For the slurry system, autoclaved (15 min at 121 C) sea-tidal flat sediment (sampled in August, 2012) was resuspended in autoclaved seawater to be approximately 40% (w/v). Sterile 160 mL serum bottles containing 10 mL of 40% sterile slurry or autoclaved seawater were prepared for the slurry and seawater systems, respectively, and 2.4 lL of BTEX mixture was injected into respective bottles with a microsyringe.