Retention and transport of an anaerobic trichloroethene dechlorinating microbial culture in anaerobic porous media

• We examined the transport and retention of three anaerobic biodegradation species.
• The three distinct species had similar transport and deposition behaviors.
• Three species displayed similar transport behaviors at three tested ionic strengths.
• Increasing ionic strength increased their retention in the column.
• The similar transport behaviors were preferred for successful bioremediation.

The influence of solution chemistry on microbial transport was examined using the strictly anaerobic trichloroethene (TCE) bioaugmentation culture KB-1®. A column was employed to determine transport behaviors and deposition kinetics of three distinct functional species in KB-1®, Dehalococcoides, Geobacter, and Methanomethylovorans, over a range of ionic strengths under a well-controlled anaerobic condition. A quantitative polymerase chain reaction (qPCR) was utilized to enumerate cell concentration and complementary techniques were implemented to evaluate cell surface electrokinetic potentials. Solution chemistry was found to positively affect the deposition rates, which was consistent with calculated Derjaguin–Landau–Verwey–Overbeek (DLVO) interaction energies. Retained microbial profiles showed spatially constant colloid deposition rate coefficients, in agreement with classical colloid filtration theory (CFT). It was interesting to note that the three KB-1® species displayed similar transport and retention behaviors under the defined experimental conditions despite their different cell electrokinetic properties. A deeper analysis of cell characteristics showed that factors, such as cell size and shape, concentration, and motility were involved in determining adhesion behavior.

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