Castro, J.

Fernandes, Bruno Daniel

Quintelas, C.

Tavares, M. T.

Universidade do Minho: RepositoriUM

COMPARISON BETWEEN THE BIOSORPTION PERFORMANCE OF THREE DIFFERENT BIOFILMS SUPPORTED ON GAC FOR  THE REMOVAL OF CR (VI) C. Quintelas, B. Fernandes, J. Castro, T. Tavares Centro de Engenharia Biológica, Universidade do Minho, 4710-351 Braga, Portugal  This study aims the investigation of the behaviour of three different biofilms supported on granular activated carbon (GAC) in terms of the removal of chromium (VI). The effect of the initial concentration of metal was tested, the polysaccharide and polymeric net were quantified and the application of these systems to a real effluent was made. The support used for the biofilm formation was GAC from MERCK. The microorganisms used were three different bacteria: Bacillus circulans, E. coli and Streptococcus equisimilis (Spanish Type Culture Collection). Minicolumns (internal diameter = 2 cm, ht = 30 cm) were used for open systems studies, partially filled with GAC (15 g) covered with the three different biofilms. The metal solutions were passed through the column with a flow rate of 5 ml/min (residence time of 19 min). Samples (5 ml) were taken, centrifuged and analyzed for metals using atomic absorption spectrophotometry, AAS. The production of polysaccharides is higher for Bacillus circulans follow by Streptococcus equisimilis and E. coli (9.19 mg/gbiosorbent, 7.24 mg/gbiosorbent, 4.77 mg/gbiosorbent). These results reveled a very good adhesion of the bacteria to the GAC. The results showed metal uptake values of 5.82 mg/gbiosorbent, 5.35 mg/gbiosorbent and 4.61 mg/gbiosorbent, respectively for Streptococcus equisimilis, Bacillus circulans and E.coli and for the the initial concentration of 100 mg/l. Studies made with the industrial effluent showed values of Cr uptake of 0.10 mg/gbiosorbent, 0.093 mg/gbiosorbent and 0.090 mg/gbiosorbent, respectively for Streptococcus equisimilis, E. coli and Bacillus circulans for an initial concentration of 4.2 mg/l. These results showed that the biofilms tested are very promising for the removal of Cr (VI) in industrial wastewater. 

Comparison between the biosorption performance of three different biofilms supported on GAC for removal of Cr(VI)

http://repositorium.sdum.uminho.pt/bitstream/1822/5516/1/Quintelas-A263%5b1%5d.pdf

Comparison between the biosorption performance of three different biofilms supported on GAC for removal of Cr(VI)

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Universidade do Minho: RepositoriUM