• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 2
  • Tagged with
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Remo??o de elementos t?xicos em efluente proveniente da descontamina??o de madeira tratada com arseniato de cobre cromatado

Santos, Heldiane Souza dos 07 January 2014 (has links)
Made available in DSpace on 2015-04-14T13:59:03Z (GMT). No. of bitstreams: 1 453334.pdf: 1788404 bytes, checksum: e0369e72898236a732dd1176eef0a02c (MD5) Previous issue date: 2014-01-07 / The use of inorganic preservative CCA (chromated copper arsenate) for wood preservation has been an alternative to increase its durability therefore generate large volumes of wastewater, either in plants as in -decontamination processes of the treated wood. The elements Cu, Cr and As are toxic components present in the CCA and, according to Brazilian environmental legislation, the effluents of any productive activity can only be discharged, if they comply with the emission standards stipulated. Thus, the main objective of this work was to develop a method for the treatment of effluent generated from the decontamination of CCA-treated wood, which evaluated the total precipitation of Cu, Cr and As and Cu electrowinning, processes studied were used in wastewater treatment of different wood species (Eucalyptus spp e Pinus resinosa). With the methodologies developed above was possible to obtain percentage of 98.5 % total removal of elements using 1,180 mg L-1 of Fe (III) and Ca(OH)2 for pH adjustment . It was possible to recover about 91% of Cu in the effluent when it applied a current of 5 A for 90 min, utilizing anodes and cathodes of stainless steel (AISI 302). The results showed that treatments proposed for effluent from CCA-treated wood were satisfactory, at the end of the process it was obtained a a suitable effluent for disposal in accordance with the emission standards set by federal and state environmental laws / A utiliza??o do preservante inorg?nico CCA (Arseniato de Cobre Cromatado) para preserva??o de madeira tem sido uma alternativa para aumentar sua durabilidade gerando grande volume de efluentes, tanto nas usinas de preserva??o como em processos de descontamina??o da madeira tratada. Os elementos Cu, Cr e As s?o componentes t?xicos presentes no CCA e os efluentes de qualquer atividade produtiva somente podem ser lan?ados em corpos d ?gua superficiais, se estiverem de acordo com os padr?es de emiss?o estipulados pela legisla??o ambiental brasileira. Desta forma, o objetivo principal deste trabalho foi desenvolver um m?todo para o tratamento de efluente, gerado a partir da descontamina??o da madeira tratada com CCA, em que se avaliou a precipita??o total dos elementos Cu, Cr e As e a eletrorrecupera??o de Cu, os processos de tratamento estudados foram utilizados em efluentes de diferentes esp?cies de madeira (Eucalyptus spp e Pinus resinosa). Com as metodologias desenvolvidas foi poss?vel obter percentuais acima de 98,5 % de remo??o total dos elementos utilizando 1180 mg L-1 de Fe(III) e Ca(OH)2 para ajuste do pH. Foi poss?vel ainda recuperar cerca de 91 % de Cu do efluente quando se aplicou uma corrente de 5 A durante 90 min, utilizando c?todos e ?nodos de a?o inoxid?vel (AISI 302). Os resultados indicaram que os tratamentos propostos para os efluentes provenientes da madeira tratada com CCA foram satisfat?rios, pois ao final dos processos obteve-se um efluente adequado para o descarte de acordo com os padr?es de emiss?o estipulados pela legisla??o ambiental nacional e estadual.
2

Variabilidade de elementos qu?micos de solos em uma ?rea de atua??o da ind?stria petrol?fera, no munic?pio de Ass?-RN, utilizando digest?o ?cida assistida por microondas

Silva, Cosme Oliveira da 31 March 2014 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-04-26T19:29:13Z No. of bitstreams: 1 CosmeOliveiraDaSilva_DISSERT.pdf: 3405424 bytes, checksum: 77af285a8e7c8fecd07283dc05e4ed95 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-04-28T23:43:19Z (GMT) No. of bitstreams: 1 CosmeOliveiraDaSilva_DISSERT.pdf: 3405424 bytes, checksum: 77af285a8e7c8fecd07283dc05e4ed95 (MD5) / Made available in DSpace on 2016-04-28T23:43:19Z (GMT). No. of bitstreams: 1 CosmeOliveiraDaSilva_DISSERT.pdf: 3405424 bytes, checksum: 77af285a8e7c8fecd07283dc05e4ed95 (MD5) Previous issue date: 2014-03-31 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / Nas ?ltimas d?cadas, a preocupa??o com os processos de contamina??o antr?pica do solo por metais e demais contaminantes, vem crescendo significativamente, dessa forma a cada dia, a necessidade de se conhecer a composi??o qu?mica natural dos diversos tipos de solos torna-se cada vez mais constante. Esse conhecimento torna-se importante principalmente para a agricultura, que necessita da quantifica??o de elementos qu?micos, em uma determinada ?rea, uma vez existindo elementos que s?o ambientalmente dispon?veis e necess?rios para o crescimento das plantas. Por?m, existem tamb?m os que s?o considerados t?xicos. O presente trabalho tem como objetivo principal avaliar a variabilidade vertical dos elementos Al, Ca, Co, Cr, Cu, Fe, K, Mg, Mn, Na, P, Ni, Pb, V e Zn, al?m do pH. Comparando duas digest?es HNO3 e HNO3/HCl e duas fra??es < 180 > 63 e < 63 ?m. Para isto, foram coletadas 16 amostras em quatro n?veis amostrais: 0-20 cm,35-55 cm, 70-90 cm e 105-125 cm, localizadas no munic?pio de Ass? ? RN, em uma ?rea situada a cerca de 300 metros a norte da Esta??o de Tratamento de Petr?leo de Estreito (ET-B), operada pela PETROBRAS. Para a valida??o dos dados, realizou-se tamb?m, um estudo estat?stico para avaliar a precis?o e a exatid?o dos dados obtidos. Concluiu-se com esse trabalho, que a maioria dos elementos apresentou uma variabilidade m?dia, sendo que a fra??o mais fina apresentou uma varia??o maior de um n?vel amostral para outro. J? a fra??o mais grossa apresentou uma varia??o menor. Os maiores teores foram encontrados na fra??o mais fina, bem como, os resultados mais eficientes foram encontrados na digest?o com HNO3. / In recent decades, the concern with the processes of contamination soil anthropogenic by metals and other contaminants, is growing significantly, in this way every day, the need to know the natural chemical composition of the various soil types becomes increasingly constant. This knowledge becomes particularly important to agriculture, which requires the quantification of chemical elements in a given area, since there are elements that environmentally available and necessary for plant growth. However, there are also those that are considered toxic. This study aims to evaluate the vertical variability elements of Al, Ca, Co, Cr, Cu, Fe, K, Mg, M, Na, P, Ni, Pb, V and Zn, beyond pH. Comparing two digestions HNO3/HCl HNO3 and two fractions < 180 > 63 and < 63 pm. To this, 16 samples were collected in four sampling levels: 0-20 cm, 35-55 cm, 70-90 cm and 105-125 cm, located in the municipe of Assu - RN in an area located about 300 meters northern Treatment Plant of Oil Estreito (ET - B), operated by PETROBRAS. To validate the data, also was held a statistical study to assess the accuracy and the accuracy of the data. It was concluded from this work that most elements showed an average variability with the finest fraction showed a greater variation from one sample to another level. Have the thickest fraction showed less variation. The highest levels were found in the finest fraction, as well as the most efficient results were found in HNO3 digestion.

Page generated in 0.0173 seconds