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Sinorhizobium meliloti 1021 Exopolysaccharide as a Flocculant Improving Chromium(III) Oxide Removal from Aqueous Solutions.

Szewczuk-Karpisz K, Wiśniewska M, Pac M, Choma A, Komaniecka I - Water Air Soil Pollut (2014)

Bottom Line: Moreover, the stability of Cr2O3 suspension in the absence and presence of S. meliloti 1021 EPS was estimated.The pooled analysis of all obtained results showed that EPS causes chromium(III) oxide suspension destabilization in the whole examined pH range.The largest change in the system stability before and after the polymer addition was observed at pH 9.

View Article: PubMed Central - PubMed

Affiliation: Department of Radiochemistry and Colloid Chemistry, Faculty of Chemistry, Maria Curie Sklodowska University, M. Curie Sklodowska Sq. 3, 20-031 Lublin, Poland.

ABSTRACT
Chromium(III) oxide is an amphoteric, dark green solid. This most stable dye is widely used in construction and ceramic industries as well as in painting. In this study, the attempt is made to determine flocculating properties of exopolysaccharide (EPS) synthesized by the bacteria Sinorhizobium meliloti 1021, which would increase the efficiency of chromium(III) oxide removal from sewages and wastewaters. The conditions under which EPS is the most effective destabilizing component of chromium(III) oxide suspension have been determined too. In order to characterize the structure of electric double layer formed at the solid/supporting electrolyte (EPS) solution interface, electrokinetic potential measurements and potentiometric titration were performed. The EPS amount adsorbed on the chromium(III) oxide surface as a solution pH function was also measured. Moreover, the stability of Cr2O3 suspension in the absence and presence of S. meliloti 1021 EPS was estimated. The pooled analysis of all obtained results showed that EPS causes chromium(III) oxide suspension destabilization in the whole examined pH range. The largest change in the system stability before and after the polymer addition was observed at pH 9. It is probable that under these conditions bridging flocculation occurs in the examined system.

No MeSH data available.


Related in: MedlinePlus

Destabilization mechanism of the Cr2O3 suspension by Sinorhizobium meliloti 1021 exopolysaccharide at pH: a 3, b 4.6, c 7.6, d 9. At pH 3 and 4.6 system destabilization is based on adsorbent charge neutralization by adsorbed macromolecules. At pH 7.6 and 9 there is bridging flocculation in the examined systems
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Fig8: Destabilization mechanism of the Cr2O3 suspension by Sinorhizobium meliloti 1021 exopolysaccharide at pH: a 3, b 4.6, c 7.6, d 9. At pH 3 and 4.6 system destabilization is based on adsorbent charge neutralization by adsorbed macromolecules. At pH 7.6 and 9 there is bridging flocculation in the examined systems

Mentions: The proposed destabilization mechanisms of the chromium(III) oxide suspension in the presence of S. meliloti 1021 exopolysaccharide in four examined solution pH values are shown schematically in Fig. 8.Fig. 8


Sinorhizobium meliloti 1021 Exopolysaccharide as a Flocculant Improving Chromium(III) Oxide Removal from Aqueous Solutions.

Szewczuk-Karpisz K, Wiśniewska M, Pac M, Choma A, Komaniecka I - Water Air Soil Pollut (2014)

Destabilization mechanism of the Cr2O3 suspension by Sinorhizobium meliloti 1021 exopolysaccharide at pH: a 3, b 4.6, c 7.6, d 9. At pH 3 and 4.6 system destabilization is based on adsorbent charge neutralization by adsorbed macromolecules. At pH 7.6 and 9 there is bridging flocculation in the examined systems
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4127006&req=5

Fig8: Destabilization mechanism of the Cr2O3 suspension by Sinorhizobium meliloti 1021 exopolysaccharide at pH: a 3, b 4.6, c 7.6, d 9. At pH 3 and 4.6 system destabilization is based on adsorbent charge neutralization by adsorbed macromolecules. At pH 7.6 and 9 there is bridging flocculation in the examined systems
Mentions: The proposed destabilization mechanisms of the chromium(III) oxide suspension in the presence of S. meliloti 1021 exopolysaccharide in four examined solution pH values are shown schematically in Fig. 8.Fig. 8

Bottom Line: Moreover, the stability of Cr2O3 suspension in the absence and presence of S. meliloti 1021 EPS was estimated.The pooled analysis of all obtained results showed that EPS causes chromium(III) oxide suspension destabilization in the whole examined pH range.The largest change in the system stability before and after the polymer addition was observed at pH 9.

View Article: PubMed Central - PubMed

Affiliation: Department of Radiochemistry and Colloid Chemistry, Faculty of Chemistry, Maria Curie Sklodowska University, M. Curie Sklodowska Sq. 3, 20-031 Lublin, Poland.

ABSTRACT
Chromium(III) oxide is an amphoteric, dark green solid. This most stable dye is widely used in construction and ceramic industries as well as in painting. In this study, the attempt is made to determine flocculating properties of exopolysaccharide (EPS) synthesized by the bacteria Sinorhizobium meliloti 1021, which would increase the efficiency of chromium(III) oxide removal from sewages and wastewaters. The conditions under which EPS is the most effective destabilizing component of chromium(III) oxide suspension have been determined too. In order to characterize the structure of electric double layer formed at the solid/supporting electrolyte (EPS) solution interface, electrokinetic potential measurements and potentiometric titration were performed. The EPS amount adsorbed on the chromium(III) oxide surface as a solution pH function was also measured. Moreover, the stability of Cr2O3 suspension in the absence and presence of S. meliloti 1021 EPS was estimated. The pooled analysis of all obtained results showed that EPS causes chromium(III) oxide suspension destabilization in the whole examined pH range. The largest change in the system stability before and after the polymer addition was observed at pH 9. It is probable that under these conditions bridging flocculation occurs in the examined system.

No MeSH data available.


Related in: MedlinePlus