The present study describes a novel synthetic method for the immobilization of calix4arene (
II) onto the surface of modified Amberlite XAD-4 resin (
4), which does not require the derivatization of ...calixarene moiety. The novel calix4arene based resin (C4 resin)
5 was used as sorbent for the removal of azo dyes. Batch-wise sorption study was carried out and observed that the C4 resin (
5) is more effective as compared to compound
II as well as pure Amberlite XAD-4 resin (
1) to remove the selected dyes i.e. Reactive Black-5 (RB-5), Reactive Red-45 (RR-45) and Congo Red (CR). The effect of sorbent dosage and pH on % sorption was studied. During the extraction process, various kinds of interactions such as electrostatic repulsion, deprotonation of the hydroxyl groups of C4 resin, dissociation of reactive dyes into anions/cations and structural variations were monitored and found that they are highly pH dependent.
The sorption of selected azo dyes is highly pH dependent and newly immobilized material 4 is potentially more effective sorbent as compared to pure silica (1) as well as p-tert-butylcalix8arene (3). ...Display omitted
▶ Sorption behavior investigation of p-tert-butyl-calix8arene immobilized material4. ▶ Azo dyes (i.e. RB-5 and RR-45) were used as sorbate. ▶ Optimization of different parameters to evaluate sorption performance of material 4. ▶ Sorption efficiency of resin 4 for RB-5 and RR-45 azo dyes is highly pH dependent. ▶ The sorption data was evaluated by sorption isotherms.
The present study describes synthesis of a new resin through immobilization of p-tert-butylcalix8arene onto silica and its application for the removal of azo dyes from aqueous media as well as from textile effluents. The newly synthesized material 4 is characterized by FT-IR spectroscopy, scanning electron microscope (SEM) and thermogravimetric analysis (TGA). Reactive Black-5 (RB-5) and Reactive Red-45 (RR-45) azo dyes were used as sorbate. Batch wise sorption experiments were conducted to optimize various experimental parameters such as the effect of sorbent dosage, electrolyte, pH, dye concentration, and contact time. The optimized pH for the effective removal of RB-5 and RR-45 dyes was 9 and 3, respectively. The increase in material 4 dosage increased the percent sorption. Both Langmuir and Freundlich isotherm models were applied to experimental data and Langmuir isotherm model found to be best fit. The results revealed that material 4 was potentially more effective sorbent for the sorption of selected azo dyes as compared to pure silica and p-tert-butylcalix8arene. The field studies also supported the effectiveness of material 4, which could be useful for the removal of both the dyes and also for the normalization of pH, TDS, conductivity and salinity near to the drinking water.
Exhaust emissions of a diesel engine are considered to be a substantial source of environmental pollution. Diesel engines are mainly used in vehicles and power generation. The usage of diesel engines ...is unavoidable as they give more power and performance, but at the same time, higher usage of diesel engines leads to increased air pollution, sound pollution, and emissions to the environment. Therefore, various attempts have been made to control the harmful emissions of engines. For this reason, different devices have been made such as catalytic convertors to overcome emission problems and purify the harmful gases. In order to meet these ends, a new system was designed that would contribute to controlling the air pollution of the engines. The system is also known as an aqua silencer, and its design is somehow different but still can be used as a silencer. The newly designed emission controller was installed in a test-bed diesel engine and a total of twenty experiments were conducted with and without the new emission controller at constant speed and at constant load. During these experiments, exhaust gases were analyzed with flue gas analyzers measuring CO2, CO, NO2, NO, and PM. The study concluded that the contaminants of diesel engine exhaust gases were) controlled by the developed emission controller.
Quantity, characteristics, and energy content in sugarcane trash of six different indigenous sugarcane varieties were computed for their possible utilization. Results revealed that the total ...sugarcane trash weight percentage was 24.0% of the total sugarcane crop. Among all examined varieties, variety 240 produced the highest and the variety HS12 the lowest percentage of sugarcane trash with 28% and 18.6% respectively. Moisture and ash content were found less in brown leaves and more in the tops of sugarcane trash parts. The fixed carbon values in brown leaves, green leaves, and tops of the variety Thatta10 were the highest found, with 18.4%, 15.5%, and 17.3% respectively. Carbon element’s percentage in brown leaves of variety HS12 was the highest with 50.0% and in Thatta10 was the lowest with 43.4%. Highest heating value was found in Thatta10 with 16.0MJ/kg, which is close to the literature reported values.
Composite materials have been used to resolve industrial problems. Considerable attention from the industrial side started in the 1960s with the introduction of polymer-based composite materials. ...Their advantages such as low weight (density), resistance to corrosion, high strength and low maintenance cost made composite materials an attractive substitute to conventional materials. A new composite material was developed with 10% natural fiber at 0o, 90o and 0/90o orientations resulting in ample improvements in the mechanical properties as compared to previous studies. The sample at 0/90o orientation gives the best results with tensile, tensile strength, tensile elongation and Young's Modulus values of 2458.19N, 4594.5MPA, 4.7% and 23.0 respectively
A review on global solar energy policy Solangi, K.H.; Islam, M.R.; Saidur, R. ...
Renewable & sustainable energy reviews,
05/2011, Letnik:
15, Številka:
4
Journal Article
Recenzirano
To overcome the negative impacts on the environment and other problems associated with fossil fuels have forced many countries to inquire into and change to environmental friendly alternatives that ...are renewable to sustain the increasing energy demand. Solar energy is one of the best renewable energy sources with least negative impacts on the environment. Different countries have formulated solar energy policies to reducing dependence on fossil fuel and increasing domestic energy production by solar energy. This paper discusses a review about the different solar energy policies implemented on the different countries of the world. According to the 2010 BP Statistical Energy Survey, the world cumulative installed solar energy capacity was 22928.9
MW in 2009, a change of 46.9% compared to 2008. Also this paper discussed the existing successful solar energy policies of few selected countries. Based on literatures, it has been found that FIT, RPS and incentives are the most beneficial energy policies implemented by many countries around the world. These policies provide significant motivation and interest for the development and use of renewable energy technologies. Also the status of solar energy policy for Malaysia is investigated and compared with that of the successful countries in the world.
Supplying present and future energy demand without adding to climate change is one of the most pressing problems today. Renewable energy is a potentially huge solution, for which governments are ...creating policies to encourage its harness and use. The dominance of photovoltaic (PV) among renewable energy technologies is owed mostly to its noiselessness, non-toxic emission, and relatively simple operation and maintenance. This study reviews the policies existing and in the making in seven leading countries that actively champion use of PV.
Environmental impact of wind energy Saidur, R.; Rahim, N.A.; Islam, M.R. ...
Renewable & sustainable energy reviews,
06/2011, Letnik:
15, Številka:
5
Journal Article
Recenzirano
Since the beginning of industrialization, energy consumption has increased far more rapidly than the number of people on the planet. It is known that the consumption of energy is amazingly high and ...the fossil based resources may not be able to provide energy for the whole world as these resources will be used up in the near future. Hence, renewable energy expected to play an important role in handling the demand of the energy required along with environmental pollution prevention.
The impacts of the wind energy on the environment are important to be studied before any wind firm construction or a decision is made. Although many countries showing great interest towards renewable or green energy generation, negative perception of wind energy is increasingly evident that may prevent the installation of the wind energy in some countries. This paper compiled latest literatures in terms of thesis (MS and PhD), journal articles, conference proceedings, reports, books, and web materials about the environmental impacts of wind energy. This paper also includes the comparative study of wind energy, problems, solutions and suggestion as a result of the implementation of wind turbine. Positive and negative impacts of wind energy have been broadly explained as well. It has been found that this source of energy will reduce environmental pollution and water consumption. However, it has noise pollution, visual interference and negative impacts on wildlife.
Solar energy is one of the cleanest forms of energy sources and considered as a green source of energy. Solar energy benefit ranges from low carbon emission, no fossil fuel requirement, long term ...solar resources, less payback time and other. However like other power generation sources, solar energy has also some Safety, Health and Environmental (SHE) concerns. This paper presents the overview of solar energy technologies and addresses the SHE impact of solar energy technologies to the sustainability of human activities. This paper will also recommend the possible ways to reduce the effect of potential hazards of widespread use of solar energy technologies.
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