Avaliação de processo de lodos ativos por batelada seguido de tratamento terciário com ênfase na remoção de matéria orgânica e na sedimentabilidade do lodo

This paper evaluate the performance of a Wastewater Treatment Plant (WWTP) in sequential batch activated sludge modality with tertiary treatment step, located in high temperature region. It also presents the analysis of organic matter’s removal and the evaluation of sludge sedimentation conditions through reactors in bench scale, fed with different substrate’s and biomass’ concentrations, from the WWTP in study. The results showed high efficiency and stability of the treatment process using Sequential Batch Reactors for domestic sewage, even with sudden changes of organic and hydraulic load, reaching more than 90% of efficiency in the removal of biodegradable organic matter. The removal of organic matter and sedimentation tests in bench reactors showed the good performance in respect of the organic matter’s removal, however, the high concentration of micro-organism results in a lower sludge sedimentation rate, which can compromise the quality of the final effluent. The relation Food/Microorganism in the conditions of the WWTP’s current operation showed a value of 0.06 gCOD/gVSS.d. and zonal sedimentation velocity of 0.59 m/h, the great ratio of the concentration of the substrate by biomass concentration, which obtained the maximum operational efficiency, showed a value of 0.09 gCOD/gVSS.d. and zonal sedimentation velocity of 1.4 m/h.

Avaliação de processo de lodos ativos por batelada seguido de tratamento terciário com ênfase na remoção de matéria orgânica e na sedimentabilidade do lodo

This paper evaluate the performance of a Wastewater Treatment Plant (WWTP) in sequential batch activated sludge modality with tertiary treatment step, located in high temperature region. It also presents the analysis of organic matter’s removal and the evaluation of sludge sedimentation conditions through reactors in bench scale, fed with different substrate’s and biomass’ concentrations, from the WWTP in study. The results showed high efficiency and stability of the treatment process using Sequential Batch Reactors for domestic sewage, even with sudden changes of organic and hydraulic load, reaching more than 90% of efficiency in the removal of biodegradable organic matter. The removal of organic matter and sedimentation tests in bench reactors showed the good performance in respect of the organic matter’s removal, however, the high concentration of micro-organism results in a lower sludge sedimentation rate, which can compromise the quality of the final effluent. The relation Food/Microorganism in the conditions of the WWTP’s current operation showed a value of 0.06 gCOD/gVSS.d. and zonal sedimentation velocity of 0.59 m/h, the great ratio of the concentration of the substrate by biomass concentration, which obtained the maximum operational efficiency, showed a value of 0.09 gCOD/gVSS.d. and zonal sedimentation velocity of 1.4 m/h.

Fast pyrolysis of biomass for energy and fuels

Bioenergy is now accepted as having the potential to provide the major part of the projected renewable energy provisions of the future as biofuels in the form of gas, liquid or solid fuels or electricity and heat. There are three main routes to providing these biofuels — thermal conversion, biological conversion and physical conversion — all of which employ a range of chemical reactor configurations and process designs. This paper focuses on fast pyrolysis from which the liquid, often referred to as bio-oil, can be used on-site or stored or transported to centralised and/or remote user facilities for utilisation for example as a fuel, or further processing to biofuels and/or chemicals. This offers the potential for system optimisation, much greater economies of scale and exploitation of the concepts of biorefineries. The technology of fast pyrolysis is described, particularly the reactors that have been developed to provide the necessary conditions to optimise performance. The primary liquid product is characterised, as well as the secondary products of electricity and/or heat, liquid fuels and a considerable number of chemicals. The main technical and non-technical barriers to the market deployment of the various technologies are identified and briefly discussed.

Swift Heavy Ion Irradiation and Thermal Annealing Induced Modification of Structural, Topographical and Magnetic Properties in Monolayer and Bilayer Films Based on FeNiMoB and Zinc Ferrite

Magnetism and magnetic materials have been playing a lead role in the day to day life of human beings. The human kind owes its gratitude to the ‘lodestone’ meaning ‘leading stone’ which lead to the discovery of nations and the onset of modern civilizations. If it was William Gilbert, who first stated that ‘earth was a giant magnet’, then it was the turn of Faraday who correlated electricity and magnetism. Magnetic materials find innumerable applications in the form of inductors, read and write heads, motors, storage devices, magnetic resonance imaging and fusion reactors. Now the industry of magnetic materials has almost surpassed the semiconductor industry and this speaks volumes about its importance. Extensive research is being carried out by scientists and engineers to remove obsolescence and invent new devices. Though magnetism can be categorized based on the response of an applied magnetic field in to diamagnetic, paramagnetic, ferromagnetic, ferrimagnetic and antiferromagnetic; it is ferrimagnetic, ferromagnetic and antiferromagnetic materials which have potential applications. The present thesis focusses on these materials, their composite structures and different ways and means to modify their properties for useful applications. In the past, metals like Fe, Ni and Co were sought after for various applications though iron was in the forefront because of its cost effectiveness and abundance. Later, alloys based on Fe and Ni were increasingly employed. They were used in magnetic heads and in inductors. Ferrites entered the arena and subsequently most of the newer applications were based on ferrites, a ferrimagnetic material, whose composition can be tuned to tailor the magnetic properties. In the late 1950s a new class of magnetic material emerged on the magnetic horizon and they were fondly known as metallic glasses. They are well known for their soft magnetic properties. They were synthesized in the form of melt spun ribbons and are amorphous in nature and they are projected to replace the crystalline counterparts.

Swift Heavy Ion Irradiation and Thermal Annealing Induced Modification of Structural, Topographical and Magnetic Properties in Monolayer and Bilayer Films Based on FeNiMoB and Zinc Ferrite

Magnetism and magnetic materials have been playing a lead role in the day to day life of human beings. The human kind owes its gratitude to the ‘lodestone’ meaning ‘leading stone’ which lead to the discovery of nations and the onset of modern civilizations. If it was William Gilbert, who first stated that ‘earth was a giant magnet’, then it was the turn of Faraday who correlated electricity and magnetism. Magnetic materials find innumerable applications in the form of inductors, read and write heads, motors, storage devices, magnetic resonance imaging and fusion reactors. Now the industry of magnetic materials has almost surpassed the semiconductor industry and this speaks volumes about its importance. Extensive research is being carried out by scientists and engineers to remove obsolescence and invent new devices. Though magnetism can be categorized based on the response of an applied magnetic field in to diamagnetic, paramagnetic, ferromagnetic, ferrimagnetic and antiferromagnetic; it is ferrimagnetic, ferromagnetic and antiferromagnetic materials which have potential applications. The present thesis focusses on these materials, their composite structures and different ways and means to modify their properties for useful applications.

New mechanical samples positioning system for irradiations on a radial channel at nuclear research reactor in a full-power continuous operation

FAPESP:97/5550

Ultrassonic Analysis of UO2 Pellets

Ceramic materials have been widely used for various purposes in many different industries due to certain characteristics, such as high melting point and high resistance to corrosion. In the nuclear area, ceramics are of great importance due to the process of fabrication of fuel pellets for nuclear reactors. Generally, high accuracy destructive techniques are used to characterize nuclear materials for fuel fabrication. These techniques usually require costly equipment and facilities, as well as experienced personnel. This paper aims at presenting an analysis methodology for UO2 pellets using a non-destructive ultrasonic technique for porosity measurement. This technique differs from traditional ultrasonic techniques in the sense it uses ultrasonic pulses in frequency domain instead of time domain. Therefore, specific characteristics of the analyzed material are associated with the obtained frequency spectrum. In the present work, four fuel grade UO2 pellets were analyzed and the corresponding results evaluated.