جستجوی مقالات مرتبط با کلیدواژه « زیست توده » در نشریات گروه « محیط زیست »

Today, the world is facing a huge crisis due to the increase in global energy demand and the greenhouse gases (GHGs) emissions caused by the use of fossil fuels. The consumption of energy carriers produces large amounts of carbon dioxide and other pollutants that pollute the environment. According to the reports of the World Energy Organization in 2019, the amount of carbon dioxide emissions has increased by 0.5% and primary energy consumption by 1.3% worldwide, which can be a warning for humans and the environment. On the other hand, most of the world's energy needs are provided by oil, coal and natural gas resources, all of which are limited and will be exhausted in a short time with the current consumption. The severe decrease in fossil fuel resources, the industrialization of most countries, their dependence on energy, and as a result the increase in the global price of fuel, on the one hand, has caused an energy crisis, and on the other hand, the increase in fuel consumption and inaccuracy in the way it is used has caused It has become a global environmental crisis. Therefore, the energy crisis, pollution and environmental effects caused by the use of fossil fuels have caused humankind to look for new sources of renewable energy, which is a type of renewable energy, biofuels. Biofuels are classified into four categories of first, second, third and fourth generation biofuels based on the raw materials used in their production. The first generation biofuels include biomass related to food products, while the second generation includes lignocellulosic biomass. The third generation has potentially renewable resources in the form of algal biomass, while the fourth generation includes genetically modified (GM) algal biomass. The main purpose of the article is to review the various sources of biofuels, compare different generations of biofuels and discuss the advantages and disadvantages of different types of biofuels.

Canola is one of the most important oilseed crops all over the world. This oilseed crop is mainly utilized for its high oil content (with about 40–45% oil). However, in recent years, the area under cultivation of canola has decreased due to water scarcity. Applying drought-tolerant cultivars with high water use efficiency can help to develop the area under cultivation of canola and increase canola production. Therefore, the current study was conducted to assess the water use efficiency of spring canola cultivars in warm and temperate climates.

This study investigated different cultivars as a strategy for increasing canola production and improving its water use efficiency under different climate types in Khuzestan and Lorestan provinces. For this purpose, four locations including Khoramabad and Kuhdasht in Lorestan Province as semi-arid climate regions and Dezful, and Shushtar in Khuzestan Province as hot and arid climate regions were selected. Daily long-term climatic data (including minimum and maximum temperatures, rainfall, and global radiation) were collected for these locations from Iran Meteorological Organization. In this study, Hyola308 (early-maturity), Hyola401 (mid-maturity), and RGS003 (late-maturity) cultivars were used. In order to simulate the growth and yield of canola in different locations, the APSIM-Canola model was employed. OriginPro 9.1 software was used for all statistical analyses and the generation of figures.

The results showed that grain yield, biomass, water use efficiency, grain weight, actual evapotranspiration, the average temperature during the canola growth period, and the length of the canola growth period were substantially affected by cultivar and region (climate type). According to the results, the highest grain yield and water use efficiency (3037 kg ha-1 and 6.9 kg mm-1 ha-1, respectively) were achieved for the mid-maturity cultivar (Hyola401). Furthermore, simulation results revealed that temperate and semi-arid regions compared to hot and arid regions increased grain yield, biomass and water use efficiency by 2507 kg ha-1, 10100 kg ha-1, and 2.7 kg mm-1 ha-1, respectively. Khorramabad × Hyola401 treatment had the highest water use efficiency, grain yield, and biomass (9 kg mm-1 ha-1, 4954, and 17943 kg ha-1, respectively) due to lower the average temperature during the canola growth period (10.9 ° C) and higher the length of the canola growth period (2424.9 day), while the lowest amount of these traits was recorded in Dezful × Hyola308 treatment (5 kg mm-1 ha-1, 1369, and 5514 kg ha-1, respectively).

The results indicated that expanding canola cultivation in temperate regions can be used to boost canola production in Iran and to improve the sustainability of canola cultivation agroecosystems. Also, using a mid-maturity cultivar such as Hyola401 in both temperate and hot climate conditions can increase water use efficiency and sustainability of canola production agroecosystems through higher production per water consumption.

Different Salicornia species are widely distributed in many parts of the world. In Iran, significant diversity of this species is observed in the plant flora of the country. These plants have high economic value, including the production of edible oil, creating a green cover to prevent land erosion, carbon sequestration, consumption as vegetables and pickles, traditional folk medicine, salt, and fodder products. Based on the latest study on different species and ecotypes of Salicornia in the country, including Salicornia sinus persica, S. persica Akhani subsp. persica and ecotypes of Gorgan and Urmia show that these species can produce about 10.4 tons per hectare in the south country under seawater irrigation (Persian Gulf) by 60 dS m-1. However, due to adaptability and longer growth period, the yield of Salicornia sinus persica depending on harvesting time could be at least 40% higher than the average value. It seems by planting the plants in the southern coastal areas while developing the plant value chain, some of the forage needed for livestock be produced. However, economic and environmental evaluations of the development of Salicornia cultivation in these areas need further research.

Given the importance of soil and water resources in the development of sustainable agriculture, increasing world population and the growing need for crop production, predicting crop yields using plant simulation models and remote sensing technology is very crucial. The aim of this study was to estimate the yield of rice components including straw, paddy and biomass of Hashemi cultivar during different growth stages with SWAP model and to provide regression equations by extracting NDVI and SAVI plant indices from Sentinel-2 and Landsat-7 and 8 satellite images. It was done in the National Rice Research Institute. Comparison of statistical variables indicated that the mean values of coefficient of determination (R2) and model efficiency factor (EF) in estimating the yield of rice components in different stages of growth with SWAP model were more than 0.70 and 0.90, respectively, and with an error of 1.93 to 6.54% was equivalent to 134.21 to 470.43 kg/ha. The slight difference between the measured and simulated values showed that the SWAP model estimates the rice yield in the study area with appropriate accuracy. The results also showed that the extracted NDVI and SAVI indices with very good accuracy estimate the yield of rice components at different stages of growth. However, the highest amount of correlation was related to the reproductive development stage. Finally, R2 for NDVI at different growth stages as well as  the entire growth period for straw, paddy, and biomass were higher than the SAVI index, revealing more accuracy of NDVI than SAVI.

to investigate the efficiency of Phytoremediation with sunflower corn and turnip, a study was conducted in 2016-2017 in agricultural lands in the south of Tehran using a complete randomized block design. Cadmium was present in all three parts of the leaves stems and sunflower seeds. the highest concentrations were observed in the leaves (0.54 mg / kg dry matter). The highest levels of iron uptake were in all three sunflower corn and turnip plants in the root zone, and its concentration in the root was significantly higher than in other parts of the plant. Cadmium biomass in sunflower and corn was 0.59 and 0.12, respectively. The manganese transfer factor in sunflower, corn and turnip was 1.88, 1.30 and 2.30, respectively. Among the three studied plants, the transfer of zinc, manganese and copper elements in the sunflower plant was 4.99, 1.88 and 2.21 respectively, which indicates the strength of its Phytoremediation . In most cases, the concentration of elements in the aerial parts of the studied plants was sufficient, but the use of plants with high adsorption capacity at the same time with wastewater consumption prevents the accumulation of these elements in the soil and the product will be usable.

In order to preserve fossil fuel reservoirs, it is necessary to find renewable resources. One option is biomass that can be converted to biofuels. One of the most important biofuels is ethanol that has been regarded as the best substituent for benzene. Bioconversion is one of the bioremediation methods in which, biomass is converted to biofuel. In this process carbohydrate content is converted to simple sugars and then fermented to ethanol. With regard to the unique structure of lignocellusic materials the pretreatment is necessary that can be done by physical and chemical methods. In saccharification, the biomass is degraded to 5 and/or 6 carbon sugars and then the fermenter microorganism is selected based on the produced sugar. In order to improve final yeild, usually this two steps will be done simulatneously. One of the most important subjects in biofuel production is development of fermentation methods to reach maximum yield one of them is biphasic fermentation.

Energy consumption has significantly increased beside of urbanization growth. It may go up so fast that it results in environmental Issues and greater natural resource depletions. Therefore, the use of renewable and clean fuel is considered necessary. Currently, macro-algae are cultivated in various regions of the world for various industrial and food usages. Macro-algae are known as a specific resource of alternative for energy production due to their biochemical properties such as high level of carbohydrate, lipid and protein. Various biotechnology methods have been developed for energy producing from macro-algae which are divided into two categories: 1) biochemical processes (fermentation, digestion) and 2) thermochemical processes (incineration, pyrolysis, and hydrothermal liquefaction). Depending on the type of methods, the product are categorized under different phases such as solid, liquid and gas. In this study, we will review the methods and studies on the energy production of different species of macroalgae.

Energy crisis is the most important crisis threatening mankind. Recently, using biogas has been put under focus due to the problems caused by widespread dependence to oil and scarcity of energy resources. In addition, using biogas as a fuel supply can saliently reduce greenhouse gases and consequently reduce global warming. Also, other advantages of biogas generation from biomass resources are waste minimization and sanitary manure generation. The aim of this study was to estimate the potential of biogas and energy production from biomass resources in the villages of Iran with anapproach to supply energy at the consumption place and to reduce transportation costs.
In this study, potential of biogas production from cattle refuse is evaluated according to the numbers of cattle existing in Iran villages and determination of cattle refuse quantity.
Results show that 11.195 million m3 biogas can be produced from 63 million cattle in villages of Iran. The extractable biogas from rustic biodegradable wastes was also determined. It was found that, annually, 487 million m3 biogas can be produced from 1249000 tons of waste per.
Generally, this study revealed that biogas and energy generation from biomass resources in villages of Iran with an approach to supply energy at the consumption place and to reduce transportation costs has economical efficiency and can be as a national strategy for achieving sustainable development.

Heavy metals pollution is very important in Environment. Toxicity and accumulation characteristics of these metals are more noticeable for health aspects. Today, using bio-sorbent is more noticeable because these ways are ecofriendly and economic. In this survey, in addition to achieving Ni and Cd bio-sorption by bio-solid, the results of other relative surveys used for comparing the results and bio-sorption affinity discussion. Bio-solid powder produced from municipal excess sludge by drying, grinding and grainsizing. Ni and Cd solutions in 0.25 and 0.75 mille molar have been contacted which 0.5, 1, 2 and 4 grams of biosolid in pH 4, 200 rpm stirring, 24-260C temperature and two hours (continuous 5-420 min in kinetic study) time and samples have been analyzed with atomic absorption spectrophotometer to kinetic and isotherm modeling study and comparing the results. The maximum equilibrium adsorption of metals observed at two hours contact time and increasing of pH up to 4 increased the adsorption rate. The equilibrium data of both metals could be fitted by Langmuir isotherm equation and the maximum adsorption capacity (qmax) for cadmium and nickel are 0.38 and 0.195 mmol/gr dry bio-solid, respectively. The same as other biomasses studied for bio-sorption of heavy metals bio-sorption affinity of bio-solid for Cd is more than Ni. Generally, the bio-sorption affinity of algae and fungi for heavy metals bio-sorption is more than sludge and bacteria that is the result of cellular wall characteristics.

Lignin and cellulose are the remarkable portions of plants biomass and agricultural wastes. In the wake of population growth and as a consequence of intensive agriculture activities and human food and other materials’ consumption, these compounds are becoming a burgeoning problem to our society and environment. However, microorganisms with the capability of biodegradation of such complex materials have not only an important role in prevention of spoilage of the wastes, but also the potential as good resource for production of high value, environmental friendly waste recycling and energy recovery. In this study, an evaluation was conducted using fungus Ganoderma sp. MM1987 growing on decomposing pulp of black tea with oak wood chips. Oak wood chips and black tea pulp are the two substrates which the various ratios of 1:1 to 4:1 of a mixture of them were tested, respectively. The most efficient and rapid formation cap growth was observed in the medium containing a 1:1 ratio. Mushroom growth curve on both substrates with a confidence p value <0.05 was obtained respectively. However, no significant difference was observed for mycelia growth in both substrates where the samples were identical using statistical weight ratio measurements. The 1:1 ratio of substrates can speed up the cap formation in a 44-day time scale. The optimum pHs for the production of fungal enzymes degrading lignin compounds were determined as 3.79 and 3.94 respectively. In conclusion, the results show that black tea residues with oak wood chips are appropriate substrates to be decomposed by Ganoderma sp. MM1987.

Introduction Energy and environmental issues are two common concerns of modern societies. Fossil fuels consumption is believed to be the primary factor contributing to severe environmental problems, such as global warming, climate change and acid rain, which are a serious threat to the world’s ecosystems. In order to stabilize the earth’s climate and prevent further global warming, the earth requires a 70% cut in present carbon dioxide emissions by 2050. In the executive summary of IEA (2006), it claims “Beyond 2020, the role of renewable energy in global energy supply is likely to become much more important”. Among these, biomass can be defined as all the biological materials produced and existing within an ecological system and as sources of renewable energy can be converted directly into energy or energy carrier materials. Regarding to biomass assessment, researchers estimated the sustainable energy potential of biomass resources in Thailand including: (i) agricultural residues, (ii) animal manure, (iii) fuel-wood saving potential through improvement of efficiency, (iv) possibility of fuel-wood saving through substitution by other fuels, (v) municipal solid wastes, and (vi) wastewater. The potential of each source was estimated for the reference year 1997 and for the years 2005 and 2010. The total energy potential of these sources in 1997, 2005 and 2010 were 525, 702 and 821 PJ, respectively. In Iran, Khorasan Razavi province is known as an important region of biomass production in the country including: crops, livestock and poultry. Hence, in this study the potential of biomass and its distribution were evaluated.

Ammonia (NH3) and nitrite (NO2) toxic chemicals which resulted from fish culture, especially in intensive fish culture systems. To evaluate the efficiency of green algae Scenedesmus quadricauda in ammonia and nitrite removal from intensive fish farm effluent and also its application as suitable culture medium for S. quadricauda, effluent water samples were collected from rainbow trout farm. Six different treatments including diluted effluent with and without BBM, raw effluent with and without BBM, and concentrated effluent with and without BBM were prepared from fish farm effluent as culture medium for S. quadricauda. Results showed that S. quadricauda could growth and reproduce well in examined treatments of fish farm effluent and ammonia and nitrite rates decreased in high levels (approximately 90 %).The maximum obtained biomass (0.99 g/L), number of algal cell (90.4 x 105 cell/mL), chlorophyll a (2.89 mg/L), removal percentage of ammonia (89.57 %) and nitrite (89.53 %) were obtained in diluted effluent with BBM (L+BBM).On the base of results of this research it seems that this algae could be used for ammonia and nitrite removal as well as algal biomass production for treatment of fish farm effluent before entering to natural environment. In addition, fish farm effluent could be used as suitable medium for algal mass culture.

Today, availability and best use of energy resources is one of important laws of development in countries. The vast reserves and cheapness of fossil fuels in Iran has lead to improper usage of these resources and a failure to use other resou ces seriously. Unlimited usage of this resource and its smuggling to foreign countries has resulted from this energy policy. An increase in the usage of this fuel created the conditions in which the government, in July 2003, rationed petrol with the aim of saving it. Energy andfuel resources have a variety of usages: in the transportation industry, providing energy for factories and domestic uses such as heating, cooling, cooking and lighting. Because of its natural geographical situation(topology) and vastness, our country enjoys a variety of energy resources in addition to fossil fuels (Sabouhi, 1998) such as wind, tide, geothermal, the sun and its rays (solar) which are renewable energies that can be used with less preparation (Taqzi, 2003). One of these resources which can be found in most villages in our country is biomass, which is the basic source of methane gas and its use for household fuel and producing electricity. Application of alternative energies, which are abundant in Iran, while providing necessary energy in villages can also help to reduce the use of fossil energy resources in the country. This article analyzes the production of energyfrom biomass resources, a simple design structure and the building of the tanks, and the influences of its usage on the environment, fabric and rural housing. The first part of this paper introduces biogas and experiments of other countries in this field. The second part analyzes the equipment and basic tools which are required for producing biogas, and also important aspects of designing and manufacturing a variety of tanks in villages. At the end, in addition to introducing design principles of the housing unit with a biogas tank, I will analyze the positive influences of ecology on the housing units.