Journal of Environmental Studies
Year:2012 | Volume:38 | Issue:63|Papers Count:18

Introduction: The human ever-increasing industrial activities in the last few decades have resulted in severe soil pollution. Soil contamination with petroleum in oil-producing countries is a serious problem in natural and agricultural environments. In oil fields of Iran, large areas are subjected to intense pollution. This can reduce the quality of physical, chemical and biological properties of the soil, and decrease the soil capacity to support plant growth. Soil contamination with crude oil may severely change diverse soil properties, which might then disturb microbial communities and activities. However, both inhibition and stimulation of microbial activities have been reported in petroleum hydrocarbon-contaminated soils.

Introduction: Human activities in areas with a high rate of urbanization and industrialization growth have contributed to the increase of environmental pollution. Soils and sediments pollution is also significantly threatening human health and environmental quality. The main reasons of anthropogenic particulate pollution in urban areas have been industrial activities and vehicle emission among others. The magnetic susceptibility (c) of soils results mainly from their magnetite and magnetite contents. Parts of the magnetic materials in the soil are inherited from soil parent material. Magnetic susceptibility could also be increased or decreased by biochemical and transformation processes.

Introduction: Pollution of natural environments by heavy metals has become a global problem. Elevated concentrations of heavy metals have been recorded in mangrove sediments all over the world, which often reflect the long-term pollution caused by human activities. Industrialization and urbanization in recent decade have led to a strong risk of environmental concern, in particular, the heavy metal contamination in the mangrove ecosystems in the (sub) tropics coastlines. Mangroves are productive habitats and may support coastal fisheries for prawns and fishes.

Introduction: Mercury (Hg) is a pollutant on a global scale; its emission spreads over long distances in the atmosphere and across the oceans. Mercury is released into the environment from a multitude of natural and anthropogenic sources. The presence and behavior of Hg in aquatic systems is of great interest and importance. Bacteria in lakes and ocean sediment can convert element and inorganic Hg into its organic compound (methyl), which may accumulate in algae, aquatic plants and fish and into the food chain. The poisoning characteristic of mercury causes many problems, including: neurological symptoms, reproductive disorders, circulatory diseases and digestive disorders. The presence of Hg in living organisms is undesirable and potentially hazardous.

Introduction: There are many environmental challenging problems for environmental scientists in Asalouyeh which is located in the south of Iran. In Asalouyeh zone, a large number of petroleum, petrochemical and natural gas industries are operating and as side effect air pollution is one of the most challengeable problems in this industrial area. Therefore, efficiently reduction and control of air pollutants are the most important programs for related organizations. In order to reduce emissions of air pollutants and their effects it is necessary to recognize the amount and spatial dispersion of air pollutants. Volatile organic compounds (VOCs) are one of the most significant pollutants in this industrial area and organic liquid storage tanks are one of the emission sources.

Introduction: In the last decades, hydro chemical investigation especially consideration of trace element pollution has changed to one of the main objectives of hydro chemical researches. Sahand Dam is one of the important dams of East Azarbaijan with 135 MCM storage located in southwest of Hashtroud city (Figure 1). Water storage of this dam supplies potable and industrial water demand of Hashtroud city. Furthermore, it is used for the irrigation of 11 hectares of the sector land.

Introduction: Phosphorus is an important mineral element for organisms' growth. Nowadays, the use of detergents and cleaners has become one of the essentials of human life. Since these materials enter into the sewage systems, the existing polyphosphate reacts with water and gradually changes to phosphate ions and cause environmental problems. Electrocoagulation is an electrical treatment process which has been progressively applied to treat water and wastewater, recently. In this process, the removal of pollutants takes place with applying the electrical current to the electrodes. When aluminum electrodes are used, the aluminum dissolves at the anode and hydrogen gas is released at the cathode.

Introduction: Performance of wastewater treatment plant is function of wastewater quality, management of treatment plant and environmental issues. The purpose of this research is to develop the efficiency of the artificial neural network model to evaluate the performance of Ekbatan treatment plant and to estimate quality parameters.

In recent decades, duo to increase in population, demand for reliable water supplies has increased. The situation is critical in places where groundwater is the only accessible water resource and the discharge rate of water is more than the rate of recharge. In such areas, artificial recharge of groundwater is an important management strategy. In establishing an artificial recharge scheme, site Selection is the prime prerequisite and its success depends on the collection and analysis of a great deal of geographic data. The use of fuzzy set theory in site selection projects allows the decision-makers to incorporate unquantifiable information into decision model. In new researches of site selection fuzzy multiple criteria decision making methods have been considered.

Introduction: Unsuitable exploitation of land is the most important problem of land resources utilization in the country. Unsuitable pattern of land use together with severe land use changes cause different environmental crisis including: environmental pollution and deterioration, expanding desertification, soil erosion, natural resources depletion, reduction of biological diversity and reduction in potential of land capability. These problems significantly influence the production of resources needed for recent and future generation and prevent sustainable development of the country. In other words, it can be concluded that the reduction of excess resources, is the result of unreasonable using of land by human.

Introduction: A dust storm is a meteorological phenomenon common in arid and semi-arid regions. Dust comes from arid and dry regions where high velocity winds are able to remove detached particles mostly silt and clay sized material. Dust consists of particles in the atmosphere that arises from various sources such as soil and lifted up by wind. The Sahara and dry lands around the Arabian Peninsula are the main terrestrial source of airborne dust, with some contributions from Iran, Pakistan and India into the Arabian Sea. In addition, China's significant storms deposit dust in the Pacific.

Introduction: Increasing concentration of atmospheric CO2 is one of the most important reasons for climate changes and global warming. one of the most appropriate solutions offered to solve this problem is its reduction by carbon sequestration in soil by plants.Concentration of atmospheric CO2 will increase to the range of 415 to 421 ppm in 21 st century. Only with optimistic assumptions and low growth rates, increase of carbon-dioxide-induced temperature will be held below 2oC over the next century. Conservation, flexible energy choices and control options could lessen the potential effects of carbon dioxide otherwise it will cause global warming crisis. Besides the economic and social disadvantages, it will lead natural ecosystems to loss their stability. Thus, effort to reduce greenhouse gas concentrations through suitable management is important and ultimately will lead to sustainable development. Methods such as filtering to reduce the concentration of carbon dioxide in the atmosphere will be high costly. So at the macro levels it will not operational. The world needs to reduce the concentration of CO2 can be satisfied by less expensive methods such as the carbon sequestration by plants.

Introduction: Provision of mental-social needs of citizens and enforcement of social cohesion are dependent to the quality of using urban open and green spaces of cities which evidently requires deliberate planning and designing. For example parks have wide benefits for cities such as personal (physical and mental), social (recreational opportunities and a place for meeting), environmental (reduction of pollution, biodiversity for plant and animal species), economic (increased property value, enhancing the attraction of properties for business), and structural (urban design and transport).

Introduction: One of the present challenges in Iran is drought as a natural hazard and the crisis of desertification. Drought and limitation of precipitation is an inherent part of nature in Iran. This warm and arid nature causes environmental issues for the inhabitants of the country. One of the suffered provinces nationwide is Isfahan Province. Progressive desertification and its geographic characteristics, neighborhood deserts, shortage of rainfall and emergence of periodic droughts are among notable characteristics.