Metals uptake by live yeast and heat-modified yeast residue

  • Geórgia Labuto Universidade Federal de São Paulo (Unifesp)
  • Bianca Trama Universidade Federal de São Paulo (Unifesp)
  • Geison Castro da Silveira Gueller Universidade de São Paulo
  • Bruna de Souza Guarnieri Universidade de São Paulo
  • Fernando Vitorino da Silva Universidade Federal de São Paulo (Unifesp)
  • Roberta Collazo Universidade Federal de São Paulo (Unifesp)
Keywords: biosorption, metals sorption, modification of the biosorbent, sorption sites

Abstract

This study evaluated the biosorption of Cd2+, Cr3+, Pb2+ and Cu2+ at pHs 3, 4, 5 and 6 for Saccharomyces cerevisiae both alive and biologically inactivated by different heating procedures (oven, autoclave or spray dry technique originated from alcohol industry). The material inactivated by autoclave (IA, at 120°C, 30 min) had the best performance for metals uptake: 1.88 ± 0.07 (Cu2+), 2.22 ± 0.02 (Cr3+) and 1.57 ± 0.08 g kg-1 (Pb2+). For Cd2+; while the material inactivated by spray dry (RY) presented the higher sorption capacity, 2.30 ± 0.08 g kg-1. The sorption studies showed that the biosorbent materials presented different sorption capacities and an ideal sorption pH. The sorption sites were investigated by potentiometric titration and FT-IR and showed that different heating processes used to inactivate biological samples produce materials with different characteristics and with a diverse sorption capacity due to modification of the available sorption sites. This suggests that inactivation by heating can be an alternative to improve the performance of biosorbents. The main sorption sites for each material were phenolic for live yeast (LY) and carboxylic for yeast inactivated by heating in an autoclave (IA).

Author Biographies

Geórgia Labuto, Universidade Federal de São Paulo (Unifesp)
Instituto de Ciências Ambientais, Químicas e Farmacêuticas Departamento de Ciências Exatas e da Terra
Bianca Trama, Universidade Federal de São Paulo (Unifesp)
Diadema, Instituto de Ciências Ambientais, Químicas e Farmacêuticas Departamento de Ciências Exatas e da Terra
Geison Castro da Silveira Gueller, Universidade de São Paulo
São Paulo, Instituto de Biociências da Universidade de São Paulo
Bruna de Souza Guarnieri, Universidade de São Paulo
São Paulo, Escola de Artes, Ciências e Humanidades
Fernando Vitorino da Silva, Universidade Federal de São Paulo (Unifesp)
São Paulo, Nestlé Brazil
Roberta Collazo, Universidade Federal de São Paulo (Unifesp)
São Paulo, GE Water & Process Technologies
Published
23/06/2015
Section
Papers