Journal of Environmental Studies
Year:2005 | Volume:31 | Issue:37|Papers Count:17

Leachate treatment as a major environmental problem has rarely been studied in Iran. To avoid using the conventional treatment methods and technologies currently employed in other countries, a bench scale study was conducted to achieve a practically applicable meanwhile cost effective leachate treatment method in an in-situ Condition. The objective of in-situ leachate treatment is to provide appropriate conditions within the landfill structure to allow the required chemical, physical and biological reactions to occur, resulting in reduction in organic loading of the leachate. The proposed method which was based on using construction and demolition wastes as the anaerobic growth medium at the bottom of the landfill, demonstrated acceptable results in reducing the organic loading of leachate sampled from Kahrizak landfill site. The method is therefore recommended as a cost effective leachate treatment system applicable to several landfills in Iran, provided the site specific tests are carried out. The results of the experiments where mixed construction and demolition wastes generated in Tehran were employed indicated about 80% reduction of organic loading in terms of total organic carbon and chemical oxygen demand. Among other advantages of the proposed system is the fact that the leachate volume is subject to a severe reduction, due to evaporation, So there is no need for effluent discharge to the environment.

In the present research, the effect of different coagulants in conditioning of digested sludge in Qods wastewater plant, have been investigated. In order to accomplish such investigation, coagulants including cationic polyelectrolyte, feeric chloride, quicklime and alum, with different concentrations, were added to the sludge samples. Jar test, then specific resistance of sludge with respect to dewatering, TSS and VSS on sludge samples before and after dewatering were performed. In addition, TSS and VSS, COD, BOD5 and turbidity were performed on supernatant in order to determine the optimized concentration of.The value of specific resistance of sludge to the dewatering process for raw sludge and conditioned sludge with cationic polyelectrolyte, ferric chloride, ferric chloride with lime, lime and alum are as follows: 7.68*1013, 0.347*1013, 0.839*10113, 0.89*1013, 2.36*1013 and 2.52*1013 m/kg. Since my decrease in specific resistance of sludge facilities the dewatering process, it could be concluded that the most suitable for fludge conditioning are, cationic polyelectrolyte, ferric chloride, ferric chloride with lime, lime and alum respectively.By considering the results of this investigations and comparing economic factors and supplier availability, ferric chloride as pilot sludge conditioner substance was preferred. By adding ferric with concentration of 440 mg/l to the outgoing sludge from aerobic digester, the required time for drying sludge (production of sludge with DS=45%) in drying beds, is reduced from 9 days to 4 days. In other word, if input sludge to drying beds in conditioned, the required bed area, is reduced considerably (at least 50%).

Many of the current procedures and tools of urban and environmental planning may need to be revised and developed at a local level to achieve more sustainable cities and neighborhoods.Furthermore, since the activities of a community would have direct impacts on the environment, many views of planning recognize that good plans spring from the local community. But how can communities be planned and developed that will meet both human and environmental needs? "Local Environmental Plans" are starting to be known as one of the most utilized tools to explore such needs .But it should be recognized that people intervention does not just happen. The most active participation in planning is found in those communities where involvement is planned and managed accurately.In addition, a plan will never achieve its goals unless it can be implemented. This reveals another significant barrier to achieve sustainable cities, which is the absence of a clear articulated method of implementation.Therefore, in this research an attempt has been made to develop a relatively inclusive methodology to produce and implement "participatory local environmental plans". It has been achieved by analyzing and comparing some case studies of such experiments in other countries.The main and first basis of this methodology is to establish an independent and empowered local organization consisting of any local interest groups, for every small city or neighborhood which is going to be changed. Then, all the steps of producing and implementing participatory plans will go through that organization, its structure and members.

The water quality Index of water has the highest degree of usage among the other water quality Indices, and it has been used for classification quality - Index of watershed area of latiyan dam. Determining the condition of water in Jajrood River and Latiyan Dam as one of the most important drinking water resources of Tehran and regarding capital's population increase is of great importance.In this research, according to the result of the measurements carried out by Tehran's water and sewage company and by the research center of Water & Energy, the quality classification of Jajrood River's and the drainage of latiyan Dam's water have been done separately. According to the result of the obtained quality Index, the quality of water near some populated ares is low of microbes and bacterias and suspended particles entering the water and making it unclear. The quality of water in the river is beter in autum than in summer. Also, the results obtained from this Quality Index have been compared and analysed with the result of other method introduced in this paper. The comparison shows nearly similar result in quality classification of the River width.

To study the ability of chemolithotroph bacteria in extracting copper from Sarcheshmeh copper ore, and also, to separate element sulphur, which is releasing into the environment as sulphur dioxide pollutant, the activity of two sulphur bacteria was studied and compared both in single and mixed cultures. Thiobacillus ferrooxidans (TF) and Thiobacillus thiooxidans (TT) were grown on 9K and Imai media respectively and equal amounts of culture solutions of each were added to mine ores containing %0.2, %0.3 and %0.4 copper. After sixty days of experiment, the results of measuring copper amount in the solutions by using atomic absorption spectroscopy showed that TF released more copper than TT and in the mixed culture of two bacteria copper amount was nearly less than those of TF media and significantly more than TT media. Element sulphur released by the activity of the bacteria was extracted by using CS2. The sulphur amounts in mixed and single cultures were significantly different. Sulphuric acid amount produced in the media was calculated based on the pH changes at the beginning and the end of experiment. The amount of the acid varied as the ore concentration changed. Bacteria count showed a positive correlation with copper amount released in the media. However, the number of TF was more than TT and TT+TF in mixed culture.

Decision making model is a way to assess environmental impact. Decision making model physically and mathematically shows the relationship between quantities and qualities in a part of the existing world, as it is a reflection of an entity or a present event in the real world. Therefore, models explain relations between data to predict circumstances of events in the real world. Degradation model (Makhdoum, 2002) is one of The mathematical models used through this research to assess environmental impacts of development in Hamedan province. In order to indicate degradation in impact units (which may be a set of areas, suburbs, factories,arbitary ecosystems or sets of the grid system depending on the level of decision making) the degradation coefficients were computed according to the following model: H =( ΣI+ Dp)/ V0 Where I is Intensity of degradation impact, Dp is Physiological density of population(Miller 1979), V is Ecological vulnerability, and H is Degradation coefficient of the habitat. To achieve this , first the boundry of study area (political boundry) was depicted on 2 sheets of topographics map (1:250000).Then the whole area was divided into 849 impact units (2×2 cm grids, 2500 ha).Ecological vulnerability was calculated and classified by using maps of slope, elevation, climate, geology, earthquake risk, soil, flora, habitat & hydrological sensivity. Then degradation impacts were detected in study area by field works, experts opinion, documentations and land use maps, as well as, their intensity. Physiological density was also obtained by dividing the population in every grid by the area of farming lands. Result of the model for every grid is a degradation coefficient. Finally according to the fuzzy theory, resulted degradation coefficients for all grids were classified into 6 classes and 3 categories. Further more the province was divided into 3 areas including prone to further development, noncritically impacted areas( need rehabilitation), critically impacted areas(need conservation measures).

In recent Years, considering environmental aspects play on very important rules in site selection of industrial sites. Paying more attention to site selection for industrial establishment to avoid of environmental problems in now and future.In this study, site selection for industrial establishment in Qom province in 1:250000 scales with utilizing of system analysis approach were done.For reaching to this goal, the environmental sources were divided to ecological source and economical-social source. These two groups were initiated, analyzed and totalized. Scientific method what utilized in this study was collecting all sources map and provided some scan of them, then digitized in GIS format and in next step, analyzed and classified them.The ecological power of land was evaluated and a model with 3 levels was provided. The next step was over laying the information layers that prepared in GIS format and remove the protected areas. The common applications of land included 17 units in four political groups of province were initiated.The area distributions were Nopelloshatu with 19964 m2 had 7. Central unit with 25603 m2 had 5, Jafarabad had 3 and Khalajestan part with 1180 had 2. Finally, based on economical and social parameters, 17 units were classified. As a result, a unit of Jafarabad got the first rank and the others unit ranked consequently. One of the results of this study that supposed to be an empirical study is proved the possibility of establishing a new model or theory in site selection for use in other places.

Heavy metals are among important pollutants of environment. They may enter to the sea from costal areas and rivers. They accumulate in body of aquatic organisms through food chain. Macrophyts as a trophic level absorb heavy metals. Thus, macrphytes can be used as an indicator of heavy metal accumulation. In the present research three species (Phragmites australis, Typha angustifolia and Potamogeton crispus) and sediment at six stations in Miankaleh Wetland have been determine concentration of zinc, lead, cupper and cadmium and effect of macrophyts in refining of heavy metals. The results show that average concentration of lead in Ph. Austrais. T. angustifolia, P. crispus and sediment are 5.3ppm, 4ppm, 5.4ppm and 19.83ppm, respectively. For zinc 290.83 ppm, 203.33 ppm, 141.55ppm and 274.33 ppm respectively. For cupper 7.63 ppm, 5.4 ppm, 4.58ppm, 0.5ppm and 1.33ppm repectively. The highest accumulation of metal in Ph. Australis and T. Angustifolia was in root and in P. Crispus was similar in different organs.

Range suitability is one of the most important factors in rangeland management. Since all of rangeland ecosystems component affect range suitability their investigation about them is very difficult. In this study physical and vegetation factors were evaluated. Tree models, including production model, water model and erosion sensibility model made final model. FAO (1991) method (recommended for land capability evaluation) was used for suitability classification. The study area is located in 50degrees, 36َ, 43ً - 50 degrees, 53َ, 20ً longitude and 36 degrees, 5َ, 19ً - 36,19َ, 19ً latitude, in the middle area of Taleghan watershed, with the area 37977 hectares. According to the results, among physical characteristics; slope, sensibility of stone and soil to erosion, elevation, and among vegetation attributes cover, production, range condition and range condition trend together are most effective factors for determining suitability classification. In the study area the most limiting factors are high slope, changing of rangeland to dry farming, presence of stones sensitivity to erosion, poor cover and early grazing. On the other hands, much ground cover including vegetation cover, stone and pebble, good distribution of water resource, number of water resources and presence of perennial species increase Taleghan rangeland suitability for sheep grazing.

In recent years, Nitrate absorption by plants, has greatly been concerned about in different countries. Some of them, have stablished standards for the amount of Nitrate concentration in edible plants. In Iran, there are few researches on this matter and because of high rate of vegetable consumption, it is necessary to be noticed. So, the primary goal of this project is to determine the concentration of Nitrate in edible parts of different plants, and then, to introduce the plants, which have the most potential for absorbing Nitrate.In this survey, samples of Spinach (Spinacea oleracea), Leek (Allium pooum), Sweet basil (Ocimum basilicum), Fenugreek (Trigonella foenum), Onion (Allium cepa), Cabbage (Brasica deracea), Lettuce (Lactuca sativa), Radish (Ruphanus sativens), Cucumber (Cucumis sativa), Tomato (Lycopersicum esculentum), Potato (Solanum toberosum) and Carrot (Daucus carota) were gathered from farms of Dorcheh, Dashti, Ziar, Falavarjan, Khomieni shahr, Najaf abad (Isfahan), Khorasgan in 1999 (July, Aug., Nov.) and 2000 (May, June). In some cases , some samples with defined harvesting place were purchased from market and added to this collection. Then, Nitrate concentration in edible parts, was measured in each sample. The averages were 2865, 412, 328, 450, 428, 673, 639, 819, 30, 14, 171 and 736 mg/kg (wet weight) in spinach, leek, sweet basil, fenugreek, onion, cabbage, lettuce, radish, cucumber, tomato, potato and carrot, respectively. In these samples spinach had the highest nitrate concentration and tomato, the lowest.Nitrate concentration in Spinach was more than the WHO standard, so it`s recommended to delete it from under one year old children`s food, in order to prevent Methemoglobinemia suffering.

In this work, we collected and determined medicinal, aromatic, postural and rare plant species from protected Area's of kalmand Bahadoran located in 30-105 km SE of Yazd city and Kuhe Bafg (Located in 110 km East of Yazd city) in the Yazd province. Analyses of the flora of these region's shows that, there are 148 vascular plant species in kalmand Bahadoran region and 139 vascular plant species in Kuhe Bafg region. Main natural and floristic characteristics of this region's are reported briefly. The results of this study shows that, in total, about 60 medicinal, aromatic and industrial plant species, about 15 grasses, 8 Legumes, 26 forbs and 23 tree and shrub species exist in this protected areas. Further more, threatened species of this region's have been analyzed, according to the IUCN criteria. On the basis of this study, four categories of rare species so called Endangered, vulnerable, Lower risk and Data deficient are determined and the list of these species has been presented. This study shows that, there are in total, 41 threatened plant species in this protected areas. Finally, we floristic composition, and species richness of this areas, are discussed.

Along with the destruction of natural habitats with urban sprawl, the need for providing green spaces for the purpose of making the ecological balance becomes crucial. Environmental characteristics, as a major urban green spaces, together with recreational activities can have a significant role in improving urban structure and ecology.This research is conducted to respond the need for design of urban forest park and through analyzing the collected documents, presents a precise definition for urban forest parks and defines the principles of sustainable landscape design. It could be useful for these sorts of parks, generally.The main objective of this research is to provide a policy for design of urban forest parks. It considers the possibility of developing them in the framework of physical or functional developments. The case study is Sheikh Tappe Forest Park which is located in Urmiah city. It has a vital role in the city and is a major green space.In the sustainable design of Sheikh Tappe Forest Park, primarily, the physical, biological and cultural characteristics of the park were identified. Afterwards, along with the assessment of ecological capability, the aesthetics and public preferences were recognized through the distribution of questionnaires. Also the recreational utilities and their interrelationships are studied. In conclusion the master plan which aims to promote the quality of the park has been presented.

The worldwide rapid growth in production and consumption of computers, have created special refuses. These refuses are categorized as hazardous wastes due to their human health risks and environmental hazards. The lead used in CRTs and soldering of computer printed circuit boards, the cadmium used in computer chips, the Mercury used in sensors, switches, discharge lamps and batteries, PVC used in the equipments and brominated flame relardants are only a few various applicated elements and compounds in computers. Many of these compounds pose high potential risks.Each year, in the US. Between 1997 to 2004, about 79000, 130, 26, 70, 257000, 23000 tones of Lead, Cadmium, Mercury, Hexavalent Chromium, Plastics and brominated flame retardants, have been entered the waste stream from discarded computers, repectively. Regardless of obsoleted computers, more than 4.6 million computers were operating in Iran in 2003. About 1.5 million persons were interenet users in 2003 whereas it is expected to reach 15 million persons in 2006(one thousand percent increase in 3 years). It is anticipated that about 85 million computers will be used by 2021. It means that about 2.2 millions tones of computer waste will be generated in this year. In Iran the accumulative amount of computer waste is about 7.38 million tones in this year. Regarding the rapid growth of computer industry in Iran, environmental crisis is predictable due to the lack of comprehensive planning and programming of computer waste management, specially in ten large cities. It is recommended that appropriate organizations such as Department of the Environment become active in creating proper rules, regulations and organizational chart for these important issues.

The industrial revolution, which began from 18th century, has caused increasing environmental degradation and crises. Since the mid-1900s, concerns about environmental impacts of industrial activities have began growing. Some standards have been developed to improve environmental performance of industrial companies since1990s. Series ISO 14000 are the most common standards for planning and implementation of Environmental Management systems (EMS), which have been developed by ISO since 1996.According to ISO 14001, success of the Environmental Management Systems depends on commitment from all levels and functions in organizations. The basis of the mentioned approach is lied on participatory management.Environmental Management System, based on ISO 14000, has been implemented in entire Iran Khodro Company (IKCO) since 2001. In accordance with IKCO"s environmental policy, developing the environmental culture and participating of personnels in EMS have been considered in IKCO"s agenda. Many cultural, educational and training actions have been carried out to realize the mentioned policy. However , the results of internal periodical auditing of IKCO's EMS show that the level of environmental culture and personnels participating is low.The findings of this research indicate that the level of organizational culture , style of management, commitment of perssonels, ability and competence of perssonels, organizational values, cognizance of perssonels and job satisfactory are the obstructions hindering the perssonels to participate in IKCO's EMS. Finally, some resolutions were proposed to remedy the obstructions.