Journal of Natural Environment
Year:2018 | Volume:70 | Issue:4 |Papers Count:22

Municipal sewage sludge (MSS) is waste material which remains in waste water treatment plants. This waste residue contains heavy metals such as copper, zinc, iron and manganese, which are considered to Hazardous environmental pollutants. Hence, during the use or disposal of this material in the environment should pay special attention to the fate of contaminants in it. Several experiments to evaluate the risk of waste, including determination of total concentration and heavy metals partition are used. However, numerous studies have shown that this procedures does not provide an appropriate response to the risk level of waste materials. Among the various factors affecting the release and leaching behavior of metals leaching solution pH is considered to the most important factor. The main goal of this research is to obtain an overview of the leachability of MSS produced in a waste water treatment plant of Serkan. PH changes after 48 hours of equilibrium, as well as indicated the buffering capacity of the sludge. The Solubility behavior for copper, zinc, iron and manganese were obtained which are very useful to predicting the leaching behavior in different scenarious. Also, the amphoteric behavior was observed for Cu and Zn. The interesting point was observed for Mn, because after pH 3 Changes in leaching behavior and solubility of Mn was very low. Furthermore, the results showed that the leaching of copper and zinc from sludge is limited due to its natural pH and if the condition is not acidic or alkaline it is not creating any problem.

As a sedentary bird, the Caspian Snowcock is a typical high-mountain and alpine species. The bird is distributed in the mountainous regions of north, northwest and western parts of Iran. In this respect, in recent years, the populations of this species are declining due to habitat destruction, unregulated hunting, overgrazing, etc. Therefore, conserving the relatively large patches of habitat is very important in order to support the species’ vital requirements. In this study, the habitat suitability of Caspean Snowcock in Charmahal and Bakhtiari Province (as a region containing mountainous landscapes) has been investigated. According to the results, elevation (44. 3%), annual precipitation (19%), slope (17. 2%) and human footprint (8. 5%) contributed the largest percents to the habitat suitability model. Potentially, the Caspian Snowcock can occurs in habitats with elevation of 1700 to 4150 m above sea level. However, only 0. 81% of suitable habitats fell within elevation of 1700 to 2000 m. The estimated suitable habitats of the species cover approximately 19. 4% of this province, but only about 15. 8% of these areas are officially protected. On the other hand, human disturbances such as residential locations, roads, overgrazing and collecting of medicinal and aromatic plants could lead to accelerating the habitat degradation and fragmentation. To further assess the impacts of habitat fragmentation on the Caspian Snowcock, it is suggested to survey the dispersal capacity of this species as well. In addition, considering ecological niches, the Caspian Snowcock can be regarded as an umbrella or flagship species in the high altitude mountains of this area.

Reproduction success rate of Cattle Egret Bubulcus ibis Linnaeus, 1758 carried out on the island of Ali Siah in Karon River in Ahvaz city since January 2013 and was completed in May 2014. In this study, the stages and success rate of species was measured in 60 nests. Observations showed that the start of nesting was late in December, the mean hatching time of eggs were 22 days, the average number of eggs per nest was 3. 9, the average growth time of the chickens was 33 days, the end of the breeding was early in June. Measuring the size of 234 eggs in 60 nests showed that the average egg shape index was 75. 56, the average volume of eggs was 20. 99 ± 14. 8 cubic meters, the mean small diameter of the eggs was 28. 36 ± 1. 96, the mean large diameter of the eggs were 37. 73 ± 1. 26 mm, the mean weight of eggs were 24. 41 ± 4. 34 gr, and the mean weight of nests were 463. 98 ± 9. 40 grams. The average Nestling time was 13 days, the average Post-Nestling time was 16 days, and the average total flight time for chickens was 14 days. The breeding period was 84-90 days and the reproductive success rate was 73. 33%. The breeding population of Cattle Egret on the Ali Siah Island was estimated 448 pairs. Observations in 2015 showed that the Ali Siah Island was destroyed and breeding colony of the Cattle Egret was destroyed on this island.

Being able to quantify the probability of tree species survival is fundamental to the management of forests worldwide that is very hard. Because there are many processes and factors affecting on it. This paper examines the possible ecological controls probability of tree species survival and quantifying abiotic and biotic variables affecting on it by artificial neural networks in Hyrcanian Forests including growing-season-cumulated potential solar radiation, seasonal air temperature, topographic wetness index in representing soil water distribution, and wind velocity generated from simulation of fluid-flow dynamics in complex terrain. Biotic variables related to tree diameter increment involve averaged 2003 tree diameter and basal area measured in individual forest plots. Allometric equations of logarithmic multiple linear regressions transformed models of power functions which have different parameters were introduced to clarify the certainty of simulating process The predictors used in survival modelling described the influence of tree size, competition and species. The model shows that trees with dbh between 20 and 100 cm survive best. Increasing competition (BAL) decreases survival, and Carpinus betulus has a slightly lower survival rate than the other species. Also, the results of this investigation, it is understood that BAL, topographic wetness index in representing soil water distribution, and wind velocity had the strongest correlation with probability of tree species survival in the fixed sample plots.

The diameter and volume growth of forest stands are the basis for determining the annual rate or cut in the planning and management of wood utilization so, forest increment and factors affecting it are one of the most important challenges in the forest. In this study, the impact of biotic and abiotic factors on diameter increment of oriental beech (Fagus orientalis lipsky) in fixed plot-level over a period of 9 years (2003-2012) was modeled by artificial neural network techniques in north forest of Iran. 258 permanent samples were taken by a 150 × 200 inventory grid. Mean of variables such as diameter increment, basal area of stand, basal area of larger trees and number of tree per hectare were measured inside each sample segment which are equal to respectively: 30. 9, 36. 8, 29. 4 and 421. Abiotic factors such as growing-season-cumulated potential solar radiation, seasonal air temperature, topographic wetness index and wind velocity and biotic factors such as diameter at breast height, basal area of larger trees were used as input variables and diameter increment of beech as output variable were used. Multi layer Perceptron network with back propagation algorithm and sigmoid functions were used. The results showed that the changes index of diameter at breast height (32%), Wind and solar energy in the growing season (a total of 20%) the combination of topography and soil wetness index (19. 5%) and basal area (16. 9 %) explain diameter increment changes in sample plot level. Also, neural networks provided acceptable accuracy for diameter increment modeling using the biotic and abiotic variable affecting on it. Also, the percentage of biotic and abiotic factors was approximately the same, which it can be concluded biotic and abiotic factors control increment of beech the same.

In this study to evaluate of Economic Value of Functions and Services in Naharkhoran Park use the choice experiment method and to estimate their parameters the conditional logit model and random parameters logit model have been used. Information required were collected by 339 completing questionnaires and interviewing from Naharkhoran Park’ s tourists. The results showed that the most important attribute in the view of tourists is contributing to forest sustainability. The tourists’ s willing to pay for attributes to forest sustainability, environmental health of the river, tourism facilities and reducing noise pollution respectively is 3567, 2219, 1145 and 2311 Rials per visit. Also age and native variables due to increase tourists’ s willing to pay.

Nowadays, the importance skid trails and in accordance with forest harvesting and silvicultural methods in the forestry sectors in the Hyrcanian forest, northern Iran, the necessity of the accurate and comprehensive assessment of these trails must be postulated. Forest machinery traffic on skid trails also has a large influence on the soil physical properties, so that, these properties cannot be restored after several years in skid trails. The aim of this study was to measure the runoff rate in two slopes classes of 0-20 and 20-40 percent in the skid trails. For this purpose, the runoff was measured in the plot level in two area on the skid trails and control area in Gorazbon district in the Kheyrud Forest. In this study, due to more reps and get more useful data, the natural rainfall were used. According to the normality of runoff data, the compare mean was used between them by parametric tests. The results showed that skid trails and forest cover change in natural forests were the main cause of the increase in runoff, and also the type of coverage, change of seasons and the interactions between them had a significant effect on the runoff yield. In other words, the amount of rainfall and the change of seasons were the important factors affecting the runoff results. But, the trail slope and their interactions had no significant effect on the runoff.

The purpose of this study is to measure airborne contaminants including volatile organic compounds (VOCs), carbon monoxide (CO), and suspended particles of less than 10 microns (PM10) from April to November 2016. Over the course of 8 months, 144 samples were collected for pollutants VOC, CO and PM10 with two replicates per month at three stations. The pollutants were measured at one o'clock in the evening. VOC and CO measurements were performed by the American-made Multi-RAE direct reading device and the Haz-Dust EPAM5000 Hazard Particle Measurement, in accordance with the US Environmental Protection Agency (EPA) standards. The air quality index (AQI) for pollutants (VOC, CO, and PM10) was calculated using linear correlation methodology according to the National Open Air Quality Standards (NAAQS). The results showed that the highest concentration of CO pollutants was related to the center of Shirazi parking with an average of 22. 31 ppm, and the lowest was related to parking exit from Imam Reza Street with a mean of 7. 5 ppm and then the parking entrance from Shirazi Streets with a concentration of 8 ppm. The concentration of carbon monoxide and PM10 at Shirazi parking station was higher than the standard of Iran Department of Environment (9 ppm, 150 μ g/m3). The air quality index for carbon monoxide for all months except November and the air quality index for PM10 for June and September were higher than the standard. In addition, the highest concentration of volatile organic compounds was reported in September and, in general, contamination was higher during the warm period than the cold period.

Determining areas with high conservation capability is the best way to conserve biodiversity, structure and functions of an area. In this study for evaluating land conservation capability in Plasjan sub-basin, criteria were determined using Delphi method. Hierarchy of study was designed and the weights of criteria were calculated by applying analytical hierarchical process (AHP). All criteria maps were prepared, necessary pre-processing’ s were done and criteria were standardized with Fuzzy and constraints were standardized using Boolean method. Land conservation capability maps for conservation were produced using multi criteria evaluation (MCE) with weighted linear combination (WLC) with medium risk and high trade-off levels and ordered weighted averaging (OWA) with medium risk and tradeoff level. Overlaying land-use/cover map on land conservation capability maps has shown that although WLC result is optimistic because it considered more area in high level conservation capability class, OWA result is more realistic with medium risk and tradeoff level by attention to current land conditions. results show in WLC and OWA methods 33. 9 and 13. 16 percent of area were given to moderate conservation capability 16. 5 and 12. 26 percent were given to high conservation capability repeatedly. Land-use/cover comprising with land conservation capability conservation maps, in both WLC and OWA has shown it is necessary to redesign all conservation area.

This study uses a system analysis to evaluate the effects of outdoor activities on some physical properties of the soil (soil bulk density, porosity and soil moisture content) and vegetation status (density, diversity and abundance) in the Qhamishloo national park and wildlife refuge has been researched. In order to achieve the desired objectives, by using the overlaying method, a map of environmental units of the region was obtained and after identifying the ecological units for the slopes, directions, elevation, resistance coefficient of rock, physical features of soil (erosion, pebbles, evolution, drainage, texture and depth of soil) and vegetation (density, pasture tendency and total production per hectare), in 38 units of the recreation zones and 38 units corresponding in untouched zones, one plot were taken (2m×2m) to assess vegetation. Action sampling of the soil profile with three replicates of the depth 0-5 cm and if there is, of the depth 5-10cm by using the method of the cylindrical-metal was performed. The results showed that the difference between vegetation status and physical properties of soil (depth 0-5 cm) in similar units with a 99% confidence was significant. However, the difference between the physical properties of soil at a depth of 5-10 cm was not significant at 5% level. In general, the results of this study showed that recreation has caused negative effects on the quality of soil and vegetation in the recreational zones of the study area.

Monitoring and managing the wildlife populations and habitats required to model the species distribution and habitat suitability. So, Gazella subgutturosa potential distribution in Mishdagh Protected Area was modeled using fuzzy (based on ecological knowledge of local communities) and MaxEnt (based on species occurrence records) approaches; thus, in addition to model the species distribution using maximum entropy algorithm (MaxEnt approach) and fuzzy inference system (fuzzy approach), we can also assess and compare the performance of each approach. In addition, the accuracy of predictive models was tested using jackknife test. Also, we applied threshold of 10%. Based on results of fuzzy and MaxEnt approaches, the most important variables for species potential distribution modelling were land use, distance to farms and distance to water sources. Also, 47. 45% and 14. 08% of study area predicted as species potential presence area in fuzzy and MaxEnt approaches, respectively. According to results of jackknife test, success rates of fuzzy and MaxEnt approaches were 80. 95% and 66. 66%, respectively (p<0. 01). Findings of this research confirmed the high performance of fuzzy inference system and maximum entropy algorithm to model species potential distribution. This study emphasized the necessity of attention to fuzzy approach for potential distribution modelling of wildlife species in Iran, and emphasized also the necessity of attention to the ecological knowledge of local communities.

The purpose of this research was to investigate the removal of chromium (VI) from an aqueous solution using the waste of bio-adsorbents, oil cake, by design of experiment and modeling via response surface methodology. The research process was conducted in two stages, taking into account different variables, including studied pH, temperature, absorber dosage, initial concentration of chromium ion and mixing speed. By response surface methodology, three-dimensional graphs were plotted which showed the effects and interactions of variables. Increasing on temperature from 30° C to 40° C caused more absorption of chromium; however more increase, to 50° C, led to a decrease in the absorption. At lower pH, higher adsorption occurred. In the more acidic environment, the changes in the temperatures were more effective. In the second stage, the resulting three-dimensional graphs showed pages with positive slope, versus three variables of absorber dosage, initial concentration of chromium ion and mixing speed. Increasing the dosage, initial concentration and speed, had great effects on the absorption of chromium. Equations obtained from response surface methodology represented the mathematical relationship between the absorption of chromium as a function of variables; with coefficients of determination above 95%. Absorption values for different circumstances were predicted using the model equations and compared with the experimental results, which showed the desirable fittings.

Air pollution is one of the most important problems in megacities. To provide comprehensive reduction plan for air pollution and pollutants emission prevention, first it must be estimated the amount and importance of major pollutants emission from various sources. The aims of this study were estimation the air pollutants emission from mobile sources and spatial modelling for each pollutant in Karaj. International vehicle emission model (IVE) was used to obtain air pollutants emission factors based on vehicle type. Finally, the annual pollutants emissions of vehicle fleet were calculated and spatial distribution of pollutants emissions based on traffic data and road networks were mapped in GIS environment. The results showed that the maximum annual emission of air pollutants including carbon monoxide (CO), nitrogen oxides (NOx), sulfur oxides (SOx), volatile organic compounds (VOCs), particulate matters (PM) and carbon dioxide (CO2) were estimated about 1688. 84, 185. 61, 6. 26, 31. 16, 120. 54 and 33737. 04 t y-1, respectively. The highways and the heavy vehicles were the major source for PM and NOx. In addition, the arterial roads and light vehicles were the main source for CO and VOCs. Despite the highest SOx emission factor was for heavy vehicles, the total SOx emission from light vehicles was higher than heavy vehicles because of their numbers. Also, the highest emissions amount of pollutants in municipal districts of Karaj were in 3, 4 and 6 and the lowest amount were in 1, 8 and 9.

According to the urban irregular expansion and the absence of appropriate consumption patterns, the most reasonable and low-cost method for the disposal of urban wastes is the landfill. Today, creating suitable places for the landfill is getting more difficult due to the urban expansion and development as well as the increase of public opposition. for this reason, it is recommended that to not choose places which located in the direction of the urban future expansion and residential areas growth. therefore, the main aim of the current study is to determine the optimum location for the landfill, regarding the urban physical expansion of Tehran city in a 28 years period Taking into account the risk parameter in decision making. In the current work, in addition to environmental, social and climate criteria for investigating Tehran physical expansion, Landsat satellite data from 1367 up to 1395 was used. In the present paper, weighing the different criteria of the paired comparison and The Ordered Weighted Averaging model is used to extract the appropriate suitable Place, taking into account the concept of risk in decision making. Lastly, suitable places for waste landfill have been selected considering the trend of urban expansion in different geographic directions over the past 28 years. The results of the Ordered Weighted Averaging model indicate that the maximum and minimum area of the suitable place for waste landfill are selected in the OR and AND modes, respectively. Investigations implied that the best places for the landfill are southern, southwest and western areas of Tehran. But due to considering the expansion of the city in different geographical directions over the past 28 years, the final suitable Place for waste landfill is the appropriate options in the geographic direction of southern Tehran.

Incorrect assumptions in the available valuation of techniques, such as don’ t consider to factors influencing and input not correct, that cause errors in the final results of the land use evaluation. Therefore, to enhance the accuracy and closer reality results from the two procedure for entering uncertainties and standardization, and DEMATEL-ANP to eliminate the problem of independence parameters, also to see the feedback and interaction among the factors used in the evaluation. In this study it was to evaluate the urban land use evaluation of Birjand's Watershed and to study the use of the DEMATEL-ANPFUZZY Technique. This assessment is based on 14 sub-factors, studied in two main classes of environmental and infrastructure factor. Then each factor was fuzzy and weighted by DEMATEL-ANP. Then protection map as a layer of banning was deleted and The final map was prepared for urban evaluation of Birjand basin using weighted linear combination method, according to each pixels was found potential for made urban land use. According to this method, it was revealed that 85/1%, 10%, 15/65%, and 23 % of the study area has a high, medium, low and unable capability to make the urban land use.