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We report the synthesis of novel [4-(3-amino-4-mehoxy-5-methyl phenyl)-1-oxo-1H-phthalaz-2-yl] acetic acid hydrazide (APPH), followed by its characterization using X-ray diffraction (XRD), Fourier transforms infrared (FT-IR) spectroscopy, 1H-NMR spectroscopy, and LC/MS. Further, the inhibition effect of the varying concentration of APPH on the corrosion of low steel (LCS) in 0.5 M H2SO4 was investigated by weight loss and electrochemical measurements at 30 °C. The percentage inhibition efficacy of APPH increased with concentration and reached about 84% at 0.5 mM at 30 °C, also rising to 88% after 6 h of exposure. According to the polarization measurements, the investigated APPH works as a mixed-type inhibitor. Furthermore, the synergistic corrosion inhibition mechanism APPH showed that the inhibition efficiency maximizes with increasing inhibitor concentration, and the maximum value was 83% at 0.5 mM APPH. The adsorption of APPH on the LCS surface is more fitting to the Langmuir isotherm model. The free energy value (–ΔG° ads) was 33.3 kJ mol−1. Quantum chemical calculation was applied to APPH and acted as excellent support for the experimental data. [ABSTRACT FROM AUTHOR]

In this study, new biochar was produced from watermelon peel residues by dehydration process. The ability of the newly generated biochar-S to remove Cu2+ ions from aqueous solutions was examined. Watermelon peel was used to make biochar-S, which was made by dehydrating by boiling with 50% sulfuric acid. Scanning electron microscopy, Brunauer-Emmett-Teller, Fourier-transform infrared spectroscopy, Barrett-Joyner-Halenda, differential scanning calorimetry, thermal gravimetric analysis and energy-dispersive X-ray analysis studies were used to characterize the biochar-S. The ideal pH for Cu2+ ion adsorption was found to be 5.6. 1.0 g L-1 of biochar-S as an adsorbents dosage with Cu2+ ions beginning concentration of 200 mg L-1 had the maximum Cu2+ ions removal percentage of 78.33%. The maximal adsorption capacity (Qm) of biochar-S was 151.52 mg g-1. Isotherm models such as Dubinin-Radushkevich, Langmuir, Temkin, and Freundlich were used to analyze the experimental data. Furthermore, the data of these isotherm models were investigated using several error function equations (average percentage errors, hybrid error function, Chi-square error (χ2), sum of absolute errors, root mean square errors, and Marquardt's percentage standard deviation). The biochar-S experimental data was best suited by the Freundlich isotherm model. Pseudo-first-order, pseudo-second-order, Elovich, and intraparticle diffusion models were used to assess the kinetic data. The adsorption rate was predominantly influenced by a pseudo-second-order rate model that had a high correlation (R2 > 0.99). The primary mechanism of Cu2+ ion adsorption by biochar-S consists mostly of surface precipitation by the formation of insoluble copper compounds in an alkaline state and ion exchange with exchangeable cations in biochar such as aluminium, silicon, and calcium ions for copper ions. The findings suggest that biochar-S is a promising adsorbent for the adsorption of Cu2+ ions and that it can be employed repeatedly without losing adsorption efficiency. [ABSTRACT FROM AUTHOR]

Textile and dye industries have discharged various kinds of toxic residual dyes particularly azo dyes into the environment. In addition to its resistance to biological degradation, Direct Red 23 (DR-23) azo dye is considered toxic, carcinogenic, teratogenic, and mutagenic to the ecosystem. The aim of this study was to investigate the efficiency of different advanced oxidation processes (AOPs) for DR-23 dye detoxification. Single and combined patterns of AOPs, namely ozonation (O3), O3/ultraviolet (UV), O3/UV/hydrogen peroxide (H2O2), and O3/ultrasonic (US), were applied. The effect of pH (3–11) and initial dye concentration (100-500 mg/L), with implication of UV, H2O2, and US, on dye removal efficiency were studied. Decolorization efficiency was found considerably depends on the initial dye concentration and the pH of the solution. The maximum decolorization was obtained at pH 9. The color removal efficiency reached 100% for 100 mg/L DR-23 dye at 15 min using both O3 and O3/UV processes. The half-life of O3, O3/UV, O3/UV/H2O2, and O3/US were found to be 12.4, 9.0, 15.8, and 10.5 min, respectively. The kinetic of AOPs for DR-23 dye removal followed the pseudo-first-order. For example, the rate constant (kobs) of 400 mg/L dye increased to about 38% using O3/UV as compared to O3 alone. Furthermore, LC-(ESI)-MS/MS analysis of the treated DR-23 dye solution was performed to study the final degradation products. It was shown that a DR-23 dye radical underwent partial and complete decomposition of the dye ring to form final products, namely oxalic acid and formic acid. [ABSTRACT FROM AUTHOR]

The hexavalent chromium (Cr(VI)) reported severe threat to the environment and public health as it is considered potentially mutagenic and carcinogenic. This communication demonstrates a chemical modification process of sugarcane bagasse cellulose for the removal of Cr(VI) from aqueous solutions. Cellulose was extracted from sugarcane bagasse followed by succination to form cellulose succinate (CS), which was then reacted with acetic anhydride to form cellulose succinic anhydrides (CSA). The latter was then reacted with triethylenetetramine (TETA) to form CS-TETA (CST). The prepared CST was characterized by Fourier transform infrared spectrometry (FTIR), scanning electron microscopy-energy-dispersive X-ray spectroscopy (SEM-EDX), and Brunauer–Emmett–Teller (BET) analyzer. The maximum removal efficiency of Cr(VI) by CST reached nearly 100% after 180 min, which was obtained at pH 1.0. The adsorption process fit well with the pseudo-second-order kinetic model, while the rate constant was 9.13 × 10−3 g/mg min. The isothermal study showed that the results closely aligned with the Langmuir isotherm model and the maximum adsorption capacity was 12.4 mg/g. [ABSTRACT FROM AUTHOR]

Acid Yellow 11 (AY-11) is a toxicant azo dye discharged into the aquatic environment from textile, leather, food, and paper industries. This manuscript demonstrates the oxidation processes of AY-11 by ozone (O3) and ultraviolet (UV) assisted ozonation for decolorization and detoxification. Parameters affecting the performance of AY-11 decolorization process were optimized. The results revealed that the initial dye concentration and pH were effective parameters controlling the decolorization performance. More than 99% of decolorization was obtained within the first 20 min of the ozonation process at 100 µg/mL AY-11 dye and pH 9. The decolorization of AY-11 by O3/UV was slightly less efficient than the individual use of O3 in terms of chemical oxygen demand and color removal. Kinetics analysis indicated that AY-11 dye decolorization followed the pseudo-second order. The final degradation products of AY-11 dye in wastewater were identified using GC-MS. The AY-11 dye degradation intermediates were identified using LC-ESI-MS/MS. The toxicity test on the zooplankton of the treated aqueous solution indicated that the O3 and O3/UV treatments reduced the toxicity effect. [ABSTRACT FROM AUTHOR]

Different nitration methods were investigated on 4‐(4‐mthoxy‐3‐methyl phenyl)‐1(2H)‐phthalazinone and its derivatives using HNO3 as a nitrating agent with different catalysts. LC–MS/MS has been used to determine the product's structure. The results showed that the most suitable catalyst was P2O5 at room temperature to introduce an ortho mono‐nitrated group for the phthalazinone derivatives bearing donating groups on the phenyl ring. In contrast, 4‐halophenyl phthalazinone derivatives gave a high yield of mono‐nitrated products using H2SO4 as a catalyst. All mono‐nitrated products were separated with good to excellent yields, and their structures were confirmed by FT‐IR, NMR, LC‐MS/MS and elemental analyses. [ABSTRACT FROM AUTHOR]

[4‐(4‐methoxy‐3‐methyl‐5 amino phenyl)‐1(2H)‐phthalazinone (APP), and [4‐(4‐mehoxy‐3‐methyl phenyl)‐1‐oxo‐1H‐phthalaz‐2‐yl]acetic acid hydrazide (PPH) were synthesized as a novel independently corrosion inhibitor for carbon steel in 0.5 M H2SO4. Nuclear magnetic resonance, Fourier transform infrared and mass spectroscopy were used to validate the structure of the two anticorrosion compounds. The corrosion rate was studied by electrochemical methods (electrochemical impedance spectroscopy and potentiodynamic polarization) and gravimetric techniques, which clarify that the average corrosion inhibition efficiency of APP and PPH are 86 and 89 %, respectively. Impedance measurements showed that corrosion processes on the surface of LCS are controlled by a charge transfer mechanism. The PPH compound has a greater inhibitory effect on corrosion of low carbon steel. The quantum chemical calculations of APP and PPH were studied using AM1, PM3, and DFT/B3LYP/31G. Moreover, both APP and PPH acted as mixed type corrosion inhibitors. Adsorption of APP and PPH on low carbon steel (LCS) surface was physisorption and best fit to Langmuir isotherm. [ABSTRACT FROM AUTHOR]

[4‐(4‐methoxy‐3‐methyl‐5 amino phenyl)‐1(2H)‐phthalazinone (APP), and [4‐(4‐mehoxy‐3‐methyl phenyl)‐1‐oxo‐1H‐phthalaz‐2‐yl]acetic acid hydrazide (PPH) were synthesized as a novel independently corrosion inhibitor for carbon steel in 0.5 M H2SO4. Nuclear magnetic resonance, Fourier transform infrared and mass spectroscopy were used to validate the structure of the two anticorrosion compounds. The corrosion rate was studied by electrochemical methods (electrochemical impedance spectroscopy and potentiodynamic polarization) and gravimetric techniques, which clarify that the average corrosion inhibition efficiency of APP and PPH are 86 and 89 %, respectively. Impedance measurements showed that corrosion processes on the surface of LCS are controlled by a charge transfer mechanism. The PPH compound has a greater inhibitory effect on corrosion of low carbon steel. The quantum chemical calculations of APP and PPH were studied using AM1, PM3, and DFT/B3LYP/31G. Moreover, both APP and PPH acted as mixed type corrosion inhibitors. Adsorption of APP and PPH on low carbon steel (LCS) surface was physisorption and best fit to Langmuir isotherm. [ABSTRACT FROM AUTHOR]

A highly rapid synthesis of cellulose propionate (CP) with high yield from commercial cotton cellulose using FeCl3·6H2O and ZnCl2 as catalysts and less amount of propionic anhydride in solvent free synthesis was investigated. It was done using different amounts of catalyst under microwave irradiation for maximum of 8 min reaction time. The degree of substitution by propionate (DSCP) was experimentally calculated and confirmed by FTIR and 1H-NMR. The yields of CP using ZnCl2 and FeCl3·6H2O as catalysts varied from 82.20 to 98.60% with the degree of substitution (DSCP) ranging from 2.47 to 2.96, and from 55.51 to 96.34% with DSCP ranging from 0.38 to 2.84, respectively. The DSCP was controlled by changing the reaction duration (2–8 min), and the amount of catalyst using fixed amount of propionic anhydride (25 mL/5.0 g cellulose). The degree of polymerization of CP is highly affected by the catalyst amount and reaction time, while the thermal stability of CP is slightly affected by the type of catalyst and reaction time. Novel cellulose nitrate-propionate mixed esters (CNP) were also synthesized by nitration of the obtained cellulose propionate with different degrees of nitration using (HNO3 + H2SO4) and (HNO3 + P2O5) as nitrating agents. The degree of nitration (DSCN) ranged between 0.10 and 2.53 for the HNO3/H2SO4 mixture and between 0.22 and 1.24 for the HNO3/P2O5 mixture. The effect of nitrating agent and reaction time on the degree of polymerization and thermal stability of CNP were also investigated using GPC, TGA, DTA and DSC analysis. [ABSTRACT FROM AUTHOR]

Propylation of cellulose from different sources with propionic anhydride using N-iodosuccinimide (NIS) under solvent-free condition was tested. It was done in the presence of NIS as a new catalyst for propylation using three different amounts of catalyst under mild reaction conditions. The degree of substitution by propionate was experimentally calculated and confirmed by FTIR and 1H NMR analyses. The propylation yields varied from 71.54 to 88.37% with the degree of substitution (DS) ranged from 1.32 to 2.80 for commercial cotton cellulose, 1.76–3.00 for rice husk cellulose, and 1.60–3.0 for wheat straw cellulose. The DS were easily controlled by changing the reaction duration (2–6 h) and the amount of the NIS catalyst (50, 75, and 100 mg for each 1.0 g of cellulose) in 25 mL of propionic anhydride. Prolonging the reaction's duration has no favorable effect on the propylation process and led to decrease in the cellulose propionate (CP). Also, increasing the amount of NIS catalyst results in decrease the DS and CP yield. NIS was recognized as a novel and more successful catalyst for propylation of the hydroxyl groups of cellulose from different sources in high degree of substitution. [ABSTRACT FROM AUTHOR]