JOURNAL OF ENVIRONMENTAL SCIENCE AND TECHNOLOGY
Year:2007 | Volume:9 | Issue:3 (34 SPECIAL ISSUE)|Papers Count:15

Shahid Hashemi Nejhad Refinery, which is one of the major gas refineries, is situated at a distance of 35 kilometers from Sarakhs and 165 kilometers from the city of Mashhad. The Refinery has five gas treatment units, two Sulphur retrieval units, two fixation units for gas liquids, one acid water reduction unit, one wastewater refinery unit and various other subsidiary units. Waste water refinery unit, has been set up to recycle sanitary wastewater of restaurant and convince services and part of industrial wastewater. However, part of unrefined wastewater is released to refinery lands nearby. Since the underground water resources in this region is high and in the other hand due to long detention time of waste water, it soaks in to underground water resources, and finally it causes an environmental catastrophy.Regarding this issue we tried to make our research based on this problem.In order to confirm the hypothesis of penetration of unrefined waste water into soil and underground water resources, in that region 5 wells were chosen and the parameters such as Cl-, SO4-2, NO2-, NO3-, COD, BOd, Color, pH, Cond., TDS, Ca+2, Mg+2, T. H., were done in June, July, October, November and December also analyzing of heavy metal and TPH were done on samples of the water wells in June, October and December. In order to have a crystal clear, comparisonal diagram which shows the fluctuation of measured parameters in five sample station were.

In this paper, we investigate dielectric constant variation behavior in the Persian Gulf waters. We assumed average salinity of water is about 38 ppt and we studied static dielectric constant behavior versus temperature. Data collection is from ROPME (2001) cruise. Our studies show that in some stations we have strong perturbation in dielectric constant which allow us to know there is a water mass which has a different properties from around waters. Besides, in some coastal stations, this behavior is completely opposite.

Leakage of petroleum constituents in the areas around Tehran Oil Refinery (TOR) has caused the hydrocarbon constituents to spread around this site. Poly aromatic hydrocarbons (PAHS) are a large group of petroleum compounds, which could be harmful for human if they are inhaled, ingested, or absorbed by the skin. In this research, 16 soil samples were collected from the south of TOR around the polluted stream with grid sampling method and 3 samples from the center of the stream. The research followed by gas chromatography analysis of the PAHs contaminants. Analyses indicate high concentration of pollutants in this area. Two hazardous PAH compounds namely; naphtalene and fluoranthene were evaluated. Physical and hazardous characteristics of these contaminants were assessed based on geotechnical properties of the soils located near to the refinery. The soils clean up levels at the site were calculated via inhalation of these volatile carcinogenic organics.In this study, acquired clean up levels or the maximum allowable concentrations of the contaminants in the site were compared with the existing concentrations. The results indicate that the concentrations of naphthalene in the all samples were also higher than required clean up level 3.9 ppm. The existing concentrations in the central axis of the stream 255 ppm also exceeded 60 times higher than the treatment limit. Based on simple structure of naphtalene and due to geotechnical properties of the soils, phyto-remediation and biological methods are recommended to clean up the site.

In order to assessment the risks of Borujerd Textile Factory on the laborers that exposure to noise pollution, a cross sectional study was conducted. 60 laborers of Spinning & Weaving saloons and official staffs (in two groups, case and control,) were randomly selected and have been audiometered, then the results have been examined through T test. At the next step the laborers have filled in 60 questionnaires (in two groups, case and control,) which have been examined with X test. In addition the diagrams of hearing loss levels have been drown (in four working years>16, 11-15, 6-10, <5) and its relation to working years. The results indicated that all group cases in all years in Spinning & Weaving saloons had hearing loss in both ears. The mean hearing loss threshold of all groups has the highest value in frequency band 2, 4, and 8 KHz If working years increase more than 10 years, hearing loss in1KHz frequency band will been seen. The lowest hearing sensitivity has been seen in frequency band 250, 500 HZ. It was indicated that If received noise have higher frequency, hearing tolerance threshold will be lower.

As civil and cultural aspects progress, the growth of industry and technology improved as a results. The mining industry as the unavoidable part of industrial developments appeared and seemed to have important effect on human being life. Mining industry has not only positive effects on human development but also decrease the quality of environmental resources by causing different kinds of pollution. In current research, the environmental effects of the Ahangaran Mining company activities in Lashgar Dar Protected area, Hamedan province is assessed, trying to assist in reducing the effects of these activities. The activities of Ahangaran Company are started in about 1956. In order to understand the environmental effects of mining in this area, we sampled from different sections such as water resources, soil, plants, solid wastes material of mining activities, and ponds and the concentrations of pollutants in samples were assessed. The results of analyzing the samples lead us to the high concentration of some pollutants in water and plants of the area. The occurrence of mining activities outputs, especially the solid wastes have severe effect on the fauna, flora and other environmental aspects such as landscapes and recreational potential of this protected area.

Air temperature is measured in synoptic and climatologic stations. It is one of descriptive parameter of climate of the earth. In this research artificial neural network is used to estimate maximum daily temperature of weather in Urmiah lake basin. Artificial neural network is trained to determine relation between maximum daily temperature and input data. Input data are Land surface temperature and NDVI which are determine using NOM data. Other input data are longitude, latitude, altitude, day of year and time of NOM image. Multilayer precipitation artificial neural network with one, two and three layer are trained and tested. Three back propagation learning rules including Delta rule, Normalize cumulative delta and extended delta-bar-delta are tested. Also two transfer function including Sigmoid and Tangent hyperbolic are tested. Root mean square error (RMSE) is used for comparison of these artificial neural networks. The best artificial neural network has three hidden layer including 4, 3 and one neuron in first, second and third hidden layers respectively. Extended delta-bar-delta gives best learning. The selected artificial neural network has less RMSE with Tangent hyperbolic transfer function. Training RMSE is 0.154 C which is less than 1.57 C of multivalute regression. Therefore suggested artificial neural network can estimate maximum daily temperature of weather better than multivalute regression.

Population density in small urban areas cause increasing demand of fossil fuels consumption, vehicles transportation and establishing a nurmous industries and factories in these areas. These kinds of factors are major reasons for continues air pollutions emissions more than receiver Environment assimilation capacity. New District 22 is located in North west of Tehran and it has a lot of constructions. This district has some plans for urban sustainable development. The study method for this investigation consists of measurement. And moniforing air pollutants in 14 selecting air pollution stations during 1 year, one week every month (12 months) in two period (morning and afternoon), preparing information maps and layers with using of GIS (Areview software), meaning the air pollutants emission maps with using air pollution dispersion inventory model in district 22, meaning vulnerable areas with considering air pollution in this district, comparison results of air pollutants measurements in studied area with others districts in Tehran and finally calculating air pollution emission for present and future conditions in district 22. Base on actived results, we presented proper methods for air pollution prevention and control to achieve urban sustainable development in this area.

In recent research, for evaluation of effects of industrial zones on environmental heavy metals content, we carried out taking samples from soil, plants and industrial wastewater in six industrial zones of Kerman province (including of Cement and Barez Tire factories, Sarcheshmeh Copper Complex, CSP, Industrial Zone NO.1 and Khazra Industrial Zone) and a non industrial zone (control). After sampling and sample preparation, pH of soil and industrial wastewater was measured with pH meter device and three heavy metals (Cd, Pb and Hg) content of soil were determined with acid digestion and atomic absorption method in total samples. The data was analyses by one-way ANOVA method (SPSS 10.0 software) statistically. The results shown that pH of soil and industrial wastewater in Sarcheshmeh Copper Complex zone decreased significantly when compared with other zones and control (pH of soil samples were all most close with the critical range of pH=5). In addition, the lead content (700 ppm approximately) in total samples of Industrial Zone NO.1 and CSP increased comparing with other zones and control significantly. The Cd and Hg content of samples increased in Sarcheshmeh Copper Complex, CSP and Barez Tire factory zones than other zones and control remarkably. Totally, the concentration of these two heavy metals in samples from latter three industrial zones increased than other zones, control and EPA standards significantly. This shows that there is relative contamination of heavy metals in these zones. This increasing of heavy metals content indicates that there are essential conditions for releasing of these elements from soil particles. Therefore, the industrial contaminant cause increasing hydrogen ions of soil and decreasing soil pH slowly. Accordingly, probability of toxicity and releasing of recent elements increases in agricultural and residential regions. Therefore, we should concern on controlling, evaluation and management on this important environmental problem.

The air pollution in Tehran is a significant problem that needs to be studied carefully in various aspects. Meteorological conditions leading to acute air pollution episode are particularly important to be studied. Period of this study has been chosen from 2001 till 2002. Azadi, Bahman, Tajrish, Markazi and Gholhak air pollution monitoring stations were chosen to cover Tehran almost completely.In this study the daily changes of pollutants in cold seasons are examined. This includes time variations of pollutants in Tehran such as CO, NOx, and SO2 in all stations. This analysis showed that during the synoptic conditions (high pressure systems) the amount of air pollutants have increased for several days and reached to their highest levels of concentration. These levels may exceed two to three times the limits.

The aim of present study is analyzing the mechanism of erosion cause and sediment production, its irregular excavation and environmental disadvantage effects on Karganrud River in Gilan province. The research is done by many field studies and by using PSIAC method the numerical factor of catchment's erosion has been achieved. Besides by using relative mathematical equations of annual river discharge, the annual sediment weight of Karganrud River has been calculated. The achieved results can be used for a proper river alluvial excavation program by conserving the environmental resources. Mean while by observing the satellite pictures in different years, some parts of river have been widening abnormally which is due to the irregular alluvial excavation by beneficiary factories. The field studies show this phenomena cause disaster around the river sides and lands. However due to the irregular alluvial excavation the river hydraulic gradient has been increased sharply and all meanders have been wash out Increment of river hydraulic gradient and decreasing the number of local fishes and their spawning which are important environmental disasters.

Physical or chemical sorption in a suitable solvent is the main method for separation of CO2 content of inlet gas. Since, CO2 content of air does not have the high value, choosing of a proper solvent plays the critical role. Thus, chemical sorption of CO2 from air with amine solution is more considerable. In this study, different amine solutions which be used for absorption of CO2, were introduced and their properties were presented. The results of investigation show that MEA is suitable solution in point of view of high activity and economic aspects. This solution is a stable chemical in spite of its high vapor pressure and corrosion rate. In the chemical sorption of CO2 in proper temperature (70-100oF) in an absorber, maximum sorption of CO2 is obtained and CO2 content if gas outlet can decreases up to 250 ppm.

The aim of present study is analyzing the mechanism of erosion cause and sediment production, its irregular excavation and environmental disadvantage effects on Karganrud River in Gilan province. The research is done by many field studies and by using PSIAC method the numerical factor of catchment's erosion has been achieved. Besides by using relative mathematical equations of annual river discharge, the annual sediment weight of Karganrud River has been calculated. The achieved results can be used for a proper river alluvial excavation program by conserving the environmental resources. Mean while by observing the satellite pictures in different years, some parts of river have been widen abnormally which is due to the irregular alluvial excavation by beneficiary factories. The field studies show this phenomena cause disaster around the river sides and lands. However due to the irregular alluvial excavation the river hydraulic gradient has been increased sharply and all meanders have been wash out. Increment of river hydraulic gradient and decreasing the number of local fishes and their spawning which are important environmental disasters.