Avaliação de bactérias nitrificantes em filtros biológicos submersos aerados

This study investigates a new treatment system of wastewater by anaerobic and aerobic biological filters for nitrogen modification. The main objective of this study was evaluate, on a pilot scale, quantitatively and qualitatively the bacterian nitrifying community in a experimental sewage treatment system made by aerobics biological filters in series, in search of figure out the dynamic of nitrogen modification process. It was collected and laboratorial analysed microbiologically, regarding NMP of Nitrosomonas e Nitrobacter, and physical-chemically considering nitrogen sequence. We conclude that: the association in aerobic biological filters under nutrition controlled conditions and oxygen level allows the appearance of bacterian community responsible for the nitrogen modification; the method used, despite its limitations, provided the selection of autotrophic nitrifying microorganisms, allowing the identification of Nitrosomonas and Nitrobacter; the flow direction tested in the experimental unit did not affect the nitrifying bacterial community, certainly because they were kept drowned and did not occur flow speed that could breake the formed biomass; the nitrification process happened in aerated biological filters in all phases of the research, comproved by microbiological tests; in the third phase of the research the increase of the oxygen rate was significant for the nitrificant bacterian community in the aerate biological filters, allowing its growth, occurring relation between the efficiency of nitrification system and the quantity of organisms responsible for this process; the conduit used in aerated biological filters showed satisfactory performance support material to the nitrifying bacteria development

Remoção de nitrogênio em biofiltros aerado e anóxico, com alto índice de vazios e sem remoção de lodo

The improper disposal of nitrogen in receiving water courses causes problems such as toxicity to living beings through the consumption of oxygen to meet the nitrogen demand, eutrophication and nitrate contamination of aquifers. For this reason it is often necessary to be carried out complementary treatment of wastewater to eliminate or reduce the concentration of this compound in the wastewater. The objective of this study is to evaluate the biological removal of nitrogen compounds using submerged aerated and anoxic filters as post-treatment of an anaerobic system, with low cost and innovative technology, which in previous studies has shown high removal efficiency of organic matter and great potential biological nitrogen compounds removal. The simple design with perforated hoses for air distribution and filling with plastic parts proved to be very efficient in relation to organic matter removal and nitrification. The system presented, in the best stage, efficiency in converting ammonia to nitrate by 71%, and produced a final effluent concentration below 10 mg / L of NH3-N. In addition, carbon concentration was removed by 77%, producing final effluent with 24 mg/L COD. However, denitrification in anoxic filter was not effective even with the addition of an external carbon source. There was a reduction of up to 56% of nitrogen caused by the process of simultaneous nitrification and denitrification (SND). The high voids space presented by this type of support material coupled with direct aeration of the sludge, allows the respiration of biomass retained between the endogenous phase, increased cell retention time and sludge retention capacity, producing a final effluent with turbidity less than 5 UT and total suspended solids around 5.0 mg/L

Educação a distância e material didático: um estudo sobre o curso mídias na educação

The thesis Distance learning and didactic material: a study about the course Media in the education in Natal shows a research about the didactic material and its insertion in the distance training course to teachers. In this sense, this research aims to contribute to some universities with reflections about the way to elaborate the didactic material to the distance training course of teachers with the following specific objectives: a) identify some aspects in the didactic material in the extension course Media in the Education that difficult media usage by the teachers members of the course in the pedagogical practice; b) discuss about the way how didactic material to the distance training course to teachers has been created; c) stimulate teachers/members to integrate media in their teacher practice. For that reason, we have developed an action-research (THIOLLENT, 2011; FRANCO, 2005), based on it we elaborated a proposal do complement activities to the course Media in the Education that were applied to two classes during the fifth edition of this course. This research is presented in four steps: 1st) analyze of the course modules; 2nd) creation of a proposal to complement the activities; 3rd) applying the proposal to the students during the fifth edition to the course; 4th) analyze of forums and log books written by teachers/students. Data was analyzed by the contents perspective of Bardin (2011). As a theoretical support, we have Tardif (2012), about teachers knowledge; Dewey (1959; 2011) and Freire (2001; 2009; 2010a; 2010b; 2012) related to learning perspective; Candau (2002), Rays (2003) and Freire (2010a), about the relation theory x practice in the teacher training; Andrade (2003; 2009) and Belloni (2010) about distance teacher training; Bérvot; Belloni (2009), Neves; Medeiros (2005) and Prado (2005), related to Media integration. This research revealed the didactic material of the course Media in the Education has not a proposal to articulate theory and practice, due to this, this course opposed the Media integration. For that reason, teachers/members have real problems to integrate Media in their scholar routine. This research confirmed the way this didactic material was formulated did not help the teachers/students to integrate media in their pedagogical activities

Desenvolvimento e análise de material compósito a base de penas de frango (fibras de queratina-KF) e matriz de poliéster insaturado

Use of natural fibres as a reinforcement material in the manufacture of composites show a series of advantages: availability, biodegradability, low weight and regeneration in relation to synthetic fibres, thus justifying its utilization. In the present research work, composites were developed with chicken feathers (KF), using unsaturated polyester resin as matrix, for diversified applications, mainly in the furniture/timber industry.At present, in Brazil the chicken feathers are used as part of the animal feed, even though this material possesses low aggregated value. The chicken feathers are hollow, light and resistant. After washing with water at room temperature, a part of the chicken feathers were treated with 2% NaOH. Composites were manufactured using treated and untreated chicken feathers with unsaturated orthothalic polyester resin and 1% peroxide as catalyser, obtained in the commerce. Samples with size 150x25x3 mm for mechanical tests were cut by laser in the composite plate. Mechanical analyses were carried out in the Laboratório de Metais e Ensaios Mecânicos UFRN. All the analyses were in accordance with ASTM standards. SEM analyses were also carried out on the samples.In the analyses of the results obtained, it was observed that the composites made with untreated chicken feathers showed better results (Traction 11.406 MPa and 9.107 MPa Bending 34.947 and 20.918 MPa for samples with and without treatment respectively) compared to the composite with treated feathers. Very low values of the water absorption results, evidenced the impermeability characteristic of the feathers. From the SEM images, the structure, fracture and the fibre/matrix adsorption can be evidenced. In the flammability test, it was observed that despite the feathers having sulfur as a constituent, natural inhibitor of flame, no burning support of the composites, because the manufacturing process of the composite