Journal of Environmental Studies
Year:2014 | Volume:40 | Issue:2|Papers Count:27

Contaminated groundwater by gasoline spill is a worldwide environmental problem. Gasoline contains methyl tert-butyl ether (MTBE) and benzene, which are the chemicals of concerns (COCs) among the gasoline components. MTBE is highly water soluble and has a low Henry’s law constant and low soil adsorption co-efficient. Therefore, MTBE can easily move through the soil and then accumulate, distribute or migrate in groundwater. Accidental releases of petroleum products from pipelines and from aboveground and underground storage tanks are the most common causes of groundwater contamination in most countries. Due to issues of taste and odor, health concerns, carcinogenic effects of benzene and MTBE, many attempts have been made to remediate contaminated groundwater. ...

Oil exploration and production zones are very frequently contaminated with petroleum hydrocarbons or its derivatives. The most important exploration and production zones are located in South-west and South of the country, in Iran. Masjed Soleiman city is located on an oil field. The soil of this region has been affected by the petroleum composition. Mach petroleum seepages and springs (asphalt, oil and gas) with active oil and gas wells in Masjed soleiman caused this contamination. Restoration of soil contaminated with hydrocarbons at the sites has become a very interesting scientific challenge, mainly because of the actual complexity of the matrix. ...

The contamination of soil and water with petroleum hydrocarbons is a widespread environmental problem. The treatment requirement and removal of this pollutant are becoming more important in these days. Total Petroleum Hydrocarbon (TPH) has been reported to be toxic, carcinogenic, and an endocrine disrupter widely used in developing countries. Various physical, chemical, and biological methods were used for removing TPH in water treatment. Soil Slurry -Sequencing Batch Reactor (SS-SBR) is one of the important in-situ or ex-situ technologies which were able to bio-remediate the soils containing high levels of organic matters. In fact, in this condition the pollutant depletion rates depend mainly on the degradation activity of the microorganisms available in the system.

Environmental pollutants are considered among the factors disturbing natural ecosystems. Among them, heavy metals due to their toxic effects and having a high bio-accumulation are known as one of the most dangerous pollutants. This leads to the concentration of these metals in the food chain, in the top of the pyramid. Many of these metals are natural components of aquatic ecosystems and some of them play a critical role in the survival of living organisms. However, if the concentration of heavy metals exceeds a certain limits, aquatic life will be threatened and ecosystem degradation will be occurred. Heavy metals have not the ability to be refined in aquatic ecosystems, so with gradual blurring of these ecosystems, they can easily accumulate in sediments. In fact, it can be said that the marine sediments are considered often as a final repository for the accumulation of metals.

Polyhydroxyalkanoates (PHAs) are naturally occurring polyester that can be accumulated in bacterial cells as a carbon and energy storage compound. They are metabolized by many microorganisms. These biopolymers accumulate in microbial cells under stress conditions such as limitation of nitrogen, phosphate, sulfur, oxygen, and excess carbon source. Currently, PHAs have attracted increasing interest as promising alternatives to conventional plastics. This is due to their biodegradability capability in being produced from renewable resources.

Introduction: Cadmium is one of the most important environmental pollutants that can be resulted from different ways. It can easily contaminate soil and water resources. Since phosphate ions for stable complexes are available with cations such as Pb and Cd, so it can cause a decrease in the solubility and mobility of heavy metals in soil. Liming is the most widely used treatment that leads to precipitation of the metals as metal–carbonates and significantly decreases the exchangeable fraction of metals in contaminated soils. Temperature is also an important factor in stabilization of heavy metals. Heat causes loss of water and hydration around cations to move them to empty spaces in clay part of soil. The aim of this study was to investigate the effect of heat and lime, and phosphate application on immobilization of Cd in contaminated soil with incubated days. ...

Air pollution is today a major problem for modern societies. It has long been recognized as a potentially lethal form of pollution. Increasing pollution levels due to rapid urbanization and growth in emission related to vehicular transportation are now caused major concern. The mobilization of heavy metals into the biosphere by human activities has become an important process in the geochemical recycling of these metals. Pollution of the natural environment by heavy metals is a worldwide problem because these metals are indestructible and most of them have toxic effects on living organisms. While some of these elements are essential for humans, at high levels they can also mean toxicological risks. According to numerous studies, the pollution sources of heavy metals in environment are mainly derived from anthropogenic sources.

Introduction: We can obtain useful information about aquatic systems by studying heavy metals in surface sediments. Marine sediments can bring out the aquatic contamination. Due to heavy metal toxicity, hard biodegradation and easy bioaccumulation in aquatic ecosystems, various indices have been developed such as sediment quality guidelines (SQGs), enrichment factor (EF), pollution load index (IPOLL) and index of geo-accumulation (Igeo). Sediment-bound heavy metals may be desorbed from surface sediment and accumulated on fine grained particles which finally move into the depositional. Grain size is an important factor to evaluate heavy metals concentration in the sediment. …

Introduction: Atmosphere health is an important environmental issue and air pollution is not a local problem in a given area of the world. Particles produced by either humans or the nature enter the atmosphere and return the Earth’s surface at local, regional, or global scales after physico-chemical interactions. According to the reports by WHO, each year 2.4 million people lose their lives worldwide due to air pollution. In recent decades, numerous investigations have been carried out on the status of heavy metals in atmospheric dust. This is mainly due to their importance and also impacts on the environment and humans. Heavy metals present in water, air, dust, soil, and sediments play an important role in human life.

Introduction: Earth has ever been exposed to environmental hazards. The hazards are continually occurring in the world in the recent years. Among them, atmospheric elements have created many human and financial losses in different regions.One of the hazards is dust events and in its severe case is dust storm. It happens more frequently in arid and semiarid regions in deserts and their surrounding areas. Dust events is a natural phenomenon occurring in regions that have large parts of arid and desert regions, devoid of vegetation cover and other surface coatings areas. Lengthy periods of drought and principle of non-interference in nature may be the cause of this phenomenon. In addition to reducing the horizontal sight and ist effects, e.g., traffic issues, it has also many environmental impacts especially on human health.

Introduction: Floods are major disasters worldwide that causes serious damage to agriculture, fisheries, housing and infrastructure. They can also disrupt socio-economic activities. As the severity and frequency of flood events have considerably increased, there is a growing global concern about the need to decrease flood related fatalities and associated economic losses. Just in 2010, 178 million people were affected by floods and the total financial losses in the exceptional years such as 1998 and 2010 exceeded $40 billion. This study has presented an exhaustive methodology of using Geographical Information System (GIS), Satellite imagery interpretation, Rain gauge station data and Analytical Hierarchy Process (AHP) method of flood hazard mapping for surveying flood hazard in Balegli Chay Watershed and subbasins. ...

Introduction: The environmental issues have been considered in all development plans of Iran. For example, the forty-fifth, forty-seventh, and fiftieth principles of “Iran Constitution” directly refer to environmental issues. According to the future outlook of the Islamic Republic of Iran “having the favorable living environment” is regarded as the characteristics of the Iranian society in the horizon of the next two decades. The environmental issues have also been considered in the economic development plans of Iran. In the thirteenth waver of the First Development Plan Act, factories and workshops are required to provide the necessary equipments and facilities to prevent the environmental pollution.

Introduction: Despite the abundant renewable energy sources, the Iranian energy sector relies almost entirely on fossil fuel energy resources. Power sector is dominant source of CO2emissions and responsible for about 35% of total CO2 emissions in the country. Additionally, long-term electricity demand of Iran is expected to grow quickly, which in turn requires extensive investment to meet the growing demand over the next decades. On the other hand, increasing domestic fossil fuel consumption had been a serious challenge due to high costs of oil and gas. Current study pays particular attention to the possible penetration rates of renewable electricity technologies and their implications for fossil fuel consumption and CO2 emissions. ...

Introduction: Sarcheshmeh Copper Mine is regarded as the second largest copper deposit in the world. This is one of the largest industrial-mining complexes in the world and the largest producer of copper in Iran. This complex plays an important role in Iran’s economy. In 2012, this complex created employment for about 8000 people in Iran and produced 203065 tons of copper cathodes.However, high amounts of pollutants are being produced and emitting into the environment from this complex. SO2 is the main type of air pollutant emitted from its smelter factory. This complex emits about 789.9 tons of SO2 per day.

Introduction: Forest for biodiversity and ecological functions is the main natural habitats. The most important function of forest is zonal and global climate regulation, recreation and ecotourism, water saving, regulation of hydrological cycle, flood control, and prevention of soil erosion. Valuation of public goods was noticeably widespread in the last decades. An understanding of the relationship between environmental economics and business economics is essential for policy makers. The influence of environmental resources functions increase vitality and joy of spirit and community development feasibility assessments of these areas. Today, a country that thinks more about economic development has seen tourism as a necessary. ...

Introduction: Conservation and management of landscapes and beautiful sceneries is one of the necessities of establishing and maintaining the protected areas. Analysis of landscape visual quality has an important place in landscape planning and designing. In this way, reviewing effective criteria and discovering the simple patterns which affect the landscapes is the most important step of modeling and problem solving. Principal Component Analysis (PCA) is a way of identifying patterns in data, and expressing the data to highlight their similarities and differences.

Introduction: One of the major tasks of urban and regional planners is allocation of land to various urban utilizations according to the role and function of the city, urban economy, and also cross-effect of the land-uses with each other. This is the quantitative aspect of the subject, but what is more important is the qualitative aspect which means appropriate distribution and deployment of land-uses or applications on a physical level (optimal location of land-use). A planning in this way by appropriate land-uses help citizens enjoy the services and facilities offered in different parts of the city. This competent planning requires no additional commuting and will reduce environmental pollution, help to create safe urban space and acceptable environment, and provides peaceful, convenient living. ..

Introduction: There is a special competition among many metropolitans for improving physical and semantic quality of urban landscape to upgrade their positions in global level and attract more tourists. Based on such characteristics, one of the important goals of metropolitan management planners of the society is to develop open populated spaces and make leisure centers. Urban spaces development in the present era without sufficient knowledge of urban rivers characteristics and taking advantage of their potentials has had many problems for the cities. Zayandeh Rud is one of the largest rivers in Iran. It is flowing on the center of the country and from west to east. Many tourists visit Zayandeh Rud each year, because several historic bridges are remained from Safavid Majesty and before over this river and it is also located in historical city of Isfahan.

Introduction: With increasing attention about environmental issues, especially in the recent century, and some problems like population growth, poverty, natural resources exhaustion, and widespread pollution it is needed to form an environmental management system. Environment is a complicated combination of various factors which is appeared from evolution of organisms and component of the earth. Thus, it affects human activities and also affected by them. Connection between human and environment result in organizations and communications that require a program compatible with the environment.

Introduction: Morphological segmentation of land surface is commonly used for land surface allocation in management and environmental sciences. The first step in assigning a piece of land to a specific application is to divide it into homogeneous morphological segments. Traditional field-based geomorphological mapping can be time consuming, costly, and challenging when large areas, particularly in remote areas where terrain is difficult to access and where the topography and landforms can be highly variable over short distances. Like other geomorphometric studies DEM is used as the basic input and SRTM DEM with 90 m resolution is actually suitable for mega landforms analysis. That is one of the most reliable elevation models worldwide. ...

Introduction: Agricultural sustainability is regarded as a key factor for long term profitability of farming in rural areas. Researchers believe that an agricultural system is sustainable if it includes environmental quality, economic viability, and employment and social performance. Agricultural sustainability can be analyzed on diverse spatial scales, from the field to a regional, national or even an international scale. Regarding the natural environment the agro-technical and socio-economic conditions in every region have raised the need for more granular scales of assessment.