Impact of atmospheric O3 and NO2 on the secondary sulfates in real atmosphere.

As an important component of secondary aerosols, sulfate plays a crucial role in regulating atmospheric radiative balance and influencing the secondary formation of ozone (O3). In real atmosphere, atmospheric oxidants NO2 and O3 can promote the oxidation of SO2 to form sulfate (SO42-) through multiphase chemistry that occur at different time scales. Due to the combined impact of meteorology, pollution sources, atmospheric chemistry, etc., time-scale dependence of SO2-SO42- conversion makes the impact of NO2/O3 on it more complex. In this study, based on long-term time series (2013-2020) of air pollution variables from seven stations in Hong Kong, the Multifractal Detrended Cross-Correlation Analysis (MFDCCA) method has been employed to quantify the cross-correlations between SO2 and SO42- in real atmosphere at different time scales, for examining the time-scale dependence of SO2-SO42- conversion efficiency. Furthermore, the Pearson correlation analysis has been used to study the influence of NO2/O3 on SO2-SO42- conversion, and the regional and seasonal differences have been analyzed by considering factors such as meteorology, pollution sources, and regional transport. Changes in the main components of secondary aerosols are closely linked with the co-control of regional PM2.5 and O3. Therefore, the exploration of the impact of co-existing NO2/O3 gases on the secondary formation of sulfates in real atmosphere is significant.

Synthesis of δ-MnO2 via ozonation routine for low temperature formaldehyde removal.

Nowadays, it is still a challenge to prepared high efficiency and low cost formaldehyde (HCHO) removal catalysts in order to tackle the long-living indoor air pollution. Herein, δ-MnO2 is successfully synthesized by a facile ozonation strategy, where Mn2+ is oxidized by ozone (O3) bubble in an alkaline solution. It presents one of the best catalytic properties with a low 100% conversion temperature of 85°C for 50 ppm of HCHO under a GHSV of 48,000 mL/(g·hr). As a comparison, more than 6 times far longer oxidation time is needed if O3 is replaced by O2. Characterizations show that ozonation process generates a different intermediate of tetragonal ß-HMnO2, which would favor the quick transformation into the final product δ-MnO2, as compared with the relatively more thermodynamically stable monoclinic γ-HMnO2 in the O2 process. Finally, HCHO is found to be decomposed into CO2 via formate, dioxymethylene and carbonate species as identified by room temperature in-situ diffuse reflectance infrared fourier transform spectroscopy. All these results show great potency of this facile ozonation routine for the highly active δ-MnO2 synthesis in order to remove the HCHO contamination.

Investigation of spatiotemporal distribution and formation mechanisms of ozone pollution in eastern Chinese cities applying convolutional neural network.

Severe ground-level ozone (O3) pollution over major Chinese cities has become one of the most challenging problems, which have deleterious effects on human health and the sustainability of society. This study explored the spatiotemporal distribution characteristics of ground-level O3 and its precursors based on conventional pollutant and meteorological monitoring data in Zhejiang Province from 2016 to 2021. Then, a high-performance convolutional neural network (CNN) model was established by expanding the moment and the concentration variations to general factors. Finally, the response mechanism of O3 to the variation with crucial influencing factors is explored by controlling variables and interpolating target variables. The results indicated that the annual average MDA8-90th concentrations in Zhejiang Province are higher in the northern and lower in the southern. When the wind direction (WD) ranges from east to southwest and the wind speed (WS) ranges between 2 and 3 m/sec, higher O3 concentration prone to occur. At different temperatures (T), the O3 concentration showed a trend of first increasing and subsequently decreasing with increasing NO2 concentration, peaks at the NO2 concentration around 0.02 mg/m3. The sensitivity of NO2 to O3 formation is not easily affected by temperature, barometric pressure and dew point temperature. Additionally, there is a minimum [Formula: see text] at each temperature when the NO2 concentration is 0.03 mg/m3, and this minimum [Formula: see text] decreases with increasing temperature. The study explores the response mechanism of O3 with the change of driving variables, which can provide a scientific foundation and methodological support for the targeted management of O3 pollution.

Rising frequency of ozone-favorable synoptic weather patterns contributes to 2015-2022 ozone increase in Guangzhou.

Objective weather classification methods have been extensively applied to identify dominant ozone-favorable synoptic weather patterns (SWPs), however, the consistency of different classification methods is rarely examined. In this study, we apply two widely-used objective methods, the self-organizing map (SOM) and K-means clustering analysis, to derive ozone-favorable SWPs at four Chinese megacities in 2015-2022. We find that the two algorithms are largely consistent in recognizing dominant ozone-favorable SWPs for four Chinese megacities. In the case of classifying six SWPs, the derived circulation fields are highly similar with a spatial correlation of 0.99 between the two methods, and the difference in the mean frequency of each SWP is less than 7%. The six dominant ozone-favorable SWPs in Guangzhou are all characterized by anomaly higher radiation and temperature, lower cloud cover, relative humidity, and wind speed, and stronger subsidence compared to climatology mean. We find that during 2015-2022, the occurrence of ozone-favorable SWPs days increases significantly at a rate of 3.2 day/year, faster than the increases in the ozone exceedance days (3.0 day/year). The interannual variability between the occurrence of ozone-favorable SWPs and ozone exceedance days are generally consistent with a temporal correlation coefficient of 0.6. In particular, the significant increase in ozone-favorable SWPs in 2022, especially the Subtropical High type which typically occurs in September, is consistent with a long-lasting ozone pollution episode in Guangzhou during September 2022. Our results thus reveal that enhanced frequency of ozone-favorable SWPs plays an important role in the observed 2015-2022 ozone increase in Guangzhou.

Enhancing ozone catalytic decomposition through acid treatment of α-MnO2 for improved activity and humidity resistance.

Post-etching method using dilute acid solutions is an effective technology to modulate the surface compositions of metal-oxide catalysts. Here the α-MnO2 catalyst treated with 0.1 mol/L nitric acid exhibits higher ozone decomposition activity at high relative humidity than the counterpart treated with acetic acid. Besides the increases in surface area and lattice dislocation, the improved activity can be due to relatively higher Mn valence on the surface and newly-formed Brønsted acid sites adjacent to oxygen vacancies. The remnant nitro species deposited on the catalyst by nitric acid treatment is ideal hydrophobic groups at ambient conditions. The decomposition route is also proposed based on the DRIFTS and DFT calculations: ozone is facile to adsorb on the oxygen vacancy, and the protonic H of Brønsted acid sites bonds to the terminal oxygen of ozone to accelerate its cleavage to O2, reducing the reaction energy barrier of O2 desorption.

Development of a net ozone production rate detection system based on dual-channel cavity ring-down spectroscopy.

A novel system for measuring net photochemical ozone production rates in the atmosphere based on cavity ring-down spectroscopy (OPR-CRDS) was developed. The system consists of two chambers (a reaction chamber and a reference chamber) and a dual-channel Ox-CRDS detector. To minimize the wall loss of Ox in the chambers, the inner surfaces of both chambers are coated with Teflon film. The performance of the OPR-CRDS system was characterized. It was found that even though the photolysis frequency (J value) decreased by 10%, the decrease in the P(O3) caused by the ultraviolet-blocking film coating was less than 3%. The two chambers had a good consistency in the mean residence time and the measurement of NO2 and Ox under the condition of no sunlight. The detection limit of the OPR-CRDS was determined to be 0.20 ppbv/hr. To further verify the accuracy of the system, the direct measurement values of the OPR-CRDS system were compared with the calculation results based on radical (OH, HO2, and RO2) reactions, and a good correlation was obtained between the measured and calculated values. Finally, the developed instrument was applied to obtain the comprehensive field observations at an urban site in the Yangtze River Delta (China) for 40 days, the time series and change characteristics of the P(O3) were obtained directly, and the good environmental adaptability and stability of the OPR-CRDS system were demonstrated. It is expected that the new instrument will be beneficial to investigations of the relationship between P(O3) and its precursors.

Chemical characteristics and sources apportionment of volatile organic compounds in the primary urban area of Shijiazhuang, North China Plain.

VOCs (Volatile organic compounds) exert a vital role in ozone and secondary organic aerosol production, necessitating investigations into their concentration, chemical characteristics, and source apportionment for the effective implementation of measures aimed at preventing and controlling atmospheric pollution. From July to October 2020, online monitoring was conducted in the main urban area of Shijiazhuang to collect data on VOCs and analyze their concentrations and reactivity. Additionally, the PMF (positive matrix factorization) method was utilized to identify the VOCs sources. Results indicated that the TVOCs (total VOCs) concentration was (96.7 ± 63.4 µg/m3), with alkanes exhibiting the highest concentration of (36.1 ± 26.4 µg/m3), followed by OVOCs (16.4 ± 14.4 µg/m3). The key active components were alkenes and aromatics, among which xylene, propylene, toluene, propionaldehyde, acetaldehyde, ethylene, and styrene played crucial roles as reactive species. The sources derived from PMF analysis encompassed vehicle emissions, solvent and coating sources, combustion sources, industrial emissions sources, as well as plant sources, the contribution of which were 37.80%, 27.93%, 16.57%, 15.24%, and 2.46%, respectively. Hence, reducing vehicular exhaust emissions and encouraging neighboring industries to adopt low-volatile organic solvents and coatings should be prioritized to mitigate VOCs levels.

How to Cope With Stress in the Desert-The Date Palm Approach.

Increasing desertification constitutes a global environmental problem, mainly driven by climate change and inappropriate land-use that limits agriculture, forestry and human colonization. The selection of suitable plant species to mitigate desertification is particularly challenging, as it usually requires simultaneous counteraction against a whole set of unfavourable environmental conditions, including heat, drought, high tropospheric ozone and salinity. It therefore seems useful to identify the survival strategies of plants native in desert environments. Date palm constitutes a plant species native in desert environments and cultivated worldwide in arid regions that have been studied intensively for stress defence during the last decade. The present review summarizes the current state of biochemical stress defence mechanisms including avoidance, osmotic and metabolic adjustments and reactive oxygen species scavenging, addresses whole-plant regulations and trade-off between stress compensation/defence and growth of date palms. The review advances our knowledge about how this typical desert species copes with both individual and multiple environmental stresses at the cellular to the whole-plant level, and identifies areas of future research required to fully understand the strategies of this plant species to survive in the desert, thereby contributing to efforts for the mitigation of climate change and desertification.

Medical Ozone as a Therapeutic Option in Musculoskeletal Pain Control: A Critical Review of Clinical Trials Considering Safety and Quality Indicators for Procedures and Devices.

Background: Drug therapies have been widely applied for pain management, however, there are important side effects such as those related to corticosteroids and opioids. Recent studies demonstrated promising results using medical ozone as a safe, effective, and low-cost intervention for pain control. Objective: to review and critically analyze clinical studies that used ozone therapy for musculoskeletal pain. Methods: a literature search of various databases was performed to identify relevant studies. From a total of 249 records, 27 studies were included. Quality indicators, human and device factors that strongly influence the generation of evidence were considered, such as study design and device safety. We also mitigated biases, considering the safety and efficacy of the intervention itself. Results: Regarding safety, 77 (8%) of studies reported no adverse effects; concerning efficacy outcomes, medical ozone shows to be an effective intervention on musculoskeletal pain control. Important information about used devices were missing. Conclusions: medical ozone shows to be safe and effective; qualification of health professionals as well as the device safety are mandatory. However, there is a lack of requirements to identify the best therapeutic scheme; further longer, clinical and rigorous trials are needed.

Air pollution exposure during pregnancy and preterm birth in Brazil.

Ambient air pollution is a significant environmental risk factor for adverse pregnancy outcomes, including preterm birth. However, the impact of different pollutants across various regions and trimesters of pregnancy has not been fully investigated in Brazil. This study aimed to examine the associations between exposure to PM2.5, NO2, and O3 during different trimesters of pregnancy and the risk of preterm birth across five regions of Brazil. We used logistic regression models to estimate the odds ratios (OR) of preterm birth associated with PM2.5, NO2, and O3 adjusting for potential confounders such as maternal age, education, and socioeconomic status. Our study included over 9.9 million live births from 2001 to 2018, with data obtained from the Ministry of Health in Brazil. On average, for each 1-µg/m3 increase in PM2.5, we estimated a 0.26 % (95 % CI: 0.08-0.44 %) increase in the risk of preterm birth nationally in the first trimester. For NO2, each 1ppb increase was associated with a percentage increase in preterm birth risk of 7.26 % (95 % CI: 4.77-9.74 %) in the first trimester, 8.05 % (95 % CI: 5.73-10.38 %) in the second trimester, and 7.48 % (95 % CI: 5.25-9.72 %) in the third trimester. For O3, each 1ppb increase was associated with a percentage increase in preterm birth risk of 1.24 % (95 % CI: 0.29-2.18 %) in the first trimester, 1.51 % (95 % CI: 0.60-2.41 %) in the second trimester, and 0.72 % (95 % CI: -0.18-1.62 %) in the third trimester. This study highlights the significant impact of ambient air pollution on preterm birth risk in Brazil, with significant regional variations. Our findings underscore the need for targeted public health interventions to mitigate the effects of air pollution on pregnancy outcomes, particularly in the most affected regions.

Cause of nocturnal surface ozone enhancement in the North China Plain.

The North China Plain (NCP), known for its dense population, extensive urbanization, and developed industry and agriculture, faces one of the foremost ozone (O3) pollution issues nationwide and even globally. Currently, most studies focus on daytime peak O3 levels, with insufficient understanding of the increase in nighttime O3 concentrations. Based on data from 204 national atmospheric composition monitoring sites in the NCP from 2015 to 2023, we investigated the characteristics of nocturnal surface O3 enhancement (NSOE) events and explored potential formation mechanisms. The mean annual frequencies of single-site and regional NSOE event in the NCP between 2015 and 2023 are 42 % and 21 %, respectively. The daytime peak O3 concentrations before and after NSOE events exceeded those during the corresponding periods of non-NSOE events by 84 ± 19 and 32 ± 15 µg/m3, respectively. The overall effect of the NSOE events was to decelerate the rate of decline in nighttime O3 concentrations and resulted in a reduction of NO2 and CO concentrations from 22:00 onwards. Low level jet (LLJ) and vertical mixing were the main factors affecting NSOE events in the NCP. The proportion of NSOE events affected by LLJ in four representative cities ranged from 57.6 % to 79.5 %. Furthermore, the high concentration of O3 in the residual layer before the NSOE event and the reduction of atmospheric stability during the NSOE event favored downward mixing of upper layer O3. The primary weather systems influencing the four most severe regional NSOE events were LLJ, typhoon, and cold fronts. The first two events were dominated by vertical mixing of O3, while the latter two events were mainly affected by horizontal transport. Our findings provide the first overview of NSOE events in the NCP from characteristics to mechanisms, emphasizing the necessity for future detailed studies based on nocturnal vertical O3 observations.

Air quality and health benefits of achieving carbon-neutrality in building sector over Beijing, China.

To meet the goal of the Paris Agreement, China pledges to realize the "Dual Carbon" targets by 2060. As the capital of China, Beijing plays a leading role in becoming zero-emission or carbon neutral in the future. We project the pollutants emissions of building sector based on current strict clean air policies (PO scenario) and China's carbon neutrality target by 2060 (CN scenario) from 2019 to 2050. Results show that PM2.5 concentration will increase by 2.62 µg/m3 under PO scenario; under the CN scenario, ozone concentration will increase by 2.53 µg/m3 but PM2.5 concentration will reduce by 9.04 µg/m3. It is projected that China carbon neutrality goals could avoid 11.12% of PM2.5-related health burden; With strict clean air policies, health burdens of ozone (3.9%) and PM2.5 (4.1%) could be avoided, respectively. This study highlights the importance of achieving co-benefits of air quality and public health.

Modification of gut and airway microbiota on ozone-induced airway inflammation.

Ground-level ozone (O3) has been shown to induce airway inflammation, the underlying mechanisms remain unclear. The aim of this study was to determine whether gut and airway microbiota dysbiosis, and airway metabolic alterations were associated with O3-induced airway inflammation. Thirty-six 8-week-old male C57BL/6 N mice were divided into 2 groups: sterile water group and broad-spectrum antibiotics group (Abx). Each group was further divided into two subgroups, filtered air group (Air) and O3 group (O3), with 9 mice in each subgroup. Mice in the Air and O3 groups were exposed to filtered air or 1 ppm O3, 4 h/d for 5 consecutive days, respectively. Mice in Abx + Air and Abx + O3 groups were exposed to filtered air or O3, respectively, after drinking broad-spectrum Abx. 24 h after the final O3 exposure, mouse feces and bronchoalveolar lavage fluids (BALF) were collected and subjected to measurements of airway oxidative stress and inflammation biomarkers, 16S rRNA sequencing and metabolite profiling. Hematoxylin-eosin staining of lung tissues was applied to examine the pathological changes of lung tissue. The results showed that O3 exposure resulted in airway oxidative stress and inflammation, as well as gut and airway microbiota dysbiosis, and airway metabolism alteration. Abx pre-treatment markedly changed gut and airway microbiota and promoted O3-induced metabolic disorder and airway inflammation. Spearman correlation analyses indicated that inter-related gut and airway microbiota dysbiosis and airway metabolic disorder were associated with O3-induced airway inflammation. Together, inhaled O3 causes airway inflammation, which may implicate gut and airway microbiota dysbiosis and airway metabolic alterations.

Genome-wide profiling of long non-coding RNA following ozone exposure: A randomized, controlled exposure trial.

BACKGROUND: Exposure to ambient ozone has been associated with extrapulmonary health, but the underlying mechanisms remain to be understood. LncRNAs are involved in the regulation of gene expression, but their regulatory mechanisms in ozone-related health effects are scarcely explored. OBJECTIVE: To investigate genome-wide lncRNA changes after short-term ozone exposure and their regulatory roles in ozone exposure and gene expression. METHOD: We conducted a randomized, crossover, controlled exposure trial in 32 healthy college students in Shanghai, China. Each participant received both 200-ppb ozone exposure and filtered air exposure for 2 h in a random order with a 14-day washout period. Blood samples were collected after each exposure and used for lncRNA sequencing. Differentially expressed lncRNAs between the two exposures were identified using orthogonal partial least squares discriminant analysis and linear regression analysis. LncRNAs-targeted mRNAs were mapped and subjected to enrichment analyses. We also constructed lncRNA-miRNA-mRNA networks. RESULTS: A total of 90 lncRNAs were differentially expressed after exposure to ozone, with 49 up-regulated and 41 down-regulated. Enrichment analyses suggested that these dysregulated lncRNAs were involved in a variety of biological processes, including those related to oxidative stress, inflammation response, and cell proliferation, development, and differentiation. Multiple pathways such as IL-17 signaling, NF-kB signaling, and Rho GTPases signaling were also enriched. Furthermore, the lncRNA-miRNA-mRNA network revealed that specific lncRNAs may regulate the expression of inflammation- and angiogenesis-related genes by interacting with miRNAs, such as NEAT1/hsa-miR-500a-3p/SIGLEC8, NEAT1/hsa-miR-6835-3p/SLC16A14, OIP5-AS1/miR-183-5p/EGR1, and SNHG25/hsa-miR-663a/FOSB axes. CONCLUSION: This study characterized a thorough profile of human lncRNAs following short-term ozone exposure and suggested the regulatory roles of these lncRNAs in ozone-induced inflammatory responses and angiogenesis, providing novel epigenetic insights into the mechanisms of the health effects of ozone exposure.

Efficient removal of succinic acid by continuous hydrodynamic cavitation combined with ozone and side influent injection.

Micropollutants (MPs) encompass a range of human-made pollutants present in trace amounts in environmental systems. MPs include pharmaceuticals, personal care products, pesticides, persistent organic pollutants, micro- and nano-plastics, and artificial sweeteners, all posing ecological risks. Conventional municipal wastewater treatment methods often face challenges in completely removing MPs due to their chemical characteristics, stability, and resistance to biodegradation. In this research, an Advanced Oxidation Process, combining hydrodynamic cavitation (HC) with dissolved ozone (O3) and side injection, was employed to efficiently degrade succinic acid (SA), an ozone-resistant compound and common byproduct. The HC/O3 process was run to treat different synthetic effluents, focusing on evaluating the influence of O3-to-total organic carbon (TOC) ratio, cavitation number (Cv) and O3 dosage. Notably, the results from a series of 14 experiments highlighted the critical significance of a low O3-to-TOC ratio value of 0.08 mg/mg and Cv value of 0.056 in HC for achieving efficient SA removal of 41.2% from an initial SA solution (106.3 mg/L). Regarding a series of four proof-of-concept experiments and their replications, the average TOC removal reached 62% when treating wastewater treatment plant effluent spiked with SA. This significant removal rate was achieved under initial conditions: Cv of 0.02, O3-to-TOC ratio set at 0.77 mg/mg, TOC concentration of 47.7 mg/L, 106 mg/L of SA, and a temperature of 25 °C. Notably, the electrical energy per order required for the 62% reduction in TOC was a modest 12.5 kWh/m3/order, indicating the potential of the continuous HC/O3 process as a promising approach for degrading a wide range of MPs.

Heatwave events and concurrent ozone concentrations between 2006 and 2022 at two sites in southern and northern Spain.

Hotter-than-usual days are becoming more common, such that heat waves are expected to increase in intensity, frequency, duration, and spatial extent in Spain. Within this framework, this paper looks at the combined effects of extreme temperatures and air pollution in two cities in Spain, Córdoba and Valladolid, over the period 2006-2022. Synoptic patterns and air mass movement were analysed during the eleven coincident heat waves at both locations in order to study what impact orography and local meteorology have on ozone concentrations. Weak flow conditions were the most frequent synoptic pattern in the Iberian Peninsula during heat waves. Moreover, west and local circulations characterised the main air trajectories at low levels (500 m agl), while southwest maritime advections and African air mass transport were more frequent at higher levels (1500 and 3000 m agl) in Córdoba and Valladolid, respectively. On average, maximum ozone values were higher in Córdoba (105.1 µg m-3) than in Valladolid (80 µg m-3) and were strongly correlated with extreme temperatures at both locations (r up to 0.8, p-value < 0.05). Mean temperature in Córdoba was 31.9 °C, with the maximum value reaching 43.7 °C, while temperatures in Valladolid were lower (28.3 °C and 37.3 °C, respectively). Calculation and assessment of some indices helped to understand the impact of extreme events. Caution actions based on the Heat Index characterised heat wave periods. Moderate risk was the general Air Quality Health Index feature recorded and reached a very high risk of unhealthy air quality in the June 2022 event in Córdoba.

Ozone disinfection of waterborne pathogens: A review of mechanisms, applications, and challenges.

Water serves as a critical vector for the transmission of pathogenic microorganisms, playing a pivotal role in the emergence and propagation of numerous diseases. Ozone (O3) disinfection technology offers promising potential for mitigating the spread of these pathogens in aquatic environments. However, previous studies have only focused on the inactivated effect of O3 on a single pathogenic microorganism, lacking a comprehensive comparative analysis of various influencing factors and different types of pathogens, while the cost-effectiveness of O3 technology has not been mentioned. This review synthesized the migration characteristics of various pathogenic microorganisms in water bodies and examined the properties, mechanisms, and influencing factors of O3 inactivation. It evaluated the efficacy of O3 against diverse pathogens, namely bacteria, viruses, protozoa, and fungi, and provided a comparative analysis of their sensitivities to O3. The formation and impact of harmful disinfection by-products (DBPs) during the O3 inactivation process were assessed, alongside an analysis of the cost-effectiveness of this method. Additionally, potential synergistic treatment processes involving O3 were proposed. Based on these findings, recommendations were made for optimizing the utilization of O3 in water inactivation in order to formulate better inactivation strategies in the post-pandemic eras.

Dry biofilms on polystyrene surfaces: the role of oxidative treatments for their mitigation.

Candida auris and Staphylococcus aureus are associated with a wide range of infections, as they exhibit multidrug resistance - a growing health concern. In this study, gaseous ozone, and ultraviolet-C (UVC) radiation are applied as infection control measures to inactivate dry biofilms of these organisms on polystyrene surfaces. The dosages utilised herein are 1000 and 3000 ppm.min for ozone and 2864 and 11592 mJ.cm-2 for UVC. Both organisms showed an increased sensitivity to UVC relative to ozone exposure in a bespoke decontamination chamber. While complete inactivation of both organisms (>7.5 CFU log) was realized after 60 mins of UVC application, this could not be achieved with ozonation for the same duration. However, a combined application of ozone and UVC yielded complete inactivation in only 20 mins. For both treatment methods, it was observed that dry biofilms of S. aureus were more difficult to inactivate than dry biofilms of C. auris. Compared to dry biofilms of C. auris, micrographs of wet C. auris biofilms revealed the presence of an abundance of extracellular material after treatments. Interestingly, wet biofilms were more difficult to inactivate than dry biofilms. These insights are crucial to preventing recalcitrant and recurrent infections via contact with contaminated polymeric surfaces.

Oxidative treatment can inactivate dry biofilms formed by C. auris and S. aureus.Both organisms showed an increased sensitivity to UVC compared to ozone.Dry biofilms of S. aureus were more difficult to inactivate than dry biofilms of C. auris.Wet biofilms of C. auris display a spongy appearance compared to its dry biofilms.Wet biofilms of C. auris proved more difficult to inactivate than its dry biofilms.

In-Situ Algal Control by Two-stage Nanobubble Technology in Taihu Lake: Efficacy and Ecological Impact.

Hydrodynamic cavitation and ozone nanobubble-coupled hydrodynamic cavitation have demonstrated effective algae control in laboratories, but their in-situ potential, especially impact on nutrient salt degradation and microbial communities remain unclear. This study applied two-stage nanobubble technology, combining hydrodynamic cavitation and ozone nanobubbles, in a 3300 m2 semi-enclosed area of Taihu Lake to address these gaps. Results show that the technology efficiently controls algae, reduces odors, improves anaerobic conditions, and lowers ammonia nitrogen. Over 20 days, chlorophyll-a concentration reduced by 77.46% and cyanobacterial phycocyanin by 89.47%. Additionally, the concentrations of 2-MIB, GSM, and DMTS fell below threshold values. Notably, the relative abundance of Cyanobacteria in sediment dropped from 8.53% in the control area to only 1.59% ∼ 3.65% in the experimental area. The technology also achieved a significant reduction in ammonia nitrogen, with removal efficiencies of 78.53% in the water column and 39.17% in sediments, though the removal of total phosphorus was limited. Furthermore, the two-stage nanobubble system enhanced the abundance of nitrogen-cycling microorganisms and genes in the water, while promoting nitrogen- and phosphorus-related microbial communities in sediments and inhibiting the cyanobacteria-associated genus Cyanobium PCC-6307. Thus, Two-stage nanobubble technology can be employed for in-situ algal control in aquatic ecosystems.

Marine sources of formaldehyde in the coastal atmosphere.

Elevated concentrations of formaldehyde and other carbonyl compounds are frequently observed in the marine atmosphere but are often significantly underestimated by atmospheric models. To evaluate the potential impact of marine sources on atmospheric formaldehyde, high-resolution measurements were conducted at a coastal site (∼15 m from the sea) during the summer in Qingdao, China. Observed formaldehyde levels averaged 2.4 ± 0.9 ppbv (1 ppbv = 10-9 L L-1), with peaks reaching 6.8 ppbv. Backward trajectories indicate that formaldehyde concentrations remained high in marine air masses. Formaldehyde exhibited weak correlations with primary pollutants such as NO and CO but showed strong correlations with marine tracers, notably methyl ethyl ketone and 1-butene. Chamber experiments confirmed that the photodecomposition of Enteromorpha released large amounts of formaldehyde and marine tracer species. When normalized to acetylene, the levels of formaldehyde, 1-butene, and MEK increased by factors of 3.8, 8.1, and 3.5, respectively. Results from an observation-based chemical box model simulation, which utilizes the Master Chemical Mechanism (MCM), revealed that formaldehyde contributes 56% to the primary source of HO2 radicals, while neglecting formaldehyde chemistry would lead to a 15% reduction in coastal ozone production rates. This study interlinks oceanic biology and atmospheric chemistry, advancing the understanding of the ocean's role as a significant source of organic compounds and its contribution to carbon cycling.