Iranica Journal of Energy & Environment
Volume:4 Issue: 4, Autumn 2013

The effect of alkaline and acid pretreatment on solubilization of solid organic matter in palm oil mill effluent (POME) and hydrogen production by Thermoanaerobacterium-rich sludge was studied. Organic matter solubilization of alkaline and acid pretreatments were increased up to 28 and 15.7% of initial soluble COD in POME, respectively. That corresponds to carbohydrate solubilization of 41 and 32% of initial soluble carbohydrate in POME, respectively. A maximum hydrogen production yield of 4.6 l H2/l-POME was achieved from POME pretreated with 1.5% w/v NaOH, which was 3-fold greater than raw POME and 1-fold greater than POME pretreated with 1.5% w/v HCl. Optimum conditions for biohydrogen production from alkaline pretreated POME using Thermoanaerobacterium-rich sludge was found at initial pH 5.5 and temperature of 60°C, which gives a maximum hydrogen production yield of 5.2 l H2/l-POME and increased 51% as compared to raw POME.The biogas was mainly composed of hydrogen and carbon dioxide with the percentage of hydrogen rangingfrom 55-60% of biogas and free of methane. During the conversion of alkaline pretreated POME into hydrogen, the acetic and butyric acids were main by-products in the metabolism. The results showed that alkalinepretreatment is an effective pretreatment methods for enhancing the hydrogen production yield from POME.The use of Thermoanaerobacterium-rich sludge is promising for future engineering practice of biohydrogenproduction from alkaline pretreated POME.

A series of various factors such as limitation of fossil fuel resources, negative impacts on environment, fossil fuels prices, political disputes and their effects on supplying sustainable energy are among the reasons which have made many politicians, energy and environment experts move toward the development of a modern structure to secure supply of energy, environment protection and efficiency improvement of energy systems. Hence, most countries have begun to realize that the need for sustainability in energy production and consumption is significantly vital. Therefore, tracking the progress of sustainability is essential. The aim of this paper is to present a set of indicators for Iran, based on the Helio International Sustainable Energy Watch (SEW) indicators, that shows how to track progress toward sustainability in the energy sector. Due to SEW framework, Iran is the closest to sustainability target based on indicators for access to electricity. Iran performs worst on the indicators for CO2 emissions and energy intensity. Iranian’s private sectors had already signed contracts to build plants (more than 600 MW) based on biomass systems and newly developed wind energy (500 MW). Based on Iran Renewable Energy Organization (SUNA) remarks the private sector has submitted a proposal for generating 3000 MW. The objective of present work is to highlight fundamental challenges about the development of renewable energy and policy framework requirements for achievements of sustainable energy in Iran.

Mycophenolic acid (MPA) is an antibiotic and immunosuppressive agent, as a secondary metabolite of Penicillium brevicompactum. Parameter optimization of culture composition using Test plan L16, available in the form of an orthogonal array and software for automatic design and analysis of the experiments, both based on Taguchi approach was performed in MAP production process by Penicillium brevicompactum ATCC 16024 in a batch submerged culture. Optimal levels of key parameters including glucose, enzymaticaly hydrolyzed casein, methionine and glycine concentrations were determined. Optimum glucose, enzymaticaly hydrolyzed casein, methionine and glycine concentrations were obtained 80, 25, 1.2 and 20 g. L 1, respectively. Theoretically expected and also experimentally actual obtained mycophenolic acid concentrations under the optimal conditions were 2.025 and 1.995 g. L 1, respectively with a good consistency as 98.5%. Analysis showed the glucose concentration was found to be the most significant factor as well as glycine concentration was the less important factor on MPA production in the investigated process. Key words: Mycophenolic acid Optimization Penicillium brevicompactum Submerged culture Taguchi method

The objective of present study is to design and fabricate a solar dryer with evacuated tube collector with and without heat storage material (gravel). The performance of solar dryerfor drying chilli under the meteorological condition of Thanjavur, Tamilnadu, India was investigated. The designed dryer compared with natural sun drying. Drying of chilli in the designed dryer reduced the average initial moisture content from87.36% to a final moisture content of 3.4% in10hours with heat storage material against 12 hours in the dryer without heat storage material and 32 hours in natural sun drying.The designed dryer reduced the duration of drying period up to 66%. The efficiency of the dryerwith heat storage material, without heat storage material and natural sun drying are found to be 34.23, 22.03 and 9.32%, respectively. The specific moisture extraction ratio of the designed dryer with heat storage material is 0.345 kg/kWh.The quality of the dried chilli in the designed solar dryer is high in terms of colour, odour and flavour. From the performance, quality and quick rate of drying it is evident that solar dryer with evacuated tube collector assisted with heat storage materialis more compatible than other modes of drying.

Bipolar plates play the most significant role in weight, volume and corresponding costs of fuel cells. Initially, metallic and graphite materials had been used for production of bipolar plates due to their electrical conductivity characteristics. Later, these plates due to their deficiency such as corrosion, weight and production expenses were appropriately substituted by composite plates. This article presents results of a study on construction of bipolar plates using conductive polymeric composites. In the constructed composites,polypropylene was implement as polymer matrix and conductive carbon black and graphite as filler in order to supply the required electrical conductivity. The added fillers have been distributed in polypropylene by using an internal mixer. Then, bipolar plate specimens were prepared by molding of composite in hot press. The prepared specimens have been characterized to evaluate their specifications such as mechanical properties and their performance properties like thermal and electrical conductivities. The results of performed tests have shown a good performance on thermal conductivity greater than 10W/m.K, electrical conductivity higher than 50S/cm and high mechanical strength, flexural strength greater than 25MPa. The constructed composite plates were optimized and their weight in compare to similar metallic plates 80% and in contrast to graphite plates 40% were reduced. This method for production of bipolar plates is more economical as it reduces the cost of used materials and expenses of manufacturing operations.

Activated carbon from cassava peels was prepared and characterized for various physiochemical properties such as moisture content, volatile matter and surface area. The effects of various parameters such as adsorbent dose, contact time, adsorption temperature and pH were studied to optimize the conditions for maximum adsorption. The mechanism of the rate of adsorption was studied using the pseudo – first order lagergren equation, Svante Arrhenius equation and the Gibbs free energy equation was used for the determination of adsorption thermodynamics. The adsorption isotherms were described by means of Freundlich and Langmuir isotherm equations and also Temkin isotherm equation which considered the effects of indirect adsorbent/ adsorbate interactions on adsorption process. The fitness of the data was measured using the value of the coefficient of correlation (R2). The thermodynamic constant (K), standard free energy (G°), enthalpyad (H°) and entropy (S°) were calculated for predicting the nature of adsorption. Results obtained show the effectiveness of activated carbon from cassava peels as suitable adsorbent for the treatment of effluent wastewater.

In the present study, mixed convection flow was investigated by Lattice Boltzmann method in a square lid-driven cavity utilizing nanofluid in presence of cubic obstacle. The fluid in the cavity was a water-based nanofluid containing Cu nanoparticles. The study was carried out for a constant Rayleigh number 10, the Richardson number ranging from 0.1 to 10 and the solid volume 4 fraction ranging from 0 to 0.03. The effects of solid concentrations on hydrodynamic and thermal characteristics were investigated. The results were presented in the form of streamlines and temperature contours for different values of solid volume fractions and Richardson numbers. The results indicated that the averaged Nusselt number increases byaugmentation of solid volume fraction. The Richardson number had more effect on Nusselt number when obstacle was located at the bottom section of enclosure.

Nanotechnology is gaining tremendous impulsion in the present century due to its capability of modulating metals into their nanosize. They exhibit a high surface/volume ratio leading to different properties far different from those of the bulk materials. The development of uniform nanoparticles has been intensively pursued because of their technological and fundamental scienti?c importance. The use of iron-based technologies is a rapidly developing field, with a range of techniques proposed which make use of iron as a reductant, or as a sorbent, which have been tested at various scales of application. In this study the iron based materials were synthesized by precipitation method and characterized with SEM equipped with EDS, UV-VIS, FT-IR, Raman, particle size determination and Zeta potential.

Having accurate values of the parameters which mainly govern the industrial processes in hand is the key aspect to handle the process and optimize it. To deal with this challenge, some mathematical models have been developed and modified to be epidemic. This Study aims to present the simulation of gas-solid flow in fluidized bed dryer. Numerical solution of two-dimensional, axis-symmetrical cylindrical model for both phases is the very base on which this study is conducted. Some of the versatile parameters like inlet gas velocity and temperature, diameter and density of particles during drying process went under magnification and also challenges of heat transfer along the bed are investigated and discussed in detail. Solid temperatures in the center and on the surface which are greatly affected by time as well as results of the study are shown. At the end, model outputs are compared with experimental data which shows reasonable agreement and good match.

The principal concern of this study is to formulate the sub-pollution indices (sub-LPIs) and evaluate the individual and overall leachate pollutant index (LPI) of pilot scale landfill lysimeter at KUET campus, Bangladesh. To these endeavors, leachate samples from collection chamber of landfill lysimeter were sampling and the relevant parameters required for evaluating LPI were measured and monitored in the laboratory. Both the open dump and sanitary landfill conditions having a base liner and two different types of cap liner were simulated. Three sub-LPIs in terms of LPI in organic pollutant (LPI), LPI or in inorganic pollutant (LPIin) and LPI in heavy metals (LPIhm) as well as overall LPI had been developed and reported. It can be noted that component of organic fraction in leachate for entire lysimeter operating system had highest against the other counterfraction i.e. inorganic and heavy metals fraction and consequently shows the highest LPIor than that of LPIin and LPIhm. it can be observed that sub-LPIs and overall LPI has decreased in relation to the increasing of elapsed period of MSW deposited in landfill lysimeter. Results showed that collection system of sanitary lysimeter-A had the highest sub-LPIs and overall LPI than that of other lysimeter operating systems. Finally, it can be monitored that overall LPI was significantly high for entire lysimeter operating systems and proper treatment will be necessary before discharging the leachate into the water bodies.

Present investigation was performed to provide heavy metal signatures of urban dusts and to evaluate potential sources in Arak, Markazi province. Twenty- nine samples of urban dusts were collected in Arak city. Then Pb, Cu, Ni, Zn, Cr, Hg and As concentrations were determined by using atomic absorption spectrophotometry. The results indicate that, in comparison with Iran soil, urban dusts in some of the area in Arak have elevated metal concentrations, except those of Ni, Zn, Hg and As. Correlation coefficient analysis, principal component analysis (PCA) and cluster analysis (CA) were performed and three main sources with corresponding cluster elements were identified: (1) Zn, Cr, Hg and As have soil and industrial sources; (2) Pb and Ni are mainly derived from industrial sources, combined with traffic sources; (3) Cu come mainly from industrial sources. Geoaccumulation index (Igeo), enrichment factors (EF) and contamination degree (Cd) were calculated, which in turn further confirms the source identification. Also, Igeo, EF and Cd give an insight of human influence degree of urban dusts.

of the treatment systems by grab and composite methods. Three samples were taken per week in three months by Bailenger method with concentration-flotation on 33 percent zinc sulphate was applied. Slide was prepared and observed under a microscope. Cyst count was done by Mac Master Slide. The average parasites in influent and effluent samples of Imam Hospital was 8.53 and 13.83 per liter, respectively. The Nematode larva with the highest number of 4.78 per liter from the influent and Oocyst with 7.81 per liter of the effluent of the system were determined. Similarly, in Boali Hospital the Nematode larva in influent and Oocyst in effluent were 9.06 and 10.97 per liter, respectively. Nematode larva with 5.97 and of Entamoeba histolytica with 4.12 ranked the highest number. Presence of Nematode in the wastewater influent in both hospitals under study did not match the Engelberg Guideline (less than one per liter).