S. Rai; P. Chand; S. P. Sharma
Abstract
This paper represented theoretically investigation of energy and exergy performance of an offset finned solar air heater. Parametric study was done to investigate the effect of variation of offset fin parameters i.e. fins spacing (1 to 5cm) and fins height (1.8 to 5.8cm) at different mass flow rates ...
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This paper represented theoretically investigation of energy and exergy performance of an offset finned solar air heater. Parametric study was done to investigate the effect of variation of offset fin parameters i.e. fins spacing (1 to 5cm) and fins height (1.8 to 5.8cm) at different mass flow rates (0.01388 to 0.0833kg/s) on the energy and exergy efficiency. The results indicated that attaching offset finned below the absorber plate at low mass flow rates can lead to noticeable enhancement of exergy efficiency. The results revealed that the trend of variation of the energy and exergy efficiencies are not the same and the exergy efficiency is the chief criterion for performance evaluation. Decreasing the fins height, reducing the fins spacing are effective at low mass flow rates, but at high mass flow rates the inverse trend is observable, such that exergy efficiency reduces sharply. The efficiencies of offset finned solar collector were compared with conventional flat-plate collectors and longitudinal fins collector.
M. Anbia; A. Sedighi; S. Salehi
Abstract
In this study nano structured zeolite 13X as adsorbent for methane gas was used. Ni and Al ions were used to modify the pores of the zeolite and the methane gas adsorption capacity was measured at room temperature and pressure between 1 to 12 bars. The textural properties and structure order of the zeolite were ...
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In this study nano structured zeolite 13X as adsorbent for methane gas was used. Ni and Al ions were used to modify the pores of the zeolite and the methane gas adsorption capacity was measured at room temperature and pressure between 1 to 12 bars. The textural properties and structure order of the zeolite were studied by XRD and nitrogen adsorption-desorption analysis. Inductive coupled plasma (ICP) technique was used to determine the amounts of metals loaded on the zeolite.
H. B. Kulkarni
Abstract
A Cylindrical parabolic trough (CPT) collector of aperture width 1.03 m and length of 1.82m was designed and fabricated. CPT was covered with glass of thickness of 3 mm to avoid convective heat loss. Reflector coated with polished aluminum sheet having reflectivity 0.87 and receiver tube made of mild ...
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A Cylindrical parabolic trough (CPT) collector of aperture width 1.03 m and length of 1.82m was designed and fabricated. CPT was covered with glass of thickness of 3 mm to avoid convective heat loss. Reflector coated with polished aluminum sheet having reflectivity 0.87 and receiver tube made of mild steelcoated with black zinc having absorptivity of 0.94 were used for CPT. mass flow rate of working fluid was 4 l/h. Thermal performance of CPT collector was tested according to ASHRAE Standardmethods. Average instantaneous efficiency of closed cylindrical parabolic trough collector system was found to be 66%. The overall efficiency of CPT system is 71% which is best suited for solar thermal applications.
M. G. Sobamowo
Abstract
The rapid increase in technological innovations and utilizations have adversely affected the environment and consequently continued to constitute a threat to the future survival of human. To counter these assaults and the threats of further degradation of the environment and human health, the basic recommended ...
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The rapid increase in technological innovations and utilizations have adversely affected the environment and consequently continued to constitute a threat to the future survival of human. To counter these assaults and the threats of further degradation of the environment and human health, the basic recommended approach for predicting the impact of the pollution and for the determination of the risk assessment strategies is through the use of mathematical models. Therefore, this work presents mathematical models for the prediction of the effects of combustion generated pollutants, such as Carbon-monoxide (CO) on human health. The developed coupled system of nonlinear partial differential equation for the ambient concentration of carbon mono-oxide in which the human subject was exposed to and the concentration of Carboxyhemoglobin (COHb) in the blood is solved numerically using Alternating-Direct Implicit (ADI) scheme. From the computations, the variables of the models show significant results in their variations and the standard error of the predicted results from the model range in between 0.5-0.85 for the different concentrations of ambient carbon monoxide. This established that the computed results show good agreement with available experimental data. Therefore, the model can be used as a means of controlling the effects of the pollutant on human health and the results will serve as a way of evaluating our technological injuries, effectively controlling our pollutants emissions and also as a tool for designing and developing better equipments and engines with lower carbon or pollutants emissions.
J. M. Patra; S. S. Panda; N. K. Dhal
Abstract
Citrus fruits world production is estimated to be over 88 million tons per year, and oranges alone account for about 55% of such amount. Orange peel waste (OPW) is the solid residue of membranes, cores, juice sacs, etc which represents over 50% of the processed fruits. Its disposal is of great concern ...
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Citrus fruits world production is estimated to be over 88 million tons per year, and oranges alone account for about 55% of such amount. Orange peel waste (OPW) is the solid residue of membranes, cores, juice sacs, etc which represents over 50% of the processed fruits. Its disposal is of great concern from the environmental point of view. Due to the large availability and composition rich in the present investigation was focused on the production of ethanol from OPW which will be an economic, environmental friendly and efficient approach. Strains of Aspergillus niger and Saccharamyces cerevisiae was used for hydrolysis and fermentation of pretreated orange waste, respectively. Spectrometry scanning electron microscopy (SEM) and Fourier transformation infrared (FTIR) were used to characterize the sample. Sugar percentage was found to be 3.64 in pretreated sample after 24 hours, which is responsible for the yield of ethanol (6.17 v/v). The results indicated that orange peel can be used as a good low cost alternative feedstock for ethanol production.
E. O. Dada; K. L. Njoku; A. A. Osuntoki; M. O. Akinola
Abstract
Wetlands play important strategic ecological and life-supporting roles. As a result, they are continuously exposed to pollutants inflow including heavy metals. The aim of this research was to evaluate the heavy metal remediation potential of a tropical wetland earthworm, Libyodrilus violaceus. L. violaceus ...
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Wetlands play important strategic ecological and life-supporting roles. As a result, they are continuously exposed to pollutants inflow including heavy metals. The aim of this research was to evaluate the heavy metal remediation potential of a tropical wetland earthworm, Libyodrilus violaceus. L. violaceus were exposed to soils contaminated with different concentrations of heavy metals using natural optimal soil density of 18 worms per kg soil, for 12 weeks. Relative to their initial concentrations, there were significant reductions of Zn, Pb and Cd at the end of the experiment. From the soil contaminated with a combination of Zn, Pb and Cd, the highest significant (p < 0.05) Cd reduction of 8.08 mg/kg soil occurred in the 12th week, the highest significant (p < 0.05) Zn reduction of 37.47 mg/kg soil occurred in the 8th week, while Pb recorded the highest but not significant (p > 0.05) reduction of 19.07 mg/kg in the 12th week. The effect of addition of cow dung on the ability of L. violaceus to reduce heavy metals was generally low. L. violaceus is recommended as a good candidate for the remediation of low to moderate heavy metal contamination in wetland ecosystem..
S. Mohite; S. Kumar; S. Maji
Abstract
An experimental investigation was carried out to analyze the performance and emission characteristics of a diesel engine fuelled with biodiesel blends (10, 20 and 30%) obtained by mixing karanja and linseed oil and diesel. Brake thermal efficiencies of biodiesel blends were found to ...
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An experimental investigation was carried out to analyze the performance and emission characteristics of a diesel engine fuelled with biodiesel blends (10, 20 and 30%) obtained by mixing karanja and linseed oil and diesel. Brake thermal efficiencies of biodiesel blends were found to be comparable with diesel with a slight reduction. BSEC increased with the proportions of biodiesel in biodiesel blends. B30 was found to cause the lowest HC emissions and the lowest CO emissions and diesel was found to deliver the lowest NOx emissions among the fuels used at all loads. Considerable reduction up to 37.32 % was found in smoke opacity of biodiesel blends. The study revealed that 10% biodiesel blend can be effectively used in an unmodified diesel engine.
N. Hairoma; M. G. Barzani; M. E. Toriman
Abstract
An environmental study was carried out at Marang River, Terengganu on determination of river water quality trend variations temporally and spatially at seven sampling stations between 2012 and 2015. Sampling stations were selected along the river started from downstream to upstream; where each station ...
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An environmental study was carried out at Marang River, Terengganu on determination of river water quality trend variations temporally and spatially at seven sampling stations between 2012 and 2015. Sampling stations were selected along the river started from downstream to upstream; where each station was 2km apart from each other. Sampling was done twice at each sampling stations which were during low and high tides in November 2012 and also was repeated in November 2015. Both samplings were conducted during Northeast monsoon period. Selected water quality parameters such as salinity, electrical conductivity (EC), total dissolved solids (TDS), dissolved oxygen (DO), pH and turbidity were measured using certified scientific instruments. One way ANOVA and Tukey Kramer multiple comparison were used for statistical analysis. This study revealed that there is significant temporal variation in DO and turbidity which was increased from downstream to upstream between 2012 and 2015 due to the increase of land use activities; while other parameters such as EC, salinity, TDS and pH were decreased. These results were concluded that global change coupled with the enactment of heavy storm and flood phenomenon during 2014 was lead to the rising of sea level and salinity dilution of the South China Sea.
M. V. Kumar; A. V. Babu; P. R. Kumar; B. Narendra
Abstract
In various countries around the world, the emissions of NOX from petrol/gasoline and diesel engine vehicles are restricted by legislation. NOX is produced in the combustion chamber of engines at high temperatures and high pressure. One of the most promising technology for effective control of NOX emissions ...
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In various countries around the world, the emissions of NOX from petrol/gasoline and diesel engine vehicles are restricted by legislation. NOX is produced in the combustion chamber of engines at high temperatures and high pressure. One of the most promising technology for effective control of NOX emissions is Exhaust Gas Recirculation (EGR) and now most modern engines require exhaust gas recirculation to meet emission standards. EGR lowers the presence of oxygen concentration and burn temperature in the combustion chamber and hence controls the NOx. The experimentation was carried out on a 5.2 kW of single cylinder four stroke direct injection diesel engines in computerized mode to investigate the performance, emissions and combustion parameters at different EGR ratios (10, 20 and 30%). From the results, O2, NOX and exhaust temperatures are found to be reduced whereas HC and CO emissions are increased as the EGR concentration increases.
K. Sharma; S. Jain; U. Chandrawat
Abstract
Nano sized BaBiO3 is prepared through Pechini method and characterized by SEM, XRD, FTIR, DT-TGA and UV DRS. The kinetic studies of adsorption and degradation phenomena involved in the photocatalytic degradation of Malachite Green dye using a batch reactor under visible light were investigated. Experiments ...
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Nano sized BaBiO3 is prepared through Pechini method and characterized by SEM, XRD, FTIR, DT-TGA and UV DRS. The kinetic studies of adsorption and degradation phenomena involved in the photocatalytic degradation of Malachite Green dye using a batch reactor under visible light were investigated. Experiments were performed in a suspended BaBiO3 photocatalyst system. The effect of catalyst loading, solution pH and initial dye concentration on dye degradation is investigated. In addition, adsorption experiment is also performed which indicates that adsorption pattern follows Langmuir model. The decomposition of Malachite Green dye follows pseudo first order kinetics and the Langmuir-Hinshelwood mechanism is found to be valid. Different kinetic parameters for adsorption and photocatalytic degradation of dye are also determined.
A. K. Ojha; M. Tiwari
Abstract
The aim of this research work is to isolate bacterial strains with high potential in the degradation and decolorization of lignocellulose compounds of paper mill effluent. Four bacterial strains were isolated from marine sediments and they were screened to their ability to degrade the lignin and decolorize ...
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The aim of this research work is to isolate bacterial strains with high potential in the degradation and decolorization of lignocellulose compounds of paper mill effluent. Four bacterial strains were isolated from marine sediments and they were screened to their ability to degrade the lignin and decolorize the Century pulp and paper mill effluent. Among four bacterial strains, three bacterial strains Bacillus subtilis, Bacillus endo-phyticus, Bacillus sp. were capable of ligninolytic activity. Consortium made by these bacterial strains enhances the degradation of lignin as well as decolorization. Various nitrogen source, carbon source, pH, temperature and low molecular weight organic acids were used in the optimization process of decolorization and degradation of lignin in paper mill effluent. Maximum decolorization 68.29% was found at pH 7.92, temperature 33°C, in the presence of glucose (as carbon source) 0.99% and yeast extract (as nitrogen source) 0.36% when it was optimized through response surface methodology.
M. Sathya; G. Muthuraman; S. Elumalai
Abstract
A bulk liquid membrane (BLM) system contained Di (2-ethyl hexyl) phosphoric acid (D2EHPA) as an extractant was used for transport of malachite green (MG) dye from textile wastewater. D2EHPA present in n-hexane is an effective, efficient and highly selective carrier for the transport of MG dye through ...
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A bulk liquid membrane (BLM) system contained Di (2-ethyl hexyl) phosphoric acid (D2EHPA) as an extractant was used for transport of malachite green (MG) dye from textile wastewater. D2EHPA present in n-hexane is an effective, efficient and highly selective carrier for the transport of MG dye through BLM. Maximum transport 88% was observed at 0.24M concentration of D2EHPA in the membrane phase and 7 moles concentration of acetic acid in the receiving phase after 300 min. The effect of parameters influencing the transport of MG dye such as pH and concentration of dye in the donor solution, extractant concentration in the membrane phase, nature of the organic solvent, the composition of receiving phase, stirring speed and kinetics parameter were elucidated. First order irreversible reaction kinetics k1 and k2 were applied for the transport of MG dye from aqueous phase BLM phase and BLM to acceptor phase. The accumulation of MG in BLM phase and the rate controlling step under different experimental conditions were also discussed. Finally, the proposed liquid membrane was effectively applied for MG dye transport from textile wastewater.
V. Garshasbi; M. Jahangiri; M. Anbia
Abstract
Synthesis of zeolite 13X from modified natural Iranian kaolin at 65˚C for 72 h at various concentration of NaOH solution was investigated. Metakaolinization process was done at 900˚C for 2 h. NaOH solution with different concentrations, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5 and 4 M were separately mixed with ...
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Synthesis of zeolite 13X from modified natural Iranian kaolin at 65˚C for 72 h at various concentration of NaOH solution was investigated. Metakaolinization process was done at 900˚C for 2 h. NaOH solution with different concentrations, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5 and 4 M were separately mixed with metakaolins. A mixture of zeolite 13X, A, quartz and hydroxysodalite (HS) was obtained. The products were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The prepared zeolite 13X has been used to study the adsorption of carbon dioxide, and the results are compared with commercial zeolite 13X.
M. A. Olutoye; O. D. Adeniyi; A. S. Yusuff
Abstract
The synthesis and characterization of clay-eggshell mixed catalysts was carried out for the transesterification of palm kernel oil using methanol as solvent. Clay from anthill and waste chicken eggshells were powdered and mixed via incipient wet impregnation in 50-50, 80-20 and 20-80% proportions of ...
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The synthesis and characterization of clay-eggshell mixed catalysts was carried out for the transesterification of palm kernel oil using methanol as solvent. Clay from anthill and waste chicken eggshells were powdered and mixed via incipient wet impregnation in 50-50, 80-20 and 20-80% proportions of clay to eggshell on mass basis. The resulting mixtures were oven dried at 120 0C and calcined in the furnance at 900 0C for 4 hours. The uncalcined raw clay sample was characterized via the X-ray fluorescence method while the as-synthesized catalyst samples were characterized via the Fourier Transform Infrared Radiation Spectroscopy and Scanning Electron Microscopy. The performance of the as-synthesized catalysts was tested in transesterification of palm kernel oil (PKO) via a 2 level factorial experimental design optimizing four variables including reaction time, reaction temperature, methanol/oil molar ratio and catalyst loading in which case the yield was the required response. The 50-50 catalyst attained a maximum yield of 56.2% at 70 0C, methanol/oil ratio of 12:1, reaction time of 180 min, catalyst loading of 5 wt.% compared to the 65.2% achieved with the 80-20 catalyst at 90 0C, methanol/oil ratio of 12:1, reaction time of 180 min., catalyst loading of 5 wt% and the 70.7% obtained for the 20-80 catalyst at 70 0C, methanol/oil ratio of 12:1, reaction time of 180 min, catalyst loading of 3 wt%, thus, indicating mixed effect of variables as fully discussed. The developed catalysts were found to be good for biodiesel production and have the ability of improved performance.
