The kinetics and mechanistic aspects of the oxidation of two beta-lactam antibiotics (A), ampicillin and flucloxacillin, by alkaline hexacyanoferrate(III) (HCF(III)) were examined using spectrophotometry at a fixed temperature. The oxidation reactions showed a 1:4 (A: HCF(III)) stoichiometry. The reaction kinetics were found to follow first-order dependence for the oxidant and fractional first-order dependence for [A] and [OH−]. The enhancement of the ionic strength and dielectric constant was found to increase the oxidation rates. Free radical tests of the reactions showed positive results. The addition of HCF(II) as a predicted oxidation product did not considerably change the oxidation rates. Under the same experimental conditions, the oxidation rate of ampicillin was found to be slightly lower than that of flucloxacillin. The acquired oxidation products were recognized using spot testing and Fourier transform infrared spectra. A conceivable oxidation mechanism was suggested. A derived rate law expression was found to be consistent with the experimental results. The activation parameters were assessed and discussed.

The inhibition impacts of two water-soluble polymers viz., maltodextrin and chitosan on the dissolution of carbon steel in 1.0 M HCl solution were investigated by three dissimilar techniques. The investigation results indicated that the inhibition efficiencies of the examined polymers increased with their concentrations and reduced by raising temperature. The results obtained from polarization measurements proved that the investigated polymers act as mixed type inhibitors. The acquired high inhibition efficiencies of the studied polymers may be owing to powerful adsorption of the polymer molecules on the C-steel surface resulting in the construction of protective layers. Adsorption of the tested polymers on the steel surface was set to accord with Freundlich adsorption isotherm. The inhibition efficiency of chitosan was set to be higher than maltodextrin because of its high molecular mass that increases the surface area of steel covered by the polymer. The acquired thermodynamic parameters for adsorption indicated that the adsorption process is spontaneous and endothermic, and the type of adsorption is physical. The acquired outcomes from the dissimilar measurements were in a good agreement

The inhibitory strength of the two soluble polymer compounds namely, poloxamer (PLX) and pectin (PEC) towards the corrosion of carbon steel in 1.0 M HCl solution was elucidated utilizing four techniques. The inhibition efficacy augments with the concentration of the tested polymer and with reducing temperature. The outcome of the corrosion parameter obtained from all utilized measurements emphasizes the inhibiting vigor of these two compounds. The inhibition was interpreted by the formation of an adsorbing coated layer that isolates the steel surface from aggressive solutions. The adsorption of PLX and PEC on the steel surface follows Freundlich isotherm. The adsorption type is a combination of physical and chemical adsorption. Also, PLX and PEC compounds inhibit the pitting corrosion of Csteel in Clions including the solutions by moving the pitting potential in the positive direction. The inhibition efficacy of PET more than PLX due to higher molar mass of PET resulting in greater surface coverage on C-steel surface. There is a clear harmony on the values of the inhibition efficacy resulting from the different techniques.

The inhibition potentials of expired glibenclamide (Glib) and glimepiride (Glim) as two significant sulfonylurea antibiotic drugs on the corrosion behavior of mild steel in 0.5 M sulfuric acid solution were explored using different chemical and electrochemical ways. As the concentration of the expired drugs increases, the weight loss, corrosion current density and the capacity of double layer decrease while the values of charge transfer resistance, surface coverage and the percentage inhibition efficiency augment, indicating that the inhibitory impact of both expired Glib and Glim. The percentage inhibition efficiency increases with decrease in temperature. The inhibition was interpreted by the spontaneous adsorption of the two expired drugs on the mild steel surface by increasing the number of adsorbed particles that cover the largest area of the metal by constructing a barrier layer between the steel surface and the corrosive acid solution. The adsorption process is subject to Langmuir isotherm. Potentiodynamic polarization data demonstrate that both expired drugs act as mixed inhibitors. The activation and adsorption thermodynamic parameters were evaluated and suggest the physical adsorption of the examined drugs

Purpose: To investigate the kinetics of oxidative removal of two β-lactam antibiotics (A), namely, ampicillin and flucloxacillin. Methods: In this study, permanganate ion (MnO4 - ) was used as an oxidant in an alkaline medium at fixed ionic strength of 0.1 mol dm-3 and a temperature of 298 K utilizing a spectrophotometric technique. The obtained oxidation products were characterized using spot tests and FT-IR spectra. Results: The stoichiometry of the reactions was 1:4 (A : MnO4 - ). The reactions were a first order credence in [MnO4 - ] and fractional-first order kinetics in antibiotic and hydroxyl ion. Influence of ionic strength was successfully explored. Dependence of reaction rates on temperature was studied and the activation parameters were computed and discussed. A plausible mechanism for the oxidation reactions has been elucidated. A consistent rate-law expression was also derived. Conclusion: This study introduces a significant treatment method for antibiotic removal, thus helping to protect the environment and human health.

Degradation kinetics and pathways of the antibiotic penicillin G (Pen) have been examined via oxidation by chromium trioxide (CrVI) in aqueous sulfuric and perchloric acid media. The oxidation reactions were monitored by spectrophotometry at 298 K. In both acidic media, penicillin G oxidation was set to proceed through acid catalysis. The stoichiometry of the reactions designated that 3 moles of Pen required 2 moles of CrVI. The kinetics of Pen oxidation in both acids was of the first order with regard to [CrVI] and less-than unity order with regard to [Pen] and [H+ ] in their variation. The rates of reactions displayed negligible impacts upon altering ionic strengths or dielectric constants of the reaction media. There was no intrusion of free radicals throughout the redox reactions. Addition of low concentrations of Ni2+, Cu2+, and Zn2+ ions enhanced the oxidation rates, while addition of Cr3+ as a described product did not noteworthily alter the rates. Under comparable investigational circumstances, the oxidation rates in HClO4 were almost 2-fold greater than in H2SO4. The oxidation products of penicillin G were identified by spectral analysis and spot tests as phenyl acetic acid, 2-formyl-5,5-dimethyl-thiazolidine-4-carboxlate ion, ammonium ion, and carbon dioxide. Reliance of reaction rates on temperature has been explored, and the activation and thermodynamic parameters were estimated and debated. In view of the noted reactions’ orders and products’ identification, a plausible mechanism for the oxidation reactions was suggested. The derived rate law was set to be in accordance with the acquired results. This study offers an unprecedented simple and low-cost treatment method for removal or degradation of certain pollutants for protecting the environment and human health.

The kinetics and mechanistic aspects of oxidation of two aminoglycoside antibiotics, namely, neomycin and streptomycin by permanganate ion (MnO4 - ) in alkaline solutions were examined spectrophotometrically. The stoichiometry of the reactions between the investigated antibiotics and MnO4 - were set to be 8.0  0.3 mol. The reactions exhibited first order dependence regarding to [MnO4 - ] and less-than unit order dependences with respect to antibiotics and OHconcentrations. Under the same investigational conditions, the rate of oxidation of streptomycin was found to be about seven times more than that of neomycin. The impact of ionic strength of the reactions medium was explored which revealed that as the ionic strength increases the oxidation rates are also increased. Also, the influence of temperature was studied and the activation parameters were calculated and discussed. The plausible reactions mechanism was proposed and the appropriate rate-law expression consisted with the acquired investigational kinetic results was derived.

Keto-acid derivatives of sulfated iota -carrageenan (ICAR) was quantitatively prepared by the oxidation of iota- carrageenan as sulfated macromolecules by potassium permanganate in alkaline medium at pH`s > 12. The diketo-derivative was characterized by formation of 2,4-dinitrophenyl hydrazone and dioxime derivatives when reacting with 2,4- dinitrophenyl haydrazine and hydroxyl amine, respectively. This oxidation product can be used as a dietary fiber and a functional fiber when added to food. In addition, it found that the product has a high affinity for chelation with most of divalent and polyvalent metal ions forming stable coordination biopolymer complexes. The product is characterized by its non-toxicity, low cost and high performance

Two newly synthesized ligands based on 1,3,4-thiadiazolethiosemicarbazone have been isolated by the condensation reaction of 2,3-disubstituted-5-acetyl-1,3,4-thiadiazole derivatives with thiosemicarbazide in acidic medium in addition to their Co(II) chelates. The synthesized cobalt chelates that have been obtained by the reaction of each ligand with cobalt acetate were confrmed to have the formulae [(LM)Co(OAc)(H2O)2]H2O (LM–Co) and [(LN)Co(OAc)(H2O)2]0.5CH3OH (LN– Co); where LM and LN are 1,3,4-thiadiazolethiosemicarbazone ligands with methyl and nitro substituents, respectively. Comparison of the IR spectrum of each ligand with that of its cobalt complex implied that both ligands acted as monobasic tridentate connecting to the cobalt ion through N atoms of both azomethine group and thiadiazole ring and S atom of deprotonated SH group as well. The two complexes have been proved to have octahedral geometrical structures. The synthesized compounds were studied as corrosion inhibitors for carbon steel in molar hydrochloric acid solution using several chemical and electrochemical techniques. The investigational outcomes displayed that the inhibition efciencies of the examined compounds were found to augment as the concentrations of such compounds raised. At comparable inhibitors concentration, the inhibition efciency was a little increased following the order: LM>LM–Co>LN>LN–Co. The acquired high inhibition efciencies of the explored compounds were ascribed to the potent adsorption of the molecules on the steel surface and construction of adherent layers. Such adsorption was found to accord with Langmuir adsorption isotherm. There is a good correlation in the results obtained from the diferent measurements used

The inhibition efficiencies of ampicillin and flucloxacillin expired drugs on mild steel (MS) corrosion in 1.0 M sulfuric acid medium was examined at 20oC using weight loss (WL), and electrochemical potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS) techniques. Examined expired drugs are set to be efficient inhibitors for MS corrosion in sulfuric acid medium. The experimental outcomes of weight loss technique displayed that the inhibition performances of the investigated expired drugs augmented with increasing concentrations of such drugs and reduced by raising the temperature. The observed high inhibition efficiencies of the studied expired drugs may be owing to powerful adsorption of the drug species on MS surface resulting in formation of protective layers. Adsorption of the tested expired drugs on the MS surface was set to accord with Langmuir adsorption isotherm. The assessed thermodynamic parameters supported the mechanism of physical adsorption of the inhibitors.