80 resultados para RADIOACTIVE WASTE

em Repositório Institucional UNESP - Universidade Estadual Paulista "Julio de Mesquita Filho"


Relevância:

70.00% 70.00%

Publicador:

Resumo:

Groundwaters and surface waters from an area of treatment of sand for industrial purposes at Analandia municipality, nearly in the center of Sao Paulo State, Brazil, were chemically and isotopically analyzed with two aims: to evaluate if the anthropogenic activities that has taken place for the last 6 years is affecting the quality of the hydrological resources and to relate the hydrogeochemical behaviour of the uranium isotopes 234U and 238U with the pattern of circulation of groundwaters.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Chemical reagents used by the textile industry are very diverse in their composition, ranging from inorganic compounds to polymeric compounds. Strong color is the most notable characteristic of textile effluents, and a large number of processes have been employed for color removal. In recent years, attention has been directed toward various natural solid materials that are able to remove pollutants from contaminated water at low cost, such as sugarcane bagasse. Cell immobilization has emerged as an alternative that offers many advantages in the biodegradation process, including the reuse of immobilized cells and high mechanical strength, which enables metabolic processes to occur under adverse conditions of pH, sterility, and agitation. Support treatment also increases the number of charges on the surface, thereby facilitating cell immobilization processes through adsorption and ionic bonds. Polyethyleneimine (PEI) is a polycationic compound known to have a positive effect on enzyme activity and stability. The aim of the present study was to investigate a low-cost alternative for the biodegradation and bioremediation of textile dyes, analyzing Saccharomyces cerevisiae immobilization in activated bagasse for the promotion of Acid Black 48 dye biodegradation in an aqueous solution. A 1 % concentration of a S. cerevisiae suspension was evaluated to determine cell immobilization rates. Once immobilization was established, biodegradation assays with free and immobilized yeast in PEI-treated sugarcane bagasse were evaluated for 240 h using UV-vis spectrophotometry. The analysis revealed significant relative absorbance values, indicating the occurrence of biodegradation in both treatments. Therefore, S. cerevisiae immobilized in sugarcane bagasse is very attractive for use in biodegradation processes for the treatment of textile effluents. © 2012 Springer Science+Business Media Dordrecht.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Radionuclides take a major role in guidelines of environmental agencies/national organizations of countries worldwide. In Brazil, CNEN-Comissão Nacional de Energia Nuclear is responsible for managing all subjects related to nuclear energy in the country. Thus, laboratories employing radionuclides for the development of their activities must submit a Radioprotection Plan to CNEN in order to get an operation license. Such plan must indicate that the laboratory is exempt of risks to the people involved and designed to fit all related environmental aspects. This was the case of LABIDRO-Hydrochemical and Isotopes Laboratory that belongs to IGCE-Geosciences and Exact Sciences Institute from UNESP - the University of the State of São Paulo Júlio de Mesquita Filho, located at Rio Claro city, São Paulo State, Brazil. The total monthly activity of the radionuclides utilized during the laboratorial activities held at LABIDRO corresponds to 0.01 μCi. This paper describes all information provided by LABIDRO in order to get the CNEN license. The LABIDRO plan also showed the expected radioactive waste released when the experiments take place and CNEN decided that it fits the guidelines established by Brazilian legislation. Therefore, LABIDRO received its license for utilizing radionuclides, which is valid until September 2016. © 2013 WIT Press.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Textile industries use large amounts of water in dyeing processes and a wide variety of synthetic dyes. A small concentration of these dyes in the environment can generate highly visible pollution and changes in aquatic ecosystems. Adsorption, biosorption, and biodegradation are the most advantageous dye removal processes. Biodegradation occurs when enzymes produced by certain microorganisms are capable of breaking down the dye molecule. To increase the efficiency of these processes, cell immobilization enables the reuse of the immobilized cells and offers a high degree of mechanical strength, allowing metabolic processes to take place under adverse conditions. The aim of the present study was to investigate the use of Saccharomyces cerevisiae immobilized in activated sugarcane bagasse for the degradation of Acid Black 48 dye in aqueous solutions. For such, sugarcane bagasse was treated with polyethyleneimine (PEI). Concentrations of a 1 % S. cerevisiae suspension were evaluated to determine cell immobilization rates. Once immobilization was established, biodegradation assays for 240 h with free and immobilized yeast in PEI-treated sugarcane bagasse were evaluated by Fourier transform infrared spectrophotometry. The results indicated a probable change in the dye molecule and the possible formation of new metabolites. Thus, S. cerevisiae immobilized in sugarcane bagasse is very attractive for biodegradation processes in the treatment of textile effluents. © 2013 Springer Science+Business Media Dordrecht.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

A simplified procedure for the preparation of immobilized beta-amylase using non-purified extract from fresh sweet potato tubers is established in this paper, using differently activated agarose supports. Beta-amylase glutaraldehyde derivative was the preparation with best features, presenting improved temperature and pH stability and activity. The possibility of reusing the amylase was also shown, when this immobilized enzyme was fully active for five cycles of use. However, immobilization decreased enzyme activity to around 15%. This seems to be mainly due to diffusion limitations of the starch inside the pores of the biocatalyst particles. A fifteen-fold increase in the Km was noticed, while the decrease of Vmax was only 30% (10.1 U mg-1 protein and 7.03 U mg-1 protein for free and immobilized preparations, respectively). © 2013 Elsevier Ltd.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

The effects of soybean and castorbean meals were evaluated separately, and in combinations at different ratios, as substrates for lipase production by Botryosphaeria ribis EC-01 in submerged fermentation using only distilled water. The addition of glycerol analytical grade (AG) and glycerol crude (CG) to soybean and castorbean meals separately and in combination, were also examined for lipase production. Glycerol-AG increased enzyme production, whereas glycerol-CG decreased it. A 24 factorial design was developed to determine the best concentrations of soybean meal, castorbean meal, glycerol-AG, and KH2PO4 to optimize lipase production by B. ribis EC-01. Soybean meal and glycerol-AG had a significant effect on lipase production, whereas castorbean meal did not. A second treatment (22 factorial design central composite) was developed, and optimal lipase production (4,820 U/g of dry solids content (ds)) was obtained when B. ribis EC-01 was grown on 0.5 % (w/v) soybean meal and 5.2 % (v/v) glycerol in distilled water, which was in agreement with the predicted value (4,892 U/g ds) calculated by the model. The unitary cost of lipase production determined under the optimized conditions developed ranged from US$0.42 to 0.44 based on nutrient costs. The fungal lipase was immobilized onto Celite and showed high thermal stability and was used for transesterification of soybean oil in methanol (1:3) resulting in 36 % of fatty acyl alkyl ester content. The apparent K m and V max were determined and were 1.86 mM and 14.29 μmol min -1 mg-1, respectively. © 2013 Springer Science+Business Media New York.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

The 131I (radioactive iodine) is one of the most used radionuclides in nuclear medicine for diagnosis and treatment. The present study evaluates the dosimetric aspects related to radioiodine therapy after thyroidectomy in patients with thyroid cancer. The samples were studied with 50 patients undergoing treatment, by assessing the exposures of workers (nursing assistants, staff hygiene, medical and physical), the general public (accompanying and family members) and on the environment. To evaluate the workers, was made a survey of the environmental conditions of the room radioiodine and routines adopted by them during the treatment period. Estimating the dose equivalent per month for each employee, we observed that the maximum levels obtained for nursing assistants, the team of hygiene, medical and physicians were considered low in relation to the extent permitted by law. In order to assess the public, some situations have been suggested for the calculation of equivalent doses in which it was possible to verify the fundamental importance of isolating the patient in the 2 days first. Regarding the environment, the radioactive waste generated by patient had volume of 1.0 m3 and activity estimated at 0.91 mCi, taking a decay time for eliminating them about 75 days to reach the allowable value of 2 μCi / kg system of collecting garbage. Therefore, all radioactive waste removed from the patient's room should be sent to the warehouse for temporary storage of radioactive waste, located away from normal work areas

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Relevância:

20.00% 20.00%

Publicador:

Resumo:

A contaminated site from a downstream municipal solid waste disposal site in Brazil was investigated by using a 3D resistivity and induced polarization (IP) imaging technique. This investigation purpose was to detect and delineate contamination plume produced by wastes. The area was selected based on previous geophysical investigations, and chemical analyses carried out in the site, indicating the presence of a contamination plume in the area. Resistivity model has successfully imaged waste presence (rho < 20 Omega m), water table depth, and groundwater flow direction. A conductive anomaly (rho < 20 Omega m) outside wastes placement was interpreted as a contamination plume. Chargeability model was also able to imaging waste presence (m > 31 mV/V), water table depth, and groundwater flow direction. A higher chargeability zone (m > 31 mV/V) outside wastes placement and following conductive anomaly was interpreted as a contamination plume. Normalized chargeability (MN = m/rho) confirmed polarizable zone, which could be an effect of a salinity increase (contamination plume), and the clay presence in the environment.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The use of post-consumer materials is directly related to reducing the cost of production and extraction of natural resources. Non-recyclable materials are randomly disposed in the environment. Brazil is one of the largest consumers of PET (polyethylene terephthalate) bottles. The purpose of this paper is to describe the opportunities and challenges of the logistics model for post-consumer PET bottle recycling in Brazil, while providing knowledge of its practices along the recycling chain. The results describe the need to educate those directly and indirectly involved in the process: to reduce consumption in order to reduce the amount of waste generated: to structure the post-consumer reverse chain and engage industrial sectors and government, through public policies, to support cleaner technologies along the PET bottle production chain. (C) 2010 Elsevier B.V. All rights reserved.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In the first paper of this paper (Part I), conditions were presented for the gas cleaning technological route for environomic optimisation of a cogeneration system based in a thermal cycle with municipal solid waste incineration. In this second part, an environomic analysis is presented of a cogeneration system comprising a combined cycle composed of a gas cycle burning natural gas with a heat recovery steam generator with no supplementary burning and a steam cycle burning municipal solid wastes (MSW) to which will be added a pure back pressure steam turbine (another one) of pure condensation. This analysis aims to select, concerning some scenarios, the best atmospheric pollutant emission control routes (rc) according to the investment cost minimisation, operation and social damage criteria. In this study, a comparison is also performed with the results obtained in the Case Study presented in Part I. (c) 2007 Elsevier Ltd. All rights reserved.