Journal of Natural Environment
Year:2016 | Volume:69 | Issue:3|Papers Count:22

In this study, Mehran and Dehloran groundwater chemical variables were studied using geostatistical methods (kriging and co-kriging). Sodium, chloride, sulfate, TDS and TH of 29 water wells, were chemical analyzed from 2001 to 2014. The method of co-kriging and kriging interpolation was done using Arc GIS 10 software. Lower RMSE and strong spatial structure were used to select the appropriate model to fit the experimental variogram. The results of RMSE and MAE showed that the co-kriging is better than the kriging method. This is due to a low RMSE and MAE in co-kriging method indicates the high precision and lower error, and the results show that water quality data in this area are the strong correlation and their spatial structure follow spherical and exponential models. Finally, zoning map of the study area were obtained using co-kriging method, fuzzy logic and Sholer classification. According to the final map, 32, 18 and 50% of the area are suitable for drinking, relatively good and inappropriate, respectively. The results showed that water quality in the study area is not desirable for drinking. Areas with high concentrations of the warning threshold are located next to each other and in inappropriate zoning map class with overlay zoning map and the map of Hot spot analysis.

The existence too much nitrogen compounds in water is one of the threatening factors of aquatic life and humans. Thus understanding and controlling the effecting variable on sources of nitrogen entering the water is crucial. Investigate of important variable symptom variety is impossible by sampling. Its can detect effective variable by using of mathematical technique and innovation computer approach simulation and neglected the variables that has little effect in practically that finance source consume for control in a count of optimize variable. Several models have been developed to estimate this phenomenon. In this article used of INCA-N to sensitivity analysis and variable reduce. INCA-N has different variable input thus detection of affectless variable of INCA-N is important. Variance based method doing well detecting of important variable and interaction between and sassing main sensitivity index of output model respected these variables. In this paper, further introduce variance based approach and estimation of sensitivity index with random balance design also defray to sensitivity analysis and reduce variables of INCA-N model in the tweed river. The results of sensitivity analysis in 500, 1000 and 2000 sample size and investigated uncertainty of result did by 50 repeating in samples. The result showed that four of seven variables (nitrate uptake rate by plants, de nitrification rates, immobilization and mineralization) of INCA-N are important. Three variable nitrogen fixation, ammonium planet uptake and maximum nitrogen uptake is no important. These four necessary variables corresponding with main effect (0.456, 0.207, 0.204 and 0.09. Also Interaction between this variable are so weak (maximum=0.036) that can surrender of them. Thus random balance design sensitivity analysis method has good efficiency in reduction of variable these phenomena.

Plant-based remediation (i.e. phytoremediation) is one of the most significant eco-sustainable techniques to cope with devastating consequences of pollutants. In the present study, the potential of a wetland macrophyt (i.e. Nelumbo nucifera) for the phytoremediation of heavy metals (i.e. Cu, Cr, Pb, As and Cd) in the Anzali wetland was evaluated. The results showed that N.nucifera tends to accumulate notable amounts of Cu, Cr, Pb, As and Cd according to their assayed concentrations as follows: 0.31mg g-1 dw, 3.07 mg g-1 dw, 0.91 mg g-1 dw1.2 mg g-1 dw and 14.32 mg g-1 dw, respectively. Further accurate perception of the phytoremediation efficiency were conducted using both bio concentration factor and translocation factor. The average of the highest bio concentration factors was presented in a descending order as: 1.83´103, 1.17´103, 1.17´103, 0.46´103 and 0.29´103 for the Cu, Cr, Pb, Cd and As, respectively. Based on the results, N.nucifera presents high potential to absorb all the alluded metals except for As and Cd. Eventually, relying on the observed findings, the results support the idea that N.nucifera species would be employed as the prospective candidate for the phytoremediation process in Anzali wetland.

Extensive loss in water table and successive decline of Lake Urmia, has induced some problems and worries in national and international levels. This has raised necessity of the application of new approaches in management practices to improve water consumption patterns in Lake Urmia area. Among existing and efficient economic policy instruments to protect natural resources, the Payment for Ecosystem Services mechanism (PES) has recently attracted attention in different countries with remarkable implications.In the present study, an effort was made to assess technical and economic aspects of the PES in terms of direct payment to hinder the farmers from crop cultivation in their owned lands. This can lead to a better clarification of socio-economic needs in applying new management practices for water resources in Simineh Rud sub-basin emphasizing water consumption reduction in agricultural sector which will increase more water release for the Lake.The results of this study showed that 55.53 percent of inhabitant farmers are agree with such an idea and it is acceptable to local community members.Also, from economic point of view, the benefit-cost ratio has been calculated as 1.7 for implanting this policy in the sub-basin. Therefore, it can be argued that direct payment to farmers to hinder them from crop cultivation is economically feasible and efficient.

During the recent years, production of biological polymers has been considered as a tool for absorbing heavy metals. This is because of their non-toxicity properties and accessibility in the environment as well as their low price. Chitosan biological polymer has showed an extraordinary capability in coagulation and flocculation of suspended and colloidal particles, absorption of dissolved grease and oil and heavy metals. In this study, removing heavy metals (Al, Cd, Co, Cu, Fe and Pb) ions from aqueous solutions using chitosan– clay nano composites was investigated. After the addition of the absorbent into the reaction environment, parameters including absorption percentage of heavy metals (Al, Cd, Co, Cu, Fe, Pb) by chitosan-clay absorbent in acidities, contact time and the amount of absorbent matter were investigated. According to the results, by increasing pH of the solution, the adsorption of the metal ions was increased and the maximum adsorption occurred in pH 5 to 6. Absorption percentage had proportion with contact time: by increasing contact time, absorption percentage increased and reached equilibrium state after 3 hours. Also absorption percentage had proportion with the amount of the absorbent. By increasing the absorbent amount into the solution, metal absorption percentage was increased. So it can concluded that chitosan-clay nano composites has a good ability in removing heavy metals (Al, Cd, Co, Cu, Fe, Pb) from solution.

Heavy metals are discharged into the marine environment through natural process and anthropogenic activities. They can remain in solution or in suspension in the water column, precipitate to the bottom, or be taken up by various marine organisms. Thus, metals can accumulate to toxic concentrations causing ecological damage, and subsequently be transferred to humans and terrestrial animals through the food and feed chains. Therefore this study was conducted for evaluation of Cd, Cr and Ni concentrations in macro benthos communities of Khor Musa and correlation with metals accumulation in sediments in 2012. For sediments sampling, cores of 40 cm length were collected with the help of a PVC tube by gently intruding it into the sediment and protruding it out, capping, and freezing it upon return to the laboratory.After digesting the sediments with Aqua Regia solution 3.1 (v/v) HCl/HNO3 in microwave device and identifying the macro benthos species, concentrations of heavy metals sediments and macro benthos samples were measured using ICP-AES. All statistical analyses were performed using the SPSS 18.0 statistical package. The results showed that maximum mean concentrations of Cd, Cr and Ni in sediment samples were 0.17±0.10, 46.50±2.0 and 41.43±2.0 ppm respectively, and maximum mean concentrations of these elements in macro benthos samples were 0.21±010, 64.10±1.0 and 41.40±1.0 ppm respectively belonged to Bivalvia. Also the mean concentrations of metals were significantly lower than permissible limits recommended by WHO (P<0.05). Although currently the sediments of study area aren' t polluted with heavy metals, but the establishment of the petroleum industries, the oil spill from drilling rigs and tankers discharging ballast water can cause a threat to sediments pollution and consequently aquatic animals of this area.

Nowadays, there is a growing interest in the issue of ecosystem services and the impact of human activities on them. Unfortunately, in many cases humans have followed economic development without paying due attention to ecosystem services. Hence, many negative changes in ecosystem services have been brought about by inappropriate land-use change and management practices. Parallel with these negative trends, quantifying and mapping ecosystem services and incorporating them into the land-use optimization process has also witnessed a lot of development. As such, ecosystem services have opened their way into the land-use planning and management process. This study attempts to examine how land-use allocation using linear programming can be enhanced with respect to soil erosion potential and water supply as two quintessential ecosystem services. The case study is located in a small part of Gorgan township. Land-use categories have been considered as different ecosystems with different capabilities for water supply and soil erosion control. The objective function used for the linear programming was based on soil erosion potential and water supply in each parcel of land. To implement the study, the land-use management support system (LUMASS) was used. The process was done in two scenarios to minimize the amount of soil erosion in comparison with the current situation. The aim of the first scenario of land-use allocation was a decrease of more than 50% in the amount of soil erosion without limiting the area of land-use categories. For the second scenario, we attempted to allocate land-use with the aim of keeping the area of agriculture as close as possible to its current coverage. Our results show that the amount of soil erosion in the first and the second scenario have respectively decreased by 61% and 10% in comparison with the non-optimized situation. However, the best configuration of the land-use depends on the management goals. In this context the primary concern is that which land-use categories must be kept, decreased or increased within the area to gain more overall benefit. Evidently, the desired decrease in soil erosion or appropriate changes in other criteria affect the results of land-use allocation.

Atmospheric dusts have nutrients elements such as iron and aluminum, which they have an impacts on primary production in the sea. In this study, ten years of AOT and chlorophylla data was used to investigate relationship between them in the Persian Gulf. Investigation of monthly aerosol optical thickness and chlorophyll concentration from 2004 to 2013 showed that there is high correlation between them. So that, with increasing of optical thickness, chlorophyll concentration increase and with decreasing of optical thickness, chlorophyll concentration decrease. Results showed that in spring and summer with high level of dust concentration, dust has significant effect on primary production but in winter with low level of dust concentration, dust has not significant effect on primary production. High frequency of dust events may reduce sea surface radiation intensity, chlorophyll concentration and primary production which they are directly related to the light and radiation intensity. But if the increasing of dust concentration is associated with increasing of nutrient elements and no significant reduction of radiation intensity, the concentration of Chla and primary production will increase. There is a time delay of a few days between AOT and Chla peaks, which is due to the time required for iron deposition, dissolution and assimilation. This study shows significant relationship between aerosol optical thickness and chlorophyll concentration in the Persian Gulf using satellite remote sensing data.

Carbon storage is a strategy that helps to reduce atmospheric carbon and reform of climate change consequences. In the present study, the carbon sequestration potential of the pharmaceutical industry _ Jashirmountain pastures Khalyfan Mahabad region, was studied. The study area Jashir site, four transects 100 m along each transect 5 randomly spaced 20 m plots, were carried out systematically. Jashir biomasses in all plots were measured by Cutting and weighing method. At the beginning and end of each transect, profiles in both 0-15 and 15-30 were drilled. Samples were sent to the laboratory and carbon storage rates for each of them were determined. The results indicate that in soil Jashir of Second depth, there is a greater proportion of carbon storage. Significant at the 5% level, there is a meaningful gap between air and ground carbon storage in biomass is observed. The contribution of carbon storage industries - pharmaceutical Jashir it is more than biomass.

This study aimed to isolate and identify the species Ochrobactrum anthropi and Pseudomonas putida as indicators for measuring lead absorption and degradation of anthracene in laboratory conditions. The results showed that the mentioned species could grow well in 50 mg/l of lead and 30 mg/l of anthracene. The maximum growth at concentrations of 50 mg/l of lead and 30 mg/l of anthracene was measured 1.39 and 0.530, respectively. The results of the study of the ability of lead uptake by O. anthropi at a concentration of 50 mg/l and anthracene removal by P. putida at a concentration of 30 mg/l indicated that the mentioned bacteria started absorbing lead and anthracene at the time of inoculation and quickly reduced their concentrations in the solution. Removal of lead and anthracene by Ochrobactrum anthropi and Pseudomonas putida from the metal and hydrocarbon solutions continued actively till the final moments of measurement and at the end of the experiment, 84% of lead and 77.986% of anthracene were removed.

Oil contaminated soils usually harbor bacterial species capable of degrading aromatic compounds. Polycyclic aromatic hydrocarbons (PAHs) such as anthracene, naphthalene, phenanthrene, are the most toxic and carcinogenic pollutants which cause severe damages to the environment and living organisms. These compounds are mainly discharged to the soil by petrochemical industries. Biological methods by using efficient microorganisms isolated from oil contaminated soils are preferred for removing these materials from soils. The microorganisms use hydrocarbons as sources of carbon and energy to produce water, CO2, biomass and harmless materials. In this study, soil samples were taken from different oil-pollute regions of the Tabriz Petroleum Refinery, Petrochemical Industry, gasoline service stations and cargarages. The soil suspensions were cultured in selective media and 100 isolates were obtained. Phenanthren, anthracene and naphthalene at a rate of 1000 mg/L were added to the Muller Hilton broth medium and then a fixed amounts of these bacteria were added, separately. They were incubated in shaker-incubator with 130 rpm at 28˚C for one week. The rate of PAHs destruction was evaluated by spectrophotometery method. Many bacterial isolates possessing different PAHs destroying rates were obtained. Among the isolates, %51, %47and %41 of them were capable of destruction (up to %30) of naphthalene, anthracene and phenanthrene, respectively. By improving the growth conditions and proliferation of effective bacteria it can be possible to remediate PAHs- polluted soils in oil contaminated regions.

In this research, the effect of titanium dioxide nanoparticles on 6 samples of freshwater algae specimens was studied. The experimental algae were recognized after purification by molecular methods and put under the effect of nano-titanium dioxide densities of 0.001, 0.01, 0.1 and 1 mgL-1. The results indicated that nano titanium dioxide has inhibitory effect on the growth of Chlamydomonas moewusii, Chlamydomonas sp., Chlorococcum oleofaciens (strain 1), Chlorococcum oleofaciens (strain 2) and Scenedesmus obliquus, whilst their lipid peroxidation was increased after at least 48 h exposure. In contrast, chlorophyll a of Chlorococcum oleofaciens (strain 3) was increased after 96 hours exposure with nano titanium dioxide, while its lipid peroxidation decreased. Finding of the present research indicated that different species could differently respond to nano titanium dioxide exposure that may result in changing of species dominance of water resources.

The crustacean Gammarus sp. lives in sediment at coastal zones having an important role on food chains. It also transfers energy to higher trophic levels i.e. fishes and birds. The littoral zone of the Caspian Sea receives many pollutants from the sea and the land. Cadmium can be found naturally in low concentrations in the environment but human intervention, anthropological discharge connected to the urban and industrial activities raise the concentration of heavy metals in costal sediment and aquatic ecosystems. In the present study, Gammarus sp. was selected as a test organism because it is the abundant in southern coast of the Caspian Sea. This crustacean absorbs metals from food or water. The concentration of cadmium in the present experiment was lower than LC50. Samples were collected from the submerged mesocosm different times, i.e.0 (control), 30, 60, 90, 150, 210 and 270 minutes. After preparing the sediment and Gammarus samples, cadmium concentration were determined using an ICP-OES. Significant differences (using ANOVA) were observed among exposure times. A t-test indicated that there was a significant difference between Gammarus and sediment in cadmium uptake. In conclusion, the present study indicated that cadmium absorption by Gammarus and sediment was a function of the exposure time and accumulation of this metal, increases over time.

In order to reach sound herbivore management, understanding of vegetation associations with herbivores, specifically where the populations of the species of interest are depleting is crucial. Hence, in this investigation, effort was made aiming to determine the current habitat status of roe deer species (Capreolus capreolus) for conservation purposes. During 2012 and 2013 in three distinct seasons, presence and absence of roe deer sign data were recorded on random transect lines. Moreover, vegetation parameters including: density, canopy cover of oak trees, Importance Value, diameter breast height (DBH) of the oak trees, and the edible plant species in Bozin and Markheil Protected Area were measured. Vegetation analysis was carried out using T-Square and plot sampling techniques. Data was modeled by performing Generalized Linear Model (GLM) approach and the best candidate model was chosen based on the least value of the Akaike Information Criterion (AIC). Additionally, a chi-square equivalent assumption was tested to compare the differentiation rates of roe deer presence between the seasons. From the generated models, the presence of roe deer demonstrated a strong correlation with canopy cover and DBH, but no significant correlation appeared for the other factors. At the same time, 27 edible plant species were identified using pellet group analysis. Finally, the density of oak trees and the composition of understory scrubs may potentially influence the population dynamic of roe deer in the area. Further the community based research survey and conservation measures need to be accomplished for enhancing the viability of this overlooked species.

The contamination of surface and ground waters by nitrogen and phosphorus is a major factor affecting estuarine eutrophication and drinking water supplies in many countries. Considering agriculture, Non-point source (NPS) pollution from croplands has reduced water quality in rivers and lakes around the world. So this study was aimed to introduce buffer zones as an effective way that reduces water pollution and also investigating their structure and function in nitrogen and phosphorus removal as an agricultural pollutant. Unfortunately, studies on buffer zones are very limited in our country. Due to the importance of Zayandehrud as a main river of the country on which the life of Isfahan city is dependent, Zayandehrud and agricultural land around this river were selected as the study area. At first, Zayandehrud margins were identified by Google earth software for the buffer zones associated with agricultural land which mostly consisted of paddy fields and had nitrogen and phosphorus pollutions. Then, structure and function of buffer zones were investigated through field studies. Measurement of perimeter, area, length, latitude and longitude and typology of Buffer zone spots are important structural characterizes that play a key role on buffer zones function and they have been studied in this research. After that, samples were taken in parallel transects at the beginning, middle and at the end of the field at the depth of 30 cm and then nitrogen and phosphorus pollution was determined in laboratory. Results have shown that buffer zone is such an effective approach in nitrogen and phosphorus removal that their amounts reduced from the beginning of field to the end of the buffer zone.

Recent environmental crisis and drying lake Urmia, now is considered as one of the biggest geological hazards in Iran. In this research, remote sensing study for a period of 35 years, 55-year climatic data processing and their relationship with lake water fluctuations were implemented, hydro geochemical monitored for 6 years and undisturbed sedimentary cores of western lake sediments were prepared by Auger coring method.23 cores having a maximum depth of 9 meters and totally 140 m of the lake sub floor sediments were verified. According to the results of the coring, the main part of the lake atleast 13, 000 years ago had been lake environment and are visible continuous lacustrine sedimentation. Anthropogenic (human) factors is important factors in decrease of Urmia lake water level that including the irregular development agriculture, the use of ground water and dams construction and construction of Shahid Kalantari causeway. Therefore, climate change and increase evaporation, especially in recent years, is considered a factor in reducing the water level, but it is not the main reason in drying of the Urmia lake. On the other hand, process brine evolution has expired in the Urmia lake and amount of brines magnesium has been more than sodium. In these conditions, with huge increase in evaporation rate, lake has become to playa or salt pan (high thickness of salt in the lake bed is more than 6 meter) and is in verge of annihilation. Entry fresh water as sectional and not once into it, with out help to save it, is cause of destruction sources of water. Thus limiting the lake, extracting of economical salt from its brine and salts reduction part of the salt lake, before dewatering is the most appropriate lake reclamation solution. The northern part of the lake due to the inherent depth, appropriate for restoration in first phase and southern part appropriate for extraction salt and economic minerals.

In recent years, a major contribution of the nitrogen needed for agricultural production was supplied from urea chemical fertilizer in Iran; this issue would lead to the serious environmental impacts. The aim of this study was to investigate the environmental impacts of the use of this important agricultural input through Life Cycle Assessment (LCA) methodology during 2007-2012. LCA in four sections including "the goal and scope definition”, “inventory analysis (inputs and outputs of the system) ”, “impact assessment, and interpretation of the impacts were calculated. Investigation was performed on three impact categories such as global warming, acidification and eutrophication for terrestrial ecosystems. The obtained data analysis showed that approximately of 1.5%, 8.6% and 42.8% of the environmental consequences of impact categories including global warming, acidification and eutrophication for terrestrial ecosystems in Iran were related to the this input consumption, respectively. The amounts of weighted indices during the period for these impact categories were calculated 1160785, 11330566 and 25384073, respectively. Urea fertilizer consumption had the highest environmental hazards in terms of eutrophication for terrestrial ecosystems impact category. Therefore, management of the urea fertilizer consumption to minimize its environmental impacts and its replacement by non-chemical nitrogen resources is vital in agriculture sector of Iran.

In recent decades, brown trout populations have been declining due to river regulation and its impact on river morphology along Lar River downstream of Lar Dam located near Tehran. Currently, due to water scarcity in the country, intensity of water regulation impacts on aquatic population of streams and specific ecologic values in tributaries of Lar River, it is necessary to present a habitat assessment model to predict ecologic response of the river to natural and man-induced changes by which can be applied to strategic management of the river. Hence, in this research, an analytically applied approach is adopted to assess brown trout population by creating relation among hydrologic, hydraulic, morphologic and ecologic processes. After field work and required measurements, Shields function was applied to derive dimensionless shear stress for minimum environmental flow, bankfull discharge and critical discharge for initiation of sediment transport for Lar, Dalichai and Sefid-Ab rivers. Then, dimensionless shear stress for initiation of the bed sediments was used to investigate effects of discharge variation on frequency and distribution of aquatic life in response to morphologic changes. It was found that when water discharge is in the range of discharge corresponding to environmental flow threshold and critical discharge for sediment motion, it is identified functional discharge for bed occupation while water discharge greater than critical discharge for sediment motion is also considered functional discharge for bed preparation. Results obtained from this research, suggest that water discharge, cross-sectional geometry and bed material size could be effective on ecologic functions and life cycle of brown trout fish and inappropriate river regulation may lead to gradual elimination of that from river ecosystem.