Although the utilization of pesticides accounted for the group of persistent organic pollutants was banned years ago, a count of pesticides are still directly or indirectly a source of contamination in Europe. One of them, simazine is still allowed for use in the United States. Aim of this experiment was development of soil remediation method which could be utilized for degradation triazine class pesticides – simazine was an example used. A method for soil remediation based on ozonation processes in fluidized bed was successfully utilized for removal of simazine from contaminated soil. For the study soil highly contaminated with simazine up to the concentration of 0.05% w/w was used. Determination of the pesticide levels in soil was performed using extraction and gas chromatography. The method allowed 80% reduction of pesticide concentration level. The degradation of pesticide was accompanied with changes of physicochemical parameters of soil, i.e., decrease of pH and a increase of nitrates concentration. Despite changes in physicochemical properties of the soil, the developed method proved to be highly effective and can be successfully applied on an industrial scale.
The influence of ozone injection mode on the effectiveness of nitrogen monoxide oxidation to nitrogen dioxide by ozone in a flow reactor was investigated experimentally in laboratory apparatus. Nitrogen monoxide was diluted to the mole fraction 100 ppm in air which served as the carrier gas flowing through the tube of the diameter D = 60 mm into which ozone was injected. The effects of a number of ozone injecting nozzles and their configuration on the effectiveness of NO oxidation were examined. In the closest vicinity from the injection site the counter-current injection mode appeared to be superior to the co-current injection mode, but in areas located further from the injection site both injection systems were almost equally effective.
The study assessed the effect of cumulative tropospheric ozone on the morphology of an ozone-sensitive (Bel W3) and an ozone-resistant (Bel B) tobacco cultivar, and two petunia cultivars (Mirage, White Cascade). The plants were exposed at two sites differing in tropospheric ozone level for two months during the 2008 growing season. Similar sets of plants were cultivated in control conditions. Morphological parameters of the plants were measured every week during the experiment. The correlation between the recorded results and the cumulative concentrations of tropospheric ozone measured at the two exposure sites was estimated. The ozone-sensitive tobacco cultivar showed increased visible damage after four weeks of the experiment, although ozone was relatively low during the preceding weeks, possibly confirming the cumulative effect of ozone on the plant response. The ozone-resistant tobacco cultivar showed higher mean plant growth and leaf growth than the ozone-sensitive one throughout the experimental period, but at the exposure sites the ozone-sensitive cultivar showed plant growth similar to or higher than the controls, especially at the forest site where ozone concentrations were higher. This suggests a plant defense against reduction of leaf assimilation area (i.e., against leaf necrosis). Petunia cv. Mirage showed lower growth at the control site and had fewer flowers than White Cascade at all sites. White Cascade had more flowers than Mirage in the last week of the experiment at the forest site where tropospheric ozone was higher. Its mean growth was higher at the forest site than at the other exposure site
The paper focuses on the modelling of bromate formation. An axial dispersion model was proposed to integrate the non-ideal mixing, mass-transfer and a kinetic model that links ozone decomposition reactions fromthe Tomiyasu, Fukutomi and Gordon (TFG) ozone decaymodelwith direct and indirect bromide oxidation reactions, oxidation of natural organicmatter and its reactionswith aqueous bromine. To elucidate the role of ammonia an additional set of reactions leading to bromamine formation, oxidation and disproportionation was incorporated in the kinetic model. Sensitivity analysis was conducted to obtain information on reliability of the reaction rate constants used and to simplify the model.
Almost all matter in our Universe exists in the form of plasma. Although it’s not easy to generate on Earth, it has a vast range of applications in medicine, biotechnology, farming and industry.
This study investigates the effectiveness of intra-mammary ozone administration in the dry period and at the time of delivery for preventing against mastitis in herds with contagious mastitis. The cows were divided into five groups with 10 cows in each. Group 1 was administered an ozone-containing foam preparation via the teat canal into four udder quarters for 5 seconds at the beginning of the dry period; Group 2 was administered ozone at the beginning of the dry period and at the time of delivery; Group 3 was administered ozone at the time of delivery; Group 4 was administered a dry period udder preparation at the beginning of the dry period; and Group 5 was administered only teat seal at the beginning of the dry period. No statistically significant difference was found between the cows with regard to the SCC values at the beginning of the dry period and at the time of delivery (in cows without clinical mastitis, n=25). The SCC values were reported to decrease when the values at the beginning of the dry period and at the time of delivery were compared. All cows except two in Group 1 were detected to have clinical mastitis according to the frequency of microbial isolation in milk at the time of delivery. In conclusion, intra-mammary ozone administration did not prevent mastitis in the dry period or at the time of delivery in herds with contagious mastitis; moreover, it was determined to increase the rate of clinical mastitis in the postpartum period.
Results of laboratory scale research have been presented on the effects of an oxidizing reactor on ozone consumption and by-producs composition and separation of simultaneous NOx and SO2 removal from a carrier gas by ozonation method and absorption in an alkaline solution. The additional Dreschel washer added before two washers containing 100 ml of 0.1 molar NaOH solution played the role of an oxidation reactor. Its effect was investigated using an empty (dry or wetted) or filled with packing elements washer. The measured by-products in a scrubber and in the oxidizing reactor were SO32-, SO42-, NO2- and NO3- ions, respectively. It has been shown that use of oxidizing reactor improves NOx removal efficiency reducing ozone consumption. Wetting of the oxidation reactor with water enables a preliminary separation of sulphur and nitrogen species between the oxidizing reactor and an alkaline absorber. Application of packing elements in the oxidizing reactor allows to retain 90% of nitrogen compounds in it. Some results were confirmed by tests in pilot scale.
Validation results of a theoretical model that describes the formation of bromate during ozonation of bromide-containing natural waters are presented. An axial dispersion model integrating the nonideal mixing, mass-transfer and a kinetic model that links ozone decomposition reactions from the Tomiyasu, Fukutomi and Gordon ozone decay model with direct and indirect bromide oxidation reactions, oxidation of natural organicmatter and reactions of dissolved organics and aqueous bromine was verified. Themodel was successfully validated with results obtained both at a laboratory and a full scale. Its applicability to different water supply systems was approved.
In this paper, we present results indicating ozone effect on visible plants response as well as on other parameters, such as dry weight, chlorophyll concentration, cell membrane stability and salicylic acid content in bioindicator plants. Ozone-resistant and -sensitive clones of white clover (Trifolium repens L. cv. "Regal") were used in the investigations. The experiment was carried out in ambient air conditions of the Wielkopolska province (Poland) in 2005 growing season. The exposure led to changes in the level of plant response parameters that might be used as potential biomarkers of oxidative stress triggered by tropospheric ozone in ambient air conditions.