Sonolysis and photochemical degradation of different compounds such as chlorinated aliphatic hydrocarbons are among the recent advanced oxidation processes. Perchloroethylene is one of these compounds that has been mainly used as a solvent and degreaser. In this work, elimination of perchloroethylene in aqueous solution by ultrasonic irradiation, andphotochemical oxidation by ultra violet ray and hydrogen peroxide were investigated. Three different initial concentrations of perchloroethylene at different pH values, detention periods, and concentrations of hydrogen peroxide were investigated. Head space gas chromatography with FID detector was used for analyses of perchloroethylene. This research was performed in 9 months from April through December 2011.Results showed that perchloroethylene could be effectively and rapidly degraded by ultrasonic irradiation, photochemical oxidation by ultra violet ray, hydrogen peroxide and a combination of these methods. Kinetics of perchloroethylene was strongly influenced by time, initial concentration and pH value. Degradation of Perchloroethylene increased with decrease in the initial concentration of perchloroethylene from 0.3 to 10 mg/L at all initial pH. The results showed an optimum degradation condition achieved at pH = 5 but did not affect significantly the perchloroethylene destruction in the various pH values. Kinetic modeling applied for the obtained results showed that the degradation of perchloroethylene by ultrasound and photo-oxidation followed first order and second order model. The percentage of removal in the hybrids reactor was higher than each of the reactors alone, the reason being the role of hydroxyl radical induced by ultrasound and photochemical reaction.

Background and objectives: Atopic dermatitis is a chronic inflammatory allergic disease that specifically affects the skin. The incidence of this disease is influenced by genetic and physical stimuli, hormones, stress and food and inhalant allergens. Given the increasing prevalence of atopic dermatitis, it is important to identify food and inhalant allergens associated with the disease. The purpose of this study was to evaluate prevalence of sensitization to food and inhalant allergens in children with atopic dermatitis. Methods: This cross-sectional study was performed on 56 children (29 males and 27 females) with atopic dermatitis who were referred to the Dezyani Asthma and Allergy Clinic in Gorgan between 2016 and 2017. Atopic dermatitis was confirmed via the Prick test. Data were analyzed using SPSS 16 at a significant level of 0.05. Results: Average age of the subjects was 4.26 ± 3.79 years. The most common inhalant allergens were mite (35.7%) and salt grass (3.6%) and the most common food allergens were egg white (35.7%) and cow's milk (26.8%). Conclusion: Considering the high prevalence of food allergy in the studied population, it is necessary to reduce the severity of allergic reactions and its subsequent treatment costs by observing the principles of a healthy diet and lifestyle.