at Google ScholarTitle data
Mikutta, Robert ; Baumgärtner, Anja ; Schippers, Axel ; Haumaier, Ludwig ; Guggenberger, Georg:
Extracellular polymeric substances from Bacillus subtilis associated with minerals modify the extent and rate of heavy metal sorption.
In: Environmental Science & Technology.
Vol. 46
(2012)
Issue 7
.
- pp. 3866-3873.
ISSN 0013-936X
DOI: https://doi.org/10.1021/es204471x
Abstract in another language
Extracellular polymeric substances (EPS) are an important source oforganic matter in soil. Once released by microorganisms, a portion may be sorbed tomineral surfaces, thereby altering the mineral̀sability to immobilize heavy metals. EPS fromBacillus subtilis were reacted with Ca-saturated bentonite and ferrihydrite in 0.01 M KCl atpH 5.0 to follow the preferential uptake of EPS-C, -N, and -P. The sorption kinetics ofPb2+, Cu2+, and Zn2+ to the resulting EPS-mineral composites was studied in single andbinary metal batch experiments ([metal]total = 50 μM, pH 5.0). Bentonite sorbed muchmore EPS-C (18.5 mg g−1) than ferrihydrite (7.9 mg g−1). During sorption, EPS werechemically and size fractionated with bentonite favoring the uptake of low-molecularweight components and EPS-N, and ferrihydrite selectively retaining high-molecularweight and P-rich components. Surface area and pore size measurements by N2 gasadsorption at 77 K indicated that EPS altered the structure of mineral-EPS associations byinducing partial disaggregation of bentonite and aggregation of ferrihydrite. Whereas mineral-bound EPS increased the extentand rate of Pb2+, Cu2+, and Zn2+ sorption for bentonite, either no effect or a decrease in metal uptake was observed forferrihydrite. The extent of sorption always followed the order Pb2+ > Cu2+ > Zn2+, which also prevailed in binary Pb2+/Cu2+systems. In consequence, sorption of EPS to different minerals may have contrasting consequences for the immobilization ofheavy metals in natural environments by inducing mineral-specific alterations of the pore size distribution and, thus, of availablesorption sites.
Further data
| Item Type: | Article in a journal |
|---|---|
| Refereed: | Yes |
| Additional notes: | BAYCEER104303 |
| Institutions of the University: | Faculties > Faculty of Biology, Chemistry and Earth Sciences > Department of Earth Sciences > Chair Soil Ecology Research Institutions > Research Centres > Bayreuth Center of Ecology and Environmental Research- BayCEER Faculties Faculties > Faculty of Biology, Chemistry and Earth Sciences Faculties > Faculty of Biology, Chemistry and Earth Sciences > Department of Earth Sciences Research Institutions Research Institutions > Research Centres |
| Result of work at the UBT: | Yes |
| DDC Subjects: | 500 Science |
| Date Deposited: | 07 Aug 2015 06:59 |
| Last Modified: | 07 Aug 2015 06:59 |
| URI: | https://eref.uni-bayreuth.de/id/eprint/17671 |