Química Nova (Jan 2009)

Uso da cinza da casca do arroz (CCA) obtida da geração de energia térmica como adsorvente de Zn(II) em soluções aquosas Use of rice husk ash (RHA) obtained from thermal energy generation as Zn (II) adsorbent in aqueous solutions

  • Thiago Faheina Chaves,
  • Zilvanir Fernandes de Queiroz,
  • Diana Nara Ribeiro de Sousa,
  • José Hélio Saraiva Girão,
  • Esiana de Almeida Rodrigues

DOI
https://doi.org/10.1590/S0100-40422009000600003
Journal volume & issue
Vol. 32, no. 6
pp. 1378 – 1383

Abstract

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The removal study was conducted using 1.00 g of the rice husk ash (RHA) and 20.0 mL solution with concentrations in the range of 10-1000 mg/L of Zn(II). The influence of contact time, initial metal concentration, agitation and pH of the removal process was investigated. Superior removals to 95% were obtained at the end of 24 h of contact. The agitation increased in 20% the removal of Zn(II), being needed only 5 min to reach the equilibrium. The adsorption process was studied by the models of isotherms of Langmuir, Freundlich and BET, obtaining results of R L and 1/n for a process favorable of adsorption. BET isotherm best represents the equilibrium adsorption. The results showed that the RHA has the largest capacity and affinity for the removal of Zn(II).

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