Iranian Journal of

Background and Objectives: Chemical spillage of equipment is possible in petrochemical processes. Occurrence of such event can result in firing and explosion and consequently would bring about some risks to the environment affected. The aim of this study was to assess environmental risks in Olefin Plant, Arya Sasol Petrochemical Company in order to identify environmental risks at producing source. Methods: The basic data was gathered through using the results of monitoring and measurement of ambient air pollutants and stack exhaust gases, safety review method and field observation. For determination the effects of hydrocarbons leakage from equipment on the environment, measuring BTEX in ambient air was performed as per EPA0030 Standard method with using Gas Chromatography at 4 stations of the complex and a portable Testo 350 XL device was used for monitoring stack exhaust gases, from 9 stacks from May 2011 to April 2012. Assessment and risk management tool used in this study was the fault tree analysis method. The main part of the risk assessment in fault tree method is selecting a top event. According to the statistics of accidents and environmental aspects of ethane cracking operations, hydrocarbon leakage is detected as top event and then composition and relationship between risk factors is determined in the form of terminal event, intermediate event and the gate “and” and “or”. With qualitative and quantitative analysis of fault tree of this accident, the main causes of the accident and the likelihood of the top event was calculated for a year. Results: Comparing with other stations, it was found that benzene with concentration of 0.37 mg/m³ in autumn, toluene with concentration of 0.13 mg/m³ in spring, and ethyl benzene with concentration of 0.09 mg/m³ in autumn, and xylene with the concentration of 1.01 mg/m³ in autumn season had the highest concentration. The fault tree developed had 16 events (including final, intermediate, and initial), which were connected to each other with seven logic gates. The maximum error percentage in the terminal events was attributed to the hardware failures such as malfunction in equipment with 55.55 percent followed by human and administrative errors in the next ranking. The highest percentage (22.2%) of the terminal events was related to the gasket unsuitable material the main reason is due to the economic sanctions and the lack of effort to provide high quality products. Conclusion: Most likely occurrence of the final event was related to the gasket unsuitable material (2×10^-2). Control action to prevent the occurrence of leakage could be supplying high quality gaskets and the failure is classified in the hardware failure category.

Background and Objectives: The presence of industrial workshops has increased urban pollution. This study aimed to investigate the heavy metal pollutants of Yazd battery repairing workshops and to identify the ecological and environmental effects resulted.

Materials and Methods: This descriptive cross-sectional study was carried out in Yazd. In this regard, the city was divided into three parts on the basis of geographical features. Then, 30 workshops were selected from each part through stratified random sampling method. Heavy metals (Pb, Cd, Cr, Zn, Cu, Fe, Mn) in the floor were measured using atomic absorption spectrophotometry (AAS). The impacts assessment of heavy metals was evaluated using environmental potential risk index (RI), cumulative pollution index (IPI), pollution coefficient factor (Cf), and the degree of modified contamination (mC_d) and Pearson’s correlation statistical test.

Results: The trend of heavy metals concentrations in floor dust particles of workshops was as Fe>Cu>Pb>Zn>Mn>Cr>Cd. Therefore, the average concentrations of Fe and Cd in the samples were 27011.52 ±4721.05 and 78.25±21.07 mg/kg respectively. The results of the RI showed that heavy metal of floor dust had very high danger (2816.29). The mCd value was as 63.35 indicating these workshops were at severe contamination class. The value of Cf was as 304.17 revealing that these workshops were at very severe contamination class.

Conclusions: This research showed that the high concentration of heavy metals in battery repairing workshops is due to the interaction of heavy metals of industrial wastes components, including electrical wastes and battery with the dust having mankind origin.