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Background and Objectives: As a green fuel and environmentally friendly energy, biodiesel has recently attracted much attention and efforts are ongoing to optimizing biodiesel production from microalgae’s. The aim of this study was to determine the appropriate method of dewatering and drying biomass and selecting a suitable organic solvent for extraction lipids from biomass. Materials and Methods: After culturing Nannochloropsis Oculata in Gillard F/2 medium and reaching at the end of the stationary growth phase, algal biomass was separated from aqueous by centrifuge and drying in three methods: fore, air-dried and lyophilized. Lipid extractions of each sample was performed using soxhlet apparatus and three solvents including diethyl ether, n-hexane and n-pentane. At each stage, the quantity and quality of the extracted lipids was determined by gas chromatography. Results: In all three drying methods, palmitic acid and palmitoleic acid were significantly the main fatty acid composition of microalgae. The fatty acid composition of palmitic acid extracted by diethyl ether was significantly more than the other two solvents. Maximum production of triglyceride was observed in air dried and lyophilized (using diethyl ether solvent) microalgae as 75.03 and 76.72 % of fatty acid respectively. Conclusion: The use of lyophilized method for dewatering and drying of biomass and diethyl ether as solvent for the extraction of lipids from biomass yielded more compared with other methods studied in this paper and would be more efficient in research works related to the production of biodiesel from microalgae’s lipid.

This study was carried out to evaluate the effects of drought stress on 12 genotypes of vetch (Vicia dasycarpa) at the experimental field of Agriculture and Natural Resources Center of East Azarbaijan Province during 2003. Field trial was conducted as a spilt plot design based on randomized complete blocks with three replications. Drought treatments (normal, medium and severe stress conditions) were included in main plots and the genotypes were allocated in subplots. During the growing season, plant height, pod length, pod width, number of grains per pod, 1000 grain weight, number of pods per plant, number of grains per plant, number of axillary branches, harvest index, biomass and grain yield were measured. Drought stress effected all traits (except number of grains per pod) significantly. Greatest amount of reduction in value due to water stress belonged to grain yield and biomass. Number of pods per plant and number of grains per plant were affected by drought more than other yield components. However, the adverse effect of water stress was not similar for all genotypes and there were significant genotype by environment interaction for important characters such as biomass, grain yield, number of pods per plant, number of grains per plant and plant height. Evaluation of the genotypes based on drought tolerance indices (STI and TOL) indicated that under medium water stress environment the genotypes 9 (from Italy) and 7 (from Turkey) showed better drought tolerance performance in terms of grain yield. Regarding biomass, the genotypes 3 (from Italy) and 6 (from Australia) were recognized as the most appropriate genotypes for hoth medium and severe drought stress conditions.

Introduction: Identification of degrading microorganisms of toxic materials is regarded as an important step to complete air treatment systems. Effective microorganisms in treatment and elimination of pollutants seems to be different depending on the type of pollutants as well as environmental conditions. Identification of these microorganisms can determine optimum conditions for the system performance and the maximum efficiency can be reached. Moreover, biotechnological methods can strengthen the microorganisms to treat the pollutants. This study aimed to identify the predominant microorganisms at two biotrickiling filters that formaldehyde was used in one and ethanol in another as the sole carbon source. Methods: In this study, two biotrickling filter pilots were made at the laboratory scale. These microorganisms were inoculated and adapted within three months. Then biotrickling filters were studies for a long time. At the end of experiments, biofilm samples were taken from biotrickling filters and predominant microorganisms were identified via microbiology studies. Results: The results of the present study managed to identify such microorganisms as Salmonella Bongori, Pneumonia, Subspecies Pneumonia, Klebsiella Terrigena, etc. at different parts of both biotrickling filters. Conclusion: Microbial species can be widely changed with operating of biotrickling filters at different conditions. Identifying active microorganisms in each biotrickling filter can lead to detecting optimum conditions as well as the risks caused by transfer of the filters' available microorganisms to the human body .

Iran is located in the dry belt of the earth and is predicted to face water stress in the next half-century. Currently, the area of sugarcane cultivation in Khuzestan is over 85,000 hectares and due to the high water needs of sugarcane and drought conditions, optimization of water consumption and irrigation management is necessary to continue production. Therefore, in this study, the values of soil moisture, canopy cover, biomass yield in five treatments and irrigation levels (start of irrigation at 40%, 50%, 60%, 70%, and 80% soil moisture discharge) during 2 planting dates in the crop year 2015-2016 on sugarcane cultivar CP69-1062 in Amirkabir sugarcane cultivation and industry located in the south of Khuzestan was simulated by AquaCrop model. The measured data on the first culture date (D1) and the second culture date (D2) were used to calibrate and validate the model. The results of NRMSE statistics in canopy cover simulation in calibration and validation sets with values of 2.1 to 15.6% and 3.8 to 18.3%, respectively, and in biomass simulation with values of 6.2 to 15.2%, and 9.5 to 12.6%, respectively and coefficient of determination (R2), range 0.98 to 0.99 indicated that the high ability of the AquaCrop model in simulation canopy cover and biomass yield. whereas, the values of NRMSE of soil depth moisture in the calibration and validation sets ranged from 11.6 to 23.8, and 12.2 to 22.7, respectively, with a coefficient of determination (R2), 0.73 to 0.96 (calibration) 0.8 to 0.93 (validation) showed less accuracy of the model in the simulation. The best scenario is related to the third proposal that water consumption, water use efficiency, and yield are 1710 mm, 1.53, and 42.27 tons per hectare, respectively, which shows a reduction in water consumption of 360 mm.

Climate change, in addition to increasing temperature, causes changes in the duration, intensity, form, and timing of rainfall in different parts of the Earth, which can cause droughts and floods. It also changes the volume, duration, and runoff duration, which will bring about many developments and changes in the water-resource management (Kamal and Massah Bavani, 2009). In order to reduce inconsistencies, studying the impacts of climate change on water resources is necessary. One of the most widely used models for these future studies is Atmosphere-ocean General Circulation Models (AOGCMs) (Wilby and Harris, 2006). In general, most studies present a high degree of uncertainty as a result of using AOGCMs in the simulation of climate change and hydrology parameters. the outputs of simulated water-resource models under climate change could be relied on when the uncertainties are taken into account at all stages (Semenov and Stratonovitch, 2010). In order to innovate the research method, in this study 10 AOGCMs under three greenhouse gas emission scenarios (A1B, A2, and B1) were used in the simulated range of hydro-climatic variables through climatic models and downscaling methods in the Dez Oliya basin during 2040-2069. In Summary, when reviewing the range of hydro-climatic variable changes in the future period, it could be observed that the uncertainty of AOGCMs under all three emission scenarios is greater than the downscaling methods.

Climate change is a serious challenge to human interest by its adverse effect on various sectors, such as water sources, agriculture, and energy. According to IPCC report, the average annual temperature of the earth has been raised between 0.3 to 0.6º because of the spread of the greenhouse gases, and this report predicts this amount will increase between 1 to 3.5º until 2100(Boberg et al ,2010). To study the effect of greenhouse gases in the atmosphere and the oceanic-atmospheric, general circulation model in regional scale is the most efficient vehicle. These models have been developed to simulate the current climate. They also performed well in predicting future changes in the climate and simulating interactions of soil, atmosphere, and oceans (IPCC, 2007). The effect of climate change on water sources is assessed using rainfall-runoff models by simulating hydrological processes. Studying future climate change and its likely events will help planners and water sources administrators to cope with the future challenge. Considering these likely changes will contribute to objective planning toward optional operations. Predicting future runoff value is one of the most important factors about dam construction, water transferring, agricultural growth and industrial activities.  Semenov (2008) assessed LARS-WG performance by data from 20 representative stations. Babaeian et al, (2004) and Khaliliaqdam, et al( 2013), studied the effect of climate change on the hydroelectric reservoir of Jor Dam by the microclimate model LARS-WG and scenarios B1, B2, and A1B. Output results of the model showed that Tmin and Tmax will increase to the amount of o.3-0.6 degrees. As a result, available water reservoirs of behind the dams for hydroelectric generation are affected by the decreased rainfall. BaniHabib et al, (2016), simulated the input flow of Shahcheraghi Dam using the generator LARS-WG, data downscaling, and the function of artificial neural networks on output of LARS. They found that nightly and daily temperatures rise 1.1 and 1.2 degrees from 2015 to 2040, and rainfall will decrease by 9% during January. By simulating artificial neural networks, it was determined that the input flow will experience 2.4-4.1 % decrease based on different scenarios.

Along with the numerous developments and facilities for constructing large dams, there is a need for developing design and construction methods for systems that can correctly discharge the floods. Weirs refer to any barrier across a channel that raises the flow level and accelerates the flow when flowing over it (Abrishami and Hoseini, 2011). Piano key weirs are the newest type of long-crest weirs and one of the best solutions for modifying the existing weirs. Reducing the energy of the flow over the weirs before their transfer downstream is a solution for preventing possible damage to the structure itself and downstream structures as well as the excess costs incurred by the builders of hydraulic structures due to constructing strong protective structures (Katourani, 2012). Lempèrière and Ouamane (2003) described the piano key weirs and stated their advantages compared to other conventional nonlinear weirs as the ability to place the weir in the crest of the reservoir dam and thus increasing the specific flow rate. Erpicum and Machieles (2011) compared the energy dissipation between two different geometries for a piano key weir and a spillway weir. Concerning the application of a block, the tests and results obtained by the US Land Renewal Organization indicate that using large blocks that separate the flow jet and create turbulence can effectively dissipate the kinetic energy of the current.

Introduction and purpose: Energy consumption is on a rapidly growing trend in the world. Accordingly, the non-renewable energy sources are expected to be run out in the future. This issue has resulted in the establishment of efforts targeted toward the development of new energy-generating methods around the world. Biogas energy is one of the new and clean energies that is produced from the anaerobic digestion of biomass wastes. Anaerobic digestion is a cost-effective and environment-friendly method, which facilitates fertilizer and biogas production as well as landfill leachate treatment. Given the high environmental hazards of leachate and its mixture with animal wastes, the present study aimed to estimate the possibility of producing biogas in various mixture ratios. Methods: In this pilot-scale experimental study, the landfill leachate of Mashhad, Iran, were mixed with caw fresh dung in different ratios, but same conditions, under anaerobic digestion. This was conducted to consider the ability to produce methane gas in different proportions and landfill leachate. At the beginning and end of the project, the parameters of EC, pH, VS, TS, COD, TOC, P, K, N, and Na were measured. Additionally, the composition of the gases produced under different operating conditions was analyzed using gas chromatography mass spectrometry. Results: Gas production began three weeks after uploading and continued for five weeks. The analysis of gas production in three ratios was indicative of the CH4 production in all three proportions. In this regard, 1/1 ratio produced the highest percentage of CH4. No gas production was observed in the two months of study. Other physical and chemical parameters, such as COD, TS, TKN, and TOC were reduced in the given mixtures during the biogas production procedure. For instance, the case with 1/1 ratio, which showed the best results, had almost 80% decrease in the given parameters. However, no gas production or change of parameters were observed in the control sample (leachate), which was examined for two months. Conclusion: The findings of the study revealed the possibility of producing biogas out of the mixture of waste leachate and animal wastes. Biogas reduces the risk of waste leachate disposal to the environment and facilitates the production of fertilizers containing nutrients (e.g., Na, K, N, and P), which are standard regarding such parameter as pH, EC, C/N, and reduced VS. Moreover, these gases are cost-effective and environment-friendly.

In the present study, CanESM2 climate change model and stormwater management model (SWMM) were employed to investigate the climate change effects on the quantity and quality of urban runoff in a part of Karaj watershed, Alborz Province. The base period (1985-2005) and future period (2020-2040) are considered for this purpose. Based on the existing main and lateral drainage system and to be more accurate, the watershed was divided into 37 sub-watersheds by ArcGIS software. To simulate rainfall-runoff, the intensity-duration-frequency (IDF) curve has been prepared for a 2-hour duration and 10-year return period, for the base period and RCP2.6 and RCP8.5 climate change scenarios based on the obtained precipitation data from Karaj synoptic station. Results showed that mean 24-hour precipitation values in RCP2.6 and RCP8.5 scenarios will increase by 21% and 11%, respectively, and maximum 24-hour precipitation values will decrease by 17% and 23%, respectively, as compared to the observed values in the base period. Also, based on the results of quantitative and qualitative runoff modeling in the study watershed, and according to the outflow hydrograph in the RCP2.6 and RCP8.5 scenarios, the outlet runoff discharge will decrease by 5.8% and 7.1%, respectively. Also, the flooded areas in the watershed will decrease by 13% and 15.28%, respectively. The concentration of pollutants in the RCP2.6 and RCP8.5 scenarios, compared to the base period, including total suspended solids (TSS), will increase by 7.48% and 9.24%, total nitrogen (TN) will increase by 6.93% and 8.48%, and lead (Pb) will increase by 7.32% and 8.91%, respectively.

Iran is located in the North Temperate Zone from 25 to 40 degrees latitude and 44 to 63 degrees longitude, with a total area of approximately 1,650,000 Km2. A 50% of total lands area is covered with high mountain ranges. Elevations range from 26 meters below sea level on the shores of the Caspian Sea to 5860 meters above sea level at the pick of the Mt. Damavand. Drought or water deficiency is one of the most critical climatic factors in Iran. About 50% of Iran can be classified as arid or semi-arid zones. Climate parameters, particularly precipitation varies significantly in different parts of the country. There is not a good annual rainfall distribution in most regions of Iran, which limits the plant development and growth. Not only high temperature in southern, central and lowlands of Iran is a limiting factor, but also low temperature in northern, western and highlands is another limiting factor too. The Caspian region receives the largest part of the country’s precipitation while the central desert (Dasht-e-Lut) is faced with permanent drought. Forest ecological zones in Iran could be categorized as: a) North, Caspian forest, b) West, Zagros forest, c) North West, Arasbaran forest, d) South, Subtropical forest in Persian Gulf areas, and e) Central, Scattering forests. Some of the main tree species of Caspian forests: Fagus orientalis, Carpinus betulus, Acer velutinum, Quercus castaneifolia, Fraxinus excelsior. In this study, whole forest areas in southern part of Caspian Sea were monitored by study on vegetation map and visiting field. Three points representing major part of Hyrcanian Forests were selected from wet part in west to drier part in east. Four meteorological stations data used for investigation. Most of climatic factors including maximum, minimum and mean annual temperature; daily and annual precipitations were investigated. Mainly trends of mean annual temperature and annual precipitations were used for conclusion. It can clearly be concluded that during last half century climate in forest area in Caspian region become warmer. Precipitation trends especially in Anzali station that has highest precipitation records in Iran and also in Gorgan station have decreased. Precipitation trends in Rasht and Baboulsar stations have shown positive change. During last 49 years in Rasht station mean annual temperature increased about 1.28 °C and even its minimum temperature shows 2.45 °C increases. Increase mean annual temperature in Baboulsar station in last 54 yeas is about 1.44 °C and its minimum temperature shows 1.80 °C increases. Decrease of annual precipitation in Anzali station during last 54 years of records is about 409.4 mm and amount of decrease of precipitation for the period of last 53 years in Gorgan station is about 55.6 mm. Distribution of plants are directly depends upon temperature and precipitation conditions in each climatic zone. Generally with increasing about 100 meter of elevation amount of temperature will decrease by one degree of centigrade. In study zones especially in Gilan and Gorgan areas temperatures shown more than one degree increases and main species of vegetation cover moved upward about 100 meters. All data statistically were analyzed.