Desorption of heavy metals from ion exchange resin with water and carbon dioxide

Adsorption and regeneration of ion exchange resins were studied using a subcritical solution of a CO₂-H₂O mixture and a fixed bed column. The commercial Amberlite IRC-50/IRC-86 cation exchange resins and Amberlite IRA-67 anion exchange resin were tested for heavy metals (Pb, Cu, Cd) adsorption from a solution with different initial metal concentrations at different temperatures. After adsorption, the loaded resins were regenerated with water and carbon dioxide at different temperatures and a pressure of 25 MPa. The efficiency of the IRC-50 resin was lower than that of the IRC-86 resin for the adsorption of metals like Cd, Cu and Pb. Results obtained for desorption of these metals indicated that the process could be used for Cd and in principle for Cu. Sorption of metal ions depended strongly on feed concentration. Mathematical modeling of the metal desorption process was carried out successfully as an extraction process. For this purpose, the VTII Model, which is applied to extraction from solids using supercritical solvents, was used in this work.

Dinâmica das transições quiral e de desconfinamento da cromodinâmica quântica com o modelo Polyakov-Nambu-Jona-Lasinio

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Search for heavy narrow dilepton resonances in pp collisions at root s=7 TeV and root s=8 TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Search for a Higgs boson decaying into a b-quark pair and produced in association with b quarks in proton-proton collisions at 7 TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Search for heavy resonances in the W/Z-tagged dijet mass spectrum in pp collisions at 7 TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Search for the standard model Higgs boson produced in association with a W or a Z boson and decaying to bottom quarks

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

Searches for light- and heavy-flavour three-jet resonances in pp collisions at root s=8 TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Search for pair production of excited top quarks in the lepton plus jets final state

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Heavy metals in cowpea (Vigna unguiculata L.) after tannery sludge compost amendment

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Heavy Metals Extracted by DTPA and Organic Acids from Soil Amended with Urban or Industrial Residues

Understanding soil responses to the application of urban or industrial residues is necessary. In the current experiment, both sources of residues were applied to the soil surface of a Hapludox soil for 8 years. The four residues studied were biodigested and centrifuged sewage sludge (LB and LC, respectively), steel slag from the metallurgic industry (E), and limed mud from the pulp and cellulose industry (LCal). The residues were applied at 0, 2, 4, and 8 Mg ha(-1) four times from 2002 to 2010 when soybean was cultivated in the summer and lopsided oat and sorghum were cultivated during the winter. The contents of heavy metals were evaluated with diethylenetriaminepentaacetic acid (DTPA) and organic acids. The LB was the residue that increased the contents of soil micronutrients and heavy metals to their greatest levels, although within limits that impair the risks of environmental contamination.