Journal of Environmental Studies
Year:2004 | Volume:30 | Issue:34|Papers Count:13

Highly hydrophobic contaminants are easily adsorbed from aqueous solutions. Since for many of these compounds sorption increases with increasing organic carbon content, natural materials, such as bituminous shales and coals may be used in permeable sorptive walls. This, however, only applies if sorption is at equilibrium, which may not always be the case in groundwater treatment system. In contrast to the natural solids, granular activated carbons (GACs) have very high sorption capacities and reasonably fast sorption kinetics. The laboratory results show that the application of GACs (e. g. FIOO) is economically feasible for in situ removal of polycyclic aromatic hydrocarbons (PAH) from groundwater at a former manufactured gas plant site (MGP). For less sorbing compounds (such as benzene, toluene, xylenes) a combination of adsorption and biodegradation is necessary.

Two barcteria, capable of petroleum biodegradation were isolated from Persian Gulf seawater. Both strains (designated as PGOl and PG02) were marine halophile, strictly aerobic, motile, gram-positive short rods. During growth (in 250 ml erlen meyer containing 100 ml mineral base medium with 1% crude oil as sole carbon source, crude oil medium), under shaking condition (150 rpm), both strains produced biosurfactant which emulsified petroleum and bacterial cells were found to attach to generated oil droplets. The optimum pH for both isolated growth in the crude oil medium was 8-8.4, similar to the pH of seawater. Both isolates could grow in mollasses medium (1%) but biosurfactant production in this hydrophilic substrate was not observed.

Anaerobic digestion, is microbial decomposition of organic materials in absence of oxygen, which results in production of methane and stable compounds. Anaerobic digestion technology has three phases: pre-treatment, digestion and post-treatment. Fermentation bacteria, hydrogen producer bacteria and methanogene bacteria, are the main three groups of metabolic micro-organisms for methanogenic fermentation. Anaerobic digestion in comparison with aerobic composting, is a net energy-producer. 500-1000 kwh energy per ton of wet waste is generated in anaerobic digestion process, while in aerobic composting, 500-750 kwh energy is consumed for treatment of each ton of wet waste. Methane yield is 0.2-0.5 Nm3 per kg volatile solids added in anaerobic digestion process. During this study, a 22 litre reactor was used for anaerobic digestion of putrescible solid wastes with high total solids (TS) content and 15-20days retention time. The reactor was heated by a hot-water coil inside it, therefore, internal temperature was kept in the range of 33-37°C.Resultsshow2500to 9400litre biogas generation per 1 m3. of reactor volume per day and more than 50%reduction in organic substances (as TS).

Market system has significant effects on quality and quantity of priced resources. However, it has not been directing firms and institutions for effective utilization of non-priced resources like environmental goods and services. In institutional perspective, utilization of non-priced resources might cause the degradation of environmental resources. The extra costs are not implied on their generated products. In fact this process could create environmental costs that never integrated in marginal price of the products. In energy sector of Iran, externality costs are those kinds of costs that are to be imposed on community and environment without integrating in marginal price of electricity. Lack of consideration of environmental costs of power generation will cause adverse effects on utilization of resources. Estimation of environmental costs and their integration in marginal pricing of electricity indicates that electricity-pricing process goes toward transparent phase and hope to create a background for moving to market-based pricing in this sector in Iran. The present study applies two approaches for estimating environmental costs in the country that are Direct Estimation Approach (DEA) and Adjusted Estimation Approach (AEA). In the first approach that is a customary one in the country, estimation exchange rate is usually used. AEA is a guideline that is advised by Asian Development Bank for estimation of any given cost like environmental ones, considering power purchase parity (PPP) of currency. It is necessary to mention that DEA does not give reality-based estimation. Because it considers only one conversion factor for estimation of measured results (in the country that the related studies have been carried out) into estimated results in the country is being studied. For dealing with the aforementioned issues in developing countries, ADB formulated guidelines for estimation of environmental costs, aiding the results of studies carried out in developed countries be easily applied in developing countries. The results revealed that there are drastic differences in estimation carried out through DEA and AEA in Iran. Standpoint of three major pollutants like S02 NOx and CO2 for steam, gas turbine and diesel power plant are about 6.2 to 6.5 time of AEA estimation. External costs of the aforementioned pollutants in steam power plant were estimated at 0.053, 0.09 and 0.23 US Cent/Kwh respectively. These measures for gas power plant are 0.0088, 0.12 and 0.3 US Cent/Kwh respectively. For gas turbines power plant they might be referred to 0.005, 0.07, and 0.18 US Cent/Kwh and for diesel power plant 0.064,0.15 and 0.30 US Cent/Kwh.

Many investigations have shown thermal data obtained from sensors have extensive applications in the study of earth features. But based on the author's information, the use of thermal remote sensing has not been widespread yet. Temperature is important factor in understanding some physico-chemical and biological properties, which can be used for describing the state of materials. Therefore, decision for selecting thermal remotelysensed data and sensor types is a crucial step in the environmental studies. So, it is necessary that the content of thermal band information and their applications be evaluated. In this study, the advantages of thermal remote sensing and its applications in the study of sustainable development, vegetation, climate, air quality, soil and seismology are discussed. Based on the obtained results it may be concluded that thermal remote sensing data are powerful tools for environmental studies.

In this research, soil pollution with petroleum constituents in Azeem-Abad area (south of Tehran's oil refinery) has been studied. Since a decade ago, the soil and groundwater in the area have been polluted due to leaking of petroleum constituents from the underground storage tanks, worn out transitory pipes, and solid wastes resulting from the raw oil refining processes. To investigate the soil pollution in the area, geotechnical tests (including grain size distribution, plastic and liquid limits, permeability, and in-situ specefic gravity), and BTEX (benzene, toluene, ethylbenzene, and xylene) analysis were carried out on soil samples. The total and leachable concentration of the contaminants were determined (leachable concentration of the compounds was measured using toxicity characteristics leaching procedure test, TCLP). Moreover, the allowable contaminants concentration's in soil were procured utilizing U.S.EPA recommended levels. The comparison of current soil pollution with the allowable contaminant levels indicated that the soil in some parts of the area was defiled with the petroleum constituents and the pollutants have the potential of leakings to groundwater. At the end, based on the soil sample's results and analysis, some strategies to control the pollution development in the area have been presented and suitable remediation procedures (such as solidification/stabilization, soil flushing, and soil vapour extraction) are suggested.

The Production of lactic acid from deproteinized whey, by immobilized lactobacillus casei on wood chips was in vestigated.The immobilized porous was studied on various supports like wood chips, brick particle and pours glass by adsorption and on egg shell with glutaraldehyde by covalent bonding. Wood chips had the highest adsorption among the all supports and it has been chosen as the best support for production. Batch production in four temperature and three various pH were studied after five days. The highest rate of production of lactic acid (16 g/l) at T= 28˚C and pH= 5.5 was observed.The optimum condition of temperature and pH for continuous system with respect to result of batch system was chosen (T= 32°c,pH= 5). The continuous reactor was designed as packe- bed from immobilized L. Casei on wood chips. The highest rate of production of Lactic acid (14. 8 g/l) with Dilution rate (D) =0.2 hr -1 was observed after 5 days.

Consideration of environmental issues in civil and industrial planning for the reduction of environmental impact of such development projects is a vital necessity. Oil industry for its widespread environmental pollution is always in domain of environmentalist's concern. This research aim at analyzing environmental problems of oil continental shelf region of Persian Gulf. Different environmental techniques arid methods (EIA, EMS) is used in analysis stage. Results of research applying EIA procedure indicate that pollution of industrial waste, burning of separated gases in flares, discharge of platforms waste water in to sea, oil spil1 resulting from production process in land (base land pollution) and in to sea (resulting from loading, transportation, platform process); and etc. are the most important environmental pollutants that impact on sensitive elements of fragile ecosystem (degradation of flora and founa of region). In final, with applying standard of Environmental Management System, plans and projects for improvement of environmental status of the field were presented.

The chukar patridge is wildly distributed in Iran and regarded as one of the most important gamebirds. An investigation was performed to characterize the chromosomal identification and description of chukar partridge ( Alectoris chukar) in Elborz and Zagros Mountain Range from 1995 to 1997 (1347-1376). Seventeen specimens from two study areas were collected. Diploid number was found to be 72. Sex choromosomes are zz in males and zw in females. z-chormosome is chromosome 5. It seems w-chromosome is a small. chromosome that probably is No. 7 or 8. It was proposed that more detailed study of karyotype in more localities and habitats should be made to determine choromosome characteristics of chukar partridge.

A Study was conducted to determine the major vertebrates fauna of Bidoieh Protected Area, South west Kirman, during 2001-2002. The Fauna were identified using. morphologic, morphometric and meristic characters. 22 species of mammals, 89 species of birds, 18 species of reptiles, 2 species of amphibian and 2 species of fish were identified. Based on IUCN and CITES categories and also Iran's DOE laws, there are 4 Protected taxa, 2 Vulnerable taxa and 2 Lower Risk/near threatened taxa of mammals as well as 2 Endangered taxa, I taxon in Lower Risk/near threatened, 9 nonaquatic protected taxa and I endemic taxon of birds, and finally 2 Protected taxa of reptiles in the study area. The distribution maps(1:100000 scale) of the major species of vertebrates of the area were prepared. Some recommendations for sound and rational management are given for the major vertebrates fauna of Bidoieh Protected Area.

The main objective of this research was to evaluate environmental capability of Kobar Kahak catchment areas. A systemic planning approach using GIS for spatial data analysis was adopted to attain this objective. Ecological and socio-economic information were organized as spatial data (maps) in a database and imported to Idrisi and Arc/lnfo. The process of geographic coordinates registration, building topology and editing the maps, were done in Arc/Info. Then in the analytic stage, Digital Elevation Model (DEM), was prepared using contour map in Idrisi. Based on the slope, aspect and elevation landform classes maps, were produced for overlaying. In the middle stage of the analysis, slope, elevation, aspect, hydrology, and vegetation type and density layers were overlayed in Arc/Info. Then environmental units attribute table was completed, considering other ecological and socio-economic data available in ArcView. Specific ecological models were adopted for the catchments area and using Structured Query Language (SQL), capability of each unit was evaluated and then mapped for allotted land use. In the last analytic stage, the priorities of suitable land use type were determined and mapped considering land use prerequisites, using SQL. Finally, compatible, incompatible and conditional land uses type were presented together with the institutional structure required for the management plan of catchment area.