819 min−1. The Arrhenius constant and activation energy for nickel were 3.48×1011min−1 and 76,907 J/mole, respectively.

Multi-stimuli responsive fluorescence of amphiphilic AIEgen copolymers for ultrafast, highly sensitive and selective copper ion detection in water

Novel multi-stimuli responsive fluorescence sensors based on amphiphilic copolymers containing hydrophilic N-isopropylmethacrylamide (NIPAM) and AIEgenic tetraphenylethylene-dipicolylamine (TPEDPA) monomers attached to side-chains of copolymers are synthesized. Two copolymers poly(NIPAM)x-co-(TPEDPA)y prepared by free radical polymerization with different molar ratios of monomers NIPAM and TPEDPA (i.e., x:y = 60:1 and 175:1 for P1 and P2, respectively) show good solubilities in organic solvents and water, which exhibit strong cyan fluorescence at 466 nm in aggregation and solid states due to AIE behaviors of TPE units. Upon various external stimuli (temperatures and acid/base conditions), P1 and P2 possess excellent reversible thermo- and pH-responsive fluorescence turn-off/on cyan emissions of TPE units. In addition, with DPA receptor, P1 and P2 are applied as ultrafast, selective and sensitive fluorescence probes for copper ion detection in water based on the TPE fluorescence quenching via photoinduced electron transfer (PET) phenomena, which can be recovered by the addition of disodium ethylenediaminetetraacetate solution. Owing to good water solubilities, amphiphilic copolymers P1 and P2 (containing only 1.6 and 0.6 % molar ratios of AIEgen) exhibit significant sensing towards Cu2+ with very prominent limit of detection values (LOD = 57 and 72 nM, respectively), which are much better than that of hydrophobic monomer TPEDPA (590 nM). Moreover, the fluorescence quenching of TPE units due to PET phenomena is further confirmed by theoretical calculations. Additionally, as an excellent quenching fluorescence sensor with good biocompatibility of P1, its recognition of copper ion and bio-imaging applications in living cells are also reported in this research.

Content determination of phenolic acids in fresh Salvia miltiorrhiza and effect of polyphenol oxidase on content

There is no consensus on the content, accumulation, transformation and content determination methods of phenolic acids in fresh Salvia miltiorrhiza. In order to find out the true content of phenolic acids in fresh S. miltiorrhiza, a variety of treatment me-thods were used in this study to prepare sample solution. The content changes of phenolic acids in S. miltiorrhiza samples with different dehydration rates were investigated during drying and shade drying processes. Polyphenol oxidase(PPO) of S. miltiorrhiza was extracted and purified by ammonium sulfate precipitation and dialysis to investigate the enzymatic properties. The content of rosmarinic acid, lithosperic acid and S. nolic acid B in S. miltiorrhiza was determined by UPLC. The results showed that the content of phenolic acids in fresh S. miltiorrhiza was highest when it was homogenized with 1 mol·L~(-1) HCl solution or 1 mol·L~(-1) HCl methanol solution. There was no significant difference in the content of phenolic acids in S. miltiorrhiza with different dehydration rates, indicating that there was no correlation between phenolic acid content and dehydration rate. The optimum pH of S. miltiorrhiza PPO was 7.6 and the optimum temperature was 40 ℃. With catechol as substrate, S. miltiorrhiza PPO had the enzymatic browning reaction which was in compliance with Michaelis equation, with Michaelis constant K_m of 0.12 mol·L~(-1) and V_(max) of 588.23 U·min~(-1). The inhibitory effect of citric acid, disodium ethylenediamine tetraacetate, ascorbic acid and sodium sulfite on S. miltiorrhiza PPO increased with the increase of inhibitor concentration, and sodium sulfite showed the strongest inhibitory effect. The present study proved that there were a large number of phenolic acids in fresh S. miltiorrhiza, which were the secondary metabolite of primitive accumulation during the growth of S. miltiorrhiza, rather than the induced product of postharvest drying and dehydration stress. This study has reference value and significance for the cultivation, harvest and processing of S. miltiorrhiza.

Corrosion mitigation performance of disodium EDTA functionalized chitosan biomacromolecule - Experimental and theoretical approach

Disodium ethylenediaminetetraacetate salt is known for its excellent coordinating properties with the metal ions. The present study deals with the investigation of the prepared Disodium EDTA functionalized chitosan in corrosion inhibition for mild steel in 1 M HCl. The modified chitosan was characterized by spectral studies, thermal analysis, and Zeta potential studies. The corrosion inhibition efficiency (%) was evaluated using the gravimetric method and electrochemical studies. The electrochemical studies included potentiodynamic polarization, linear polarization resistance, and electrochemical impedance methods. The modified chitosan polymer showed an inhibition efficiency of 96.63% for 500 ppm at 303 K. Adsorption process obeyed Langmuir isotherm. Experimental results and theoretical calculations endorsed initial physisorption followed by a chemisorption process. Surface characterization studies supported the formation of a protective film that enabled the inhibition process. Density functional theory, Monte Carlo studies, and molecular dynamics simulation studies show a good agreement with the experimental results. Two-way Analysis of Variance was performed to test the influence of immersion period and inhibitor concentration on the corrosion rate using the statistical software IBM SPSS 20.0. A quartic model was generated as the best fit with the highest R2 value of 0.973. Design Expert software was employed for statistical modeling fit.

Further studies of photodegradation and photocatalytic hydrogen production over Nafion-coated Pt/P25 sensitized by rhodamine B

TiO2 is an excellent photocatalyst in photodegradation and hydrogen production. Herein, through simple modification of Pt/TiO2 (P25) by Nafion (Nf), photocatalyst Nf/Pt/P25 was prepared and characterized. Photodegradation of rhodamine B (RhB) and photocatalytic hydrogen production over the Nf/Pt/P25 were investigated and compared with those of Nf/P25, P25 and Pt/P25. The results showed the Nf coating caused remarkable improvements in RhB degradation and hydrogen production with RhB as sensitizer. Especially, for the first time, the influence of sacrificial reagent (SR) on hydrogen production performance was studied in detail and the results indicated replacing disodium ethylene-diamine tetraacetate (EDTA) used in literature with triethanolamine (TEOA) leads to a significant enhancement in activity. The H2-evolving rate of RhB-Nf/Pt/P25-TEOA system is up to 12 times that of RhB-Nf/Pt/P25-EDTA. Besides, other H2 evolution parameters were optimized and cycling H2 evolution tests over the Nf/Pt/P25 were conducted. The results confirmed that concurrent H2 evolution and RhB degradation can be achieved even with very few RhB. Finally, reasons for the enhanced H2 production performance were proposed. It addressed the importance of selecting a suitable SR and will be very helpful for further work on photocatalytic hydrogen production and photodegradation.

Disorders on cardiovascular parameters in rats and in human blood cells caused by Lachesis acrochorda snake venom

In Colombia, Lachesis acrochorda causes 2–3% of all snake envenomations. The accidents promote a high mortality rate (90%) due to blood and cardiovascular complications. Here, the effects of the snake venom of L. acrochorda (SVLa) were analyzed on human blood cells and on cardiovascular parameters of rats. SVLa induced blood coagulation, as measured by the prothrombin time test, but did not reduce the cell viability of neutrophils and platelets evaluated by the 3-(4,5-dimethylthiazol-2yl)-2,5-diphenyl tetrazolium bromide (MTT) reduction assay and by the lactate dehydrogenase (LDH) enzyme assay. In fact, SVLa increased the absorbance in tests made with platelets subjected to the MTT assay. SVLa induced platelet aggregation whose magnitude was comparable to that of the positive control adenosine diphosphate (ADP), and occurred earlier with increasing SVLa concentration. Acetylsalicylic acid (ASA, a cyclooxygenase inhibitor) or clopidogrel (an ADP receptor blocker) inhibited the aggregating effect of SVLa. Inhibition of SVLa-elicited platelet aggregation also resulted from the treatment with disodium ethylenediaminetetraacetate (Na2-EDTA; metalloproteinase inhibitor) and with 4-(2-aminoethyl) benzenesulfonyl fluoride hydrochloride (AEBSF, serine protease inhibitor). In isolated right atrium of rats, SVLa increased slightly, but significantly, the magnitude of the spontaneous contractions and, in isolated rat aorta, SVLa relaxed KCl- or phenylephrine-induced contractions. In vivo, SVLa induced hypotension and bradycardia in rats, with detection of hemorrhage in pulmonary and renal tissues. Altogether, under experimental conditions, SVLa induced blood coagulation, platelet aggregation, hypotension and bradycardia. Part of the effects presented here may be explained by the presence of snake venom metalloproteinases (SVMPs) and snake venom serine proteases (SVSPs), constituents of SVLa.

Calcium disodium ethylenediaminetetraacetate as a safe compound for crop protection with the potential to extend the basic substances group

Excessive use of commercial synthetic fungicides in agriculture is a globally discussed issue. This topic is seen as particularly important in modern plant protection and cultivation systems, where the total fungicide burden of the agroecosystem should be controlled and reduced. Basic substances (BSs) are a relatively novel, legally recognised group of substances which can be applied. The present study tested calcium disodium ethylenediaminetetraacetate (CaNa<sub>2</sub>-EDTA), a substance whose properties and environmental safety make it another useful alternative for plant protection in modern farming. The study demonstrated the high antifungal activity of the substance against Pyrenophora (anamorph: Drechslera) tritici-repentis (Died.) Drechsler, (MIC50 0.195–0.223 mg/ml), safety for plant tissue and especially for non-target organisms, and positive effects on the yield of wheat (Triticum aestivum Linnaeus). CaNa<sub>2</sub>-EDTA surpassed the effect of chitosan hydrochloride, a registered and utilised substance, and a synthetic conventional fungicide. CaNa<sub>2</sub>-EDTA is an excellent candidate for registering within the BS group, with benefits for environmentally sound systems in plant protection.