Current Issue : July - September Volume : 2011 Issue Number : 3 Articles : 10 Articles
Removal of color from aqueous solution by using low cost adsorbent was conducted by batch experiment. The potential of the low cost adsorbent Azadirecta indica leaves (Neem) to remove Methylene Blue from aqueous solution were assessed at room temperature. Laboratory investigation of the potential of Azadirecta indica leaves (Neem) powder to remove methylene blue dye from aqueous solution has been studied. The effects of various experimental parameters, such as pH (3-11), adsorbent dosage (1-12 g/l), contact time (15-240 min) and initial dye concentration were investigated. The results showed that the dye removal increased with increase in the initial concentration of the dye and also increased in amount of biosolid used and initial pH....
A photometric procedure for the determination of ClO- in tap water employing a miniaturized multicommuted flowanalysis setup and an LED-based photometer is described. The analytical procedure was implemented using leucocrystal violet (LCV; 4,4, 4-methylidynetris (N,N-dimethylaniline), C25H31N3) as a chromogenic reagent. Solenoid micropumps employed for solutions propelling were assembled together with the photometer in order to compose a compact unit of small dimensions. After control variables optimization, the system was applied for the determination of ClO- in samples of tap water, and aiming accuracy assessment samples were also analyzed using an independent method. Applying the paired t-test between results obtained using both methods, no significant difference at the 95% confidence level was observed. Other useful features include low reagent\nconsumption, 2.4 �µg of LCV per determination, a linear response ranging from 0.02 up to 2.0 mgL-1 ClO-, a relative standard deviation of 1.0% (n = 11) for samples containing 0.2 mgL-1 ClO-, a detection limit of 6.0 �µg L-1 ClO-, a sampling throughput of 84 determinations per hour, and a waste generation of 432 �µL per determination....
While a significant amount of work has been conducted to assess the concentration of pollutants in soils and waterways near land that has been amended with biosolids, a relatively small body of research investigating emissions to atmosphere is available in the literature. Some studies have indicated that while the CO2 emissions from soils decrease with fertiliser application, the CH4 and N2O emissions might be increased, offsetting the benefit. The objective of the research presented in this paper was to address this gap, by the use of a flux chamber technique to measure soil-atmosphere gas exchanges from the application of biosolids to land. This was done by applying three different types of biosolids to soils and measuring gases at the soil-atmosphere interface. The measurements were taken on areas with three different types of vegetation. The gases were collected using a flux chamber technique and analysed by gas chromatography. The results presented here are preliminary findings of an ongoing experiment. Insignificant variation appeared to occur between different areas of vegetation; however, small variations in gas concentrations were observed indicating a need for continued monitoring of soil-atmosphere gas exchanges to determine the long-term impacts on the atmosphere and the environment....
The brightness temperature (BT) of Taklimakan Desert retrieved from the data of Landsat-7/ETM+ band 6 and Terra/MODIS band 31 and 32 indicates the following features: (1) good linear relationship between the BT of ETM+ and that of MODIS, (2) the observation time adjusted BT of ETM+ is almost equal to that of MODIS, (3) the BT of Terra/MODIS band 31 is slightly higher than that of band 32 over a reservoir while opposite feature is recognized over desert area, (4) the statistical analysis of 225 sample data of ETM+ in one pixel of MODIS for different landcovers indicates that the standard deviation and range of BT of ETM+ corresponding to one pixel of MODIS are 0.45?C, 2.25?C for a flat area of desert, while respective values of the oasis farmland and shading side of rocky hill amount to 2.88?C, 14.04?C, and 2.80?C, 16.04?C....
The clean and pure drinking water is important in today's life but current water sources are usually brackish with bacteria that cannot be used for drinking. About 78% of water available in the sea is salty, 21% of water is brackish, and only 1% of water is fresh. Distillation is one of the feasible processes applied to water purification, and it requires the energy inputs, such as solar radiation. Water is evaporated in this distillation process and water vapor can be separated and condensed to pure water. Now, with the change from conventional fuels to renewable and environment friendly fuels sources, the modern technology allows to use the abundant energy from the sun. It is better to use solar energy to process the water desalination since it is more economical than the use of conventional energies. The main focus of this paper is applying computer-aided modeling and simulation to design a less complex solar water distillation system. The prototype of this solar still system is also built to verify its feasibility, functionality, and reliability. The computational simulation and prototype testing show the reliability and proper functionality of this solar water distillation system....
An automated multiparametric water analyser was developed and evaluated. The system was based on Sequential Injection Analysis and featured a photometric detection system comprising a tricolour RGB LED source and a photodiode. A program compiled in Visual Basic was used to control the SIA flow system, the LEDs, and the data acquisition and processing. The program loads and executes methods written in ASCII and stored as text files. The system was capable of handling up to four methods simultaneously. When used to carry out methods based on the APHA standard methods, the figures of merit obtained were considered satisfactory for the purpose. The total cost was under US $4600. It was concluded that the analyser is appropriate for routine use and has potential for an increased number of simultaneous methods and for enhanced capabilities if new versions of the software are developed....
Wind turbine blades play important roles in wind energy generation. The dynamic problems associated with wind turbine blades are formulated using radial basis functions. The radial basis function procedure is used to transform partial differential equations, which represent the dynamic behavior of wind turbine blades, into a discrete eigenvalue problem. Numerical results demonstrate that rotational speed significantly impacts the first frequency of a wind turbine blade. Moreover, the pitch angle does not markedly affect wind turbine blade frequencies. This work examines the radial basis functions for dynamic problems of wind turbine blade....
Many researchers had investigated carboneous material as an adsorbent for the uptake of various dying agent form the textile effluent. The potential feasibility of spent tea leave removal of methylene blue from aqueous solution was investigated in the paper. The availability, inexpensive and its adsorption characteristic had made it an alternative media for the removal of dying agents. The effects of various experimental parameters such as contact time, solution pH and temperuture were investigated. The extent of methylene blue removal increased with the increased in contact time, solution pH and amount of temperature during adsorption used....
Treatment of textile wastewater at industrial-scale has met with limited success due to complex structural properties of dyes. The present work focuses on the complete removal of Levafix Orange CA (LO), a reactive textile dye through zinc oxide (ZnO) photocatalysis. The photocatalyst was characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM) and UV-Visible spectroscopy. The progress of dye degradation was followed by chemical oxygen demand (COD) and UV-Visible absorption measurements. The rate of degradation was found to be higher under UV-light than under sunlight. The optimum operating parameters for UV assisted degradation were found be 3.0 g/L of ZnO for 100 ppm LO and higher degradation rates were observed at alkaline pH owing to enhanced production of hydroxyl radicals. Nearly 100% decolourization and ~ 92 % COD removal was achieved under optimum experimental conditions after 3 hours of irradiation. Complete degradation leading to mineralization of LO was observed after 8 hrs which suggests that the method may be successfully employed for the UV assisted photocatalytic degradation of Levafix CA dyes in textile wastewater....
A theoretical model for predicting noise reduction in coupled workshops is presented by using statistical energy analysis (SEA) method. An opening between the coupled workshops is considered into the theoretical model properly. The leakage issue is dealt with in the process of SEA modeling. An experiment is also carried out. A reasonable agreement between the prediction of noise reduction and the experimental data is observed. Moreover, it is concluded from the simulations that the sound energy transmit through the opening was the most important way to affect the noise reduction and the leakage is a significant element to influence the effect of noise treatment....
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