Journal of Natural Environment
Year:2017 | Volume:70 | Issue:3 |Papers Count:23

Reduction of vegetative cover by forest harvesting generally increases the average surface runoff volume and sediment yield for a given area of land. Forest harvesting in northern forests of Iran is managed using a selective harvesting and logging system. Towards this attempt, the present study has been conducted to investigate the effect of forest harvesting on hydrological components in plot scale (2m*1m) with four replicates in tow slope scale (0-20%, 20-40%) in the northern forests of Iran during December 2014, December 2015. The rain depth was measured by using a rain gauge installed in the study area. The runoff volume and coefficient and sediment yield were also measured through field data collection and lab analyses by weighting and decantation methods. The results of the study showed that there was no significant effects of forest harvesting (P<0. 05) on runoff volume and sediment yield and there was significant effects of seasons change (P<0. 05) on sediment yield. So that, the ratios of runoff and runoff coefficient, and sediment concentration in harvested area was respectively found some 1/4, 2/3 and 1/16 times of those recorded for control forest area.

Soil erosion causes the accumulation of phosphorus in the river sediments which may increase the phosphorus release to surface waters. Phosphorus release from sediments has been recognized as a key factor responsible for eutrophication of fresh waters and for this reason knowledge of phosphors concentration and its fractions is very important. The aim of this study was evaluation and comparison of phosphorus fractions in suspended and bed sediments of Rozeh-Chay river, Urmia, west Azarbayjan province, Iran. Six Suspended sediment samples and 19 bed sediment samples were collected from the river and some of physicochemical properties were determined. Phosphorus in sediments was fractionated by sequential extraction method, in which the phosphorus fractions were defined as exchangeable (KCl-P), Fe and Al bound (NaOH-P), Ca-bound (HCl-P), and residual phosphorus (Res-P) fractions. Results indicated that, percent of sand in bed sediments was higher than suspended sediments. But, silt fraction was higher in suspended samples than bed sediments. The organic matter content of the bed sediments was also higher than the suspended sediments. In the bed sediment samples order of phosphorus fractions was HCl-P (54. 8%) > Res-P (40. 8%) > NaOH-P (3. 5%) > KCl-P (0. 9%), while for suspended sedimentsthe order was Res-P (64. 9%) > HCl-P (31. 9%) > NaOH-P (2. 8%) > KCl-P (0. 4%). Multivariate analysis was used to identify factors which influence the phosphorus fractions. Principal component analysis results indicated that the first four components explained 85. 4% of overall variation in sediments properties. Silt, sand and organic matter content seem to play significant role in regulating the distribution of phosphorus fractions in the sediment samples.

Evaluation of soil contamination by heavy metals such as cadmium in soils is essential for human health and also for environment management. As direct measurement of soil cadmium is time-consuming and costly, in this study, the two methods of artificial intelligence, artificial neural network (ANN) and adaptive fuzzy neural network (ANFIS) used to estimate the amount of cadmium in soil as one of the dangerous heavy metals. For estimating of cadmium, soil readily available properties such as clay and sand percentage, organic carbon, EC, T. N and P used as input parameters and the relationship between these parameters and the concentration of cadmium established by ANN and ANFIS models. For training and testing the models, 250 soil samples collected from soils of Guilan province. For assessment of artificial intelligence models the statistical criteria such as the coefficient of determination (R2), mean absolute error (MAE), root mean square error (RMSE) used. The results showed that ANN model with R2 = 0. 83 and RMSE= 1. 01, and MAE= 0. 54 is superior to ANFIS model. Also the results of the sensitivity analysis on the input variables to the model showed that organic carbon and EC have the most and the least effect on the amount of Cd. The proposed model could be used to estimate the amount of cadmium in other parts of the studied area which the concentration of cadmium has not been measured, as well as for other areas with similar conditions.

Prediction of the spatial distribution of Festuca Ovina and Bromus briziformis in Siahbisheh Rangelands using artificial neural network was the purpose of this study. Random classification sampling was done for vegetation in 29 homogenous units. 290 plot 1 m² were established in the area and was recorded percent of canopy cover. 3 soil samples were collected from a depth of 0-30 in any homogenous unit. In this study, 20 Environmental factors (Slope, aspect, elevation, distance from road, distance from river, precipitation, distance from livestock, geology, percent of silt, clay, sand, moisture, carbon, organic matter, ph, EC and N. P. K) were independent variables and species presence data of Festuca Ovina and Bromus briziformis was dependent variable. The information layers of each these factors prepared in Arc GIS and were classified using the frequency of each these factors. The results showed that the most important environmental variables affecting the distribution of the studied species were elevation, soil texture and nutrients. Then 70 and 30 percent of the data were used for training and test network respectively. In this study, artificial neural network structure with the 20 neurons in the input layer and the hidden layer and one neuron in the output layer, values of MSE were calculated for festuca 0. 75 and Bromus 0. 72. Then zoning maps of plant species were prepared with 4 zones including absence and presence of low, medium, high. Zoning maps were evaluated using ROC curves and Kappa coefficient that accuracy with ROC curves were 97. 10, 84. 10 and with kappa coefficient were 0. 78, 0. 66 percent for Festuca ovina, and Bromus briziformis respectively that represents a good evaluation of model.

A human activities can affect river water quality are fish farming development projects. In this study, with design and construction of natural filters in the fish farms, the output water quality changes will be investigated. For this purpose, a series of columns (PVC tubes) with height of 70 cm was used to investigate changes in nitrate and phosphate. Any tube divided in half and in the middle of it was placed a geotextile layer. Then the variety of materials such as beet pulp, wheat bran and maize to a height of 10 cm was poured into pipes and water continuously for 4 hours from the column was passed. Then the inlet and outlet were taken samples at different times. The results showed nitrate absorbing in wheat bran and maize have become increasing-decreasing trends and sugar beet pulp absorption over time, as is decreasing. Also, the percentage of phosphate absorption in sugar beet has an increasing trend and in maize and wheat bran have increasing-decreasing trends in the duration of 4 hours. So, among the three agricultural materials, maximum of nitrate and phosphate absorptions in wheat bran is taken and Nitrate absorption is more than three other materials. Also, the results show significant differences between treatments in one percent probability level in terms of nitrate and phosphate output. On the other hand, with a significant interaction between treatments output over different periods can be understood that the plant material selected as the filters have a high potential to absorb nitrates and phosphates.

Cr (VI) is one of heavy metal that its presence in water and waste water, results in many problems for environment and organisms especially human health. Recently, because of its low cost, availability and abundant, use of mineral adsorbent were considered. The aim of present study was to evaluate Cr (VI) removal from aqueous solutions and investigation of influence of main parameters on removal using of some mineral adsorbent by using of Taguchi experimental design method. Taguchi experimental design method save time and cost of experiments. In this experimental study, Cr (VI) removal from aqueous solutions by 4 mineral absorbent i. e., perlite, expanded perlite, zeolite and acid modified zeolite were investigated. The effect of adsorbent dose, the concentration of Cr (VI), stirring time, pH and type of adsorbent on the adsorption process were examined using Taguchi experimental design in batch extraction mode. Design Expert (v. 8) and Microsoft Excel were used for experimental design and statistical analysis, respectively. Isotherm and kinetic analysis were performed. The results showed that the best adsorbent for Cr (VI) removal was expanded perlite. Optimal conditions for adsorption were Cr (VI) concentration 1ppm, expanded perlite dose 25g L-1, 1h shaking time and pH 2 with 100% extraction efficiency. Percent Parameters contribution most to least is as follows: pH, Cr (VI) concentration, adsorbent dose, shaking time and type of adsorbent. Expanded perlite, has the ability of Removal of Cr (VI) under the obtained conditions experimentally designed by Taguchi method.

One of the most important environmental problems of national and international concerns has become. So that inappropriate utilization of natural resources and land in Iran, to challenging security environment And now it requires a basic approach is improved. The approach taken in this paper is a sociological approach; This means that to improve the environmental situation in life should be to protect the environment and the people looked And through changes in environmental attitudes and actions of people moved toward environmental sustainability. Therefore, this paper seeks to explain the environmental attitudes of students through cultural bias them. To achieve these goals Inductive strategy and survey technique has been used. Using stratified random sampling 400 students of the three variables of sex, course of study and academic groups were selected. The findings show that students' environmental attitudes is desirable and satisfying And students who group their education more relevant environmental issues (Agricultural Sciences and Science) attitude towards the environment have been more appropriate. Promoting educational, environmental attitude makes them more desirable. In addition, Hypothesis testing confirmed the impact of cultural bias on environmental attitudes and multiple regression model revealed that 28% of environmental change in attitude by four cultural biases, fatalism, individualism, hierarchical and egalitarian explained and in the meantime, had the greatest impact egalitarian bias.

Rivers are considered one of the most important resources of providing fresh water. Restrictions faced by such resources underline the necessity of preserving their quality. Water quality indices are usually resorted to qualitatively monitor water resources. Any of such indices is calculated with regard to a series of specific qualitative parameters. The process of sampling and quantification of the aforementioned parameters are, however, time-consuming and costly. Finding a reliable method comprised of minimum qualitative parameters could be, therefore, of great help in classifying water quality. As an alternative to the common NSFQWI, the advantages of the Probabilistic Neural Network (PNN) as a classifier are used in the present study to classify water quality of Karun River. In order to fulfill this objective, the qualitative statistics of 172 samples were used in a way that qualitative parameters and water quality classes derived from NSFWQI are used respectively as the input and output of the model. The assessment criteria of error rate, error value, accuracy and Spearman’ s correlation coefficient were used to evaluate the performance of PNN model. The results showed that through making use of merely three parameters of turbidity, fecal coliform and total dissolved solids, PNN model is capable of classifying water quality with the accuracy of 94. 365% and 90. 7769% at two stages of training and test respectively which in turn indicates considerable accuracy of PNN in determining water quality classification.

The mobility of heavy metals plays an important role in soil and groundwater contamination. The aim of this study was to investigate the influence of leonardite on distribution of chemical forms of cadmium (Cd) in the compacted soil of Urmia landfill. For this purpose, soil samples were collected from the landfill and physico-chemical properties and clay mineralogy was determined. The rate of leonardite (0, 2. 5, 5, 7. 5 and 10 %) were added to soils and then treatment soils compacted in the columns. Cadmium solution (100 mg/l) poured to the soils and then soil samples collected from three depths of column (surface, middle and subsurface) after 72 days for determine chemical forms of Cd in soils. The studied soil contain 43. 9% clay and illite (49%), montmorillonite (21%) kaolinite (20. 5%) and chlorite 9. 5% were dominate clay in soil. Compaction reduced the infiltration rete and concentration of Cd in the middle and subsurface layers but application of leonardite increased the Cd concentration in supernatant more than 10 times compared to control. Also, geochemical forms of Cd (Fe-Mn oxides, exchangeable and carbonate forms) decreased in the surface layer (P<0. 001) of leonardite treatment but, resulted in increase 54% of Cd bonded to organic carbon. It was concluded that the use of leonardite to stabiles of heavy metals in compacted soil is not recommended.

The objective of the present study was arsenic removal from aqueous solutions by MCM-48 mesoporous silica functionalized by 3-Aminopropyl trimethoxysilane (APTMS) in batch system. This sorbent synthesized by sol-gel methods and its structural features were characterized by means of X-ray diffraction, nitrogen adsorption-desorption, thermogravimetric analysis, scanning electron microscopy, and Fourier transform infrared spectroscopy. The effects of different independent variables including pH, initial As (V) concentration, sorbent dosage, contact time and temperature in adsorption were studied. The obtained results revealed that MCM-48 particles size exhibited from 400 to 500 nm with spherical morphology having a pore size about 2. 44 nm, specific surface areas 1326 m2. g-1 and total pores volume were 1. 11 cm3. g-1. The results of the As(V) adsorption by NH2-MCM-48 revealed that the optimum values for pH, initial As(V) concentration and sorbent dosage were found to be 2, 50 mg. L-1 and 1 g. L-1, respectively. In addition, Thermodynamic study indicated the endothermic behavior and spontaneous nature of adsorption. The study of the kinetics also showed that data from the experiments fitted well to pseudo-second order equation. On the other hand, Langmuir model better fitted with the experimental data among the two adsorption isotherm models used.

Human activities cause to the accumulation of heavy metals in soil. Soil pollution will significantly reduce environmental quality and affect human health. This study aimed to determine the concentration of some heavy metals (Ni, Pb, Fe, Zn, Cr and Cd) and evaluate the effects of Kerman steel industry on concentration of soil heavy metals. A total of 60 samples from the surface soil and a depth of 0-15 cm were collected at different distances from Kerman steel complex and analyzed with Atomic Absorption Spectroscopy (AAS). Some indices of pollution including Contamination factor (Cf), Pollution index (PI), Pollution load index (PLI), Pollution Intensity index (Ipoll), Potential contamination index (Cp) were calculated to assess the levels of soil contamination. The Pearson correlation, principal component analysis (PCA), hierarchical clustering analysis (HCA) was used to determine the origin of pollutants. The results were showed the trend of heavy metal concentration in the study area as Fe>Zn>Pb>Ni>Cr>Cd respectively. The maximum of studied indices was related to Pb and then Zn. Pearson correlation was showed that Zn with Cd and Pb with Cr had significant positive correlation. A PCA results of Cf index was stay Zn and Pb in the first cluster. In the other words, these two elements are more human origin. This study showed that the study area does not need to severe remedial action; however, continuous monitoring of environment is essential.

Cadmium is one of the most important heavy metals in soil that it is important in terms of environmental and human health. The main purpose of this study was to evaluate the effect of Spirulina algae and incubation time on chemical forms of cadmium in a calcareous soil. The experiment was conducted in a factorial (2 × 3 × 3) arranged in a completely randomized design with three replications. Treatments consisted of three Spirulina levels (0, 500 and 1000 mg kg-1 soil), cadmium levels (5, 20 and 40 mg kg-1 soil as cadmium sulfate (CaSO4. 6H2O) and incubation times (1 and 2 months). Results showed that addition of 500 and 1000 mg Spirulina kg-1 soil in all of the cadmium levels in the first month decreased exchangeable fraction and increased the organic and carbonate fraction and cadmium that bound to iron and manganese oxides. Over the incubation time (in the second month), due to decomposition of algae, the organic fraction of cadmium decreased and soluble fraction of cadmium increased. In general, at first application of Spirulina decrease the bioavailability of metals and increase the organic and less soluble fraction of them, but over the time, it can increase the bioavailability of metal and therefore might be increase the uptake of Cd for plants. Therefore before application of Spirulina as an organic fertilizer, in cadmium polluted soils, it should be applied with caution. Further investigation using Spirulina at more incubation time and on a larger number of soils is recommended.

This study investigated physiological response of Caspian locust and River red gum affected by Cadmium sulphide nanoparticles. First we grew one-year old seedlings of two plants in similar conditions. The experiment designed was a randomized complete block with three replications and two concentrations of Cadmium Nano-sulphide (20 and 80 mg/lit) beside the control treatment was conducted in greenhouse. After 30 days sampling was done for plants and the amounts of proline, chlorophyll, soluble sugar, Mallon di-aldehyde and amount of Cadmium sulphide in roots and aboveground parts were measured. Analysis of variance was conducted to test differences and Duncan test for compare means. Results showed that more aggregation of nanoparticles was seen in roots than aboveground parts. Also absorption of nanoparticles in River red gum was more than Caspian locust. The results also showed that increasing the amount of nanoparticles affected the amounts of Mallon di-aldehyde. Amount of chlorophyll was decreased in River red gum while inversely was increased in Caspian locust. In general, the concentrations of cadmium sulfide nanoparticles was studied under this experimental conditions, have many negative effects on Caspian locust. Reducing the amount of sugar and proline in this species, is most likely due to the effect of nanoparticles on creating water stress. In fact, nanoparticles have been indirectly reduced the amount of sugar and proline. While River red gum increased production of sugar and proline to regulate osmotic level. However, plant protection and anti-oxidants may also be involved.

In order to studing the water quality of Pireghar river, Chaharmahal & Bakhtiari Province, that plays an important role in the main water supply for urban, rural, agriculture and aquaculture, water samples were collected from 5 stations along the river in February 2016 to measure physical and chemical parameters (pH, temperature, turbidity, oxygen biochemical demand, chemical oxygen demand, dissolved oxygen, conductivity, nitrate and phosphate, total suspended solids, total solids) and microbial parameters (total coliform, fecal and heterotrophic bacteria). Sampling methods and analysing was performed according to Standard Methods for the Examination of Water and Wastewater, American Public Health Association. According to the first European standard of the World Health Organization, the degree of bacterial contamination of the river, in comparison with the amount of total coliform was in the third group (ie pollution that be eliminated by costly methods) and in comparison with the amount of fecal coliform was in the first group. The results showed that water quality parameters of river according to the Aquatic standards, Environmental Protection Agency standard, the World Health Organization Institute of Standards and Industrial Research of Iran were in optimum state.

Linear alkyl benzene sulfonate is widely used in detergents. The annual amounts of the surfactant through irrigation with wastewater or the use of sewage sludge as organic fertilizer into the soil ecosystem and the continued use may result in adverse effects on health and quality of soil. To assess the risks of contamination of the soil ecosystem with surfactant there are several methods that one of these methods is pollution induced community tolerance (PICT). In this study the impact of different levels of surfactant lauryl benzene sulfonate (LBS) on microbial activity in soil were evaluated with PICT assessment. For this purpose, different levels of LBS include 0, 0. 025, 0. 05, 0. 1, 0. 5 and the 1% were added to the pots containing 2 kg of soil in 3 repeats and kept for 90 days at moisture of 65 to 75% of field capacity (equivalent to 10 kPa) and 25 ° C temperature. Dehydrogenase activity as a measure of microbial activity was measured in 3, 7, 15, 30, 60 and 90 days of incubation. The results were obtained after incubation with different levels of LBS and soil microbial population was gradually induced tolerance. Increased tolerance in soil microbial was started from day 60 and increased thereafter. In 60 and 90 days of incubation increasing PICT amount to 0. 05 percent was observed gradually, after that the tolerance increased strongly. In fact this concentration is a critical level for LBS.

Heavy metals, especially mercury due to its toxicity, persistence and the impact on aquatic organisms is important in terms of public health noteworthy. This study aimed to assess mercury concentrations in surface sediments of estuaries Mahshahr, Khuzestan province, eight stations were selected and three sediment samples were collected from each station. Sampling operations were conducted in January 2016. After laboratory analysis, the content of mercury using cold vapor atomic absorption technique was measured. The average concentration of mercury in sediments of stations studied in the range of 90-490 was nanogram per gram. High levels of mercury were found in petrochemical estuary and with increasing distance from this estuary, the pollution of the gradually decreased. In general, the calculation for regional factor pollution, pollution is too severe for most stations showed, while According to global factor pollution was low to moderate.

This study evaluates monthly and seasonal changes in carbon dioxide emission in five classes of soil erosion in Ghara aghaj basin in Isfahan province. Amounts of water erosion were calculated in working units, using EPM model. Afterward, carbon emission were measured on a monthly basis, for a period of one year using alkali traps in five classes of soil erosion including very low, low, moderate, high and very high. Data on emission levels and erosion classes were analyzed as a factorial experiment in a completely randomized design with four replications. The highest rate of emission occurred in July (3. 7 gC/m2/day) in very high eroded lands and the lowest in February (0. 022 gC/m2/day) in very low erosion rate. Moreover, the greatest amount of carbon emission happened in summer and lowest in winter. Generally, CO2 emission increased by increasing erosion intensity, so controlling erosion is recommended to reduce Carbon losses via detachment or emission.

Comparative study of Heavy metals accumulation (Cd, Pb, Hg, Cu) in liver, skin and muscle tissues and Fatty acids profile of Persian sturgeon was done in West and East Southern coasts of Caspian Sea. The results showed that the metals were in accptable ranges in fish muscle (P>0. 05); but metals concentration in lever was more than skin and muscle (P<0. 05). Amounts of Pb (2. 05 & 2. 21 µ g/g) were higher than acceptable range in the fish liver from both SE and SW areas. In skin and liver, Hg (0. 46 & 0. 47 µ g/g) was more than to muscle. Also heavy metals accumulation in fish caught from SW (Mazandaran province) were more than another. There was a different between muscle and other organs in the pattern of heavy metals accumulation. On the other hand, sum of unsaturated fatty acids (UFA) in SW and SE Persian sturgeon were 85. 54 and 77. 48 g/100g, respectively (P<0. 05). Moreover sum of Omega-3 had a level of 14. 17 and 7. 35 g/100g, respectively (P<0. 05). Also there was a correlation between fish lipid and heavy metals concentration in different organs. These correlations were positive in liver, skin and muscle tissues; conversely, ther was no any relations between omega-3 fatty acids fillets and accumulation of heavy metals. The Pb in the measured metals was more than standard level in fish liver which caugth from SE area. According to the results edible muscle tissue of Persian sturgeon in the southern coasts of the Caspian Sea is healthy.