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Population and industrialization growth is the major reason for the indoor air quality depletion. So, air quality control in sensitive area is needed to avoid air pollution-based hazards. Small economical air pollutant controlling equipment may be helpful in indoor air quality control. Present work covers the performance study of lab scale air purifier tower, 37 × 37 × 140 cm3 (LSAPT) for the removal of PM2.5, PM10 and TVOC from the polluted air in a control volume (75 m3). LSAPT follow 3 step pollutants removal procedure in which coarse particles are separated by prefilter and the fine particles are separated with the help of negative ioniser and activated carbon beds. More than 99 % of percentage of PM2.5, PM10 and TVOC removal are achieved within 100 s for initial pollutants loading of PM2.5: 1000 μg/m3 & PM10: 1000 μg/m3 and TVOC: 7.2 mg/m3 respectively. The assessment study suggests the proposed lab scale air purifier tower can be used continuously up to 10–15 days without much variation in pollutants removal efficacy. Approximately 7700 ₹ (92.40 US$) is used as installation cost and 30 ₹/hr (0.36 US$/hr) is used as consumable energy cost. [ABSTRACT FROM AUTHOR]

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. Highlights: • Complete microbial disinfection achieved in 20 min. • The pseudo-first-order kinetic rate constant: 22.3 × 10–3 min−1 and synergy coefficient: 2 for US + O3. • The operational cost of $ 1.5 × 10–2 /MLD for US + O3 [ABSTRACT FROM AUTHOR]

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. Highlights: • Complete microbial disinfection achieved in 20 min. • The pseudo-first-order kinetic rate constant: 22.3 × 10–3 min−1 and synergy coefficient: 2 for US + O3. • The operational cost of $ 1.5 × 10–2 /MLD for US + O3 [ABSTRACT FROM AUTHOR]

This study evaluates the application of different additives viz. H2O2, Fe (II), Fe metal powder, sodium bicarbonate, and t-butanol, for intensifying the sonochemical degradation of chlorobenzene. It has been observed that the degradation of chlorobenzene is controlled by the pyrolysis mechanism, and dominant zone of degradation lies around the region of cavitating bubble. Hydroxyl radicals formed during cavitation were also useful for enhancing the mineralization of intermediates formed during degradation. It has been established that the use of Fe powder, sodium bicarbonate, and t-butanol, which leads to enhancement in the cavitational effects, gives better degradation of chlorobenzene among the different additives investigated in the study, and maximum degradation is observed in the presence of Fe powder. The presence of t-butanol, a conventional radical scavenger, leading to a marginal increase in the extent of degradation confirmed that degradation mechanism is dominated by the pyrolysis effect of cavitation. The higher Henry constant pollutant was easily degraded due to pyrolysis mechanism. A three-step degradation mechanism scheme has been established on the basis of the intermediate products formed in the process such as phenols, chlorophenols, and benzene. Rate of mineralization was also quantified in terms of total organic carbon removal, and it was established that the trends in mineralization are not necessarily the same as parent compound removal confirming that both radical and pyrolysis mechanism are important for overall mineralization. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Biodiesel synthesis from nonedible oils, which offerexcellentpotential as sustainable feed stock, is highly energy-intensive andslow operation, because it requires considerable processing due tohigher initial acid values and due to the fact that the reaction ismass-transfer-controlled. The present work reports the intensificationof synthesis of biodiesel from the high-acid-value Nagchampa oil usingsonochemical reactors. The synthesis process is a two-step methodof esterification in the presence of homogeneous acid catalyst followedby transesterification using an alkaline (KOH) catalyst. The synthesishas also been attempted using conventional methods of reflux for analyzingthe degree of intensification. With an objective of avoiding possiblesaponification reaction in the transesterification based on use ofan alkaline catalyst, the acid value of oil was reduced from 18.4mg KOH/g of oil to 1.4 mg KOH/g of oil, using the first-stage esterificationmethod. The reduction in the acid value allows for an efficient secondtransesterification stage. The reaction temperature, molar ratio,and catalyst concentration were optimized for esterification and transesterificationstages for the ultrasound and conventional techniques. It has beenobserved that the reaction temperature and reaction time requiredfor esterification, as well as the transesterification stages, aresubstantially lower in the case of sonochemical reactors, comparedto the conventional heating method. Also, the percentage excess ofthe reactants is significantly reduced, leading to energy savingsin the subsequent separation processes for getting the purified product.Overall, the present work has clearly established the efficacy ofsonochemical reactors for the intensification of biodiesel synthesisbased on a sustainable raw material. [ABSTRACT FROM AUTHOR]

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 (Se in -E-B) nanocomposite photocatalysts in this work. The Se in -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 Se in -E-B nanocomposite photocatalyst was measured using UV-DRS, and the result was around 2.06 eV. to investigate the generated Se in -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., (© 2024 Wiley-VHCA AG, Zurich, Switzerland.)