Bacterial Deposition in Porous Media: Effects of Cell-Coating, Substratum Hydrophobicity, and Electrolyte Concentration
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- 作者：Huub H. M. Rijnaarts ; Willem Norde ; Edward J. Bouwer ; Johannes Lyklema ; and Alexander J. B. Zehnder
- 刊名：Environmental Science & Technology
- 出版年：1996
- 出版时间：October 1996
- 年：1996
- 卷：30
- 期：10
- 页码：2877 - 2883
- 全文大小：805K
- 年卷期：v.30,no.10(October 1996)
- ISSN：1520-5851
文摘
Deposition of seven bacterial strains on sphericalglass and Teflon collectors was studied in vertical down-flow columns at an ionic strength (I) of 0.1 M.Thevarious bacteria had either one of the followingtypes of major cell-surface constituents: nonpolysaccharide (NP), amphiphilic (AMPH), or anionicpolysaccharide (AP) macromolecules. Deposition wasanalyzed in terms of the clean bed collision efficiency
0 (the probability of a cell to attach uponreachinga substratum free of cells) and a blocking factorB (the ratio of the area blocked by an attachedcellto the geometric area of a cell). The value of0decreased from 1.0 to about 0.01 in the following orderof cell-surface constituents/collector combinations: NP/Teflon and AMPH/Teflon > NP/glass > AMPH/glass, AP/Teflon, and AP/glass. The value forB,at a Peclet number of 1 × 105, increased fromabout3 to 18 in the order NP/low cell charge < NP or AMPH/high cell charge < AP/high cell charge. Thisindicatesthat cell-cell repulsion enhances blocking.Blockingis higher on Teflon than on glass. Most likelycell-surface macromolecules adsorb in the surroundings of the attached cells and enhance blocking onTeflon. The deposition of four bacterial strains wasinvestigated at 0.0001 M < I < 0.1 M. ForI valuessmaller than a critical level, 0 decreasedwithdecreasing I. The critical I is determinedby therange over which cell-surface macromolecules canpenetrate the repulsive Gibbs energy barrier betweencell and solid. The value for B increases about 1orderof magnitude upon changing I from 0.1 to 0.001M.Maximal control of microbial mobility in porous mediacan be reached in systems for which B and 0arehigh at high I (0.1 M): the high B valueminimizesthe occurrence of pore-clogging whereas the dependencies of 0 and B on I allowmanipulation of deposition by varying the ionic strength.
0 (the probability of a cell to attach uponreachinga substratum free of cells) and a blocking factorB (the ratio of the area blocked by an attachedcellto the geometric area of a cell). The value of0decreased from 1.0 to about 0.01 in the following orderof cell-surface constituents/collector combinations: NP/Teflon and AMPH/Teflon > NP/glass > AMPH/glass, AP/Teflon, and AP/glass. The value forB,at a Peclet number of 1 × 105, increased fromabout3 to 18 in the order NP/low cell charge < NP or AMPH/high cell charge < AP/high cell charge. Thisindicatesthat cell-cell repulsion enhances blocking.Blockingis higher on Teflon than on glass. Most likelycell-surface macromolecules adsorb in the surroundings of the attached cells and enhance blocking onTeflon. The deposition of four bacterial strains wasinvestigated at 0.0001 M < I < 0.1 M. ForI valuessmaller than a critical level, 0 decreasedwithdecreasing I. The critical I is determinedby therange over which cell-surface macromolecules canpenetrate the repulsive Gibbs energy barrier betweencell and solid. The value for B increases about 1orderof magnitude upon changing I from 0.1 to 0.001M.Maximal control of microbial mobility in porous mediacan be reached in systems for which B and 0arehigh at high I (0.1 M): the high B valueminimizesthe occurrence of pore-clogging whereas the dependencies of 0 and B on I allowmanipulation of deposition by varying the ionic strength.