Evaluation of correlation between emission of sulfur oxides and sulfuric acid mists and workers personal exposure in a petrochemical complex

Background and Aim   The oxides of sulphur are among those chemical substances that are increasingly used and their consumption is even growing in different places everyday. Sulphuroxides are used in chemical industries, paper manufacturing, printing rollers, recovering burned (consumed) coal, supplying and producing sulphuric acid, and in bleaching liquids. Determination and evaluation of the accumulation rate of sulphor oxides and sulphoric acid mists through personal breathing zone, and sources emission from occupational areas of the petrochemical complex.  &nbsp;  Methods   Sampling (NO=32) was done from the working places and ambient using ASTM D4490 method for the measurement of source pollutants and the standard method of NIOSH.  Appendix VIII for pollutants measurement of the breathing zone. Measurement and evaluation of the samples from the occupational areas were performed during the two working shifts (morning and the afternoon) at the ground floor and the first floor of the building.  &nbsp;  Results   The average concentrations for sulphur dioxides at the ground floor over the working   time of both shifts (in the morning and in the afternoon) were 0.011 PPM and 0. 015PPM,  respectively. In addition, the average concentrations for the same shifts at the first floor of the   building were 0.019PPM and 0.014PPM, respectively. The average concentrations of sulphuric acid mists at the ground floor for the morning and afternoon shifts were 0.36 mg/m 3 and 1.47 mg/m 3 and at the first floor they were 0.66 mg/m 3 and 1.35 mg/m 3 ,respectively. The results of measurements for sulphur dioxides gas revealed that contact with this gas in the Units of 300 and 600 was less than the permitted limit from NIOSH for the exposed workers to permissible exposure limit contacts (PEL TWA= 2PPM). Further, the rate of working contact had a significant correlation with each of the indicators of both shifts and the place where this contact accured (P<0.001).The measurement results of sulphoric acid mists also revealed that the rate of contact with the mists for the workers being exposed to the gas in the Units of 300 and 600 in the morning shift was less and in the afternoon shift was more than the permissible limit from NIOSH (PEL TWA= 1 mg/m 3 ) . In addition, the rate of working contact with sulphoric acid mists in terms of the working time and place showed a significant correlation (P<0.001).  &nbsp;  Conclusion   It is concluded that the assumption &quot; the amount of sulphur dioxides is beyond PEL in the breathing zone of workers &quot;is disproved; and also the assumption that&quot; the rate of sulphuric acid mist concentration is more than the permissible limit in the workers breathing zone in the afternoon shift is confirmed while in the morning shift is disprove

Degradation of MTBE using Fenton reagent

Methyl tertiary-butyl ether (MTBE) has been commonly used as a fuel additive because of its many favorable properties that allow it to improve fuel combustion. Unfortunately, increased production and use have led to its introduction into the water supplies. Accordingly, research studies have been initiated to investigate the treatment of contaminated water. Degradation of MTBE in aqueous solution by Fenton reagent (Fe2+ and H2O2 ) was investigated. This study used Fenton reagent to oxidize MTBE with an attempt to explore the behavior of MTBE decomposition and measure how factors such as pH, [H2O2 ] and [Fe2+] may influence the degradation of MTBE, and finally the optimum conditions were obtained. Under optimum conditions of 50 mL H2O2 , 0.65 g/L Fe2+, pH=3-4 and room temperature, the initial 1000 mg/L MTBE solution was reduced by 99% within 120 min. The results showed that application of Fenton reagent was an effective method for degradation of MTBE