نشریه علوم محیطی
سال دوم شماره 3 (پیاپی 7، بهار 1384)

In most places heavy metals exits to environment as environmental pollutants in different physical and chemical forms. One of the objectives of this research has been finding a solution to purify this kind of industrial run-offs. The research was initiated by screening lead-absorbing bacterium from among other microorganisms, and, finally, a particular bacterial strain, which demonstrated a maximum capacity for absorbing lead waschosen, identified, and enhancing the conditions of its absorption was carried out. From the outset, selection and collection of samples were made from the industrial andmanufacturing centers the major part of whose wastes consisted of lead. Altogether, this research has two phases of screening: selecting strains resistant to high lead density and screening selected strains, based on absorption capability. After the initial stage of screening, about 35 different bacterial strains resistant to lead were identified, which consisted of a particular strain of gram-positive and gram-negative bacteria. It should be mentioned that all these strains were capable of resisting a 5mM concentration of lead in a cultural environment, containing this metal. For achieving the goal in the second phase, a particular method (Pümpel et al., 1995) was employed. By proximating H2S to the colony, it became evident that in lead-contaminated regions, the interaction between H2S and lead would create the black sediment of PbS and consequently, a thin and transparent layer occurs around those colonies capable of absorbing lead. The 8 strains with typical metal absorption haloes were selected and their biomasses were proximated with the metal solution. At last, the amount of the metal in the supernatant measured with the help of atomic absorption spectrophotometer. Thus, the sample that shows the maximum reduction in percentage of lead concentration in supernatant represents the maximum absorption of the metal by the related bacterium. In this strain, bioaccumulation was more than biosorption.

Evin-Darakeh Mountain region is situated in the northeastern part of Tehran. The area is located at 51 23' north longitude and 35 48’ to 35 54' east latitude. This region is as a part of mountain area of central Alborz confined to eastern the hills of Aliabad of Velenjak, westward to highest of east Hessarak, northward Touchal and heights of Shahneshin, southward Evin region. The annual rainfall is 300-400 mm and the mean annual temperature is 16/7 C. The present survey was carried out to introduce the flora, identify the biotypes and determine the phytogeographical dispersal of plant species existing in the said region. The results of this survey indicate that 296 species out of 214 genera belong to 56 plant families are exist: Compositae with 47 species, Papilionaceae with 32 species, Cruciferae with 30 species, Graminae with 30 species, Labiatae with 17 species comprise the highest number of species. From viewpoint of biotypes Hemicryptophytes 44. 3% Therophytes 38% Chamephytes 10. 5% cryptophytes 4. 4% Phanerophytes2. 8% are, from viewpoint of chorological elements Irano-Turanian elements are 51. 9% Irano-Turanianm-Mediterranean Viewpoint are 14% Cosmopolitan elements are 10. 5% and others species are belong to the other regions. From the said numbers, 21 (%7. 1) species are endemic species.

The second industrial township of Ardabil, with average ground area of 600 hectare, with geographical coordinates of latitude/longitude and with the capacity of 678 units included in 9 industrials groups is located 13 km west of Ardabil.In this study, through tests carried upon water, air, sound and soil necessary data was gathered, and an assessment of the present status of the area obtained. Then, based on the scientific and technical evidences and through the application of appropriate knowledge, experience and mathematical models and calculations, the probable environmental effects were predicted.Direct and indirect, short and long term effects were surveyed and introduced. In this assessment two alternatives; "No" and "Practical" were assigned to the cases. The choice "NO" meant: what are the consequences of the nonexcution of the project upon the environment? And when the project was recognized as practicable all effects of the related activities were taken into consideration. The importance and range of the effects of both "No" and "Practical" alternatives surveyed in two operational factory buildings and the intensity and importance of effects upon environmental factors analyzed using Leopold Matrix. In the analogous check list, the results obtained from positive and negative effects of both "No" and "practical" alternatives in operational factory buildings were examined meticulously and the optimal choice was selected. The final mean of the two"No" and "Practical" alternatives was positive to the benefit of practical alternative and so the establishment of the second industrial township of Ardabil was confirmed. From among the positive consequences of the plan implementation one can refer to the job creation, relative uptick in the welfare of the society, decrease in the migeration and social crimes rate, society's psychological health amelioration, added regional and national importance, providing clear horizen for the future developmentalprojects in the region, especially in industry section and the dded value steming from manpower changing raw materials into he processed products which will lead to the economical rosperity in the province.

Past experience has revealed the crucial fact that the development of human activities must be carried out in a sound manner. Making the Boushehr Province coastal area increasingly available to the economic sector, particularly the oil and gas sector, has led to extensive development. As a result, the impacts of past developments have endangered health and the quality of the environment. In this present research, the shoreline of Boushehr Province in the northern Persian Gulf has been classified on the basis of Environmental Sensitivity Index (ESI) using sate light data (IRS-PAN & ETM) and a direct observation method by means of GIS. On the basis of the findings of this research, about 76.25 percent of the study area has been identified as sheltered tidal flats, 21.8 percent as fine- to medium-grained sandy beaches, 1.02 percent as gravel beaches, 0.7 percent as exposed rocky shoreline, 0.06 percent as sheltered rocky shore, 0.05 percent as mangroves and 0.12 percent as riprap. The results showed that about 99.3 percent of the study area is not resistant to oil spill pollutants, taking into consideration the ecological susceptibility of the coastal area ecosystems, in spite of its abundant ecological resources.

A Preliminary Survey on Diet of Capoeta capoeta gracilis in Talar and Yasalegh Rivers from the Southern Basin of Caspian Sea.Hossein Mostafavi, M.Sc. Instructor, Environmental Sciences Research Institote, Shahid Beheshti University Asghar Abdoli, Ph.D. Assistant Professor, Environmental Sciences Research Institute, Shahid Beheshti University Abstract The diet of C. capoeta gracilis was studied in the autumn of 1998 in the Talar and Yaslegh Rivers, the latter being a branch of the Gorganrood River. After determining the study station in those rivers, sampling was carried out by electroshocker as well as using a cast net. The beginning 1/3 of the bowels in these fish with different ages were then surveyed using formulas and an invert microscope. Among Priphytons which constitute a main food source for these fish, four phyla and 27 genera of Priphytons were identified. Most of the fish feeding at different ages were from the Chrysophyta phylum during this season. The main food for fish in these two rivers at the ages of 0+ and 1+ was Coconeis sp. However, it seems that at older ages (2+ and 3+), the kind of diet is different from that of the younger fish and from those two river fish.

Urban parks have many recreational values for people’s leasure activities. Pardisan and Lavisan Parks are located to the West and East of Tehran and they provide some qualitative services to the people of this city and its suburbs. The economic valuation of these qualitative services, in comparison with normal criteria, is a very complicated exercise and should generally be made using certain indicators for estimating their economic values. In this article, the socio-economic valuations of Pardisan and Lavisan Parks have been estimated using the Clawson Method. This method is based on maps, visitors’ views, their socio-economic characteristics, the increase in access costs and the distance of parks from their living areas. Demand curves related to the total number of visitors and the cost of access, estimate the daily recreational economic value of Pardisan Park at 77.6 million Rials and for Lavizan Park at 53 million Rials. Moreover, the analysis of questionnaires indicates that 91.4% visitors to Pardisan Park and 66.3% of them to Lavizan Park have high school certificates and that the monthly income for 39.8% and 69.8% of them is less than 1,000,000 Rials.

This short speech is on attempt to obtain a deeper understanding of the world of existence and discover the mysteries hidden behind this scenery. Nature is a phenomenon (a creature) and God is the Creator of this tremendous masterpiece, therefore it continuously moves forward with a harmonious motion as an intellectual system. The hope, then, is that humans can find themselves a part of this unlimited and boundless nature through recognition of such harmony and grandeur and institute a unity with the world of existence, resulting in perfection and bliss for humans since the goal and destination of Creation is nothing more than that.