University of TehranJournal of Environmental Studies1025-8620354920090522Comparison between MPDATA and High Order Upwind Compact Finite Difference Methods in Air Pollutants Dispersion ModelingComparison between MPDATA and High Order Upwind Compact Finite Difference Methods in Air Pollutants Dispersion Modeling28318FAJournal Article19700101In this paper high order multidimensional positive definite advection transport algorithm (MPDATA) and compact finite difference methods are applied to one (1-D) and two-dimensional (2-D) advection equation. MPDATA methods are designed based on upwind scheme using anti-diffusive velocity that compensates diffusivity of upwind method. In high order compact method one implicit relation between a function and its first derivative is added to the governing equation of flow and this combination increases the accuracy of the method. In the present study, the grid study is carried out at 11, 21, 41, 81, 161, 321, and 641 grid points in 1-D case. Also, the number of grid points in 2-D case are , , , , and for MPDATA method and , , and for compact scheme. Two important characteristics of numerical schemes are investigated. First, the accuracy of two mentioned methods is compared together. It shows that in 1-D case the accuracy of MPDATA scheme at 641 grid points is approximately equal to the accuracy of compact method at 161 grid points. In 2-D case this comparison shows that the accuracy of MPDATA scheme at grid points is approximately equal to the accuracy of compact method at grid points. Second, the comparison of computational cost of two methods shows that the computational cost of compact method is 333 and 306 times of MPDATA scheme computational cost in 1-D and 2-D cases, respectively.In this paper high order multidimensional positive definite advection transport algorithm (MPDATA) and compact finite difference methods are applied to one (1-D) and two-dimensional (2-D) advection equation. MPDATA methods are designed based on upwind scheme using anti-diffusive velocity that compensates diffusivity of upwind method. In high order compact method one implicit relation between a function and its first derivative is added to the governing equation of flow and this combination increases the accuracy of the method. In the present study, the grid study is carried out at 11, 21, 41, 81, 161, 321, and 641 grid points in 1-D case. Also, the number of grid points in 2-D case are , , , , and for MPDATA method and , , and for compact scheme. Two important characteristics of numerical schemes are investigated. First, the accuracy of two mentioned methods is compared together. It shows that in 1-D case the accuracy of MPDATA scheme at 641 grid points is approximately equal to the accuracy of compact method at 161 grid points. In 2-D case this comparison shows that the accuracy of MPDATA scheme at grid points is approximately equal to the accuracy of compact method at grid points. Second, the comparison of computational cost of two methods shows that the computational cost of compact method is 333 and 306 times of MPDATA scheme computational cost in 1-D and 2-D cases, respectively.https://jes.ut.ac.ir/article_28318_77dba2479a8c8019f51b94fba1276d5b.pdfUniversity of TehranJournal of Environmental Studies1025-8620354920090522Nickel Biosorption from Aqueous Solutions Using Bios lidsNickel Biosorption from Aqueous Solutions Using Bios lids28319FAJournal Article19700101Recently, the use of biological absorbent in removal of hazardous pollutants such as heavy metals has increased because of the decrease in sludge problems, economical issues, high efficiency and compatibility with the environment. This study was done over the Biosorption of Nickel by Biosolids obtained from the municipal wastewater treatment in a batch reactor. The pretreatment of the Biosolids includes dewatering, grinding and grain sizing with meshes between 50 to 120. Nickel adsorption kinetics follows the pseudo second model and maximum equilibrium adsorption observed at two hours. The optimum stirring rate in this system is 150 to 250rpm. The increase in pH results in adsorption increase and there is a significant adsorption increase between 3 and 4. The results from adsorption modeling shows that the Nickel adsorption follows the Langmuir model and the maximum Nickel adsorption (qmax) by biosolids is 0.195 milimole per gram of dry biosolids (11.442 mg/g) and the Langmuir constant (kd) is 0.238 milimole per liter (13.96 mg/lit).Recently, the use of biological absorbent in removal of hazardous pollutants such as heavy metals has increased because of the decrease in sludge problems, economical issues, high efficiency and compatibility with the environment. This study was done over the Biosorption of Nickel by Biosolids obtained from the municipal wastewater treatment in a batch reactor. The pretreatment of the Biosolids includes dewatering, grinding and grain sizing with meshes between 50 to 120. Nickel adsorption kinetics follows the pseudo second model and maximum equilibrium adsorption observed at two hours. The optimum stirring rate in this system is 150 to 250rpm. The increase in pH results in adsorption increase and there is a significant adsorption increase between 3 and 4. The results from adsorption modeling shows that the Nickel adsorption follows the Langmuir model and the maximum Nickel adsorption (qmax) by biosolids is 0.195 milimole per gram of dry biosolids (11.442 mg/g) and the Langmuir constant (kd) is 0.238 milimole per liter (13.96 mg/lit).https://jes.ut.ac.ir/article_28319_62efa210d1526a8b5058c4825a4cfe7c.pdfUniversity of TehranJournal of Environmental Studies1025-8620354920090522Solid waste generation forecasting by hybrid of artificial neural network and wavelet transformSolid waste generation forecasting by hybrid of artificial neural network and wavelet transform28320FAJournal Article19700101Quantitative Prediction of municipal solid waste generation has an important role in the optimization and programming of municipal solid waste management system. But, this concept was companied with many problems, because of the non homogenous nature and the effect of various factors out of the control on solid waste generation. In this study, the combination of artificial neural network and wavelet transform (wavelet-neural network) is used to predict the weekly generation in Tehran, concerning complexity and dynamic municipal solid waste management system. In order to this forecasting, time series of generation of this city arranged weekly in the period of 1380 to first three months of 1385, are used. The results achieved in this research indicate the positive effect of preprocessing of input variables by the wavelet transform in prediction of weekly generation in this city so that it has led to noticeable increasing in the accuracy of model calculation. The correlation coefficient (R2) of models, in the stage of testing, has improved from 0.41 in the model of neural network to 0.91 in the model of wavelet-neural network.Quantitative Prediction of municipal solid waste generation has an important role in the optimization and programming of municipal solid waste management system. But, this concept was companied with many problems, because of the non homogenous nature and the effect of various factors out of the control on solid waste generation. In this study, the combination of artificial neural network and wavelet transform (wavelet-neural network) is used to predict the weekly generation in Tehran, concerning complexity and dynamic municipal solid waste management system. In order to this forecasting, time series of generation of this city arranged weekly in the period of 1380 to first three months of 1385, are used. The results achieved in this research indicate the positive effect of preprocessing of input variables by the wavelet transform in prediction of weekly generation in this city so that it has led to noticeable increasing in the accuracy of model calculation. The correlation coefficient (R2) of models, in the stage of testing, has improved from 0.41 in the model of neural network to 0.91 in the model of wavelet-neural network.https://jes.ut.ac.ir/article_28320_b45648fa611188a212c485fdd4dba5f5.pdfUniversity of TehranJournal of Environmental Studies1025-8620354920090522Evaluation of Biocompatibility and Biodegradation of Three Different Oil Dispersants in Persian Gulf: Siri Island WaterEvaluation of Biocompatibility and Biodegradation of Three Different Oil Dispersants in Persian Gulf: Siri Island Water28321FAJournal Article19700101Many methods have been used to remove oil spills from water and/or land. Such methods include physical removal of the petroleum from the water or land, chemical remediation of the spilled petroleum through the use of dispersants and so-called "sinking agents," and, in some cases, intentionally burning floating petroleum slicks. Chemical remediation through the use of liquid, oil dispersant agents is the most frequently employed clean-up method because such liquids can be readily applied to large oil spills and because this method is generally more cost-effective than physical remediation methods.However, not all surfactant compositions are effective in dispersing spilled oil products and many of the more effective ones have the drawbacks of being toxic and/or not biodegradable In this study we tested Biodegradation of oil and dispersants"pars 1, pars 2, Gamlen OD4000".These dispersants are in fact used for chemical remediation of spilled oil. Our objective is the selection of the most suitable dispersant for Siri Island that are more compatible with environment and be able to remediate by microorganisms live this place.In this study we chose 8 staions for sampling of water in Siri Island.Then microorganisms were isolated to test their ability for degradation of oil and dispersant. The ability of growth of microorganisms at the sides of wells containing oil or dispersant or mixture of them were identified by Well method.The microorganisms were then transferred to culture medium that containing oil and dispersant as the sole source of carbon and energy; This media was incubated at 120rpm and during 28 days. In this study we tested BOD5 and COD of oil , dispersant, and mixture of them in the presence of the total microorganisms that were isolated from the total sampling stations. Finally, our results showed that dispersant pars 1 & Pars 2 were the most degradable as compared with dispersant Gamlen.Many methods have been used to remove oil spills from water and/or land. Such methods include physical removal of the petroleum from the water or land, chemical remediation of the spilled petroleum through the use of dispersants and so-called "sinking agents," and, in some cases, intentionally burning floating petroleum slicks. Chemical remediation through the use of liquid, oil dispersant agents is the most frequently employed clean-up method because such liquids can be readily applied to large oil spills and because this method is generally more cost-effective than physical remediation methods.However, not all surfactant compositions are effective in dispersing spilled oil products and many of the more effective ones have the drawbacks of being toxic and/or not biodegradable In this study we tested Biodegradation of oil and dispersants"pars 1, pars 2, Gamlen OD4000".These dispersants are in fact used for chemical remediation of spilled oil. Our objective is the selection of the most suitable dispersant for Siri Island that are more compatible with environment and be able to remediate by microorganisms live this place.In this study we chose 8 staions for sampling of water in Siri Island.Then microorganisms were isolated to test their ability for degradation of oil and dispersant. The ability of growth of microorganisms at the sides of wells containing oil or dispersant or mixture of them were identified by Well method.The microorganisms were then transferred to culture medium that containing oil and dispersant as the sole source of carbon and energy; This media was incubated at 120rpm and during 28 days. In this study we tested BOD5 and COD of oil , dispersant, and mixture of them in the presence of the total microorganisms that were isolated from the total sampling stations. Finally, our results showed that dispersant pars 1 & Pars 2 were the most degradable as compared with dispersant Gamlen.https://jes.ut.ac.ir/article_28321_130f62c64e0abfd28fb4241fadb6654f.pdfUniversity of TehranJournal of Environmental Studies1025-8620354920090522Study of Soil Pollution in the Kerman Urban Areas with Trace ToxicStudy of Soil Pollution in the Kerman Urban Areas with Trace Toxic28322FAJournal Article19700101The study of regional variations and the anthropogenic contamination by trace toxic elements of soils is very important for environmental planning and monitoring in urban areas. Soil, sediment and rocks of urban areas of Kerman studied to assess the degree of pollution by trace elements as a consequence of anthropogenic sources. 37 samples were collected and analyzed by ICP-MS for 29 elements. These concentrations were compared with environmental investigation limits. From this study it was possible to observe that the fresh rocks (limestone) near Kerman city contain relatively low concentrations of trace elements as shown by background values. Soils of Kerman are anomalously rich in some trace elements. Most of the soil samples displayed concentrations of these element higher than natural background values that wich suggests an anthropogenic input besides the rock and sediment influences. The accumulation of these contaminants is likely to accelerate as a consequence of rapid traffic, economic and industrial growth in the urban environment of Kerman. It seems that traffic and wind- blown dust are responsible for high soil concentration in some of elements like Pb and Cu. Also the results revealed very high values of lead (>10000 ppm) and copper (>700ppm) in some soil and sediment samples. The most polluted and dangerous points are caused soils close to battery repairing stores or discarded batteries and machinery oil painting ( Pb>5000 ppm). However some of elements such as Bi, Cd, Co, Hg, Mn, Th and U, did not show any pollution in this area. Geochemical maps of some trace elements in the rock, sediment and soils were produced based on geographical information system (GIS) technology. Geochemical maps showed a increasing in concentrations of some potentially toxic elements from rural areas to center of Kerman city.The study of regional variations and the anthropogenic contamination by trace toxic elements of soils is very important for environmental planning and monitoring in urban areas. Soil, sediment and rocks of urban areas of Kerman studied to assess the degree of pollution by trace elements as a consequence of anthropogenic sources. 37 samples were collected and analyzed by ICP-MS for 29 elements. These concentrations were compared with environmental investigation limits. From this study it was possible to observe that the fresh rocks (limestone) near Kerman city contain relatively low concentrations of trace elements as shown by background values. Soils of Kerman are anomalously rich in some trace elements. Most of the soil samples displayed concentrations of these element higher than natural background values that wich suggests an anthropogenic input besides the rock and sediment influences. The accumulation of these contaminants is likely to accelerate as a consequence of rapid traffic, economic and industrial growth in the urban environment of Kerman. It seems that traffic and wind- blown dust are responsible for high soil concentration in some of elements like Pb and Cu. Also the results revealed very high values of lead (>10000 ppm) and copper (>700ppm) in some soil and sediment samples. The most polluted and dangerous points are caused soils close to battery repairing stores or discarded batteries and machinery oil painting ( Pb>5000 ppm). However some of elements such as Bi, Cd, Co, Hg, Mn, Th and U, did not show any pollution in this area. Geochemical maps of some trace elements in the rock, sediment and soils were produced based on geographical information system (GIS) technology. Geochemical maps showed a increasing in concentrations of some potentially toxic elements from rural areas to center of Kerman city.https://jes.ut.ac.ir/article_28322_2bf190c336928091796f67ebedc3d6b3.pdfUniversity of TehranJournal of Environmental Studies1025-8620354920090522Risk Assessment of Industrial Sites of Asalouye by UsingRisk Assessment of Industrial Sites of Asalouye by Using28323FAJournal Article19700101Pars economical ly special zone “Asalouye area” is located in the extreme south of central of Iran along the Persian Gulf. “Asalouye area” consists of industrial refineries, petrochemical and different industries.
Due to existence of various industries site in “Asalouye”, it is necessary to know and classify the major risks which can affect the area. Risk simulation is one of the most applicable procedure to localize and assessing the risks.
The purpose of this paper is to identify the risk grading by identifying major dangers in some current land uses with applying semi-quantitative risk assessment method. For this purpose, risks of accidents such as fire accident, seeping of gases, toxic gases, and explosion were calculated with semi-quantitative method for each land use site and then the results were simulated by GIS. The relative weight of different risks was computed by means of AHP analysis, special vector technique, and two by two zonal risks comparing. Moreover the total risk that is the result of all risks in each land use was computed and simulated by GIS. The results of this paper can support environmental management system (EMS) in the zone of Asalouye by specifying the potential location of risks and also for safety measure planning.Pars economical ly special zone “Asalouye area” is located in the extreme south of central of Iran along the Persian Gulf. “Asalouye area” consists of industrial refineries, petrochemical and different industries.
Due to existence of various industries site in “Asalouye”, it is necessary to know and classify the major risks which can affect the area. Risk simulation is one of the most applicable procedure to localize and assessing the risks.
The purpose of this paper is to identify the risk grading by identifying major dangers in some current land uses with applying semi-quantitative risk assessment method. For this purpose, risks of accidents such as fire accident, seeping of gases, toxic gases, and explosion were calculated with semi-quantitative method for each land use site and then the results were simulated by GIS. The relative weight of different risks was computed by means of AHP analysis, special vector technique, and two by two zonal risks comparing. Moreover the total risk that is the result of all risks in each land use was computed and simulated by GIS. The results of this paper can support environmental management system (EMS) in the zone of Asalouye by specifying the potential location of risks and also for safety measure planning.https://jes.ut.ac.ir/article_28323_d2f7b1c7c54c38bb77725a49789bc25e.pdfUniversity of TehranJournal of Environmental Studies1025-8620354920090522( Biodiversity and Economic Growth: A Cross -Country (with Emphasis on Developing Countries( Biodiversity and Economic Growth: A Cross -Country (with Emphasis on Developing Countries28324FAJournal Article19700101In this study an attempt has been made to empirically examine the relationship between biodiversity and economic growth using indicators of species diversity and income per capita as proxies for biodiversity and economic growth, respectively.Also the effects of agricultural value added as a percentage of GDP, trade freedom index, exchange rate, population, percantage of land developed for agriculture, percentage of protected land area and climate variables were studied. For this study, utilizes data for 121 countries on 2002, that gathered of World Bank and FAO sites. The results show that increase income per capita to cause decrease species number, so decrease biodiversity. Increase agricultural value added, to cause decrease species diversity and biodiversity. This variable, specially are significanct on decrease biodiversity for developing countries. Increases trade freedom index and exchange rate to cause decrease biodiversity. Population has a significant positive effect on biodiversity, that sign of population coefficient is unexpected. Increase percantage of land developed for agriculture, to cause decrease biodiversity. Increase percentage of protected land area to cause, improvement biodiversity. Climate dummy variable has a significant positive effect on biodiversity. So in equatorial and tropical regions are more, mammals, birds and plants species diversity and number. Also observed, Environmental Kuznets Curve for developed countries but didn t observed for developing countries. Therefor turning point exist for developed countries but there is not for developing countries. Therefore, in the developing countries, environmental policy must be applied to improve biodiversityIn this study an attempt has been made to empirically examine the relationship between biodiversity and economic growth using indicators of species diversity and income per capita as proxies for biodiversity and economic growth, respectively.Also the effects of agricultural value added as a percentage of GDP, trade freedom index, exchange rate, population, percantage of land developed for agriculture, percentage of protected land area and climate variables were studied. For this study, utilizes data for 121 countries on 2002, that gathered of World Bank and FAO sites. The results show that increase income per capita to cause decrease species number, so decrease biodiversity. Increase agricultural value added, to cause decrease species diversity and biodiversity. This variable, specially are significanct on decrease biodiversity for developing countries. Increases trade freedom index and exchange rate to cause decrease biodiversity. Population has a significant positive effect on biodiversity, that sign of population coefficient is unexpected. Increase percantage of land developed for agriculture, to cause decrease biodiversity. Increase percentage of protected land area to cause, improvement biodiversity. Climate dummy variable has a significant positive effect on biodiversity. So in equatorial and tropical regions are more, mammals, birds and plants species diversity and number. Also observed, Environmental Kuznets Curve for developed countries but didn t observed for developing countries. Therefor turning point exist for developed countries but there is not for developing countries. Therefore, in the developing countries, environmental policy must be applied to improve biodiversityhttps://jes.ut.ac.ir/article_28324_baf5855db35096080d9f0ae1e78258bc.pdfUniversity of TehranJournal of Environmental Studies1025-8620354920090522Urban Storm runoff Quality and Sediments with Heavy Metals in Shiraz City Infiltration Pond and Investigation of Sorbent Materials fot Polution ReductionUrban Storm runoff Quality and Sediments with Heavy Metals in Shiraz City Infiltration Pond and Investigation of Sorbent Materials fot Polution Reduction28325FAJournal Article19700101Heavy metals are considered one of the most important environmental pollution and are dissolved form or adsorbed to the suspended solides in the urban storm runoffs and infiltratire ponds. In this article the heavy metals of urban storm runoff and sediments of infiltration pond in Shiraz city have been investigated. The results show different pollutions in the urban storm runoffs such as dissolved heavy metals with low consentration, although most of them adsorbed to the suspended solids and displaced. Based on the result, (95-100)% Iron, (91-100)% Copper, (79-100)% Zinc and (47-100)% Manganese , have been adsorbed on the suspended solids of storm .Heavy metals such as Zinc, Iron and Copper are also existed in the surface layer of infiltration pond and existence of them in the bottom layer represents that these metals have been moved downward; however the upper layers have sufficient adsorption capacity. For treatment of urban storm runoffs contamination, different sets of batch adsorption tests in the laboratory scale have been conducted with some low cost adsorbents such as, sawdust, flyash and sand. In order to zinc metal has a most mobility in the soil, so it has been selected and optimum ph for maximum adsorption of it obtained.Treatment of total dissolved solid by sawdust represent that maximum adsorption is 39% for 20 g/l adsorbent also; greatest removal of suspended solid is 80% for 10 g/l sawdust. Therefore to protect the groundwater resources under infiltration ponds and achieve the desired water quality management goals, such low cost adsorption systems could be carefully designed before ponds by using sufficient site specification information of storm quality.Heavy metals are considered one of the most important environmental pollution and are dissolved form or adsorbed to the suspended solides in the urban storm runoffs and infiltratire ponds. In this article the heavy metals of urban storm runoff and sediments of infiltration pond in Shiraz city have been investigated. The results show different pollutions in the urban storm runoffs such as dissolved heavy metals with low consentration, although most of them adsorbed to the suspended solids and displaced. Based on the result, (95-100)% Iron, (91-100)% Copper, (79-100)% Zinc and (47-100)% Manganese , have been adsorbed on the suspended solids of storm .Heavy metals such as Zinc, Iron and Copper are also existed in the surface layer of infiltration pond and existence of them in the bottom layer represents that these metals have been moved downward; however the upper layers have sufficient adsorption capacity. For treatment of urban storm runoffs contamination, different sets of batch adsorption tests in the laboratory scale have been conducted with some low cost adsorbents such as, sawdust, flyash and sand. In order to zinc metal has a most mobility in the soil, so it has been selected and optimum ph for maximum adsorption of it obtained.Treatment of total dissolved solid by sawdust represent that maximum adsorption is 39% for 20 g/l adsorbent also; greatest removal of suspended solid is 80% for 10 g/l sawdust. Therefore to protect the groundwater resources under infiltration ponds and achieve the desired water quality management goals, such low cost adsorption systems could be carefully designed before ponds by using sufficient site specification information of storm quality.https://jes.ut.ac.ir/article_28325_ae0ddd787116d885a3a8a467d09c0ce2.pdfUniversity of TehranJournal of Environmental Studies1025-8620354920090522Evaluation of Geothermal Power Plants Development:An Environmental Economics PerspectiveEvaluation of Geothermal Power Plants Development:An Environmental Economics Perspective28326FAJournal Article19700101In the sector of electricity production, the existence of investment resources limitation and environmental factors are the main factors that influence this process. The reduction of costs and the destructive impacts of environmental have been always mentioned by specialists. Consequently, the drasticality of the environmental protection and the electric-energy production lead to focus on solar power plants. Obviously, in our country the issue of required resources for investment surpasses the environmental factors. Here, the main question is that in the current situation of our country, the replacement of fossil power plants with solar power plants is possible or not and can we be hopeful that it would be possible in future ? Also considering the high costs of electricity production by solar power plants and the situation of electricity production costs and social costs, this research endeavours to do an economic evaluation on the above mentioned subject in Iran. In this study, the marginal cost of 1kwh electricity production, in each power plant was estimated, then the evaluation was done considering pollutants and green-house gases emission from fossil power plants and to put the imposed social costs into consideration. In conclusion, it is indicated that using solar power plants electricity is not economical yet, but using photovoltaic systems electricity is economical in the same situations.Regarding that electricity demand, resources scarcity and the large amount of pollution, using fossil power plants electricity would not be economical .In the sector of electricity production, the existence of investment resources limitation and environmental factors are the main factors that influence this process. The reduction of costs and the destructive impacts of environmental have been always mentioned by specialists. Consequently, the drasticality of the environmental protection and the electric-energy production lead to focus on solar power plants. Obviously, in our country the issue of required resources for investment surpasses the environmental factors. Here, the main question is that in the current situation of our country, the replacement of fossil power plants with solar power plants is possible or not and can we be hopeful that it would be possible in future ? Also considering the high costs of electricity production by solar power plants and the situation of electricity production costs and social costs, this research endeavours to do an economic evaluation on the above mentioned subject in Iran. In this study, the marginal cost of 1kwh electricity production, in each power plant was estimated, then the evaluation was done considering pollutants and green-house gases emission from fossil power plants and to put the imposed social costs into consideration. In conclusion, it is indicated that using solar power plants electricity is not economical yet, but using photovoltaic systems electricity is economical in the same situations.Regarding that electricity demand, resources scarcity and the large amount of pollution, using fossil power plants electricity would not be economical .https://jes.ut.ac.ir/article_28326_a79591e4c53aacb6aad754eea2e9a9be.pdfUniversity of TehranJournal of Environmental Studies1025-8620354920090522Floristic Study of Biotopes in the City Area of Babol (Mazandaran) from Urban Ecology PerspectiveFloristic Study of Biotopes in the City Area of Babol (Mazandaran) from Urban Ecology Perspective28327FAJournal Article19700101https://jes.ut.ac.ir/article_28327_9be1a86497065b82d5650d1294774067.pdfUniversity of TehranJournal of Environmental Studies1025-8620354920090522Spatial analysis of the development of green space indicators In all eleven zones of Isfahan(A Case Study: Isfahan Urban ZonesSpatial analysis of the development of green space indicators In all eleven zones of Isfahan(A Case Study: Isfahan Urban Zones28328FAJournal Article19700101https://jes.ut.ac.ir/article_28328_95dfd335c7a193722df600dec1c8cd00.pdfUniversity of TehranJournal of Environmental Studies1025-8620354920090522Assessment of CO2 and CH4 greenhouse gasses emission from rice and wheat cultivation soils in Ab-Teymor areaAssessment of CO2 and CH4 greenhouse gasses emission from rice and wheat cultivation soils in Ab-Teymor area28329FAJournal Article19700101The global temperature has increased over the past years, and international community attempt to reduce greenhouse emissions to the atmosphere. In this study the potential of some agriculture sections for emission and absorption of CO2 and CH4 was examined. Rice and wheat which are two strategic crops in Iran were selected for this purpose and the amounts of organic carbon loss in the form of carbon dioxide and methane from two fields under this crops in Ab-Teymor area in south of Ahvaz were measured. Static chamber method was used to collect gas samples and gas chromatography technique was used to analysis the samples. Results show that rice field produced methane with the mean of 2.22 (mg C m-2 day-1), because of continuous anaerobic conditions in soil and so increased the anaerobic bacteria activity that produced methane. While wheat field absorbed atmospheric methane with the mean of 0.11 (mg C m-2 day-1), because of aerobic soil conditions and methane oxidant bacteria activity that consumed the atmospheric methane. Carbon dioxide emission from both fields increased after the November and there was a good correlation between CO2 emission with plant presence in the field, decomposition of organic residuals and environment temperatureThe global temperature has increased over the past years, and international community attempt to reduce greenhouse emissions to the atmosphere. In this study the potential of some agriculture sections for emission and absorption of CO2 and CH4 was examined. Rice and wheat which are two strategic crops in Iran were selected for this purpose and the amounts of organic carbon loss in the form of carbon dioxide and methane from two fields under this crops in Ab-Teymor area in south of Ahvaz were measured. Static chamber method was used to collect gas samples and gas chromatography technique was used to analysis the samples. Results show that rice field produced methane with the mean of 2.22 (mg C m-2 day-1), because of continuous anaerobic conditions in soil and so increased the anaerobic bacteria activity that produced methane. While wheat field absorbed atmospheric methane with the mean of 0.11 (mg C m-2 day-1), because of aerobic soil conditions and methane oxidant bacteria activity that consumed the atmospheric methane. Carbon dioxide emission from both fields increased after the November and there was a good correlation between CO2 emission with plant presence in the field, decomposition of organic residuals and environment temperaturehttps://jes.ut.ac.ir/article_28329_da95dcdb7ccce5547806750e668d9b26.pdf