Utilization of an Activated Sludge for the Improvement of an Existing Thermophilic Wastewater Treatment System

Removal kinetics of acetone and MIBK from a complex industrial wastewater by an acclimatized activated sludge

“…Acetone has a very low octanol/water partition coefficient, K ow , of 0.575 [21]. The observation that acetone is not greatly adsorbed onto suspended solids found here is in agreement with the reports in the literature [6,8,15,16]. The data obtained were used to describe the volatilization of acetone from this experiment, with a first-order rate (K v ) constant of 0.58 day −1 (r 2 = 0.66, data not shown).…”

“…The system consistently exhibited virtual complete removal of acetone and MIBK. It was previously determined that biodegradation was the primary pathway of the VOC removal accounting for the bulk of the acetone and MIBK disappearance (approximately 90% by mass) and volatilization accounting for approximately 10% by mass, of the VOC removal from this system [16]. These results clearly demonstrated that the biological sludges in this system were acclimatized to the wastewater matrix and had been able to biodegrade acetone and MIBK.…”

“…As mentioned elsewhere [16,17] and shown above, the activated sludge utilized as seed had a demonstrated ability to biodegrade acetone and MIBK down to the MDL of 10 g/L for acetone and 5 g/L for MIBK. The return activated sludge TSS in the pilot scale system at the time of the biodegradation studies was 5430 mg/L and the VSS:TSS ratio for the system was 0.7 while the acetone and MIBK concentrations in the initial seed sludge were at their respective MDLs.…”

“…This would then imply that the Barton et al [19] study would have had a much greater active fraction of biomass, whereas the active fraction of the biomass in this study would have been significantly lower. Additionally, the pulp mill influent experiments were operated at 30 • C, where the present work was performed at room temperature of approximately 20 • C. Furthermore, the influent wastewater used in the present work has been reported to contain substantial amounts of VSS [16,17] that may not contribute to active biomass. However, it should be mentioned that the influent VSS of the wastewater utilized in the present work does not contribute a significant BOD fraction.…”

“…The influent wastewater was characterized by containing varying concentrations of acetone and MIBK. Samples of acclimatized biomass were taken directly from the return activated sludge of the operating pilot scale-activated sludge system [16,17].…”