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Furfural is one of the main pollutant materials in petroleum refinery wastewater. This work used an ozonized bubble column reactor to remove furfural from wastewater. The reactor applied two shapes of packing materials and two dosages of CuO nanocatalyst (0.05 and 0.1 ppm) to enhance the degradation process. The results indicated that adding 0.1 ppm of nanocatalyst provided an efficient rate of furfural degradation compared to that of 0.05 ppm. Also, the packing materials enhanced the furfural degradation significantly. As a result, the contact area between the gas and liquid phases increased, and a high furfural removal efficiency was achieved. It was found that the CuO nanocatalyst generated more (OH•) radicals. At a treatment time of 120 min and an ozone flow of 40 L/h, the furfural degradation recorded values of 80.66 and 78.6% at 10 and 20 ppm of initial concentration, respectively. At 60 ppm, the degradation efficiency did not exceed 74.16%. Furthermore, the kinetic study indicated that the first-order mechanism is more favorable than the second-order mechanism, representing the furfural degradation with a correlation factor of 0.9837. Finally, the furfural reaction can be achieved successfully in a shorter time and at low cost.

Furfural is one of the main pollutant materials in petroleum refinery wastewater. This work used an ozonized bubble column reactor to remove furfural from wastewater. The reactor applied two shapes of packing materials and two dosages of CuO nanocatalyst (0.05 and 0.1 ppm) to enhance the degradation process. The results indicated that adding 0.1 ppm of nanocatalyst provided an efficient rate of furfural degradation compared to that of 0.05 ppm. Also, the packing materials enhanced the furfural degradation significantly. As a result, the contact area between the gas and liquid phases increased, and a high furfural removal efficiency was achieved. It was found that the CuO nanocatalyst generated more (OH•) radicals. At a treatment time of 120 min and an ozone flow of 40 L/h, the furfural degradation recorded values of 80.66 and 78.6% at 10 and 20 ppm of initial concentration, respectively. At 60 ppm, the degradation efficiency did not exceed 74.16%. Furthermore, the kinetic study indicated that the first-order mechanism is more favorable than the second-order mechanism, representing the furfural degradation with a correlation factor of 0.9837. Finally, the furfural reaction can be achieved successfully in a shorter time and at low cost. [ABSTRACT FROM AUTHOR]

In the ozonation process, the phenol degradation in wastewater undergoes a low mass transfer mechanism. In this study, ozonized packed bubble column reactor was designed and constructed to remove phenol. The reactor’s inner diameter and height were 150 and 8 cm, respectively. The packing height was kept constant at 1 m in accordance with the reactor hydrodynamics. The gas distributor was designed with 55 holes of 0.5 mm. The phenol removal efficiency was evaluated at ozone concentrations of 10, 15, and 20 mg/L, contact times of 15, 30, 45, 60, 75, 90, 105, and 120 min, and phenol concentrations of 3, 6, 9, 12, and 15 mg/L. The results indicated that the highest phenol removal efficiency of 100% was achieved at 30 min in presence of packing. Moreover, the use of packing improved the contact between the gas and liquid, which significantly enhanced the phenol degradation. Actually, a thin film over a packing surface enhances the mass transfer. Also, it was found that the phenol is degraded into CO2 and H2O through a series of reaction steps. Additionally, a kinetic study of a first-order reaction provided an efficient estimation of reaction parameters with a correlation factor of 0.997.

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Indoor secondary organic aerosols (SOAs) generated from reactive organic gases (ROGs) reacting with O 3 have a substantial impact on indoor PM 2.5 levels. China's recent decrease in atmospheric PM 2.5 and increase in atmospheric O 3 have resulted in correspondingly lower levels of indoor PM 2.5 and higher levels of indoor O 3 , which will further affect indoor SOA concentration. Thus, the aims of this study were to evaluate indoor SOA concentrations and their contribution to indoor PM 2.5 and analyze the impact of the air exchange rate, window-opening status, proportion of indoor organic particles, and O 3 concentrations on indoor SOA generation. To this end, measurements were conducted in Beijing, Shanghai, and Shenzhen, China by synchronously collecting samples of indoor ROGs and O 3 , along with indoor and outdoor PM 2.5 concentrations. We found a maximum indoor SOA concentration of 35.23 μg/m3, contributing over 50% to indoor PM 2.5 , although most samples had an average concentration of 1.65 ± 4.89 μg/m3. Shanghai had the lowest average SOA concentration and contribution, whereas Shenzhen had the highest. Terpenoid compounds were identified as crucial precursors for indoor SOA generation, with the indoor O 3 concentration being an important influencing factor. Compared to the measured benchmark scenario, when the O 3 concentration reached 156 ppb, the average indoor SOA concentration increased approximately 20-fold while its contribution to indoor PM 2.5 increased by approximately 7-fold. Our results provide a meticulous look at indoor SOA pollution and its determinants, the knowledge of which is pivotal for the implementation of effective strategies to mitigate indoor SOA pollution. • We evaluated the indoor SOA concentration and its contribution to indoor PM 2.5 • In over 80% of samples, indoor SOA was <1 μg/m3, contributing <10% to indoor PM 2.5 • Terpenoid compounds were identified as crucial precursors for indoor SOA generation. • Indoor O 3 concentration had the most substantial impact on indoor SOA generation. • Shanghai had the lowest, while Shenzhen had the highest average SOA concentration. [ABSTRACT FROM AUTHOR]

Abstract: An advanced ozone membrane reactor that uses membranes for ozone distribution, reaction contact and selective water separation was used for ozone treatment of a recalcitrant endocrine disrupting compound in water. Experiments and model calculation were employed to examine the ozonation of phthalate in the new reactor. Experimental results showed that fast ozone mass transfer rate is responsible for membrane reactor''s superb performance compared with a semibatch reactor. Selective water removal further enhanced phthalate conversion and TOC removal by concentrating the pollutants in the reaction zone. Clean water was produced by membrane separation. Mathematical model was used to investigate the effect of membranes, reactor design and reaction operation on pollutant conversion and removal. [Copyright &y& Elsevier]