Journal of Natural Environment
Year:2012 | Volume:64 | Issue:4|Papers Count:13

One of the major environmental problems in the world, especially in Iran is deficiency of water resources. This with respect to the entrance of wastewater (especially industrial wastewaters due to their toxic effects) into the water bodies emphasizes the importance of wastewater treatment. Heavy metals such as cadmium, lead and vanadium are part of oil and hence are of the major pollutants produced in oil and gas industry. In this study, the efficiency of Cd, Pb and V removal from Bidboland gas refinery was investigated using a natural wetland system. Wastewater samples and the samples of common reed were collected from the wastewater outflow of the refinery and the surrounding environment, respectively. The concentrations of heavy metals were measured in the collected wastewater samples and the treated samples after two, six and 10 days, after acid digestion. The removal efficiency of V was the highest with 66%, followed by 61% of Pb and 59% of Cd. The highest removal efficiency of heavy metals was observed to be after six days. This treatment method showed to be a proper method in order to release the treated wastewater into surface waters, wells and for agricultural usage. Therefore, this method is suggested for the treatment of the wastewater of Bidboland gas refinery.

In this study, 52 specimens of adult Indian Gerbil (Tatera indica) were collected by live traps (Sherman traps, Havahart Traps and Locally made traps) from range of different habitats of two localities, Geno Protected Area (or Geno Biosphere Reserve) and Minab County, Hormozgan Province. At first, external, cranial and dental characters were measured and then the ratio of measured characters to head, and body lengths were calculated. All measurements and ratios were represented by the descriptive statistics. The results of Independent Sample T-Test showed that there are no significant differences between sexes. Furthermore, in order to show variation between samples and the significance of external and cranial variables, Independent Sample T-test was performed. Results of T-test showed that morphometric characteristics of the Indian gerbil populations in these regions are slightly different. Moreover, analysis showed that in Geno protected area population, 13 from 20 characters are significantly different than those in Minab population. The results from the PCA and MANOVA served to differentiate populations from mentioned regions based on the morphometric characteristics. In general, findings of the present study confirm the presence of significant morphological differences among populations of two studied regions.

In forest harvesting, there is an ongoing trend to increase constantly the size, power and load of logging machines. This may cause soil degradation in forest ecosystems as the passes of these machines modify important soil structural characteristics. The present study was conducted to examine impact of skidding traffic, trail slope, traffic frequency, and soil depth on bulk density and soil compaction due to tree-length logging method using rubber-tired skidder in Namkhaneh district in Kheyrud Forest. The level of soil compaction at eight levels of traffic (1, 4, 8, 10, 15, 20, 25, and 30 passes), four levels of slopes (0, 10, 1-10, and -20) and three soil depth (5, 15, 25 cm) were applied in three replicates consequently. Bulk densities were measured on the undisturbed surface (UD) and within the tracks (WT). Result showed that in four different slopes most bulk density increasing was occurred during the first few passes of skidder, although density continued to increase in amount and depth with the number of passes. About 5.2% of total area of harvesting unit were disturbed and compacted. Uphill skidding increases compaction more than downhill skidding.The increases in bulk density were still important at the maximum sampling depth of 20-30 cm. The results indicated that slope steepness had a strong effect on the soil physical properties and soil disturbance. Designated skid trails should be used to minimize the influence on the forest stand.

Healthcare waste is a by-product of healthcare. Poor management of these wastes exposes the community to infections, toxic effects and injuries. The purpose of this study was to investigation the qualities and quantities characteristics of infectious and domestic wastes of Dehgolan clinics in Kurdistan province. For this purpose health care centers was identify including hospitals, clinics, infirmary clinic, veterinary centers and the other related medical centers. The medical wastes were measured during both cold and warm seasons. For each season in a period of 15 days infection and domestic solid wastes were weighted by a 10 gr laboratory scale separately. The current condition of qualities, gathering, keeping and final eliminating, was investigated by questionnaire and observation techniques for each health care centers. Our results indicated that total produced waste in any 24 hours duration equal to 61 kg, including 37.8, 22.5 and 0.7 kg of domestic wastes, infectious solid wastes and sharp objects respectively. The average per annual was 1.9 kg in 24 hours each hospital bed of the study area. Finally the indicator characteristics of hospital wastes in Dehgolan health care centers were investigated. City Hospital is equipped with an incinerator and 41.2% of health care centers used the incinerator for disposal of infectious solid waste and sharp objects.

Particulate and gaseous emissions of pollutants from industries and auto-exhausts are responsible for rising discomfort, aggravates respiratory and cardiovascular. In this study, a system for air quality information in Tehran city has been developed, using an online Web-based geographic information system. This Web-based GIS application allows users to recognize areas with a potential increase in its air pollution situation. In the developed system, all spatial positions of the monitoring stations are shown in the map of Tehran. Every 15 minutes the system is connected to the CO, NO2, SO2, PM10, PM2.5 and O3 data collected in the existing database in Air Quality Control Company through the designed web server. After processing the transmitted data, Pollutant Standard Index (PSI) will be calculated. Then with connecting to the monitoring stations, results will be shown on the Tehran map as graphic web pages and texts.

The present research was performed in Patom, Namkhaneh, Gorazbon, Chelir and Baharbon districts in Kheyrud forest. Due to existence of forest typology map and extension of study area, this study was confined to beech dominated forests. A stratified sampling method based on landform is used to locate 1000 m2 circular sample plots. The number of Fagus orientalis Lipsky trees ³ 7.5 cm in DBH within each plot is recorded along with elevation, aspect and slope of the ground.Furthermore, at the center of plot, soil samples from A horizon are taken for analyzing soil texture.Gaussian response function was used. Instead of direct estimation of Gaussian parameters, it is customary to fit an equivalent polynomial model. This can be easily fitted as a generalized linear model (GLM) with a logarithmic link function. This function showed beech has 1347 and 464-2231 m a.s.l for its optimum and ecological amplitude, respectively. North-facing slopes (optimum 43 degree) are the most suitable slope for Fagus occurrences. Beech tree can distribute from gentle to steep slopes in the study area, but this species in 39% slope has the best performance. Using generalized linear model showed Fagus can tolerate slopes from 3 to 74%. In light of sand, clay and silt, Beech tree has 25%, 43% and 35 % for optimum and 4-46 %, 25-60% for clay and 15-55 % for silt for ecological amplitude, respectively.

Raccoon is a native species to North and Central America. At present, it is an invasive species in many countries such as Japan, Germany, Russia and Iran. Raccoon was observed for the first time in Gilan province in Iran in 1991. This research was employed Ecological Niche Factor Analysis (ENFA) method to model habitat selection of Raccoon in Lavandevil wildlife refuge. The results showed that this species habitat is located mainly in Punica plant communities with densities more than 40%. They also placed in the protected zone, which can be a major threat to biodiversity in Lavandevil wildlife refuge. In addition, results showed that the species tend to be in marginal habitats and has low tolerance to environmental variations. Due to biological and geographical conditions, there is a possibility of invasion to many habitats of Gilan province.

Human activities induced changes in land cover/use have extensive impacts on the landscape. In recent years, these changes had an increasingly growth due to irrational use of the natural resources in Iran. Hence, considering the negative effects of the inappropriate use of land and land-use change, understanding of the landscape changes over time is necessary to planning and implementation of sustainable management. This study has been carried out aiming to investigate trends in the landscape changes in Korganrud watershed during 1975-2007. In order to generate the land use/cover map and analysis of the changes, satellite images, including Landsat (MSS), IRS/P6 (LISS III) were applied and landscape metrics, including Class Area (CA), Patch Number (PN), Mean Patch Size (MPS) and Average Weighted of Mean Shape Index (AWMSI) were used to quantify the landscape patterns. Results of the present study revealed an extensive change in the landscape metrics in distribution and ratio of the land uses due to the increase in the area of disturbing patches (agriculture, urban and barren lands) in expense of decrease in the natural resources (forests and rangeland) during the study period. Degradation and reduction of integrity of the landscape have also been observed due to the increase in patch number of the land uses that were in association with the increase in shape complexity and decrease in the patch size in the study area. If such a trend continues, without any appropriate management plan and or land-use planning, it could result in adverse impacts on the structure of the ecosystems. Therefore, the results suggest the necessity of implementation of land use planning in order to determination of the suitability between land supply and demand, and decreasing degradation of the natural resources.

One of the major environmental problems in large cities is air pollution. In this study, the monthly and annual changes in the average concentrations of carbon monoxide and PM10 were investigated during a five-year period (winter and fall of 1383-1387 A.H.S) in Tehran. The effects of meteorological parameters on these parameters were also investigated. The study area was divided into three zones (light, medium, and heavy traffic areas). Linear regression was employed to correlate [CO] with speed of wind (So W). The significance of changes and the validity of assumptions were evaluated using student’s t-test. Comparison of the data acquired from EO’s in the five-year period indicated that Azadi and Sorkhehesar stations have the most and the least [CO], respectively. Also, Tajrish and Sorkhehesar stations demonstrated the most and the least [PM10], respectively. The AQCC, Bazar and Golbarg stations have the most and the least CO pollution, respectively. Besides, Aghdasieh and Geophysics stations showed the most and the least [PM10], respectively. The highest concentrations of CO were observed in November and December and PM10 in September. Negative correlations were observed between the decrease in [CO] and the increase in the So W. However, no significant relationship was found between the increase of [PM10] and So W.

The purpose of this research was to investigate the attitude of vegetable growers towards sources of soil pollution in Ray County. The study consisted of all vegetable growers (N=700) in Ray county, located in Tehran Province, from which 70 vegetable growers were selected through random sampling technique. A planned questionnaire was used as the main instrument to collect data. The content validity of the questionnaire was approved through getting opinions of specialists and experts in the fields of Agricultural Extension and Education, Soil Science and Horticulture in the University College of Agriculture and Natural Resources, University of Tehran. The reliability of the scale for measuring attitude of respondents was approved by using Cronbach Alpha coefficient, which was measured as 0.72. The findings indicated that all vegetable growers used to consume the polluted water for irrigation, and 38.6% of respondents had an intermediate attitude towards sources of soil pollution. A further finding of the study about sources of soil pollution was that the usage of factory sewage and agricultural machinery in the field had the first and the last priority in turn.According to stepwise regression analysis, 15% of the changes happened in the respondents' attitude towards sources of soil pollution, was due to the rate of implementing prevention strategies of soil pollution and the attitude towards prevention practices of soil pollution.