Simultaneous removal of sulfate and arsenic using immobilized nontraditional SRB mixed culture and alternative low-cost carbon sources.
Nenhuma Miniatura disponível
Data
2017
Título da Revista
ISSN da Revista
Título de Volume
Editor
Resumo
This study was designed to obtain simultaneous sulfate (SO4
2−) and As(III) ions removal by non-traditional
sulfate-reducing bacteria (SRB) growing in the presence of a protein biomass (PCF), a solid residual material
produced by the poultry industry. Microbial cells and PCF were immobilized into calcium alginate beads to
reduce mass losses. Microbial consortium efficiency was tested under different operational conditions: sodium
lactate, glycerol and PCF as carbon sources; increasing As(III) content; acidic pH (5.0). Microbial diversity was
evaluated by PCR-DGGE. Pantoea agglomerans, Enterobacter sp., Citrobacter sp., Cupriavidus metallidurans,
Ralstonia sp. and Burkholderia cepacia were found. With the aim to obtain SO4
2− and As(III) simultaneous removal,
three semi-continuous up-flow reactors were constructed and operated for more than 100 days to prove
their feasibility and reliability. Both SO4
2− and As(III) ions were removed with 74.8% and 80% efficiency,
respectively. Solid products were characterized by SEM-EDX, confirming PCF and non-traditional SRB roles
during arsenic immobilization. Arsenic/sulfur compounds (possibly As/sulfides) were produced by reaction
between As(III) and biogenic sulfide. Microbial consortium proved its ability of growing in an acidic environment
without losing its sulfate reductive capacity by using glycerol and PCF as alternative carbon sources and
tap water as micronutrients source. The non-traditional SRB culture removed both SO4
2− and As(III) ions simultaneously,
with no prior step needed to guarantee As(III) oxidation to As(V). Two different mechanisms
could be involved: (i) precipitation as arsenic sulfide or, (ii) adsorption onto PCF/cells calcium alginate beads.
Descrição
Palavras-chave
Glycerol, Semi-continuous up-flow bioreactor, Arsenite, Calcium alginate beads
Citação
MATOS, L. P. de et al. Simultaneous removal of sulfate and arsenic using immobilized nontraditional SRB mixed culture and alternative low-cost carbon sources. Chemical Engineering Journal, v. 334, p. 1630-1641, 2017. Disponível em: <https://www.sciencedirect.com/science/article/pii/S1385894717319472>. Acesso em: 05 abr. 2018.