Air-water partitioning equilibrium of tetrahydrofuran in an activated sludge system

This study evaluate the effect of liquid tetrahydrofuran (THF) concentration and biomass content on the THF air-water partitioning equilibrium for a simulated activated sludge system. The equilibrium of the partition at the air-water interface is given by a partitioning coefficient (pc) = Cg*/CL, where Cg* denotes the gaseous concentration in equilibrium with the aqueous THF concentration (CL). Variations of pc with CL in static pure water are evaluated, and high solubility of THF in water caused pc values to drop as the CL increased from 29.81 +/- 0.16 to 297.75 +/- 2.28 mg/L at a constant temperature of 27 degrees C. Meanwhile, the hydrophilicity of THF in water induced a biomass effect, causing pc to increase in the activated sludge liquor. Due to the co-effect of liquid THF concentration and biomass content, the pc values of THF for the liquor of mixed liquid suspended solid (MLSS) concentration = 1220 +/- 86 mg/L and THF CL = 242.91 +/- 69.09 mg/L increased 22.5% compared to those in the pure agitated water. The biomass effect on pc of hydrophilic VOC increases the gaseous VOC emission rate from the activated sludge facilities.