Investigation of the role of chemotaxis in bacterial transport through saturated porous media using Taguchi approach

•Contribution of chemotaxis to bacterial transport was significant in combination with the other effective factors.•Chemotaxis greatly influenced the spatial distribution of deposited bacteria.•Colloid filtration theory should be modified before application to motile bacteria.

It is generally agreed today that effective parameters such as ionic strength, surfactant concentration and the flow rate of the containing fluid have a significant impact on the bacterial transport through porous media. The present study aimed to investigate whether chemotaxis can equally contribute to bacterial deposition in the same environments. To this end, a series of experiments were designed using Taguchi approach in which saturated glass bead packed columns served as the porous media and naphthalene was used as chemo-attractant. Then the contributory role of the factors involved in bacterial filtration through porous media was carefully measured by employing related statistical analyses. The results revealed that the percentage value of chemotaxis contribution to the process was about 20% which was significant compared with ionic strength (43%), surfactant concentration (32%) and fluid flow rate (3%). Notably, the minimum bacterial transport through the columns was about 0.41 of the initial inlet concentration at optimal conditions.

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