Transforming Pharmaceutical Synthesis with Sein-E-B Nanocomposite Photocatalyst through 1,4-NAD(P)H Cofactor Regeneration and C-N Bond Activation.

The need for sunlight chemical renewal and contemporary organic transformation has fostered the advancement of environmentally friendly photocatalytic techniques. For the first time, we report on the novel crafting of a bright future with selenium-infused Eosin-B (Sein-E-B) nanocomposite photocatalysts in this work. The Sein-E-B nanocomposite materials were created using a hydrothermal process for solar chemical regeneration and organic transformation under visible light. The synthesized samples were subjected to UV-DRS-visible spectroscopy, FT-IR, SEM, EDX, EIS and XRD analysis. The energy band gap of the Sein-E-B nanocomposite photocatalyst was measured using UV-DRS, and the result was around 2.06 eV. to investigate the generated Sein-E-B catalytic activity as a nanocomposite for 1,4-NADH/NADPH re-formation and C-N bond activation. This novel photocatalyst offers a promising alternative for the regeneration of solar chemicals and C-N bond creation between pyrrole and aryl halides.

Biologically treated industrial wastewater disinfection using the synergy of low-frequency ultrasound and H2O2/O3.

Biological wastewater treatment is mostly used in many industries to treat industrial influents. Treated water is consisting of an extremely high concentration of pathogenic microorganisms. Present work demonstrate the treatment of biologically treated sugar industry wastewater (BTSWW) using a low-frequency ultrasound (US). BTWSS consists of Enterobacter, Salmonella, and Escherichia Coli with a total coliform concentration of 2500 ± 300 CFU/mL. Experiments were performed using the individual effect of US, H2O2, and O3 and the combined effect of US with H2O2, O3, and H2O2 + O3. The complete removal of total coliform was obtained for the synergy effect of US with H2O2 and O3. The performance of the process was analyzed based on pseudo-first-order kinetic rate constant and synergy coefficient. The pseudo-first-order kinetic rate constant was 21.6 and 22.3 × 10-2 min-1 with a synergy coefficient of 2 and 1.9 for a combined effect of US with H2O2 and O3, respectively. Another advantage of the synergy of US and O3 was lower requirement of the initial dose of H2O2 (2.1 mM/L). The operational cost of the process was found to be $ 1.5 × 10-2 /MLD.

Sono-chemical treatment of per- and poly-fluoroalkyl compounds in aqueous film-forming foams by use of a large-scale multi-transducer dual-frequency based acoustic reactor.

Aqueous film-forming foams (AFFFs) contain a mixture of organic chemicals, including per- and poly-fluorinated, alkyl sulfonate substances (PFAS) (1-5%, w/w). Some longer-chain PFAS can be toxic, moderately bioaccumulative and persistent in the environment. In the present work, decomposition of PFAS present in two commercially available AFFFs (ANSUL- and 3M-) was investigated using a sono-chemical reactor of volume 91 L. The reactor consists of 12 transducers with operating frequencies of 1 MHz or 500 kHz and total input power of 12 kW. Degradation of PFASs performed using various dilutions of AFFF revealed that release of F- and SO4-2 ions was inversely proportional to initial pH of up to 4. Defluorination of ANSUL-AFFF resulted in an increase in the concentration of F- released from 55.6 ±â€¯0.3 µM (500× dilution) to 58.6 ±â€¯0.6 (25× dilution), while for 3M AFFF it increased from 19.9 ±â€¯0.7 µM (500× dilution) to 217.1 ±â€¯2.4 µM (25× dilution). Though amounts of F- released were less for ANSUL-AFFF than for 3M-AFFF, there was a considerable increase in removal of TOC and release of SO4-2 present in ANSUL-AFFF. Approximately 90.5% and 26.6% reduction of perfluoroalkyl sulfonates (PFSA) and perfluoroalkyl carboxylates (PFCA) in 3M, respectively, and 38.4% reduction of fluorotelomer sulfonates in ANSUL-AFFF were achieved in 13 h. Estimated costs of energy for the treatment of ANSUL-AFFF and 3M-AFFF at a 500× dilution were $0.015 ±â€¯0.0001/L and $0.019 ±â€¯0.0002/L, respectively.

Cavitation assisted synthesis of fatty acid methyl esters from sustainable feedstock in presence of heterogeneous catalyst using two step process.

The present work reports the intensification aspects for the synthesis of fatty acid methyl esters (FAME) from a non-edible high acid value Nagchampa oil (31 mg of KOH/g of oil) using two stage acid esterification (catalyzed by H2SO4) followed by transesterification in the presence of heterogeneous catalyst (CaO). Intensification aspects of both stages have been investigated using sonochemical reactors and the obtained degree of intensification has been established by comparison with the conventional approach based on mechanical agitation. It has been observed that reaction temperature for esterification reduced from 65 to 40 °C for the ultrasonic approach whereas there was a significant reduction in the optimum reaction time for transesterification from 4h for the conventional approach to 2.5h for the ultrasound assisted approach. Also the reaction temperature reduced marginally from 65 to 60 °C and yield increased from 76% to 79% for the ultrasound assisted approach. Energy requirement and activation energy for both esterification and transesterification was lower for the ultrasound based approach as compared to the conventional approach. The present work has clearly established the intensification obtained due to the use of ultrasound and also illustrated the two step approach for the synthesis of FAME from high acid value feedstock based on the use of heterogeneous catalyst for the transesterification step.

Sonochemical degradation of chlorobenzene in the presence of additives.

The present work deals with establishing the pathway for the selection of additives for intensification of the sonolytic degradation of chlorobenzene. The degradation of chlorobenzene has been investigated in the presence of different additives such as CuO, TiO2, nano-TiO2 and NaCl. The reaction has been monitored in terms of the concentration of the parent pollutant as well as the extent of mineralization. The first-order kinetic rate constant for the removal of chlorobenzene has been evaluated for different loadings of additives. It has been observed that the extent of degradation and mineralization was maximum in the presence of nano-TiO2 and minimum in the presence of CuO. A three-step mechanism has been developed for the degradation of chlorobenzene based on the identification of intermediates. The removal of chloride from the benzene ring due to pyrolysis was the dominant mechanism with minimal contribution from the attack of hydroxyl radical present in the bulk of solution. The oxidation products also react subsequently with the hydroxyl radicals resulting in mineralization. The rate of mineralization has been quantified in terms of total organic carbon removal. The observed trends for the mineralization confirm that the extent of mineralization depends on the ease of generation of hydroxyl radicals.