Increasing Surface UV Radiation in the Tropics and Northern Mid-Latitudes due to Ozone Depletion after 2010

Excessive exposure to ultraviolet(UV)radiation harms humans and ecosystems.The level of surface UV radiation had increased due to declines in stratospheric ozone in the late 1970s in response to emissions of chlorofluorocarbons.Following the implementation of the Montreal Protocol,the stratospheric loading of chlorine/bromine peaked in the late 1990s and then decreased;subsequently,stratospheric ozone and surface UV radiation would be expected to recover and decrease,respectively.Here,we show,based on multiple data sources,that the May–September surface UV radiation in the tropics and Northern Hemisphere mid-latitudes has undergone a statistically significant increasing trend[about 60.0 J m^(–2)(10 yr)^(–1)]at the 2σlevel for the period 2010–20,due to the onset of total column ozone(TCO)depletion[about−3.5 DU(10 yr)^(–1)].Further analysis shows that the declines in stratospheric ozone after 2010 could be related to an increase in stratospheric nitrogen oxides due to increasing emissions of the source gas nitrous oxide(N_(2)O).

UV-Catalytic Treatment of Municipal Solid-Waste Landfill Leachate with Hydrogen Peroxide and Ozone Oxidation

Theperformance of UV/H2O2,UV/O3,and UV/H2O2/O3 oxidation systems for the treatment of municipal solid-waste landfill leachate was investigated. Main objective of the experiment was to remove total organic carbon(TOC),non-biodegradable organic compounds (NBDOC) and color.In UV/H2O2 oxidation experiment, with the increase of H2O2 dosage,removal efficiencies of TOC and color along with the ratio of biochemical oxygen demand(BOD) to chemical oxygen demand (COD) of the effluent were increased and a better performance was obtained than the system H2O2 alone. In UV/H2O2 oxidation,under the optimum condition H2O2(0.2time),removal efficiencies of TOC and color were 78.9% and 95.5%, respectively,and BOD/COD ratio was significantly increased from 0.112 to 0.366.In UV/O3 oxidation,with the increase of O3 dosage,removal efficiencies of TOC and color along with BOD/COD ratio of the effluent were increased and a beter performance was obtained than the system O3 alone.Under the optimum condition UV/O3(50mg·min^-1),removal efficiencies of TOC and color were 61.0% and 87.2%,respectively,and BOD/COD ratio was significantly increased from 0.112 to 0.323. In UV/H2O2/O3 system,color removal and BOD/COD ratio were improved further and TOC removal efficiency was found to be 30.4% higher than the system UV/O3 without H2O2.

Disinfection of Primary Municipal Wastewater Effluents Using Continuous UV and Ozone Treatment

UV radiation and ozonation were investigated as disinfection alternatives for the wastewater treatment plant. The inactivation of total and fecal coliforms using ozone and ultraviolet radiation as separate treatments was evaluated. Different ozone concentrations (3 to 40 mg O3/L) were applied and UV fluencies ranging from 8.5 to 12 mJ/cm2 at different pH values (from 5 to 9) were tested. Best results were obtained for ozone doses near 20 mg/min with removals of 72% and 78% of fecal and total coliforms, respectively. The ozone also was capable of oxidizing organic matter in the effluent measured as COD (the highest removal obtained was 36% for 20 mg O3/min). Maximum bacterial resistance was observed at pH 7 in both cases. The UV light offered a high bacterial inactivation (over 80%) and the lowest bacterial inactivation was observed at pH 7. Finally, we obtained the electric energy per order (EEO, kWh/m3/order), defined as the electric energy (kW-h) required to degrade a contaminant by one order of magnitude in a unit volume of contaminated water, being noteworthy that EEO values for the UV process resulted were lower than those determined for the process with ozone in all the water flow tested.

Treatment Processes of Leachate from a Landfill by Advanced Oxidation Fenton and Ozone-UV

In this paper it is presented the results of advanced oxidation of leachates from a technified sanitary landfill located in the State of Querétaro, Mexico. One characteristic of already stabilized leachates from sanitary landfills like this case, is their difficult degradation, mainly because the organic matter contained is recalcitrant. For the samples collect, four sites were selected, where three points per site were sampled, measuring at each site the parameters: temperature, pH, conductivity, redox potential (ORP) and dissolved oxygen (DO) and leachate samples were collected. On the other hand, the Chemical Oxygen Demand (COD) of crude leachates, leachates acidified and leachates oxidized by Fenton reagent and Ozone-UV combined were analyzed. COD was used to monitor the degradation kinetics. With the results, the ArcGIS software was applied to study the distribution of temperature, dissolved oxygen and COD mainly in the leachate lagoon. For the application of Fenton reagent in the crude leachate oxidation, the pH was first adjusted and Fe2+/H2O2 ratio was optimized. The efficiency of Ozone-UV treatments was studied through COD degradation kinetics. The graphs of in (Ci/Co) vs time, showed that the kinetic processes are of order one, with very acceptable regression coefficients (R2) and extraordinarily similar speed constants (K). With Fenton oxidation, the highest percentage of COD degradation was achieved and with Ozone-UV oxidation, it was possible to practically degrade all the COD.

UV-Enhanced Room Temperature Ozone Sensor Based on Hierarchical SnO_2-In_2O_3

SnO2-ln2O3 hierarchical microspheres were prepared by the hydrothermal and solvothermal method. The morphology, phase crystallinity of the obtained SnO2-In203 were measured by X-ray diffraetion（XRD）, scan electron microscopy（SEM）, respectively. A room temperature ozone sensor based on SnO2-In2O3 hierarchical microspheres was fabricated and investigated. The gas sensing properties of the sensor using SnO2-In2O3 strongly depended on the proportion of SnO2 and In2O3. The sensitivity and response/recovery speed were greatly enhanced by UV illumination. A gas sensing mechanism related to oxygen defect was suggested.

UV-ozone-treated MoO_3 as the hole-collecting buffer layer for high-efficiency solution-processed SQ:PC_(71) BM photovoltaic devices

The enhanced performance of a squaraine compound, with 2,4-bis[4-（N,N-diisobutylamino）-2,6-dihydroxyphenyl] squaraine as the donor and [6,6]-phenyl-C71-butyric acid methyl ester （PC71BM） as the acceptor, in solution-processed or- ganic photovoltaic devices is obtained by using UV-ozone-treated MoO3 as the hole-collecting buffer layer. The optimized thickness of the MoO3 layer is 8 nm, at which the device shows the best power conversion efficiency （PCE） among all devices, resulting from a balance of optical absorption and charge transport. After being treated by UV-ozone for 10 min, the transmittance of the MoO3 film is almost unchanged. Atomic force microscopy results show that the treated surface morphology is improved. A high PCE of 3.99% under AM 1.5 G illumination （100 mW/cm2） is obtained.

Ground－based measurements of column abundance of ozone and UV－B radiation over Zhongshan Station，Antarctica in the 1993＂OzoneHole＂

Measurements of column amounts pf ozone, and UV-B radiation by using Brewer Ozone Spectrophotometer over Zhongshan Station (69. 38°S, 76. 37°E ),Antarctica in the 1993 'Ozone Hole' are introduced. Low total ozone amount near or below 200 DU had been detected from August to November with focus moon light or direct solar light. High coherent variation between the ozone column amounts and the temperatures within altitude from 70 hpa to 50 hpa is very obvious. UV-B radiation is greatly controlled by the Solar Zenith Angle (SZA),total ozone amount as well as the sky conditions. Preliminary statistics analysis shows that noontime biologically weighted damaging UV-B (DUV-B) dose rate is a negative exponential function of the ozone slant column abundance (OSCA).The ratios of noontime irradiance for wavelength at 300.5 urn to that at 323. 5 nm reveal that ozone is one of the most important factors for the surface UV-B enhancing during the ozone depletion period.

Treatment of Swine Slurry by an Ozone Treatment System to Reduce Odor

Development of a technology that can reduce the odor of liquid swine manure during agitation and land application could prove beneficial to the swine industry. The purpose of this study was to evaluate a commercial ozone treatment system for swine slurry under production scale conditions. The facility used for this study was a curtain sided finishing building housing 500 grow–finish market hogs located over a manure pit measuring 12.2 m wide × 25.9 m long × 2.4 m deep with a total pit capacity of 770,142 l, containing 577,607 l. The system evaluated exposes air to ultra-violet light creating O3. The O3 is then injected into slurry at a rate of 851.6 l/min. treating 51,097 l/h. In this study the entire pit contents were treated every 11.3 h. At 0, 24, 48, and 96 h two slurry samples were collected with a 3.05 m probe and six air sample bags were collected via a vacuum pump. No significant differences were detected in slurry samples between time periods. Mean slurry values were 13.6 ± 4.6% solids dry wt., 850 ± 70 mg/l settable solids, 54,200 ± 4384 mg/l total suspended solids, 61,050 ± 12,657 mg/l chemical oxygen demand, 0.86 ± 0.14%N, 0.49 ± 0.27%P, 0.45 ± 0.01%K and dissolved oxygen below detection limits. Ammonia concentrations decreased (P = 0.004) from 0 to 96 h. Odor panelists analyzed air samples for intensity at recognition (IR), offensiveness at recognition (OR), intensity at full strength (IFS) and offensiveness at full strength (OFS). Panelists found OR, IFS and OFS were reduced (P < 0.01) at 48 h and 96 h compared to 0 h and IR was reduced (P < 0.04) at 24 h and 48 h and not at 96 h but trended lower (P = 0.12) at 96 h. The system evaluated significantly improved air quality within the building suggesting that odor emanating from swine buildings and odor generated during land application of slurry should be reduced.

磁混凝-UV/O_(3)深度处理诺氟沙星制药废水工艺研究

以某诺氟沙星制药企业生物处理单元出水为试验用水,探究磁混凝-UV/O_(3)工艺对制药废水深度处理的效果。磁混凝试验中,COD去除方面,聚合硫酸铝铁(PFS)絮凝效果明显优于聚合氯化铝(PAC)和聚合硫酸铝铁(PAFS);COD、色度、浊度去除效果方面,阳离子聚丙酰胺(CPAM)助凝效果明显优于阴离子聚丙酰胺(APAM)及非离子聚丙酰胺(NPAM);48μm磁粉投加量为300 mg/L,PFS投加量为400 mg/L,CPAM投加量为6 mg/L,投加顺序为两段式磁粉+PFS—CPAM。在UV/O_(3)实验中,调整UV/O_(3)工艺:臭氧投加量为26 mg/min,初始pH为9,初始温度为20℃,氧化时间为60 min。经磁混凝-UV/O_(3)联合工艺处理后,出水COD小于30 mg/L,色度小于2倍,浊度低于1 NTU,满足当地《贾鲁河流域水污染物排放标准》(DB 41/908—2014)。

Degradation of nitrobenzene in aqueous solution by ozone-ceramic honeycomb

The degradation of nitrobenzene by ceramic-honeycomb catalyzed ozonation was investigated. The results showed that the presence of ceramic honeycombs significantly increased the oxidation rate of nitrobenzene by ozone compared to the case of ozone oxidation alone. In this paper, the effects of various factors on the catalytic oxidation were investigated, such as the amount of catalysts, the ozone dosage, the temperature, the pH value and the presence of tert-butanol. With the addition of tert-butanol the removal of nitrobenzene decreased sharply, which appeared to support that, the degradation of nitrobenzene by ozonation followed a radical type mechanism. The EPR experiments verified that higher nitrobenzene removal rate was attributed to more OH radicals generated in the catalyzed ozonation than ozonation alone.

Pilot plant study on ozonation and biological activated carbon process for drinking water treatment

A study on advanced drinking water treatment was conducted in a pilot scale plant taking water from conventional treatment process. Ozonation-biological activated carbon process （O3-BAC） and granular activated carbon process （GAC） were evaluated based on the following parameters： CODMn, UV254, total organic carbon （TOC）, assimilable organic carbon （AOC） and biodegradable dissolved organic carbon （BDOC）. In this test, the average removal rates of CODMn, UV254 and TOC in O3-BAC were 18.2%, 9.0% and 10.2% higher on （AOC） than in GAC, respectively. Ozonation increased 19.3-57.6 μg Acetate-C/L in AOC-P17, 45.6-130.6 μg Acetate-C/L in AOC-NOX and 0.1-0.5 mg/L in BDOC with ozone doses of 2 8 mg/L. The optimum ozone dose for maximum AOC formation was 3 mgO3/L. BAC filtration was effective process to improve biostability.

Toxicity and Carcinogenicity of Ozone in Combination with 4-(N-methyl-N-nitrosamino)-1-(3-pyridyl)-1-butanone and Dibutyl Phthalate in B6C3F1 Mice for 16 and 32 Weeks

Objective To evaluate the toxic and carcinogenic potential of ozone alone or in combination with 4-（N-methyl-N-nitrosamino）-1-（3-pyridyl）-1-butanone （NNK） and/or dibutyl phthalate （DBP）. Methods Male and female B6C3F1 mice were exposed, through inhalation, intravenous administration and diet, to 0.5 ppm of ozone, 1.0 mg/kg of NNK and 5000 ppm of DBP, individually and in combination for 16 and 32 weeks. Results No treatment-related death was seen, but significant differences in body and organ weights between control and treated mice were observed during the study. No incidence of lung tumor incidence was recorded in mice exposed to either ozone alone or combined treatment. Oviductal carcinomas were observed in female mice exposed to ozone or DBP alone for 16 weeks and ozone in combination with NNK and DBP for 32 weeks. Conclusion Although ozone alone and in conjunction with NNK and/or DBP does not induce lung cancer under our experimental conditions, they induce oviductal carcinomas in B6C3F1 mice.

Ozone decomposition under the irradiation of 253.7 nm in the presence of methyl bromide

In this paper the mechanism and kinetic of ozone decomposition under the irradiation of 253.7 nm UV\|light were studied. The quantum yield of the ozone depletion in the presence of methyl bromide is further determined and a reaction model is provided to explain the experimental fact.

Pilot Study on Nanofiltration Combined with Ozonation and GAC for Advanced Drinking Water Treatment

A pilot-scale study of advanced drinking water treatment was carried out in test site, and a combination of ozonation, granular activated carbon (GAC) and nanofiltration was employed as the experimental process. By optimizing the operational parameters of ozonation and GAC, a large quantity of micro-pollutants in drinking water was removed, which made the post-positioned nanofiltration operate more reliably. It was evident that nanofiltration shows good performance for removing residual organic matter, meantime partial minerals can also be retained by nanofiltration. Therefore the quality of drinking water can be further improved. In addition, NF membrane fouling and scaling can be solved by concentrate recycling, anti-scalant dosing and chemical rinsing effectively. By GAC adsorption for the residue chlorine and ozone self-decomposition, their oxidation on NF membrane material can be eliminated completely.

Histopathological changes in retinas and F-ERG features of streptozotocin-induced diabetic rats treated with ozone

AIM： To study the histopathological changes in the retina and flash electroretinogram （F-ERG） features of ozone-treated streptozotocin （STZ）-induced diabetic rats. METHODS： Seventy male Sprague Dawley rats were grouped as follows： blank group （GB, n=10）, model control group （GM, n=18）, ozone group （GOs, n=19）, and oxygen group （GO2, n=18）. The model was induced by single intraperitoneal injection of STZ. Ozone or oxygen enteroclysm was given twice per week for 4wk. F-ERG and histopathological examinations were performed one month after treatment. RESULTS： Under dark adaption, as compared to GB, the other groups each had differential decreases in the a-wave amplitudes （P〈0.05）; the latencies were delayed in GM, GO2, and GO3 rats （P〈0.05）. Similar results were observed under light adaption, with the exception that the a-wave of the amplitudes （F=0.28, P〉0.05）. There were significant differences in the apoptosis index among the groups （P〈0.05）. Under ozone treatment, apoptosis was decreased in GO3 as compared to GM and GO2 . CONCLUSION： Ozone administration alleviates nerve damage and reduces pathology and apoptosis in the retinas of diabetic rats.

Causes of Ozone Layer Depletion and Its Effects on Human: Review

This study was conducted at University of Gujrat during 2014-2015 as a term paper for Master of Philosophy. The data regarding effect of ozone depletion on human was reviewed and compiled as a review paper from various published articles of international reputed journals, annual/environmental reports of recognized organization and e-books. The causes, mechanism and bio-effects of ozone layer depletion on humans were addressed. It is revealed that introduction of Chloroflourocarbons (CFCs) in the environment is the most rated cause of said depiction. Ozone depletion is allowing the UV radiation to earth surface. The exposure to these radiations is severely affecting all life forms on earth, especially the humans. Permanent or temporary blindness, skin cancer and immunity suppression are the main effects of these radiations reported by various researchers on humans. The prospects of ozone recovery are still undiscovered. The current situation of ozone depiction demands urgent remedial measures to protect lives on this earth.

A method for calculating the total ozone amount in the clear skies

A new method for calculating the clear day total ozone amount was obtained by the regression analysis of the observation data of ozone,solar UV radiation, and meteorological parameters.With this method the monthly mean total ozone amounts for the year 1991 in Beijing were calculated. Generally, the calculated values agree well with the Dobson spectrophotometer measurements, the average relative deviation between them being less than 2. 2%. According to the F-test,the photochemical reactions in the atmosphere,the solar UV radiation,and the aerosols are three most important factors to affect the column total ozone amount.

Development of Atmospheric Plasma Sprayed Dielectric Ceramic Coatings for High Efficiency Tubular Ozone Generators

Oxidative degradation of hazardous materials by ozone treatment like in sterilization of water, dump waste, pulp bleach and chemical processing, is superior to the traditional chlorine chemistry with respect to by-products and environmental protection. For an efficient and cost effective production of ozone for applications in drinking water and wastewater purification, a new concept of tubular composite material components has been developed. A borosilicate glass tube was coated with a layer system consisting of an intermetallic electrode and a dielectric oxide ceramic surface layer. Thermo-mechanical and dielectric properties are investigated with respect to the use of different thermal spray powders as well as the use of a high and a low energetic atmospheric spray gun. The materials and ozone production system of thermal sprayed ozonizer tubes are described and analyzed.