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  • Statistical Behavior of O3, OX, NO, NO2, and NOx in Urban Environment
    Ozone Sci. Eng. (IF 1.253) Pub Date : 2019-05-02
    Amaury de Souza; Deniz Ozonur

    This paper presents the results of the statistical modeling of the ozone concentration in Campo Grande, Brazil in 2016. Five sets of data, summer (January–March), autumn (April–June), winter (July–September), spring (October–December), and all year round were used. The results show that the maximum concentrations of oxidants occur at 3:00 p.m., the diurnal NO variation, the concentrations show a cycle with two peaks at 7:00 and the other at 11:00 p.m. It has been found that the best distribution for the five datasets is the lognormal distribution of three parameters. The seasonality of the datasets shows greater asymmetry during the summer, due to the greater tail distribution, mainly due to the greater photochemical activity.

  • Editorial
    Ozone Sci. Eng. (IF 1.253) Pub Date : 2019-12-14
    Barry L. Loeb

    (2020). Editorial. Ozone: Science & Engineering: Vol. 42, No. 1, pp. 1-2.

  • Improving Dewaterability and Other Properties of Citric Acid Wastewater Treatment Sludge by Ozone and Peroxone
    Ozone Sci. Eng. (IF 1.253) Pub Date : 2019-04-12
    Ning Ding; Can Peng; Hong Liu; Yuxiao Ren; Xiao Wang; Ping Wang; Liming Dong; Xiuyu Hu

    The efficacies of ozonation and peroxone (O3/H2O2) pretreatments were compared for citric acid wastewater sludge conditioning with the objective of improving dewatering characteristics of the sludge. Treatment with 84 mg O3/g dry solid (DS) and 12.5 mg/g DS H2O2 greatly enhanced the effectiveness of ozonation, providing sludge dewaterability similar to that obtained by ozonation at 250 mg O3/g DS. Most importantly, treatment of citric acid wastewater sludge with 84 mg O3/g DS and 12.5 mg/g DS H2O2 led to the preservation of the nutrient elements nitrogen, phosphorus, and potassium in the sludge with a minimal volatile suspended solids/total suspended solids reduction of 5.5%, which is much lower than that with ozonation at 250 mg O3/g DS.

  • UV-induced Persulfate Oxidation of Organic Micropollutants in Water Matrices
    Ozone Sci. Eng. (IF 1.253) Pub Date : 2019-04-09
    Niina Dulova; Eneliis Kattel; Balpreet Kaur; Marina Trapido

    The efficacies of UV photolysis, UV-activated persulfate (UV/PS), and combined UV/Fe2+-activated persulfate (UV/PS/Fe2+) systems for degrading of different organic micropollutants in ultrapure water and groundwater were examined and compared. The studied micropollutants belonging to the different classes involved an artificial sweetener acesulfame K (ACE), beta-lactam antibiotic amoxicillin (AMX), and endocrine disrupting compound 4-nonylphenol (NP). Among the studied systems, the UV/PS/Fe2+ process showed the highest performance both in degradation and in mineralization of ACE (UVA-induced systems; kapp = 0.126 1/min and 80.3% TOC removal) and AMX (UVC-induced systems; kapp = 1.383 1/min and 85.4% TOC removal), followed by the UV/PS process. In the case of NP trials, the application of UVC/PS systems was the most promising, and after careful adjustment of oxidant concentration, it demonstrated a considerable improvement in the target compound degradation (at a NP/PS molar ratio of 1/4 kapp = 0.024 1/min) compared with the UVC photolysis (kapp = 0.016 1/min). Irrespective of the applied UV-induced treatment process, the efficacy of target compounds degradation was lower in groundwater as compared with ultrapure water trials.

  • Effectiveness of Bio-Activated Carbon Filtration and Ozonation on Control of Halo Acetic Acids Formation during Chlorination of Ganga River Water at Kanpur, India
    Ozone Sci. Eng. (IF 1.253) Pub Date : 2019-04-26
    Nagasrinivasa Rao Naladala; Rambabu Singh; A.S. Venkatesh; P. Bose; Prasad Babu K; I. D. Narayan

    Chlorinated water from River Ganga is the main source of drinking water in Kanpur, India. But, this water contains a significant amount of disinfection by-products (DBPs) that include haloacetic acids (HAAs) as a major contributor, which pose a carcinogenic risk on long-term ingestion. Therefore, in order to control HAAs formation, different combinations of ozonation and bio-activated carbon filtration (BAC-filtration) were studied. The results elucidate that slight ozonation followed by BAC-filtration proved effective in reducing (75.8%) HAAs formation and meet the USEPA drinking standards. These findings open a path to explore cost-effective treatment techniques in continuous mode for safe drinking water.

  • Inactivation of Fusarium oxysporum Conidia in Soil with Gaseous Ozone – Preliminary Studies
    Ozone Sci. Eng. (IF 1.253) Pub Date : 2019-04-28
    Jhon Harley Muñoz Romero; Cindy Alejandra Sepúlveda Cadavid; Natalie Cortés; Julián Esteban López Correa; Juan David Correa Estrada

    In this study, the efficiency of gaseous ozone (O3) injected in the soil as an oxidizing agent for the inactivation of F. oxysporum was evaluated under laboratory conditions. The results show the treatment reached an inactivation efficiency of 76% after an applied dose of 0.40 g O3 kg −1 soil. This shows that the injection of O3 can be a viable alternative to control pathogenic organisms in the soils. Nevertheless, it is clear that more studies on determining the effects of this treatment on soil quality are needed.

  • Antimicrobial Activity of Ozone against Pathogenic Oral Microorganisms on Different Denture Base Resins
    Ozone Sci. Eng. (IF 1.253) Pub Date : 2019-06-05
    Yeliz Hayran; Sule Tugba Deniz; Ali Aydın

    The present study aimed to evaluate the antimicrobial effect of gaseous ozone against specific oral pathogens on denture base resins. 1080 round samples were prepared (10mm-diameter, 2mm-thickness). Candida albicans, Streptococcus mutans, Streptococcus gordonii, and Aggregatibacter actinomycetemcomitans, polyamide-Deflex, heat-cured polymethyl-methacrylate (PMMA)-QC-20, and cold-cured-PMMA-Meliodent. The doses and durations: 25, 50 and 100µg/ml, 5, 10, 20, 30 minutes. For Cell viability (CV) MTT was used. 100µg/ml was most effective dose for C. albicans, S .gordonii, and A. actinomycetemcomitans were in heat-cured-PMMA and polyamide for S.mutans. For polyamide, lowest CV was 43% in S.mutans and A.actinomycetemcomitans. CV of heat-cure and cold-cure PMMA were 31% and 32% in S.gordonii, respectively. CV was similar for all resins and durations in S.mutans and A.actinomycetemcomitans and for polyamide for C.albicans and for heat-cure PMMA for S.gordonii. 30-min ozone application killed 80% of all microorganisms in all resins except for C.albicans in polyamide (65% cell death) and cold-cure PMMA (57% cell death). Optimal dose/duration combination was 100 µg/ml-10 min. Gaseous ozone can be considered as an effective cleansing agent for denture base resins.

  • Optimization of Ozonation Process for Disinfection of Dental Unit Waterlines Using Response Surface Methodology
    Ozone Sci. Eng. (IF 1.253) Pub Date : 2019-06-10
    Mohsen Haghighi; Vahid Kazemi Moghaddam; Arasb Dabbagh Moghaddam; Nastuna Ghanbari Sagharloo; Reza Kouhi

    The reduction of microbial contamination in dental unit waterlines (DUWLs) appears to be necessary because of a potential risk of infections in immunocompromised patients and medical staff, which are regularly exposed to water and aerosols generated from DUWLs. In the present study, the qualitative and quantitative microbial contamination of water in DUWLs were determined and the conventional biomedical diagnostic tests were applied to identify microorganisms. A 3-level, 2-factor central composite design was utilized to investigate the effects of chief operating parameters and optimize ozone disinfection conditions. Also, the activity of three disinfectant (ozone, NaOCl, and peracetic acid) in microbial decontamination of DUWLs were compared. The results indicated that Microbacterium laevaniformans were the most prevalent genera (21%) among both Gram-negative and positive species in all samples. Regression analysis illustrated the good fit of the experimental data to the predicted model with R2 and R2adj correlation coefficients of 0.988 and 0.980, respectively. Moreover, under the optimal circumstances (Ozone concentration = 1.2 ppm and reaction time = 13.5 min) the disinfection efficiency was 97.52%. The results also revealed that ozone was effective disinfectant to reduce prevalent genera (with the removal of 93.75%, 92.57% and 96.15% of Pseudomonas aeruginosa, Microbacterium ‎laevaniformans, and Alcaligenes faecalis, respectively) and already formed biofilms under optimum conditions. Based on achieved results, ozone was highly effective on microbial decontamination compared to peracetic acid and NaOCl disinfectant and can be used for disinfection of DUWLs.

  • Prediction of Ozone Concentration in Ambient Air Using Multilinear Regression and the Artificial Neural Networks Methods
    Ozone Sci. Eng. (IF 1.253) Pub Date : 2019-04-08
    Milica Arsić; Ivan Mihajlović; Djordje Nikolić; Živan Živković; Marija Panić

    This article presents the results of the statistical modeling of the ground-level ozone concentration in the air in the close vicinity of the city of Zrenjanin (Serbia). This study is aimed at defining the dependence of ozone concentration on the following predictors: SO2, CO, H2S, NO, NO2, NOx, PM10, benzene, toluene, m,p-Xylene, o-Xylene and ethylbenzene concentration in the air, as well as on the meteorological parameters (the wind direction, the wind speed, air pressure, air temperature, solar radiation, and RH). Multiple linear regression analysis (MLRA) and artificial neural networks (ANNs) were used as the tools for the mathematical analysis of the indicated occurrence. The results have shown that ANNs provide better estimates of ozone concentration on the monitoring site, whereas the multilinear regression model once again has proven to be less efficient in the accurate prediction of ozone concentration.

  • Water-Dissolved Ozone Mediates Potyvirus Sanitation during In Vitro Propagation of Dioscorea Cayenensis Subsp. Rotundata (Poir.) Miège
    Ozone Sci. Eng. (IF 1.253) Pub Date : 2019-04-02
    José Efraín González Ramírez; Manuel Cabrera Jova; Annia Robaina; Daniel Rodríguez Pérez; Aramis González Cadalso; Orelvis Portal

    Yam (Dioscorea spp.) is an important food source for a large part of the population in tropical regions. However, yam is susceptible to a range of serious and debilitating diseases including viruses. The application of water-dissolved ozone (1.5 ppm for 10 min) allowed to get potyvirus-free in vitro yam plants, with an efficiency rate statistically similar to the electrotherapy (63.5% and 62.5%, respectively). Besides, the application of ozone stimulated the growth of the in vitro-produced plants, which represent an important advantage over other sanitation methods used during the Biotechnology Seed Production program of yam in Cuba.

  • Effects of Ozone Treatment on Microbiological Quality and Physicochemical Properties of Turkey Breast Meat
    Ozone Sci. Eng. (IF 1.253) Pub Date : 2019-08-12
    Ufuk Gokce Ayranci; Orhan Ozunlu; Haluk Ergezer; Hakan Karaca

    The effects of ozone treatment (1 × 10−2 kg m−3, for up to 8 h) on quality parameters of turkey meat were investigated. Ozone was effective in inactivating microorganisms. Approximately 2.9, 2.3 and 1.9 log reductions were achieved in the counts of total aerobic mesophilic bacteria, Enterobacteriaceae and yeast-mold, respectively. Ozone caused significant changes in carbonyl contents, thiobarbituric acid reactive substances, color and pH values of the samples. Water holding capacity and cooking yield of treated samples increased significantly (p < .05). This is the first report demonstrating that quality parameters of turkey breast meat are markedly affected by ozone treatment.

  • What’s New in Ozone?
    Ozone Sci. Eng. (IF 1.253) Pub Date : 2019-11-20
    Barry L. Loeb

    (2019). What’s New in Ozone? Ozone: Science & Engineering: Vol. 41, No. 6, pp. 489-489.

  • Upcoming IOA Meetings
    Ozone Sci. Eng. (IF 1.253) Pub Date : 2019-11-20

    (2019). Upcoming IOA Meetings. Ozone: Science & Engineering: Vol. 41, No. 6, pp. 490-490.

  • Ozone: An Advanced Oxidation Technology for Starch Modification
    Ozone Sci. Eng. (IF 1.253) Pub Date : 2019-03-01
    R. Pandiselvam, M.R. Manikantan, V. Divya, C. Ashokkumar, R. Kaavya, Anjineyulu Kothakota, S.V. Ramesh

    Ozone processing is one of the encouraging non-thermal and bio-friendly techniques in the food processing sector. The applicability of ozone technology in food industry is increasing due to its antimicrobial action and modification of functional properties of the foods. The structural modifications of starches have major applications in the food and bakery industry for producing products with increased shelf life, improved texture, and retention of moisture content. The positive response of ozonation in carboxyl and carbonyl group alters the viscosity of starch molecules. Rheological characteristics like low viscosity even at an increased concentration, desirable binding properties, and film-forming ability have increased its use in the food processing industry. The influence of ozonation in the physicochemical properties is mainly retrogradation and cross-linking of amylose and amylopectin molecules and enzymatic modifications. Ozonation cause change in crystallinity, viscosity, expansion ratio, and gelatinization temperatures. Finally, ozonation induces many possible changes in native starches for the effective utilization in the processing sectors. In this review, starch modifications utilizing ozone and various research achievements and scientific reports focusing on the effect of ozonation in terms of physical, chemical, and thermal properties of native starches and on the possible modifications have been summarized and discussed. In conclusion, ozone is a green technology that can be effectively used as an alternative oxidation technique for starch modification.

  • An Integrated Approach to Lysis-Cryptic Growth (Sludge Ozonation) and Sequencing Batch Reactor Coupled to an Anaerobic Side-Stream Reactor (SBR-ASSR): Performance and Characteristics
    Ozone Sci. Eng. (IF 1.253) Pub Date : 2019-02-12
    Moslem Salehiziri, Hasan Amini Rad, John T. Novak

    Anaerobic side-stream reactors (ASSR) have been suggested to reduce waste activated sludge volumes benefiting from relatively low capital/operation costs and design simplicity. In this study, an evaluation of the feasibility of combining the ASSR system with the lysis-cryptic growth (ozonation) process was made so that a part of the sludge which passed through the ASSR anaerobic tank would be then treated by ozonation before returned to the aeration tank. The main independent factor was the ozonation flowrate (OFR), which is defined as the percent of return sludge which passed through the both the anaerobic tank and the ozonation unit. Three systems were studied, an ASSR control without ozonation (OFR-0), a combined ASSR with ozonation designated as OFR-2.5 (anaerobic interchange rate [AIR] of 10% per day and 25% of the exchanged sludge being ozonated [ozone interchange rate or OIR]), and OFR-3.1 (AIR = 12.5%, OIR = 25%). The results revealed that the insertion of an ozonation step led to an enhanced total microbial activity, eukaryotic population, and nitrogen removal. The linear relationship between the observed yield and the specific oxygen uptake rate indicated that microbial predation was the major relevant mechanism for the enhanced sludge reduction. The results of measurements of particle size distribution, and sludge dewaterability rates suggest that additional studies are needed to better understand and optimize this system.

  • The Function of Surface Hydroxyl Groups of Incorporated Alumina on Catalytic Ozonation of Heavy Oil Produced Water
    Ozone Sci. Eng. (IF 1.253) Pub Date : 2019-02-22
    Qiushi Zhu, Wei Yao, Haibo Ye, Shuofan Li, Mengmeng Si, Jinfu Chen, Feifei Chen

    γ-Al2O3 was incorporated with SiO2 and used as carrier to support Ni and Cu oxides for catalytic ozonation of heavy oil produced water. The change of catalytic activity was in accordance with that of surface hydroxyl density after incorporation or reuse of catalysts. Nitrogen adsorption and X-ray power diffraction analysis indicated that the specific surface area decreased and the mineral phase and crystal structure of metal oxides unchanged after incorporation. The results confirmed that the neutral surface hydroxyl groups of the carrier were the active sites during catalytic ozonation. Increasing of surface hydroxyl could be another way of improving the catalytic efficiency of catalytic ozonation.

  • Effect of Different Concentrations of Ozone on in Vitro Plant Pathogens Development, Tomato Yield and Quality, Photosynthetic Activity and Enzymatic Activities
    Ozone Sci. Eng. (IF 1.253) Pub Date : 2019-03-29
    Zhenghong Guo, Zuoming Wang, Yingdong Li, Quanxi Wang

    As an effective alternative to traditional pesticides, ozonated water has been used for direct immersion and spraying applications, respectively, against the pathogenic bacterium Ralstonia solanacearum (R. solanacearum) and fungus Alternaria solani (A. solani) that are pathogens of tomato. Immersing R. solanacearum in 0.8 mg/L ozonated water resulted in complete inactivation, while the growth-inhibition rates of the A. solani radial mycelia gradually increased with a 67.0% decrease compared to those of the control at an ozonated water concentration of 7.5 mg/L. This indicated that ozonated water was effective at restraining pathogens in the tomato plant. In addition, spraying wild tomato species (Solanum lycopersicum) plants with ozonated water at concentrations below 10 mg/L for 25 d had no negative effects after treatment compared to those of the control. Photosynthetic activities and the antioxidant system response in the untreated and ozonated water-treated plant leaves had no observable changes. To determine the optimal ozonated water concentration for the pathogen and its host plant, we examined a variety of modes of action, and then, below 10 mg/L of ozonated water. Thus, ozonated water not only inhibits the proliferation of plant pathogens, but is an effective alternative to the pesticides traditionally used to prevent disease in agricultural production.

  • Graphite Felt Supported MgO Catalytic Ozonation of Bisphenol A
    Ozone Sci. Eng. (IF 1.253) Pub Date : 2019-03-21
    Xiaofang Zhang, Tongdong Shen, Yalei Ding, Shaoping Tong

    Graphite felt supported magnesium oxide (MgO/GF) catalyst was prepared by the equal volume impregnation method. Bisphenol A (BPA) was chosen as the target contaminant to be degraded by different ozone-based processes. The results of X-ray powder diffraction/scanning electron microscopy showed that MgO was uniformly loaded on graphite felt. The results showed that the removal percentages of BPA and COD by MgO/GF catalytic ozonation in 9 min could reach 88.2 and 42.1, respectively, but only 48.2 and 10.5 by O3 under the same conditions. The catalytic activity of the MgO/GF catalyst was relatively stable in 5 recycling tests. The mechanism study deduced that the high activity of MgO/GF in ozonation of BPA resulted from effective mitigation of pH change of the solution. The results show that MgO/GF is a potential catalyst in ozonation of refractory chemicals.

  • Ozonolysis Post-Treatment of Anaerobically Digested Distillery Wastewater Effluent
    Ozone Sci. Eng. (IF 1.253) Pub Date : 2019-03-22
    Benton Otieno, Seth Apollo, John Kabuba, Bobby Naidoo, Aoyi Ochieng

    In this study, the ozonolysis of real anaerobically digested distillery wastewater (DWW) was carried out. The effect of operating parameters, such as pH, initial concentration, and ozone dosage, on the efficiency of ozone utilization, color removal, and sludge solubilization was studied. The highest ozone utilization of 99% was observed at the highest initial concentration (COD of 3000 mg/L) and lowest ozone flowrate (22.5 mg O3/L/min), but with a very low color reduction of 20%, after 60 minutes of ozonolysis. To achieve a higher color reduction >80% and at ozone utilization >95%, the DWW had to be diluted twice (COD 1500 mg/L), and the flowrate doubled to 45 mg O3/L/min. The reduction in color signified the oxidation of the color causing biorecalcitrant aromatic melanoidin compounds. This was confirmed by the 47% reduction in ultraviolet absorbance at 254 nm indicating the breakdown of the complex aromatic compounds into low molecular weight organics. Moreover, increases in average oxidation state from −0.6 to −0.2 suggested a decline in aromaticity and formation of easily biodegradable aliphatic compounds. The ozonolysis process was found to follow the first-order reaction kinetic model with the highest rate constant of 0.0326 min−1 obtained. A reduction in suspended COD by 88% indicated solubilization of the sludge contained in the effluent.

  • Effect of Ozone as a Disinfectant on Microbial Load and Chemical Quality of Raw Wheat Germ
    Ozone Sci. Eng. (IF 1.253) Pub Date : 2019-07-18
    Sara Jafari Sarooei, Azam Abbasi, Samaneh Shaghaghian, Enayat Berizi

    While raw seed sprouts can threaten consumers’ health by foodborne pathogens, thermal or chemical disinfection of sprouts may cause some negative effects; instead, ozone can be a good alternative treatment. This study investigated the effect of nine ozone treatments (2000, 4000, and 6000 ppm within 1, 2, and 4 h) on wheat germ chemical compositions and microbial flora. The results indicated that ozonation with 2000 ppm during 4 h was the optimized treatment with the greatest effect on decreasing the microbial load while it had the minimum effect on antioxidant properties, lipid oxidation, and moisture content of raw wheat germ.

  • The Effect of Ozone Gas on IL-1β and IL-10 Levels of Gingival Crevicular Fluid in Aggressive Periodontitis Patients
    Ozone Sci. Eng. (IF 1.253) Pub Date : 2019-02-07
    Metin Çalışır, Ahmet Cemil Talmac, Bilal Ege, Ömer Poyraz, Ebru Dumlupınar

    Although the use of ozone therapy in dentistry has become widespread, the number of controlled clinical trials evaluating its effectiveness in periodontal therapy is limited. The aim of this study was to evaluate the efficacy of ozone treatment, that is used in concert with scaling and root planning (SRP), on clinical periodontal parameters and to analyze its effect on cytokine levels of GCF in aggressive periodontitis patients. Totally, 27 patients with aggressive periodontitis were randomly selected into groups of treatment with either subgingival SRP followed by application of ozone with a periodontal probe (SRP+ozone) or subgingival SRP followed by irrigation with serum irrigation (SRP-control). The following parameters were evaluated at baseline (T0), and 6 weeks (T1): plaque index (PI); gingival index (GI); probing pocket depth (PPD), clinical attachment loss (CAL), GCF volume, GCF Interleukin-1β (IL-1β), and GCF Interleukin-10 (IL-10) cytokine levels. There was a significant difference in terms of clinical periodontal parameters before and after treatment in both groups. When comparing between groups, there was no significant difference between the treatment methods after 6 weeks with respect to the PI, PPD, CAL, and GCF IL-10 levels. In contrast, GI, GCF volume, and GCF IL-1β levels were statistically significantly different between the two groups at the 6th week after treatment. Application of ozone as an adjunctive therapy to SRP was shown to provide a statistically significant improvement in treatment results compared to SRP plus serum irrigation.

  • Novel Pretreatments of Whole Blood Using Fenton-like Processes for Trace Metal Analysis.
    Ozone Sci. Eng. (IF 1.253) Pub Date : 2017-11-25
    Samuel M Rosolina,Kimberly N Johnson,Zi-Ling Xue

    Whole blood is a complex mixture of biological and chemical species. Its pretreatment, which is often conducted by dry ashing, is needed before the analyses of trace metals in whole blood. Recently photo-Fenton Advanced Oxidation Process (AOP) process has been used in the pretreatment of whole blood. Two new AOP processes using simple heating and microwave irradiation have been developed in the current work to pretreat blood samples. The treatments are based on a Fenton-like AOP with acid deactivation of the enzyme catalase. The first treatment is performed with a lab oven over 5 h, while the second uses microwave irradiation for 6 min. These methods allow for either cost-effective pretreatment through the use of the lab oven, or time savings through the use of the microwave oven. The degradations of blood and pure hemoglobin samples are compared through UV/visible spectroscopy, and the copper concentration in the treated samples were analyzed via anodic stripping voltammetry as a demonstration of analyzing trace metals in the pretreated whole blood.

  • Shelf Life Extension of Greenhouse Tomatoes Using Ozonation in Combination with Packaging under Refrigeration
    Ozone Sci. Eng. (IF 1.253) Pub Date : 2018-11-21
    Evangelia S. Karakosta, Ioannis K. Karabagias, Kyriakos A. Riganakos

    Greenhouse tomatoes were exposed to gaseous ozone for 1 h at different concentrations (0.5, 1, and 2 mg/L), packaged in low-density polyethylene (LDPE) bags and stored at 4 ± 1 °C for 49 days. Peel firmness, color parameter, browning index values, weight loss, acidity, total viable count, psychrotrophs, yeasts and molds, and sensory analyses were carried out. Results showed significant differences on parameters determined, depending on storage time and treatment (p < 0.05). Sensory evaluation showed that ozonated tomatoes (especially at 2 mg/L) retained a fresh character compared to untreated samples, for an extended period of ca. 15 days.

  • Tomato Crop Improvement Using Ozone Disinfection of Irrigation Water
    Ozone Sci. Eng. (IF 1.253) Pub Date : 2018-12-05
    I. Anahí Landa Fernández, Ignacio Monje-Ramirez, María Teresa Orta Ledesma de Velásquez

    Plant–parasitic nematodes diminish the yield of tomato crops worldwide. Irrigation water may be contaminated with such parasites, including Meloidogyne enterolobii. In this study, ozone treatment was applied to inactivate M. enterolobii eggs. Eggs were rendered inviable in water after exposure to 0.55 mgO3 L−1 ozone residual for 15 min. Additionally, the effect of temperature, alkalinity, and organic matter of the water were evaluated. The results showed that ozonation is an effective and promising alternative method for nematode control in irrigation water, which could reduce tomato crop infestation caused by plant–parasitic nematodes.

  • The Effects of Ozone-Enriched Storage Atmosphere on Pesticide Residues and Physicochemical Properties of Table Grapes
    Ozone Sci. Eng. (IF 1.253) Pub Date : 2018-12-06
    Hakan Karaca

    The persistence of residues of some common pesticides was investigated during the cold storage of table grapes in atmospheres of air or 0.64 mg m−3 ozone-enriched air. Residues of two of six pesticides evaluated in the study declined more rapidly in the ozone atmosphere than in air. The highest effect of ozone was on azoxystrobin fungicide. Decrease in the level of this pesticide was 2.8-fold higher in the samples stored in ozone atmosphere than that in air. Ozone did not cause any significant differences in Brix, pH, and total acidity values but increased the weight loss by about 1%.

  • Catalytic Ozonation of Biologically Treated Leachate from Municipal Solid Waste in a Microbubble Reactor
    Ozone Sci. Eng. (IF 1.253) Pub Date : 2018-12-09
    Xiaoxue Huang, Wen Cheng, Xuejun Quan, Chen Cheng, Zhiliang Cheng, Lu Yang

    Catalytic ozonation using activated carbon (AC) as catalyst for advanced treatment of biologically treated leachate (BTL) from municipal solid waste incineration plant was carried out in a microbubble reactor. The removal efficiency of chemical oxygen demand (COD) in the leachate was significantly improved over that in the conventional bubble reactor. The effects of AC dosage, ozone concentration, ozone flowrate and liquid reaction temperature on COD removal efficiency were studied. The results show that the COD removal efficiency increased with increasing AC dosage, ozone flowrate and inlet ozone concentration, and the reactor liquid phase temperature has little effects on the COD removal efficiency. The maximum COD removal efficiency reached 89.87% in the AC/O3 system under the optimal conditions. The catalytic activity of the AC still remained stable after five cycles of use. Ultraviolet-visible (UV-Vis) spectra and GC-MS analysis indicated that the AC-catalyzed ozonation can enhance the efficiency of the organic pollutants; the mechanism of AC deactivation was explored using the variation of AC-specific surface area and X-ray diffraction analysis. In addition, the regeneration of AC was proved effective by hydrochloric acid leaching. These results show that the combination of a microbubble reactor with AC provided a highly efficient ozonation process for the BTL.

  • Effect of Ozonation on Biodegradation and Methanogenesis of Palm Oil Mill Effluent Treatment for the Production of Biogas
    Ozone Sci. Eng. (IF 1.253) Pub Date : 2019-01-18
    Anwar Ahmad

    Anaerobic fermentation of palm oil mill effluent (POME) with ozonation doses of 2.0, 5.0, and 10.0 g O3 L−1 were applied for the contact time of continuous 110 h. Preliminary tests showed that the volatile fatty acids (VFA) were reduced up to 70% and biological oxygen demand (BOD) reduced by 89%, while the chemical oxygen demand (COD) degradability efficiency was 90% in 70 h of ozonation at 5 g O3 L−1. At initial stage, the BOD/COD ratio of 0.871 reduced to 0.110 under anaerobic conditions. Under the operational conditions, ozonation enhanced the biodegradability of the organics, as illustrated by increasing biodegradable dissolved organic carbon 7185 mg L−1 and mixed liquor suspended 40500 mg L−1. The specific methanogenic activity was 1160 mg-CH4-COD/g-VSS d at 5 g O3 L−1. SEM morphology further confirmed the effect of ozonation in fermentation at different h on granulation of POME. The ozonation improved the biodegradation of POME and reduced the VFA and COD through granulation and methanogenesis.

  • Ozone Production in Coaxial DBD Using an Amplitude-Modulated AC Power Supply in Air
    Ozone Sci. Eng. (IF 1.253) Pub Date : 2019-01-21
    Yafang Zhang, Linsheng Wei, Xin Liang, M. Šimek

    In this study, a traditional tubular reactor and an amplitude-modulated AC power supply are employed to develop a unique practical ozone generator with a widely adjustable ozone concentration and simultaneously a constant ozone yield. The amplitude-modulated AC high-voltage waveform driving the discharge consists of the TON (burst of four consecutive AC cycles) and TOFF periods. The characteristics of the ozone generation in air were experimentally investigated at different energy densities, duty cycles and air flow rates, as well as cooling conditions and frequencies. The experimental results show that a unique ozone generator has an almost constant ozone yield of 51.68 ± 2.97 g/kWh in the energy density range of 50–350 kJ/m3, while a wide range of ozone concentration and output can be developed through changing the applied voltage amplitude. A higher ozone yield of can be achieved by decreasing the duty cycle and increasing gas flow rate, while higher ozone concentration can be easily achieved by changing air flow rate. The maximum ozone yield of 92 g/kWh is achieved. In contrast to only a single AC cycle in one complete TON period, changing duty cycle for a consecutive AC cycles in one complete TON period cannot be employed to develop a unique ozone generator with a widely adjustable ozone concentration and simultaneously a constant ozone yield because of different Lissajous figures, discharge energies, positive peaks, negative peaks and their differences for each AC cycle. In addition, the total capacitance of the reactor is not only independent of energy density, duty cycle and cooling condition, but also of AC frequency. A higher AC frequency of the applied high-voltage waveforms leads to a lower dielectric capacitance while increasing gap capacitance.

  • Surface Modification of Polyethersulfone (PES) with Ozone
    Ozone Sci. Eng. (IF 1.253) Pub Date : 2018-11-18
    Shin Lutondo, Marc Toro, Shreen Sachdev, Joel Shertok, Alla Bailey, Michael Mehan, Surendra K. Gupta, Gerald A. Takacs

    Polyethersulfone (PES) is a thermoplastic polymer able to maintain its toughness and stability at high temperatures with applications, such as, in water ultrafiltration. This research focused on altering the surface properties of PES film, making it more water-liking, hydrophilic, and repulsive to organic waste. The oxidative technique used ozone to modify the surface of PES as a function of treatment time. Atomic force microscopy (AFM) measurements did not show significant changes in surface roughness compared to untreated PES. X-ray photoelectron spectroscopy (XPS) detected an increase in concentration of O atoms up to ca. 25 atomic % (at %) and the formation of primarily C–O and sulfonate/sulfate groups due to the reaction of ozone with the C–S bond in PES. The water contact angle (CA) decreased by ca. 28% indicating an increase in hydrophilicity as a result of the formation of polar oxygen moieties on the surface.

  • Optimization of Soil Remediation by Ozonation for PAHs Contaminated Soils
    Ozone Sci. Eng. (IF 1.253) Pub Date : 2019-05-20
    A. Tamadoni, F. Qaderi

    Soil remediation is one of the most important issues in environmental engineering. In this study, the effect of phenanthrene, anthracene, and benz(a)anthracene chemical structures on their removal from different soil slurries were investigated. Also, the effects of initial pollution concentration, injected ozone, water content and processing time on soil remediation were examined by response surface methodology. In the optimized condition for the soil of industrial site, anthracene, phenanthrene, and benz(a)anthracene have 67.87%, 85.2%, and 45.9% removal efficiencies, respectively. Based on these results, better water solubility, and less fine-grained soil particles are contributors to more efficient soil remediation system by ozonation.

  • Flexible Heavy Tail Distributions for Surface Ozone for Selected Sites in the United States of America
    Ozone Sci. Eng. (IF 1.253) Pub Date : 2019-02-07
    I. E. Okorie, A. C. Akpanta, B. O. Osu

    The generalized extreme value distribution, generalized Pareto distribution, Pareto type-I distribution, Pareto type-II distribution, Burr distribution, log-logistic distribution, Fréchet distribution, log-normal distribution, log-Cauchy distribution, Lévy distribution, and Dagum distribution are fitted to four data-sets consisting of surface-level ozone for Weaverville, California (WVR); Tundra Lab, Niwot Ridge, Colorado (TUN); South Pole, Antarctica (SPO); and Mauna Loa, Hawaii (MLO) sites in the USA. Based on the probability distribution with the smallest Akaike information criterion, Bayesian information criterion, corrected Akaike information criterion, mean square error, mean absolute deviation, and maximum deviation values and probability-probability plots, the Dagum distribution emerged as the best fitting distribution for Weaverville, the Burr distribution emerged as the best fitting distribution for Niwot Ridge and Mauna Loa, and the log-Cauchy distribution emerged as the best fitting distribution for the South Pole site. The value at risk for each of the ozone sites is given and a backtest based on the Kupiec test is used to verify the appropriateness of the selected distributions.

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