Bahman Ramavandi; Mehdi Ahmadi Moghaddam; Narjes Shah Heidar; Maryam Bighami
Volume 23, Issue 2 , March and April 2016, , Pages 253-261
Abstract
Background & Purpose: Volatile organic compounds (VOCs) significantly affect the chemistry of atmosphere and human health and petroleum storage has been identified as largest emitters of VOCs. With models of air pollution can model the concentration and distribution ...
Read More
Background & Purpose: Volatile organic compounds (VOCs) significantly affect the chemistry of atmosphere and human health and petroleum storage has been identified as largest emitters of VOCs. With models of air pollution can model the concentration and distribution of VOCs from oil tanks. The aim of this study was to investigate and model of VOCs emissions from an oil tanks field in Iran using the TANKs 4.0.9d software and the distribution of these compounds in the study area using AERMOD model. Materials & Methods: In this study, the rate and percentage of monthly emissions of VOCs from 22 oil storage tanks in 12 months year 2014(1392-1393) using the TANKS software were determined according to losses and tank type in Esfahan, Iran. Then, by using AERMOD model the maximum concentration of VOCs in the area with the surface of 10 × 10 km2 and with a network distance of 200m and then in the range of 50 × 50 km2 and with a network of 1000 m in the statistic period of 12 months and for a average time of 1, 3, 8 and 24 hours, one-month and one -year statistical period at the height of 1.5m of the Earth's surface was determined and the distribution of VOCs in the area was simulated and displayed by GIS software. Results: The results of TANKS software showed that the studied tanks were annually emitted 1485801.26 tons VOCs in which the tanks with external floating roof 99.98% and with fixed vertical roof 0.017% were contributed. The results of AERMOD software also indicated that maximum concentrations of VOCs occur in the area 10×10 km2 in cold seasons. This phenomenon is due to reduce of mixing depth and resulting in the formation of the inversion phenomenon. Conclusions: This work can help plant engineers to decide on an appropriate strategy to control VOCs. Employing the tanks with fixed vertical roof and modification of operational pattern could lead to a reduction of VOCs emissions and eventually affect the economical, ecological and hygienic aspects.
Bahman Ramavandi; Mostafa Leili
Volume 21, Issue 3 , July and August 2014, , Pages 502-513
Abstract
Background: Dyes are used in many industries. The discharge of colored wastewater and effluents from these industries to receiving water bodies could cause many significant problems such as increasing the toxicity and chemical oxygen demand (COD). So, these types of wastewater should be appropriately ...
Read More
Background: Dyes are used in many industries. The discharge of colored wastewater and effluents from these industries to receiving water bodies could cause many significant problems such as increasing the toxicity and chemical oxygen demand (COD). So, these types of wastewater should be appropriately treated. The efficiencies of activated carbon derived from date stone in the removal of methylene blue (MB) from aqueous solutions were assessed in this study.
Material and Methods: In this research that was an experimental study and was done in laboratory scale, the effects of different parameters such as initial pH (2-12), adsorbent dose (0.25-5 mg/L), initial dye concentration (50 -400 mg/L), and contact time (20-430 min) on methylene blue adsorption with activated carbon derived from date stone were evaluated. The reaction isotherm using the appropriate equations was also investigated.
Results: The results showed that dye adsorption with high efficiencies were obtained at pH 8. The evaluation of adsorption isotherm showed that laboratory data was best fit with Langmuir isotherm (R2= 0.998) and maximum adsorption capacity was obtained 478.3 mg/g.
Conclusion: Based on the removal efficiency of used MB-concentrations in this study, we found that activated carbon derived from date stones could be applied as an efficient and inexpensive adsorbent in the removal of dyes from wastewater.