جستجوی مقالات مرتبط با کلیدواژه « ترکیبات btex » در نشریات گروه « محیط زیست »

Aromatic hydrocarbons such as benzene, toluene, ethylbenzene and xylene isomers (BTEX) are pollutants in industrial plants that cause problems in various sources, especially air. Elimination of these toxic compounds, even to a very small extent, from these constant sources of pollutants is important not only from an environmental but also from an economic point of view. Nowadays, the rapid industrialization of societies, especially developing countries, to meet the needs of citizens is recognized as the main cause of air pollution. Therefore, maintaining environmental standards is necessary to reduce the potential for pollutions and support sustainable development. Waterproofing production plants are one of the main sources of emissions of this group of pollutants, so the implementation of control measures and optimization of the performance of these industrial units in Delijan city as the capital of Waterproofing production is necessary and undeniable.

In this study, the process of removing BTEX contaminants from Izogam Parsian Delijan factory has been evaluated and studied through simulation and process modification based on insulator design and using thermal oxidation of pollutants (BTEX) method. Questions related to the efficiency and environmental benefits of designing incinerator serve as the primary motivation for the present work. The purpose of this study is to help this evidence by assessing the environmental and technical evaluation of the performance of the incinerator unit in a BW production plant located in Delijan-Iran. Moreover, energy consumption and pollutant emissions of system have been optimized by changing the temperature and residence time of incinerator using SPSS software. It should be noted that the process of removing BTEX contaminants has been accomplished by simulation using Aspen Hysys software. In this regard, the process modification based on the Incinerator designing and using the thermal oxidation method has been evaluated.

Based on the results, the temperature and residence time in optimal conditions are 732 and 0.84, respectively. Furthermore, the incinerator's control efficiency (CF) reveals that 98.5% of BTEX compounds in the exhaust gases were removed. It should be noted that the system's energy efficiency has also improved significantly in such a way that the amount of fuel consumed by the system in optimum condition has decreased by 23% compared to the initial state.have been optimized by implementing software such as SPSS and hardware elements. The results of using the incinerator in this study, the rate of control efficiency (CEF) of the device in removing the desired compounds is reported to be 98.5%. Also, the energy consumption index in this case, compared to the performance of the system without insulator in the same mode, has caused a 23% reduction in fuel consumption.

The optimization results revealed that using incinerator in certain condition can be considered as an applicable solution for removing BTEX from industrial activities. In this regard, temperature and residence time can be determined as two significant operating indexes affecting the pollutants emission and energy consumption. According to the results, the proposed method has acceptable environmental and economic performance thus, It is also suggested the possibility of large investments to reduce the effects of BTEX pollutants in the region by coupling them to renewable energies.

In recent years, production and use of petroleum products, such as gasoline, have been increasing. This increase is followed by numerous ecological consequences. Among them, the most important ecological effects of using gasoline is contamination of soils at refineries and gas stations. Hazards of gasoline leakage into the soil and its migration to groundwater could be attributed to the existence of BTEX compounds, which are the main constituents of gasoline with high toxicity and volatility values.
In this study, the removal of BTEX contaminants from soil samples contaminated with gasoline has been investigated using Soil Vapor Extraction technique. The treatment tests were conducted at 3 time intervals of 4, 8 and 12 hours and 3 different temperatures of 20, 40 and 60°C.
The results of tests indicate the high suitability of SEV technique showung %99 removal efficiency for BTEX compounds from soil samples. Moreover, the results of the analysis present that the removal of contaminants an inverse relation with their boiling points in this techniques. Also, raising the temperature of the samples from 20°C to 40°C and from 40°C to 60°C during 12 hours increased the removal efficiencies of BTEX compounds by %10 and %26, respectively.
The results of this study revealed that SVE technique for the removal of aromatic organic compound from soil is an efficient technique which can lead to high efficiency for the removal of such contaminats from soil, if implented properly.

The fuel loss at gas stations is one of the main sources of volatile organic compounds in the ambient air. The study shows 52000 liter of gasoline per day is lost from the gas stations across the city of Tehran. Each station losses approximately 415 liters per day, which makes the area on and around the gas stations polluted. In this study, the BTEX were measured at two gas stations and 20 main cross streets, during summer and winter. The results indicated Benzene concentration is higher than the ambient air limits for both the gas station areas as well as the 20 measured places across the city. The average concentration of Benzene in the gas stations were between 8 to 16 times higher than the threshold limit value – time weight average for work area, and 250 to 500 times higher than the ambient air standard. The average concentration of Benzene near the traffic areas were 60 times higher than ambient air standard. Also we studied the ways to control gasoline vapor. Cooling the vapor has been experimented. The results show, 50% of vapor in 0 – 60C could be recycled.