Application of Ozone Post-Harvest Treatment on Kabkab Date Fruits: Effect on Mortality Rate of Indian Meal Moth and Nutrition Components

Methyl bromide (MB) was used for years to treat infested stored date fruits; however, MB is due to be phased out by 2015. In this study ozone is used for disinfestations of Kabkab date against Indian meal moth in three life stage. They were exposed to four ozone concentrations (300 ± 10, 1050 ± 40, 2000 ± 40, and 4000 ± 50 ppm) during four periods (2, 4, 6, and 8 h). The findings show 2000 ppm of ozone concentration within 8 h resulted in complete mortality of larvae and adult insects and over 90% mortality of eggs. The proposed ozone treatment is a promising approach replacing application of MB for disinfestations of examined date fruits, as no remarkable changes were observed on pH of the date fruits and its chemical compositions (total phenolic content, anti-oxidant activity and free radicals).     

Ozone as an Alternative for Disinfection of Explants during In Vitro Mass Plant Propagation

Ozone was used as an alternative for replacing sodium hypochlorite in the disinfection of yam nodal segments during the establishment stage for in vitro mass plant propagation. The purpose of this work was to evaluate the effect of ozone on disinfection of yam nodal segments in gaseous and aqueous phase in comparison to sodium hypochlorite. The immersion of yam nodal segments in water containing dissolved ozone with an ozone concentration of 1.0, 1.5 and 2.0 ppm during for 5 to 10 min gave the best results; 100% of yam nodal segments were free of microbial contamination. In terms of sprouting initiation (7.5 days), sprouting percentage (88%), and sprouts growth (4.81 cm), all were improved in comparison to the conventionally used sodium hypochlorite.     

Investigation of gaseous ozone as an anti‐fungal fumigant for stored wheat

In this study, gaseous ozone was used as a fungicide to preserve stored wheat. The following operating parameters were investigated for their effects on the fungicidal efficacy of ozone: (1) the applied ozone dose; (2) ozonation time; (3) water activity of the wheat; and (4) temperature of the wheat. The effect of ozonation on germination of the wheat was also studied. Experimental results revealed that gaseous ozone was very effective in the inactivation of fungi associated with the wheat. Within 5 min of ozonation, 96.9% of the fungal spores were inactivated by applying 0.33 mg of ozone (g wheat)^?1 min^?1. It was also found that increases in both water activity and temperature of the wheat enhanced the fungicidal efficacy of ozone. In addition, results of this study indicated that the inactivation processes could be controlled by simply monitoring the ozone exiting from the reactor and, consequently, the time‐consuming microbial examination processes could be avoided. This finding would make the application of ozone in the preservation of cereal grains easier, simpler, and more cost‐effective. It was also found that although the applied ozone doses above certain thresholds may reduce the germination of wheat, the inactivation of fungi could be achieved using applied ozone doses far below those thresholds. Copyright © 2006 Society of Chemical Industry     

Optimization of Ozonation Process for Disinfection of Dental Unit Waterlines Using Response Surface Methodology

ABSTRACT

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 R²_adj 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.     

Application of Slurry Type Photocatalytic Oxidation‐Submerged Hollow Fiber Microfiltration Hybrid System for the Degradation of Bisphenol A (BPA)

Abstract

A pilot scale, slurry type photocatalytic reactor, followed by submerged hollow fiber microfiltration (MF) membrane hybrid system was evaluated for simultaneous and complete destruction of toxic organic chemical bisphenol A (BPA) and separation of photocatalyst TiO₂; in order to obtain a reusable quality water. With simple modification to the treatment operation, the effect of photocatalytic reaction at modest variations in temperature was examined. Adsorption pretreatment was carried out prior to photocatalysis (UV/TiO₂). BPA adsorption ability on TiO₂ was very less (about 15%) at 25°C. However, adsorption pretreatment followed by photocatalytic oxidation (UV/TiO₂) at an elevated nearly constant temperature (about 70°C) helped in increasing the BPA degradation efficiency. The effect of ozone introduction into the treatment stream was also analyzed. Applying ozone along with UV/TiO₂, brought about a synergistic effect on BPA degradation. Within 3 h, entire 10 ppm of BPA and the by‐product organic compounds were completely removed. TiO₂ particle separation performance using hollow fiber membrane was enhanced by adopting a two‐stage coagulation/sedimentation pretreatment. With initial turbidity of 4000 NTU, the turbidity of the final permeate water was well below 0.1 NTU. Almost complete removal of particles was achieved. Some of the main advantages of this hybrid treatment system include, large‐scale treatment, complete and efficient BPA and its organic intermediates degradation, TiO₂ easily separated after treatment and capable for reuse as it is free from chemical coagulant contaminants, reusable quality water is obtained, and the system has the potential for continuous operation with simple process modifications.     

Feeding Deterrents and Sensitivity Suppressors for Pieris rapae Larvae in Wheat Germ Diet

Rejection of wheat germ diet by cabbage-reared Pieris rapae larvae is explained by the fact that the diet contains strong feeding deterrents to the larvae. These deterrents were present mainly in hexane and butanol (BuOH) fractions of diet extracts, but the post-BuOH water fraction also showed some deterrent activity. Although minor diet components such as sorbic acid had a weak deterrent effect, wheat germ was primarily responsible for the activity. Seven compounds isolated from the BuOH extract of wheat germ were deterrent to the larvae. UV spectra suggested that most of these compounds are apigenin-based flavones. Fractionation of the hexane extracts showed that most of the active compounds were methanol-soluble, and HPLC of the MeOH fractions revealed the presence of active compounds that were absent in the BuOH extract of wheat germ, as well as other compounds that were common to both fractions. Acceptance of nasturtium by P. rapae larvae reared on wheat germ diet is explained by a type of “cross habituation” of the larvae to feeding deterrents. When larvae were reared on cabbage leaves treated with chemical fractions from wheat germ diet, they readily accepted nasturtium, which is normally refused by cabbage-reared P. rapae larvae, due to the presence of strong feeding deterrents in the plant. A high percentage of diet-reared larvae also fed on Erysimum cheiranthoides and Iberis amara, which are normally rejected. The chemical constituents encountered in wheat germ can almost completely account for the larval acceptance of nasturtium. The suitability of wheat germ diet for rearing phytophagous insects for behavioral assays must be questioned.     

Application of Ozone in Stripping of Cotton Fabric Dyed with Reactive Dyes

ABSTRACT

This paper discusses the color stripping of cotton fabric dyed with four reactive dyes using ozone. An ozone color stripping process has been optimized in terms of pH, ozone dose, treatment time and dye concentration. Color stripping efficiency of the process is evaluated in light of the color properties including Lightness (L*), Lightness Difference (?L*), and Color Difference (?E*) in addition to strength properties, i.e., copper number and degree of polymerization as well as compared with a control method (conventional reductive color stripping method). The results demonstrate maximum color stripping at an ozone dose of 10 g/h, exposure time of 45 min, and pH maintained at 5. The Stripping Efficiency, however, decreases with increasing dye concentration from 0.5% to 4%, which implies that decolorization of dyed fabric with higher initial dye concentration requires higher ozone dose and/or longer exposure time. The strength of the ozone-stripped fabric sample is almost similar to that of control. The chemical oxygen demand of effluent generated by ozone stripping process is 97% lower than the effluent produced by the conventional stripping method. The Ozone Stripping Process hence proves to be environment-friendly as it consumes less water, energy, and chemicals.     

Research Note: Inactivation Efficiency of Ozonated Water for Fusarium oxysporum Conidia Under Hydroponic Greenhouse Conditions

Ozonated water was used for inactivation of Fusarium oxysporum conidia in sterilized water and inorganic soil-less nutrient medium at different treatment temperatures. F. oxysporum conidia were effectively inactivated in both water and nutrient media and the inactivation curves were almost same at 15°C, 25°C and 30°C. Approximate 4-log orders of F. oxysporum conidia were killed when the ozonated water with initial ozone concentration of 1.0 ppm had been used. The surviving curves, however, were characterized by a tailing-off effect, and the effect was related to the residual ozone concentration in the ozone treated suspensions.     

Simultaneous removal of NOx, SO2 and Hg in nitrogen flow in a narrow reactor by ozone injection: Experimental results

A process capable of removing NO_x, SO₂ and mercury simultaneously was proposed, which utilizes the injection of ozone and assist with a glass made alkaline washing tower. Experiments were conducted in a quartz flow reactor within an electrical heated furnace. Oxidation properties of NO and Hg, removal efficiency of NO and SO₂ behind the washing tower were investigated. Results show that the oxidation efficiency of NO and Hg greatly depends on the amounts of ozone injected. With the increasing amounts of ozone added to the main flow, NO and Hg oxidation efficiency all improved individually. About 85% of NO can be oxidized with 200 ppm of ozone added and 89% of elemental Hg can be oxidized with 250 ppm of ozone added. The optimal temperature for NO oxidation should be lower than 473 K, and the optimal temperature range for mercury was 473 K to 523 K. The appearance of SO₂ has little effect on the NO oxidation process. NO has priority compared to mercury when react with ozone. With the assistance of washing tower, about 97% of NO and nearly 100% of SO₂ can be removed simultaneously with 360 ppm of ozone added.     

Impact of Ozone Treatment on Seed Germination – A Systematic Review

ABSTRACT

Rising world population necessarily increases the food requirement. At the same time, agricultural land has been reduced drastically due to the rapid urbanization and industrialization which severely affects the land availability for the growers. However, the enhancement of seed germination has the potential to secure the food safety of masses by improving crop production. The traditionally followed chemical methods to improve seed germination have major limitations including being environmentally unhealthy, time-consuming, and are labor-intensive. Of late the application of ozone on plant growth and seed germination has attained greater significance. This promising technique and its various potential applications in the food industry have started emerging. Ozone is a strong antimicrobial agent as well as a germination enhancer. Ozone, in limited quantity, enhances seed germination rate; on the other hand, excess ozone can also cause some negative effects. Generally, ozone is applied either in gaseous or aqueous phases; however, the method and treatment conditions of ozone vary with the subject samples. This review mainly discusses the impact of ozone treatment on seed germination, the quality changes that accompany the treatment as well as the factors affecting the efficiency of ozone.     

The application of ozonation for the detoxification and biodegradability improvement of a textile auxiliary: Naphtalene sulphonic acid

From the environmental point of view, the textile industry dealing with operations such as fibre and fabric preparation, dyeing, finishing, printing etc. can be identified among the very chemical intensive sectors. Therefore the characterisation and management of textile auxiliaries within aqueous dyehouse effluents are becoming a challenging responsibility for the textile manufacturer. Although there is much speculation about the types and quantities of these chemicals released to the environment during textile manufacturing, there are only few data about the behaviour of these chemicals both in receiving water bodies and in wastewater treatment systems. Besides current understanding of industrial pollution control emphasizes the relevance of segregated stream management. This issue gains a further importance when segregated effluent streams containing auxiliaries with xenobiotic nature are considered.In this context the objective of the present study is to investigate the effect of ozonation on the toxicity and biodegradability of a naphthalene sulphonic acid derivative commonly applied in textile mills. The naphthalene sulphonic acid derivative prepared to simulate the actual situation in a dyebath discharge from a textile finishing industry has a COD of 1150 mg/l and a BOD of 10 mg/l, and pH of 5.5. Due to the highly soluble characteristic of the sulphonic groups the sample is completely soluble in nature. Ozonation experiments [conducted under the following conditions: 1200 mgO₃/h and 2400 mgO₃/h both at pH 5 and pH 11; 5325 mgO₃/h at both pH 12 and at the original pH (pH = 5.5)] show that the application of 5325 mgO₃/h ozone for 30 min at original pH can be considered as the optimum condition which is further evaluated in terms of inert COD fractions and acute toxicity. According to the experimental findings, raw naphtalene sulphonic acid derivative has an inert COD content of 1027 mg/l. With ozone application of 30 min 5325 mgO₃/h at original pH the inert COD concentration can be reduced down to 295 mg/l. The molecular weight cut-off experiments indicate that 58% of the COD originates from the 10 kDa-30 kDa fraction for the raw naphtalene sulphonic acid derivative. Due to chemical degradation under ozone, the fraction with the highest COD shifted to the < 1 kDa range for the ozonated naphtalene sulphonic acid derivative. Since the results related to the acute toxicity (in 50% v/v EC values) towards the marine algae Phaeodactylum tricornutum indicate that the toxicity of the formulation under investigation is increased considerably, it is recommended to run a further investigation by the use of another chemical oxidant instead of ozone.     

Industrial-scale Malting Barley (Hordeum vulgare L.) Seed Disinfection by Fog of Ozonated Water Application

The aim of this study was to underscore that seed treatment by the fog of ozonated water constitutes a promising alternative tool, in terms of health and environmental gains, regarding traditional ozone treatment. In order to obtain a clear vision of this performance, the technology was implemented on an industrial scale (malting industry). Under an exposition of barley seeds to 9.8 ppm of dissolved ozone into water, our results showed a significant disinfection effect of 80% for Fusarium sp. and 70% for Aspergillus sp., but no effect was established on Alternaria sp.     

Use of Ozone as A Disinfectant for Raw Animal Skins—Application as Short-Term Preservation in Leather Making

Ozone is a strong oxidant and potent disinfecting agent. While the destruction of bacteria by ozone has been studied extensively on various food products, not much information is available on the effect of ozone on action with regard to preservation of raw skins/hides in leather making. Hence a detailed study has been undertaken in this aspect. Samples of fresh goatskins were treated with ozone for 0.5, 1, 1.5 and 2 hours and the microbial activity was monitored for a period of two weeks. Experimental skins were exposed to ozone gas at 2 g/h in a specially designed glass column reactor. A sample pair was exposed to ozone; while one sample was kept in open atmosphere in order to adopt conventional practices, the other was kept in a sealed bag at room temperature in order to eliminate the effects during post ozone treatment period. Conventional salting method was done separately as control for comparison with ozone treatment. Bacterial cell count was made from skin samples before and immediately after the ozone treatment as well as for control. Microbial growth in skin for different experiments was monitored by optical density measurement from the skin washings. These samples were also checked periodically for hair slip, quality and odor for different days. The results show that ozone could effectively eliminate the microorganisms present in the raw skin by ozone treatment for 30 min. It was also observed that the ozonized samples kept in the open environment were preserved while those kept in the sealed bag were putrefied in the period of 2 days. In addition, ozone-treated skins kept in the open environment were resistant to microbial action for periods more than two weeks. This opens up the possibility of applying ozone technology for short term preservation of skins and facilitates the elimination of common salt used for conventional preservation thereby reducing the pollution load.     

Comparison of the Effects of Ozone,UV and Combined Ozone/UV Treatment on the Color and Microbial Counts of Wheat Flour

The effects of direct ozone treatment, UV treatment and combined ozone/UV treatment on the color and microbiological count of milled wheat flour were compared. The changes in color and microbiological properties during a 19-week storage period were also examined. Each of the treatments significantly reduced the microbial count of the flour and resulted in whiter flour. The results showed that only the combined treatment furnished flour suitable for consumption. The effect of the combined treatment was similar to, but more pronounced than that of ozone treatment. Changes in the quality of the dough were observable, similar by as in response to other oxidizing agents.     

Dairy Waste Water Treatment by Combining Ozonation and Nanofiltration

Abstract

The aim of this investigation was to examine the applicability of the membrane technique and the effect of preozonation in dairy waste water treatment technology. The best degree of surfactant removal from model anionic surfactant solution by nanofiltration was achieved at 20°C and 40 bar. Investigations on the effects of ozone treatment of the waste water indicated that preozonation decreased the flux and increased the chemical oxygen demand and surfactant removal efficiency. Ozone treatment enhanced the biodegradability of the retentate from 68.8% to 96.4%.     

Ozone Treatment of Defrost Water for In-Plant Reuse

Many fruit and vegetable processing operations are examining technologies to reduce effluent volume and encourage water recovery and reuse. Implementing technologies and programs to promote in-plant reuse and recycling of discharge water is cost-effective and may improve processing efficiency. The efficacy of ozonation of defrost water has been investigated to determine the appropriate treatment level for in-plant reuse at a fruit processing plant in Clovis, California. Treatments of 0.5 ppm and 1.0 ppm of aqueous ozone achieved water quality acceptable for in-plant reuse, while an ozone treatment of 1.0 ppm was needed to significantly (P < 0.05) reduced the microbial load of flume wash effluent.     

Effect of α-Tocopherol During In Vitro Ozonation of Methyl Linoleate: Its Implication in Ozone Therapy

Systemic ozone therapy is widely used as an oxidant therapy to treat many conditions and diseases. It is known that ozone therapy acts through a transient oxidative stress produced by lipid ozonation products. The convenience of supporting patients with antioxidants during systemic ozone therapy applications is now under discussion. We studied the reaction of linoleate (one of the main constituents of cellular membranes and plasma phospholipids) with ozone in presence or absence of α-tocopherol, in order to explore whether the combination of ozone and antioxidant has some effect on fatty acid ozonation products. Proton nuclear magnetic resonance spectroscopy (¹H NMR) was used for following the reaction between 4.8mol mmol of methyl linoleate and 2.08 or 4.32mmol of ozone, with addition of different amounts of α-tocopherol (0.10, 0.18, and 0.26μmol). Ozonide (δ=5.15ppm) and aldehydes (δ=9.63ppm and δ=9.74ppm) intensities from ¹H NMR signals markedly decreased with α-tocopherol addition. When αtocopherol is absent, the intensities from olefinic proton signals diminished with ozone concentration increment; however, with αtocopherol in the mixture a smaller decrement was achieved. No detectable signals were found with the ozonation of α-tocopherol without methyl linoleate in the reaction mixture. These results suggest that α-tocopherol reacts with those products released from the reaction of ozone with methyl linoleate. This fact points out that antioxidant supplementation during systemic ozone therapy (major and minor autohemotherapy, rectal insufflation, and so forth) can be detrimental toward achieving the needed transient oxidative stress responsible for biological activities.     

An NMR spectroscopic investigation of the oxidation reactions of DL-selenomethionine

Oxidation reactions of DL -selenomethionine (DL -SeMet) with hydrogen peroxide and ozone were investigated by ¹H and ¹³C NMR spectroscopy. Chemical shifts of the reaction products were measured at different pD values in D₂O solutions. In the moderate (4–8) pD range, a pair of singlets of equal intensity appeared at 2·71 and 2·80 ppm, with the disappearance of the DL -SeMet methyl peak at 2·04 ppm. As the pD of the solution decreased, the chemical shifts of both peaks increased relative to 3-trimethylsilylpropionic acid-d₄ sodium salt. In strongly acidic solutions (pD<3), the pair collapsed to one singlet at 3·18 ppm. As pD values increased the chemical shifts decreased in numerical value with only a singlet at 2·69 ppm observed in strongly basic solutions (pD>10). These data were assigned to Met selenoxide in basic solution, stabilized by intermolecular hydrogen bonding, and to the hydration of Met selenoxide to Met dihydroxyselenide in acidic solutions. In moderate pD solutions (pD = 4–8), both forms of the selenoxide can exist. For the reaction of DL -SeMet with CNBr, two parallel reactions occur, i.e. oxidation and bond cleavage with cyanization: the bond cleavage giving the expected products, i.e. 2-amino-4-butyrolactone and methyl selenocyanate, with an additional singlet observed at 2·54 ppm. © 1988 SCI     

Antioxidant Activities and Phenolic Compositions of Wheat Germ as Affected by the Roasting Process

Wheat germ is a good source for wheat germ oil, and it is a by‐product with highly concentrated nutrients from the wheat flour‐milling industries. In the present study, raw wheat germ was firstly heat‐treated at 180 °C for 20 min in a fluidized bed dryer, and further roasted at 180 °C for different periods of time. Roasting influence on total phenolic content (TPC), antioxidant activities, and phenolic compositions of wheat germ were evaluated. The roasting process significantly increased the TPC and antioxidant activities including free radical scavenging against DPPH and ABTS radicals, FRAP, and ORAC. In particular, the wheat germ roasted at 180 °C for 20 min showed higher antioxidant activity than those roasted at 180 °C for 5 and 10 min. Three major phenolic acids, namely, ferulic, chlorogenic, and caffeic acid, and four main flavonoids, namely, schaftoside and its isomers or adduct of sinapic acid were identified by HPLC. In general, the content of individual phenolic compounds decreased with prolongation of the roasting time except for ferulic acid. The results suggest that the antioxidant activities of wheat germ can be enhanced by roasting, and the enhancement effect might be partially attributed to the formation of Maillard reaction products (MRP).     

Ozone Consumption in Natural Waters: Effects of Background Organic Matter,pH and Carbonate Species

It was demonstrated that, in natural waters, the overall kineticsof dissolved ozone consumption can be characterized by the “specific ozone utilization rate”, w[time ^?1]. The dependency of w on the chemical quality of the raw water was analyzed. And, the variation of w values measured in different water samples was explained in terms of the pH, alkalinity, and total organic carbon content of the solution matrix.