• Energy Research
• 2016-2025close
• 11. Sustainability close
• 1. No poverty close
• Persian close

Abstract Background and Aim: Increasing energy consumption has created an energy crisis in the world. Fossil fuels are limited and depleting. Biogas is considered a fuel that has attracted the attention of researchers. To increase biogas production, different pretreatments have been utilized. The purpose of this study was to investigate the optimal mixing ratio of Municipal Solid Waste (MSW) and Sewage Sludge (SS), as well as the effects of various conditions of alkaline pretreatment on biodegradability of wastes and the amount of biomethane production. Materials and Methods: This study was done in a laboratory digester with 1 L volume at 37 °C with different concentrations of NaOH in a completely randomized design. Biogas volume, methane volume, and changes in pH were measured daily. Measurement parameters in the anaerobic digestion including total solids, volatile solids, and carbon and nitrogen content in the feedstock were determined according to the APHA standard methods. Results: The optimal mixing ratio of MSW to SS was 60:40 with the highest methane yield of 254.87 mL/g VS. Next, the effects of 2, 6, and 10% NaOH concentrations were evaluated on the amount of gas produced, indicating that 6% NaOH concentration significantly improved waste decomposition. Methane production, VS, and TS removal were compared to the control treatment, and there were increases of 30, 27.94, and 27.25%, respectively. Conclusion:The results showed that the mixing ratio of MSW to SS at 60:40 with 6% NaOH improves the decomposition of organic wastes and increases biomethane production. Keywords: Alkaline Pretreatment; Anaerobic Digestion; Biogas; Municipal Solid Waste; Sewage Sludge

Background and Objective: In recent years, management and disposal of municipal solid waste has become a global problem and the most important environmental concern. Anaerobic digestion is a cost-effective solution for treatment of both solid waste and wastewater. The aim of this study was to investigate the positive or negative effects of calcium chloride content in anaerobic digestion process of municipal solid waste and leachate on biogas production. Materials and Methods: Experiments with 8 levels of calcium chloride on co-digestion of municipal solid waste and leachate were investigated in 500 ml digesters under mesophilic conditions in a completely randomized design with three replications. Reactors with a ratio of substrate to inoculum of 2 (on VS basis) were operated and the volume of the biogas was measured daily. Volatile and total solids, carbon/nitrogen of waste, COD, BOD and heavy metals were measured by following APHA. Results: The results of the experiment showed that the pH was decreased with increasing calcium chloride concentration. The highest amount of cumulative biogas production was obtained in CaCl2 of 2 g/L with the highest VS and TS reduction. Higher concentrations of CaCl2 (≥3 g/L) caused a reduction in the degradability of volatile and total solids and, as a result, a decreased performance of the digester. Conclusion: The results clearly confirmed that the addition of calcium chloride was an effective solution to improve biodegradability in co-digestion of the MSW and leachate and consequently to reduce the total and volatile solids and to increase the amount of‌ biogas.

Today’s world faces two major crises including environmental pollution due to fossil fuels and the reduction of these fuels, so energy supply through renewable energies has been considered a sustainable solution. The purpose of this study was to assess factors affecting the tendency to use biofuels among villagers. Heads of households in rural areas in Chavarzagh district, Tarom township, Zanjan province formed the statistical population of the study (N=2742). The sample size was estimated using the Cochrane formula (n=161) and samples were selected using multi-stage cluster sampling method. The descriptive and correlational research method was used in this study. The validity of the questionnaire was approved by a panel of related faculty members. Cronbach's alpha coefficient was used to confirm the reliability of the questionnaire (0.70-0.83). Data was analyzed using SPSS 21. Regression analysis showed that risk, attitudes towards biofuels, self-efficacy, training, eliminating subsidies for fossil fuels and encouraging the use of biofuels, increasing public awareness about the benefits of biofuels and perceived barriers explained 40.6 percent of the variation of villagers’ tendency to use biofuels.

One of the main sources of greenhouse gas (GHG) emissions is the use of energy for groundwater pumping. Reducing energy consumption is very important to achieve the environmental sustainability and decrease the climate change impacts. In this paper, the amount of greenhouse gas emissions from groundwater pumping in the Guilan’s aquifers was investigated. Firstly, groundwater depletion and the types of pumps for water pumping were examined in the current condition; then, the values of consumed energy, GHG emissions and climate change indicator of the current condition were estimated. The primary investigations showed that 55 percent of wells in the studied region had a diesel engine pump, while 51.3 percent of the required energy for groundwater pumping was supplied by electric pump. Calculated total GHG emissions and the value of climate change indicator in the current condition were equal to 8.98 and 7.59 Milion kg CO2 eq , respectively. In order to achieve environmental sustainability and energy security, scenarios of replacing electric pumps and applying solar energy were examined. The results of the scenarios showed that diesel fuel wells had no significant effect on the reduction of greenhouse gas emissions, but the use of solar energy reduced them. GHG emissions, in comparison with the base scenarios, were decreased by 44.4% in June, July and August, respectively, by applying the scenario of using the solar pump in agricultural section. Therefore, it is preferred to apply policies in future planning to use renewable energies such as solar energy instead of diesel and electricity energy.

Importance of renewable-energy resources because of scarcity, greenhouse-gas emissions, and their fundamental roles in production and sustainable development, has made governments to reduce energy consumption and improving energy efficiency. In this regard, targeting subsidies rule was running in Iran since 2010. Since energy additionaly to labor and capital is one of the important inputs in production, running this rule with increasing energy price, affects manufacturing industries due to the type of energy and industry. In this research, the impacts of price liberalization on electricity efficiency have evaluated. Partial adjustment model, generalized method of moment and energy intensity measure are applied to this purpose. Data are collected from Statistical Center of Iran during 1995-2013. The research innovations are: using a partial adjustment model in evaluating efficiency, assessment whole industrial groups, and the period of research. The results show that in 95 percent level of confidence, the Iranian manufacturing industries are significantly flexible for changing the use of electricity. But the electricity efficiency has gotten worse after running the rule. In general, apposite of expectations, targeting subsidies rule has failed to improve electricity efficiency at least in short run.

Abstract: Fuzzy DEA methods have been introduced to deal with the fuzziness of variables. Although, some of these variables are affected by uncertainty and also information granularity, the membership function of fuzzy set is certain and this contrasts with the fuzzy concept as a whole. Type-2 fuzzy sets are introduced because of this and their membership functions have the nature of fuzzy type-1. The calculations of type-2 fuzzy sets are very complicated. However, interval type-2 fuzzy sets which have the characteristics of type-2 fuzzy sets and do not add any complexity to the calculation process can be applied to deal with such a problem. That is why in this paper, it is explored that how an extension of interval type-2 fuzzy dynamic network DEA approach helps to measure airports’ sustainability. Sustainable airports play an irrefutable role in making transportation systems sustainable. Such an integrative approach in DEA models is unprecedented. So, this extension of DEA is valuable from both technical and conceptual aspects. Introduction: Airports are an essential component of aviation (Knudsen, 2004). The importance of airports becomes clearer when it comes to the fact that aviation traffic is more than before and, therefore, sustainability becomes difficult. While, various studies have suggested that the sustainability of airports is essential to improve the performance of these systems, improve the living conditions of the public and increase the airport's credit (Brian, 2005; ICAO, 2012; SAGA, 2015). Paying attention to the concept of sustainability in managing airports has various benefits, such as increased competitiveness by purifying activities, reducing operating costs, and reducing costs for life cycle of materials and equipment, better use of assets, utilization newer and better technologies, reducing asset development costs, getting more support from the community, improving working conditions and, as a result, improving employee productivity, reducing environmental risks, health, safety and promotion (SAGA, 2015; Bretzke, 2013; TRB, 2012; ACARE, 2011; Too, Earl, 2010). For the reasons mentioned, it can be said that it is necessary to pay attention to the sustainability of the passenger airports of the country. Certainly, before adopting any approach, the current situation must be assessed correctly. Various methods have been used to evaluate performance, but Data Envelopment Analysis (DEA) is one of the most widely used methods (Azizi et al., 2004). Data envelopment analysis is a functional and nonparametric method that allows consideration of various components as input and output or intermediate activities (Bray et al., 2015). However, no research has been found to determine the performance of airports in accordance with the principles of sustainability in Iran. Materials and Methods: Type-2 fuzzy Dynamic Data Envelopment Analysis (DEA) is used to assess the performance of Iran’s passenger airports based on sustainability development. By use of Dynamic Network Data Envelopment Analysis, one can see how the different parts of a decision unit can be linked. It also shows how the past performance of a decision-making unit can affect its current performance. In this type of data envelopment analysis, the function of the decision-making unit is transmitted through time-based intermediaries to the next period. Thus via using dynamic data envelopment analysis method, it is possible to consider the activities of different parts of a decision unit and also the efficiency with respect to time periods. However, the point is that in the real world, due to the increasing socioeconomic complexity and the inherent ambiguity of human thinking, there is no possibility of precise determination of many of the components. For this reason, type-2 fuzzy theory is employed that its membership function is the fuzzy of the first type. Since the complexity of calculations while using type-2 fuzzy set is high, interval type-2 fuzzy is applied. The 20 most popular passenger airports in Iran are selected to evaluate their performance in accordance with the principles of sustainability principles and via the help of the developed DEA model. Results and Discussion: Results of investigation show that Larestan Airport is the most efficient one among all and the last rank is allocated to the Isfahan airport considering fixed return to scale while in variable return to scale, Shiraz airport gets the last rank. The efficiency intervals of airports such as Larestan, Gorgan, Rasht and Yazd have little difference in two modes of return to scale. For this reason, we can say that there is no significant function inefficiency about these airports. But this difference is more evident in the efficiency of airports such as Mashhad. Airports, whose performance is generally low or are inefficient, are able to provide a groundbreaking improvement with appropriate benchmarking. Since airports operate in different conditions, difference in climatic conditions and the in workforce etc. should be considered while benchmarking. References ACARE (Advisory Council for Aeronautics Research in Europe) (2011). "Flight path 2050 Europe’s Vision for Aviation". Luxembourg: Publications Office of the European Union. Azizi, H., Kordrostami, S., & Amirteimoori, A. (2015). "Slacks-based measures of efficiency in imprecise data envelopment analysis: An approach based on data envelopment analysis with double frontiers". Computers & Industrial Engineering, 79, 42-51. Azizi, H., Jafari Shaerlar, A., & Farzipoor Saen, R. (2014). "A new Approach for Considering a Dual-Role Factor in Supplier Selection Problem: DEA with efficient and inefficient frontiers". Journal of production and operation management. 6(2), 129-144. Bray, S., Caggiani, l., & Ottomanelli, M. (2015). "Measuring transport systems efficiency under uncertainty by fuzzy sets theory based Data Envelopment Analysis: theoretical and practical comparison with traditional DEA model". Transportation Research Procedia, 5, 186 – 200. Bretzke, W.R. (2013). "Service Quality Versus Sustainability: A New Conflict of Objectives". Information Technology in Environmental Engineering Part of the series Environmental Science and Engineering, Springer, 179-190. Brian, E. (2005). "The Modern Airport Terminal: New Approaches to Airport Architecture". 2nd Edition, Taylor & Francis. ICAO (International Civil Aviation Organization) (2012). "Sustainable Future for Aviation: ICAO Rio+20 Global Initiative". http://climate-l.iisd.org/news/icao-publishes-booklet-for-rio20-decision makers (accessed 14.09.2015). Knudsen, F.B. (2004). "Defining Sustainability in the Aviation Sector". Brussell: Eurocontrol Experimental Centre. SAGA (Sustainable Aviation Guidance Alliance) (2015). "Learn". http://www.airportsustainability.org/learn, (accessed 16.12.2015). Transport Research Board (TRB) (2011). "Critical Issues in Aviation and the Environment 2011". Washington, DC: TRB. Too, L., & Earl, L. (2010). "Public transport service quality and sustainable development: a community stakeholder perspective". Sustainable Development. 18(1), 51-61.

Introduction: The latest report of the Intergovernmental Panel on Climate Change (IPCC) states that future emissions of greenhouse gases (GHGs) will continue to increase and cause climatic change (16). These conditions are also true for Iran. The three greenhouse gases associated with agriculture are carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O). The three GHGs associated with agriculture CO2, CH4, and N2O differ in their effectiveness in trapping heat and in their turnover rates in the atmosphere. This environmental change will have serious impacts on different growth and development processes of crops. Increasing temperature could affect physiological processes such as photosynthesis, respiration and partitioning of photoassimilates. Farmers are not able to change or manage the climatic conditions, but some factors such as soil, water, seed and agricultural practices can be managed to reduce the adverse impacts of climate change (32). Mitigation and adaptation are two known ways for reducing the negative impacts of climate change. Mitigation strategies are associated with decreasing greenhouse gas (GHG) emissions through management practices such as reducing chemical fertilizer application, mechanization, increasing carbon storage in agroecosystems, planting biofuel crops and moving towards organic farming (42), etc. Material and Methods: This study was carried out at the experimental field of the Ferdowsi University of Mashhad in 2011 and was repeated in 2012. The Research Station (36°16´N, 59°36´E) is located at about 985 m a.s.l. Average temperature and precipitation rate of the research station in two years are shown in Figure. 1. The three-factor experiment was set up in a strip-split-plot arranged in a randomized complete block design with three replications. The experimental treatments were tillage systems (conventional and reduced tillage) and residual management (remaining and leaving of maize residual) assigned to main plots and different levels of N fertilizer (0, 150, 300 and 450 kg urea ha-1) was randomized as a subplot in tillage treatment. The seedbed preparation was made based on common practices at the location. Plot size under the trial was 4 m × 3 m so as to get 70 cm inter row spacing. Maize seeds (single-cross 704 cultivar) were hand sown in May for two years. The ideal density of the crops was considered as spacing 20 cm inter plant. As soon as the seeds were sown, irrigation continued every 10 days. No herbicides or chemical fertilizers were applied during the course of the trials and weeding was done manually when necessary. Measurement of CO2 emissions was performed by the closed chamber method. For this purpose, PVC plastic rings (20 cm in diameter and 30 cm height) were scattered on each of the plots. The chambers were placed in soil for two hours and the gathered air was collected by 10 ml vacuum syringe. Then, the samples were transferred to the laboratory and CO2 was measured using GC-mass. Results and Discussion: The results showed that CO2 emissions for conventional tillage was about 15 and 10% higher than the reduced tillage in 2011 and 2012, respectively. The CO2 emissions can be taken as indicators of soil tillage effects on the soil ecosystem, because CO2 emissions are closely connected to the microbial turnover and the physical accessibility of organic matter to microbes. These parameters were more available in the conventional tillage than the reduced tillage. CO2 emissions were strongly higher in the remaining residual condition rather than leaving condition in two years. CO2 emissions in the remaining residual condition was about 4.36 and 5.37 times higher than that of the leaving residual condition in 2011 and 2012, respectively. The microbial respiration and humidity of soil in the remaining residual condition is higher than that of the leaving residual condition. CO2 emission was elevated with increasing the rate of N fertilizer. The N fertilizer can increase the microbial activity of the soil. Cover cropping and N fertilization can increase CO2 emissions in full and reduced tilled soils by increasing the amount of crop residue returned to the soil. The results showed that CO2 emissions in 2011 were higher than 2012 in all treatments. The residual treatment had more effect on daily CO2 emission in comparison with tillage and N fertilizer treatments in both years. The trait was higher under conventional tillage, residue remaining and higher N fertilizer levels compared to reduced tillage, residue leaving and lower N fertilizer application. Linear regression for air temperature and mean CO2 emission illustrated that there was a positive correlation between air temperature and CO2 emission. Conclusion: In essence, the results showed that CO2 emissions for conventional tillage were higher than that of reduced tillage in two years. Remaining residual condition had strongly higher CO2 emission rather than leaving condition. CO2 emission was elevated with increasing the rate of N fertilizer.

Introduction: The increasing Greenhouse Gases in atmosphere is the main cause of climate and ecosystems changes. The most important greenhouse gas is CO2 that causes global warming or the greenhouse effect. One of the known solutions that reduces atmospheric carbon and helps to improve the situation, is carbon sequestration in vegetation cover and soil. Carbon sequestration refers to the change in atmospheric CO2 into organic carbon compounds by plants and capture it for a certain time . However, the ecosystems with different vegetation have Impressive Influence on soil carbon sequestration (SCS). Soil as the main component of these ecosystems is a world-wide indicator which has been known to play an important role in global balance of carbon sequestration. Furthermore, carbon sequestration can be a standard world trade and becomes guaranteed. Costs of transfer of CO2 (carbon transfer From the atmosphere into the soil) based on the negative effects of increased CO2 on Weather is always increasing, This issue can be faced by developing countries to create a new industry, especially when conservation and restoration of rangeland to follow. This research was regarded due to estimation of SCS in three land use types (orchard, paddy rice and forest) in a Part of Ramsar Lands, Northern Iran. Materials and Methods: Ramsar city with an area of about 729/7 km2 is located in the western part of Mazandaran province. Its height above sea level is 20 meters. Ramsar city is situated in a temperate and humid climate. Land area covered by forest, orchard and paddy rice. After field inspection of the area, detailed topographic maps of the specified zone on the study were also tested. In each of the three land types, 500 hectares in the every growing and totally 1,500 hectares as study area were selected .For evaluation the sequestration of carbon in different vegetation systems,15 soil profile selected and sampling from depth of 0 to 100 centimetres of each profile was done by collecting 15 samples with the total number of 45 samples. Soil sampling (at the 0-100 cm depth) was carried out following determination of points on map. Some of soil features (i.e., Soil structure, Bulk density ,Texture, Acidity, CEC, total Nitrogen and Organic Carbon) were measured in the laboratory. Then, the ANOVA and Duncan tests were employed due to statistical analysis using of SPSS software package. Also The map of carbon sequestration was prepared using of GIS approach. Results and Discussion :According to obtained results, the amounts of SCS were imposed by different land uses as non-significant. The amounts of SCS were found in forest (4532.35 ton/ha), orchard (2997.66 ton/ha) and paddy rice (2682.55 ton/ha) land use, respectively. The differences may be resulted from the variation among the ecosystem types and plant species. Forests are located in wetlands in the high forest and agricultural land more organic carbon levels (0 to 20 cm), but non-significant difference was observed in the soil depth in these areas. The Increased amount of carbon sequestration in the Orchard of the Paddy Rice can be interpreted due to long-term use of fertilizer in the orchards. In Paddy Rice of study due to deep plowing, results showed more decline of organic matter and the loss of carbon from soils.In addition, the maximumtotal nitrogen, organic and sequestrated carbon in top soil (0-10cm depth) were detected in forest (866.968 ton/ha),whereas the least amount dedicated in paddy rice (393.4 ton/ha) land uses. Four classes of detected soil in the study area were included AlfiSols, Inceptisols, Entisols and Mollisols Conclusions: We found no significant differences in terms of carbon sequestration in land use due to the impact of climate, annually high rainfall and washing clay seems logical. The plant communities in forest ecosystems can become more capable to absorb and retain carbon than other vegetation cover. Agriculture and farming operations are due to dispersion aggregates, reduce of organic matter and carbon sequestration compared to forest intact soils. Considering the vital role of soil carbon sequestration as one of the known values in terms of natural ecosystems and the importance of soil conservation programs, further research works are recommended on the effects of biotic factors such as grazing and land-use changes.

In recent years, human activities induced increases in atmospheric carbon dioxide (CO2) which caused global warming and climate change. Climate change is anticipated to cause negative and adverse impacts on water systems throughout the world. Higher temperatures are expected to lead to a host of problems. These include melting snowpack, altering both the intensity and frequency of precipitation, increasing evapotranspiration and else. (Delghandi, 2016). Reference evapotranspiration (ETo) is a key hydrological variable quantifying a major water loss from catchments and basins, which can be used to calculate actual evapotranspiration (ETa), scheduled irrigation and prepare input data for hydrological models. The irrigation water requirement basically represents the difference between the crop water requirement and effective precipitation. The only factors affecting ETo are climatic parameters as water is abundantly available at the reference evapotranspiring surface (Allen et al., 1998). The first of climatic parameters is air temperature. As temperature increases, evapotranspiration also goes up. Some study conducted to indicate climate change impact on ET (e.g, Behmanesh et al., 2015; Sheidaeian et al., 2015; Babaeian and Kouhi, 2012). In this study, climate change impacts on reference evapotranspiration (ETo) and precipitation deficit (PD) were studied from 2010 to 2099 in Semnan region. The objective of this study was to examine the climate change impact on the ETo regarding the uncertainty of Atmosphere-Ocean General Circulation Models (AOGCM) and Greenhouse Gases Emission (GHG) scenarios.

The occurrence of wind erosion and the spread of dust particles can be regarded as one of the most important and threatening environmental factors. Climate change and the frequency of droughts have played an important role in exacerbating or weakening these events. The primary objective of the present study was to investigate the trend of changes in four important climatic elements (precipitation, temperature, wind speed and relative humidity) and dust storm index (DSI) in Qazvin city using the Mann-Kendall pre-whitened test and to determine the relationship between them based on the multiple linear regression method. Assessment of the meteorological drought status based on two standardized precipitation index and standardized precipitation, as well as the evapotranspiration index and analysis of their effect on activity level of dust events, was the other objective of this study in the study area. For this purpose, after preparing and processing the climatic data and calculating the dust storm index, the trend of changes and the relationship between climatic parameters and dust events were investigated. The results showed that the changes of trend in the annual precipitation and relative humidity in Qazvin city were increasing, while the trend of annual changes in the wind speed and the mean air temperature was a decreasing one. Investigation of the monthly changes in the dust events also showed that there was a sharp decrease in the occurrence of wind erosion and the spread of domestic dust particles only in July. On a seasonal scale, with the exception of winter that has been reported without trends, in other seasons, the intensity of these events was significantly reduced. The effect of the meteorological drought on wind erosion was estimated to be 11% at the confidence level of 99%. In general, these findings indicate a decreasing trend of land degradation and desertification caused by wind erosion in Qazvin.