Technical Feasibility of Recycling Waste Cooking Oils (WCO) Produced in Qom to Biodiesel

Background: The aim of this research was to study the technical feasibility of recycling waste cooking oils (WCO) produced in Qom to biodiesel. Methods: This cross-sectional study was performed in Qom in the first half of 2013. In this study, 147 domestic, commercial, and industrial sources producing WCO were identified, selected, and asked to collect and deliver the WCO produced by them within a week. The samples obtained from the sources were mixed separately at a ratio of one to one, and finally, a WCO sample was obtained from each source. Then, some characteristics of samples such as chemical profiles were analyzed and the esterification and transesterification process were used to convert WCO into biodiesel. Finally, some of the technical characteristics of produced biodiesel such as flash point, viscosity, density, moisture, and acidic number were determined and compared with the standard. Results: In terms of basic properties, domestic WCO had the best quality for conversion to biodiesel. Also, in terms of viscosity, density, acidic number and flash point, biodiesel produced from domestic WCO had more favorable conditions. In terms of the percentage of humidity, biodiesel produced from industrial WCO was the best one. Conclusion: WCO produced from domestic and commercial sources has the potential to be converted into biodiesel with standard features but WCO produced from industrial sources due to their very poor quality needs more pre-treatment processes

Protective Effect of N-acetylcysteine (NAC) Administration on Prevention of Noise-Induced Hearing Loss (NIHL) in Rabbit

Background and Objectives: Oxidative stress due to free radicals formation plays an important role in noise-induced hearing loss (NIHL). Many hypotheses have been proposed regarding the biochemical prevention of this complication. This study was performed with the purpose of determining the preventive effect of N-acetylcysteine (NAC) administration, as an antioxidant agent, on NIHL in Rabbit.Methods: In an experimental study, 24 adult white male rabbits were divided into four groups, including: 1) control, 2) noise exposure (100dB octave band noise centered at 4000Hz for 40h), 3) noise exposure plus NAC administration (325mg/kg, daily ip injection), and 4) no exposure and NAC administration. Audiometric test of rabbits was assessed by auditory brainstem response (ABR) technique in three stages. The Kruskal-Wallis and Mann-Whitney tests were used to compare the groups, and a p<0.05 was considered significant.Results: The mean ABR threshold shift for the noise exposure plus NAC administration group, 1 hour after exposure at 1, 2, 4 and 8kHz frequencies were, respectively, 16.66±1.63, 21.66±1.75, 33.5±2.34, and 39.33±2.25dB. These values were significantly less than the same values in the noise exposure group.Conclusion: The results of this study showed that NAC can provide a proper protective effect against hearing loss resulting from noise exposure

Concentration of Nitrate in Bottled Drinking Water in Qom, Iran

Background &amp;amp; Aims of the Study: The global consumption of bottled water is growing with substantial growth in sales volumes on every continent. The highest growth rates are occurring in Asia and South America. Biological and chemical monitoring of these waters is necessary. The aim of current study was determination of nitrate concentration in bottled drinking water in Qom, Iran in 2012. Materials &amp;amp; Methods: A cross-sectional study carried out in Qom, Iran. First of all, 18 most frequent brands of bottled drinking waters were purchased in June 2012 randomly. Then concentration of nitrate was measured according to the spectrophotometric method. In next step, experiment data were analyzed by Excel Software and P value was obtained by statistical calculations. Finally data were comprised with written nitrate concentration on labels and recommended permissible values . Results: The median nitrate concentration was 2.1 mg/L with the minimum 0.8 mg/L and maximum 8.1 mg/L. In 66.7 % of the samples, the measured nitrate concentrations were less than the written nitrate concentrations and in 33.3% of samples, the nitrate concentration was higher. The statistical calculation proved the significant difference between the median of written nitrate concentration on the label and investigated nitrate concentration (P value > 0.05). Conclusions: It be concluded that the measured nitrate concentration in all of the water samples is below the recommended permissible level