Intensification of ozonation processes in a novel, compact, multi-orifice oscillatory baffled column

A novel approach for the intensification of ozonation of water and wastewater is presented using a highly efficient and compact Multi-Orifice Oscillatory Baffled Column (MOBC) ozonation contactor. The MOBC uniquely yielded full (i.e. 100%) use of the ozone supplied with a very short (2.25 min) liquid contact time under continuous operation and reducing the need of further gas-liquid contacting equipment downstream from the MOBC. The increased performance of the MOBC ozonation reactor was benchmarked against a bubble column (BC) design and resulted in 20% increase on the rate of p-hydroxybenzoic acid (p-HBA) degradation, 75% increase in the rate of mineralization of p-HBA per mole of ozone consumed, and 3.2-fold increase in the rate of mineralization of p-HBA per mole of ozone supplied. This results from the very small size of bubbles (few hundreds of microns) and enhanced gas-liquid mass transfer and hold-up generated in the presence of small fluid pulsations and orifice baffles

Humic acids adsorption and decomposition on Mn2O3 and α-Al2O3 nanoparticles in aqueous suspensions in the presence of ozone

© 2018 Elsevier Ltd. The removal and decomposition of humic acids (HAs) in the presence of ozone and aqueous suspensions of Mn2O3 and a-alumina (Al2O3) nanoparticles was investigated. Mn2O3 presented lower BET specific surface area (15.6m2 g-1 vs 45.8m2 g-1) but a higher point of zero charge (PZC) (5.9 vs 4.2) than α-Al2O3. Solution pH played a key role in the adsorption of HAs and catalytic oxidation on the surface of α-Al2O3 and Mn2O3 nanopart icles. The adsorption capacity of α-Al2O3 at the natural pH of HAs in water (pH 5.5) was up to2.903 gHAs g-1, but no adsorption occurred onto the Mn2O3 nanoparticles, due to the unfavorable surface charge at pH 5.5. In consequence, although Mn2O3 was a more efficient catalyst (khet=0.7 L-1 min-1 g-1) than α-Al2O3 (khet=0.2 L-1 min-1 g-1) for the decomposition of O3, Mn2O3 did not exhibited catalytic action duringthe ozonation of HAs at pH 5.5. Instead, the Mn2O3 catalytic action was significant at pH equal to PZC (catalytic ate constant ratio k1-HAcat/k1-HA=1.562). Overall, α-Al2O3 exhibited the highest catalytic removal rate of HAs during ozonation (k1-HAcat/ k1-HA=2.298) due to favorable surface charge and larger specific surface area. The main mechanism for HAs removal in the presence of α-Al2O3 involves simultaneous adsorption of both HAs and O3, the reaction of ozone from the bulk solution and the catalytic decomposition of HAs on the solid surface by ROS, through complex series-parallel reactions. The α-Al2O3 dosage up to 0.5 g L-1 required to remove HAs by catalytic ozonation was significantly lower than in other studies employing granular activated carbon, iron coated zeolite or γ-alumina catalysts

MC1568 inhibits HDAC6/8 activity and influenza A virus replication in lung epithelial cells: Role of Hsp90 acetylation

Aim: Histone deacetylases (HDACs) regulate the life cycle of several viruses. We investigated the ability of different HDAC inhibitors, to interfere with influenza virus A/Puerto Rico/8/34/H1N1 (PR8 virus) replication in Madin-Darby canine kidney and NCI cells. Results: 3-(5-(3-Fluorophenyl)-3-oxoprop-1-en-1-yl)-1-methyl-1H-pyrrol-2-yl)-N-hydroxyacrylamide (MC1568) inhibited HDAC6/8 activity and PR8 virus replication, with decreased expression of viral proteins and their mRNAs. Such an effect may be related to a decrease in intranuclear content of viral polymerases and, in turn, to an early acetylation of Hsp90, a major player in their nuclear import. Later, the virus itself induced Hsp90 acetylation, suggesting a differential and time-dependent role of acetylated proteins in virus replication. Conclusion: The inhibition of HDAC6/8 activity during early steps of PR8 virus replication could lead to novel anti-influenza strategy

Treatment of winery wastewater by sulphate radicals: HSO5−/transition metal/UV-A LEDs

© 2016 Elsevier B.V.In this study, the effectiveness of the HSO5-/M n+/UV process on the treatment of winery wastewater (WW) was investigated. The optimal operating conditions were determined: [HSO5-]=2.5mM; [M2(SO4) n ]=1.0mM; pH=6.5 and reaction temperature=323K. Under the given conditions, 51%, 42% and 35% of COD removal was achieved using respectively Fe(II), Co(II) and Cu(II) as catalysts. Different UV sources were tested with the previously selected optimal conditions in order to increase the treatment efficiency. The highest COD removal (82%) was achieved using a UV-A LEDs system (70W/m2). These conditions were also promising for the treatment of WW with COD concentrations of 5000mg O2/L, reaching 79% and 64% of COD and TOC removal, respectively, after 180min of treatment. At 323K, the most effective treatment was obtained when Co(II) was used as catalyst (79% and 64% of COD and TOC removal), while at ambient temperature (293K) the highest COD (65%) and TOC (52%) removals were obtained with Fe(II) catalyst. Moreover, it was demonstrated that the use of HSO5-/M n+ in several consecutive doses was more efficient than adding the reagents as a single dose at the beginning of the reaction. A comparison between the performance of the HSO5-/Fe(II)/UV-A LED process and the conventional photo-Fenton demonstrated important advantages associated with the HSO5-/Fe(II)/UV-A LED process, including the absence of the costly pH adjustment and of the hydroxide ferric sludge which characterise the photo-Fenton treatment process. The HSO5-/M n+/UV-A LED process demonstrates a high COD and TOC removal efficiency, and it can be considered a promising technology for application in real scale agro-food wastewater treatment plants

Nurse participation in legal executions: An ethics round-table discussion

A paper was published in 2003 discussing the ethics of nurses participating in executions by inserting the intravenous line for lethal injections and providing care until death. This paper was circulated on an international email list of senior nurses and academics to engender discussion. From that discussion, several people agreed to contribute to a paper expressing their own thoughts and feelings about the ethics of nurses participating in executions in countries where capital punishment is legal. While a range of opinions were presented, these opinions fell into two main themes. The first of these included reflections on the philosophical obligations of nurses as caregivers who support those in times of great need, including condemned prisoners at the end of life. The second theme encompassed the notion that no nurse ever should participate in the active taking of life, in line with the codes of ethics of various nursing organisations. This range of opinions suggests the complexity of this issue and the need for further public discussion