Efficiency Evaluation of Organic-Metal Nanostructures in Photodegradation of Ethylbenzene from Air Stream

By using photocatalytic processes, it is possible to reduce volatile organic compounds in the air under special conditions. The aim of this study was to evaluate the efficiency of the photocatalytic process in the presence of organic-metallic nanostructures model Bi2S3@NH2-MIL125(Ti) in reducing ethylbenzene concentration. The concentration of 150-300 ppm and the amount of deposited catalyst (1-3 g/m2) were studied. By increasing the airflow rate contaminated with ethylbenzene, the efficiency of the process decreased from 79% at 0.5 l/min to 41% at the flow rate of 3 l/min. By increasing the amount of catalyst coated on the reactor wall, the efficiency of the process increased from 65% at a dosage of 0.5 g/m2 to 86% at a dosage of 3 g/m2. By increasing the amount of input concentration. Of ethylbenzene, the efficiency of the process decreased from 94% at a concentration of 150 ppm to 55% at a concentration of 300 ppm. The optimal process conditions were determined at a flow rate of 0.5 l/m, the concentration of ethylbenzene, 150 ppm, and the amount of catalyst, 3.0 g/m2. The presence of different light sources including UV A, C, and visible light could reduce the initial concentration of ethylbenzene by.94, 95, and 67% respectively

On the reliability of CALPUFF and AUSTAL 2000 modeling systems regarding smoke and vapor plume mergence

Observations at power plants have shown that smoke plumes from stacks frequently merge with vapor plumes from cooling towers. Wind speed and direction play a key role in merging vapor and smoke plume. Mergence of stack and cooling tower plume leads to formation of undesirable substances such as sulfuric acid aerosols, acid mist, and acid fly ash. The present study shows that smoke and vapor plume mergence is a common phenomenon in Mátra power plant in Hungary; however more studies must be conducted in the future to reveal the type and number of plume mergence in the mentioned plant. The present work also indicates that the CALPUFF and AUSTAL 2000 modeling systems cannot provide enough information with regard to vapor and smoke plume mergence

The Integrated Fuzzy AHP and Goal Programing Model Based on LCA Results for Industrial Waste Management by Using the Nearest Weighted Approximation of FN: Aluminum Industry in Arak, Iran

The worldwide recycled aluminum generation is increasing quickly thanks to the environmental considerations and continuous growing of use demands. Aluminum dross recycling, as the secondary aluminum process, has been always considered as a problematic issue in the world. The aim of this work is to propose a methodical and easy procedure for the proposed system selection as the MCDM problem. Here, an evaluation method, integrated FAHP, is presented to evaluate aluminum waste management systems. Therefore, we drive weights of each pair comparison matrix by the use of the goal programming (GP) model. The functional unit includes aluminum dross and aluminum scrap, which is defined as 1000 kilograms. The model is confirmed in the case of aluminum waste management in Arak. For the proposed integrated fuzzy AHP model, five alternatives are investigated. The results showed that, according to the selected attributes, the best waste management alternative is the one involving the primary aluminum ingot 99.5% including 200 kg and the secondary aluminum 98% (scrap) including 800 kg, and beneficiation activities are implemented, duplicate aluminum dross is recycled in the plant, and finally it is landfilled

Sustainable energy strategy for Iran

The book shows that the implementation of a sustainable energy strategy in Iran provides the opportunity for further economic and social development. In this context, the aim of the book is to provide some of the analyses needed to rethink the country’s energy strategy and to grasp the chances. The authors hope to make a contribution to the emerging and rapidly growing discussion on better energy alternatives and the respective opportunities for investment, innovation and modernization. The work presented in the book should provide ideas for such opportunities and create a vision of how this could contribute towards developing a more sustainable, efficient and prosperous future energy system for Iran. The book is based on long-term academic cooperation between Iranian researchers from several universities and the Iranian Energy Association and German researchers from the Wuppertal Institute, Büro Ö-quadrat and the University of Osnabrück. The book in hand is an important result of the collaboration. So its publication lends itself to taking stock of these twelve years of continued cooperation

Study of Air Pollution Due to Plasma Cutting Process and Designing Local Ventilation System with Collector in Central Workshop of Mobarakeh Steel Company

Background & Objectives : Cutting leads to production of different hazardous agents such as fumes, particles, gases and vapors. In various studies, the effects of fumes, gases, and vapors on workers and environment have been proved. Meanwhile, cutting alloying plates with plasma cutting machine due to containing various alloy materials produces a lot of air pollution. Therefore, using the ventilation system to remove the mentioned pollution has always been noteworthy. Method: This study was performed on plasma cutting machine at Mobarakeh Steel Company. At first, according to ASTM the elements from alloy plates with optical emission spectrometry crm-35000-quantometery were detected, the air pollution from cutting the mentioned plates was sampled and measured using NIOSH 7300 method and according to the ACGIH:VS-72-20, VS-70-12, VS-70-11 VS-916 push-pull ventilation with bag filter collector was designed. Results: Results of sampling from pollution of cutting the alloy material, concentration of iron, lead and cadmium fumes were more than the standard limits. After calculation for push system, air flow volume of 195.163 cfm, outgoing air velocity of 5937.4 fpm and for pull system air flow volume of 12498 cfm, minimum duct velocity of 3000 fpm and velocity pressure of duct of 0.717 inwg, for fan, total pressure of 6.301 inwg, static pressure of 0.587 inwg and power of 20.65 Bhp and for collector with pulse jet cleaning system air to cloth ratio of 7 and dimensions of 6.88ft × 6.56ft × 9.84ft were obtained. Conclusion: The result of study indicated that push pull ventilation compared to other ventilation system s for plasma cutting has more efficiency and makes suitable control for pollution

GIS-based assessment of cancer risk due to benzene in Tehran ambient air

Objectives: The present study aimed to assess the risk of cancer due to benzene in the ambient air of gas stations and traffic zones in the north of Tehran. The cancer risk was estimated using the population distribution data for benzene levels and the unit risk for benzene proposed by the United States Environmental Protection Agency (US EPA). Material and Methods: Sixteen sampling locations were monitored, once every week, during 5 April 2010 to 25 March 2011. Results: The results showed that the mean annual benzene concentration was 14.51±3.17 parts per billion (ppb) for traffic zones and 29.01±1.32 ppb for outside gas stations. The risk calculated was 1026×10-6 for gas station 27 and 955×10-6 for gas station 139. Conclusions: According to our results, the annual benzene level in Tehran ambient air is 2 to 20 times higher than the respective value specified in International Standard (1.56 ppb). Moreover, the results showed a notable increase of cancer risks, ranging from 10% to 56%, for the vicinity population close to the gas stations in comparison to the vicinity population in the traffic zones

The Survey of NOX Distribution Using Dispersion Models AERMOD and CALPUFF at a Gas Refinery

Background & Objectives: Nowadays, air pollution is one of the major challenges in the world, therefore, in the present study, according to the importance of the fourth refinery gas as the largest gas refinery in the region, the amount of emissions from stacks has been initially determined and then the distribution has been identified in the region. Methods: In this research, AERMOD and CALPUFF models have been used as the tools for the analysis of NOX emissions of stacks of 4th South Pars gas refinery located in Assaluyeh. First, NOX emissions from refinery stacks have been obtained by field measurements. Then, the distribution of these emissions has been examined using dispersion models AERMOD and CALPUFF in an area of 50 × 50 km in each direction x and y in the one-year period of 2013 to the average time of 1, 3, 8, and 24 and the amounts resulting from the implementation of the models have been compared to the results of field measurements at 9 receiving stations as a separate receptors in the model. Results: Review of charts and statistical parameters has shown that, according to the evaluation of predictions made, the CALPUFF model was better than AERMOD model, in the studied area. Conclusion: It could be concluded that performance of both models to predict the concentration of pollutants in the region can be generally considered acceptable

Long run energy demand in Iran: a scenario analysis

Purpose - Iran as an energy-rich country faces many challenges in the optimal utilization of its vast resources. High rates of population and economic growth, a generous subsidies program, and poor resource management have contributed to rapidly growing energy consumption and high energy intensity over the past decades. The continuing trend of rising energy consumption will bring about new challenges as it will shrink oil export revenues, restraining economic activities. This calls for a study to explore alternative scenarios for the utilization of energy resources in Iran. The purpose of this paper is to model demand for energy in Iran and develop two business-as-usual and efficiency scenarios for the period 2005-2030. Design/methodology/approach - The authors use a techno-economic or end-use approach to model energy demand in Iran for different types of energy uses and energy carriers in all sectors of the economy and forecast it under two scenarios: business as usual (BAU) and efficiency. Findings - Iran has a huge potential for energy savings. Specifically, under the efficiency scenario, Iran will be able to reduce its energy consumption 40 percent by 2030. The energy intensity can also be reduced by about 60 percent to a level lower than the world average today. Originality/value - The paper presents a comprehensive study that models the Iranian energy demand in different sectors of the economy, using data at different aggregation levels and a techno-economic end-use approach to illuminate the future of energy demand under alternative scenarios

Scenario analysis of the potential for CO 2 emission reduction in the Iranian cement industry

Abstract: This article investigates the impact of various policies on the reduction of CO2 emissions from Iranian cement industry using a long range energy alternative planning (LEAP) model. A Business-as-Usual (BAU) scenario for the existing Iranian cement industry was applied. Moreover, the current and future demands for the cement industry were defined for 2005-2020. The current and future productivity of the cement industry was predicted in the BAU scenario. Then, three alternative scenarios were considered: replacement of heavy oil with natural gas, implementation of energy efficiency policies and integrated emission reduction, which includes all of the options over a 15-year period. The results indicated that in 2020, CO2 equivalent emissions would reach 61 million tons in the baseline scenario and 53 million tons in the integrated emission reduction scenario. If fuel switching were employed, the emissions would reach 58 million tons (4.9 % reduction) and in the energy efficiency scenario, the emissions would reach 55 million tons (9.8% reduction) in 2020. Therefore, the integrated scenario reduces the total CO2 equivalent emissions by 8 million tons (13% emission reduction)