نشریه علوم و تکنولوژی محیط زیست
سال شانزدهم شماره 3 (پیاپی 62، پاییز 1393)

In this study a neural network model is proposed for modeling tri-halo-methane concentration in drinking water. After training, the neural network model predicts tri-halo-methane concentration based on input data. Parameters such as pH, Temperature, free chlorine residue and TOC were used as input data. To validate the proposed method, a case study was carried out, based on the data obtained from Guilan grand treatment plant (Sangar). The Levenberg-Marquardt algorithm was selected as the best of thirteen back-propagation algorithms. The optimal neuron number for Levenberg Marquardt algorithm is 8 neurons. The performance of modeling was determined. The trends of the forecast and measured data were in good agreement.

Gas transportation pipelines production plans, unlike technical and economical justification in the field of energy supplying for societies, by having danger on environment, needs the continuous studies of assessment and environmental risk management in manufacturing and benefiting stage. In this study, for purpose of environmental risk assessment for gas transportation pipelines the indexing system method and Analytical Hierarchy Process were combined. Indexing System is a compulsive and applicable method that was based at the basis of characterizing index effect and ranking. By using this method, we can classify, quantify and prefering types of environmental risk in pipelines according to the determined criteria’s and typical. In the mentioned method, typical of dangers, show the possibility of danger occurrence and effects of typical show the effect intensity. Final grade for environmental risk in this method produce via possibility of danger occurrence multiply with effect intensity. According to that efficiency scale for whole of criteria are not equal in the final level of risk. In addition for the purpose of weighting the criteria’s, the Analytical Hierarchy Process was used and for the purpose of weighting the digital layers of information related to the criteria Ordered Weight Analysis method was used. For the purpose of examination results of this research, environmental risk assessment of gas transportation pipelines 24 inches for Tasuj-Salmas with approximate length about42 kilometer as a case study was exerted. Via usage of Geographic Information Systems abilities, the identified risks and risk zonation in the path of pipelines were considered. Results showed that 46% of gas pipeline path of Tasuj-Salmas, has a high risk level (5467- 6054 grade), 48% of it, has a medium risk level (6055- 6641 grade), 2% of it, has a low level of risk (6642-7228 grade) and 4% of it, has a little risk (7228< grade). Adjacency of southern zone of pipelines path with Orumieh lake national park, is an important ecological sensitivity that is under investigation. 15 kilometer of pipeline path (kilometer 18+220 to 33+220) is aligned with 5 kilometer of biosphere reserved.

The coastal environment of Bushehr is supposed to be affected by polycyclic aromatic hydrocarbons (PAHs) and oil pollution. Despite carcinogenic characteristics of PAH compounds to living organisms and human beings, the available information concerning PAHs contamination in Bushehr is not sufficient. This study was carried out to investigate concentration and distribution of PAH compounds based on number of rings in their structure, in the coastal sediment of Bushehr. Samples were collected from five different stations along intertidal zone of the shoreline. The samples were digested; their PAHs contents were extracted and analyzed using High Performance Liquid Chromatograph (HPLC). Results showed that the total PAHs (tPAHs) concentration in stations Rafael, Sheghab, Abshirinkon, Lian and Helyleh were 844.95, 3078.42, 4790.32, 2988.06 and 2430.62 ng g-1(dw) respectively. A significant difference was observed between tPAHs concentrations in different stations. The maximum tPAHs concentration was measured in station Rafael, while its minimum level was observed in Abshirinkon. Based on the number of the rings in the molecules, the PAHs composition in different stations varied significantly (P<0.05). Compared to previous studies from other locations of the world, PAHs contamination in the Bushehr coastal sediment was evaluated as moderate to severe. The major part of contamination was comprised by High molecular weight PAHs with 5 or 6 rings while 2, 3 and 4 rings compounds had less contribution. Since the adverse and carcinogenic effects of high molecular weight compounds are more severe in aquatic organisms and because its continuous anthropogenic discharges in Bushehr, regular monitoring of PAHs in the area is necessary.

Heavy metals pollution is very important in Environment. Toxicity and accumulation characteristics of these metals are more noticeable for health aspects. Today, using bio-sorbent is more noticeable because these ways are ecofriendly and economic. In this survey, in addition to achieving Ni and Cd bio-sorption by bio-solid, the results of other relative surveys used for comparing the results and bio-sorption affinity discussion. Bio-solid powder produced from municipal excess sludge by drying, grinding and grainsizing. Ni and Cd solutions in 0.25 and 0.75 mille molar have been contacted which 0.5, 1, 2 and 4 grams of biosolid in pH 4, 200 rpm stirring, 24-260C temperature and two hours (continuous 5-420 min in kinetic study) time and samples have been analyzed with atomic absorption spectrophotometer to kinetic and isotherm modeling study and comparing the results. The maximum equilibrium adsorption of metals observed at two hours contact time and increasing of pH up to 4 increased the adsorption rate. The equilibrium data of both metals could be fitted by Langmuir isotherm equation and the maximum adsorption capacity (qmax) for cadmium and nickel are 0.38 and 0.195 mmol/gr dry bio-solid, respectively. The same as other biomasses studied for bio-sorption of heavy metals bio-sorption affinity of bio-solid for Cd is more than Ni. Generally, the bio-sorption affinity of algae and fungi for heavy metals bio-sorption is more than sludge and bacteria that is the result of cellular wall characteristics.

The heavy metals are from the pollutants which create too much problems in aquatic ecosystems for aquatics and human. This study was done on concentration of heavy metals Hg, Cd and Pb in the muscle, liver and gill tissues of Liza Abu in the Karoon and Dez Rivers in Khoozestan Province in winter 2010. In this reaserch 216 sample of Liza abu were used randomly. Metals were extracted from the tissues using wet Digestion method and concentration of the heavy metals was measured by Atomic Absorption Spectrophotometer Perkin Elmer 4100. Analysis of the data was done by using of the SPSS17 software and analysis of the t-test determined exist or non exist of the significant difference in level 95 (P=0.05). The highest concentration of Cd, Hg and Pb 0.540±0.264, 0.027±0.002 and 1.08±0.128 mg/Kg and the determined lowest concentration of Cd, Hg and Pb 0.346±0.040, 0.903±0.037 and 0.023±0.001 mg/Kg. This study showed there is not any significant difference in concentration of heavy metals Hg and Pb in muscle, liver and gill of Liza abu in Karoon and Dez Rivers. There was a significant difference in Concentration of Cd in muscle and gill (between (P<0.05) but there was not a significant difference in concentration of Cd in livers of all of them (P>0.05).

Decomposition of economic activities to formal and informal, the formal activities are those which monitored by official data and on the other hand the informal economic activities are those that arent reflected through official statistics. They arent transparent as much to be traced by authorities in spite their considerable volume. One of the main reasons that economic agents prefer to transform their business to informal part of economy is to avoid regulations such as: tax, duties, standards and etc. One of the main features of these regulations is environmental consideration (e.g. environmental tax and standards) which is sensibly important for industries. Especially for pollutant ones which are usually behave unofficially and their activities have much more degrading effects on environment. We are to study the effect of informal economic activities on environmental quality a cross country approach. We used a basic Kuznets model through panel data technique for 140 countries. The result implies a considerable impact of informal activities on environment not only in high income countries but in low and middle ones.

In recent years, the increased effects of agricultural systems on the environment concerned scientists and policy-makers in different countries. The indiscriminate use of chemical fertilizers and use of excessive ground water are included in these effects. Current study using a Multiple Goals Fuzzy Non- Linear Programming model, analyzed the possibility of ideals realization reducing consumption of fertilizers and water in compromising with maximizing gross margin, minimizing risk of production, and increased social benefits goals in the crop pattern of three cities located in three major weather Regions of Fars Province. Results showed that in many cases there isnt the possibility of complete ideals realization in the multiple goals model in comparison with single goal patterns. But considering the outcome and the relevant weight assigned to each of the goals by the decision maker consisting of the Fuzzy Composite Distance Function, appeared that the crop patterns based on multiple goals are superior to current patterns and even single goal pattern in supply of multiple compromised ideals. Implementation of these models in study areas has significant influence on reducing water and fertilizer uses in addition increasing the gross margin, reducing risk and increasing employment of labor in the region.

According to daily increasing request of people for promenades and recreational centers, social and economic analysis and full review of people requirements is a key factor in providing required facilities. In this study, Zonal Travel Costs Method (Z.T.C.M) was used for recreational valuation of Koohrang waterfall. This method is based on map, overview, socialeconomical characteristics of visitors of promenades and also increasing in cost and distant from region. Obtained data from completed questionnaire by visitors, statistical calculations regarding to distribution of visitors and estimating travel costs showed that the recreational value of Koohrang waterfall is 156.377.600.000 Iranian Rials. Money making value depends on the best natural location and beautiful sights around it. Results showed that variables like age, education and amount of visitor’s income had significant impacts on use of promenades. Investigating amount of visitor’s income showed strong correlation between this variable and number of visited days of promenade and also their interest to pay entrance charges. It also showed that level of education has a key role in absorbing visitors for Koohrang waterfall as most of the visitors were university graduates. Level of advantage has direct relation with income, as relief times of people would increase by increasing level of education. Investigation of studying in some promenades of the country showed that there are more interest among teenagers and middle ages but our results showed most of the visitors 25%) were in the range of 30-34. Results provided some valuable information to graduate promenade level of Koohrang waterfall.

In this research social (external) cost of NOx, SO2 and CO2 emissions from energy sector (power plants) in Iran were estimated. For the first time, we used benefit transfer method and by adjusting international coefficients of social costs, these costs estimated for each kind of power plants (including steam, gaseous, and combined cycle). Different scenarios in this research are consisting of carbon trading, life statistical indexes, etc. At first level we survey 5 selected power plants (for case study) in Iran and then the results generalized to all power plants. Social (external) costs for 3 above mentioned gases; each type of power plants and for one kilowatt hours of electricity was estimated. The range of social (external) cost for each Kwh of electricity is 690 to 1330 Rials. The results define that average social (external) cost per kilowatt hours is about 1330 Rials.

Iranian Coppice Oak Forest has been an appropriate of a wide range of middle Zagros region vegetative. Whereas Iranian oak (Quercus persica) has shown in the wide gamut of different habitat climate, conjecture that on the limited altitude, habitat, have considerable affects on diameter increment in this species. In this study, in order to determining the site affects on diameter increment, three sites were selected on foothill, heights and plain area and in each site 40 coppice were selected randomly. One the several rudiment of each coppice, one pillar was selected randomly and cut a disk and scan with loop and caliper on lab. Results showed that the mean of medium diameters increment (on contemporary classes) have been increased by sequential site issue. Thus ANOVA test was done and result was significant (P= 0.05), Krusk al-Walis Nonparametric test ratifies these results as well. Also comparing percentage of diameter increment at three 5 year period of latest growth has been done between three sites discretely and result doesnt show any significant difference.

Because of high urbanization rate and especially fast development of metro policy like Tehran, environmental pollution, like air, water, soil and visual pollutions have been increased. All of these factors have important effects on reducing of life quality and public urban spaces in these cities. In this research, the Park-e-Shahr as the first public park of the city of Tehran has been studied and the reasons were its environmental values, its functionality, culture and beauty. The principal of this research is to protect and reinforce the historical perspective of the park, qualitative elevation of the environment and the park's view with the minimum degree of damages to it and the protection of its historical values and also the fulfillment of the current emotional, mental, spiritual and the educational needs of the visitors and ultimately keeping the memory and the spirit of the place in designing the environment as such which remains in harmony with the location in the past and the present. Since this sphere is located in the old fiber of the city of Tehran (Sang-e-Laj district), the study has been done from a broader outlook. At the high level of the recognition of Tehran city and its location in the natural- historical situation, for the recognition of historical districts, at the intermediate scale of general recognition of Sang-e-Laj district in Tehran and historical identity since before, at the microscale of the recognition, all the current of the Park-e-Shahr in the current conditions have been analyzed. Analysis of natural and historical segments, analysis of the outlook and the view and analysis of behavioral patterns of visitors were done. Finally, the results showed that principles related to the techniques of revitalization and the preservation of the Park-e-Shahr. Utilization of questionnaires and SWOT method were done for the revitalization of Park-e Shahr.

The purpose of this study was to investigate floral and plant species diversity in west of Oshtorankooh region, Lorestan, Iran. In 1600-1800 m altitude range at the study area 62 species from 24 families were found which 10 species of them are endemic within territory of Iran. In this study in order to avoid effecting factors such as slope, aspect, altitude, and soil three sites were chosen with the possible similarity. The results from One-Way analysis of variance and Duncan average comparison tests showed that the status of diversity indices in the site 1 and 2 were better than site 3. At probability level of 99% there was significant difference between species dominance index for the site1, 2, and 3. In terms of richness and diversity, site 1 and 2 has better conditions compared to the site 3. Also the comparison of diversity diagrams in three sites shows that diversity level in the site 2 is more than the others, while productivity in the site 1 is better. On the other hand both diversity and productivity in the site 3 is low and the rate of extinction is high.

Kor River is a valuable ecologic area and source of water for the Bakhtegan Lake in Fars province, Iran. This river has been contaminated with various waste pollutants including agricultural, industrial, urban and rural. Cadmium is one of the common hazardous heavy metals entering the natural environments. This study mainly aimed at isolation and identification of the cadmium resistant bacteria, determining the resistance spectrum and investing the growth of opted bacteria against Cd. Additionally, physic-chemical and biological factors have been monitored quarterly. Samples were taken from five different stations at Dorudzan dam downstream to the mouth of the river to the Bakhtegan Lake since these areas are believed to contain more contaminants. Two sets of water and sediments samples were taken simultaneously to measure physic-chemical and biological factors and detection of cadmium resistant bacteria. More resistant bacteria were screening through MIC and MBC. Tow opted (G+ and G-) bacteria were studied in batch culture at three different containing harsh conditions by growth kinetic curve. The presence of cadmium was found to be more dominant in sediments than the water. Serratia marcescens MT015 and Pseudomonas aeruginosa ET017 showed maximum cadmium resistance up to six mille molar. P.aeruginosa ET017 and Bacillus OA017 represented proper growth in the harsh conditions. Discussion and The Kor River is a significant ecological area in Fars province, Iran where annual monitoring seems essential. Some indigenous bacteria in this river have represented high ability of cadmium resistance which enabling them to be exploited as valuable agents for bio-remediation in bio-filters and "in-situ" form for cadmium contaminated environments. No need of genetically manipulation and wide spectrum of study upon physicochemical, biological and bacterial assessing are advantages of our research. In compare to recent researches, our presented strains demonstrated more resistance to cadmium.

The presence of computers and working equipments in official and educational buildings caused the increasing of internal temperature and using glass façade vastly has caused more negative effects of this problem. The question is how to reach to the comfort degree of internal temperature without using excessive energy at the same time of benefitting the visual beauty of the glass façade. The aim of this study is to evaluate the effects of the quantity of layers of the internal and external of double skin façade on energy consumption. Methods of study: The method of this research is based on causal modeling and simulation. The used equipment was the software of thermostatic simulator called “Design Builder”. In order to reach to the lowest level of energy consumption, different modes of the layers in the double skin façade were analyzed by using the design builder software. The results revealed that in double skin facades, changes in the number of inner layer are efficient in reducing energy consumption, while the outer layer of glazing does not play any role. Using the double skin facade in southern side is more effective because of the sun radiation on this side. Due to the heating and cooling degree days in Tehran which is equal to 1610 and 1435°C respectively, in the summer, habitability and comfort level of residents were demanded mostly. So in the summer, change in the number of inner layers is more effective than the outer layer.