Gas-liquid oxygen transfer in aerated and agitated slurry systems with high solid volume fractions

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Switzerland : 1996), 2018-10, Vol.350, p.1073-1083
• Main Authors: Pino-Herrera, Douglas O., Fayolle, Yannick, Pageot, Sylvain, Huguenot, David, Esposito, Giovanni, van Hullebusch, Eric D., Pechaud, Yoan
• Format: Article
• Language: English
• Subjects: Environmental Sciences; Oxygen mass transfer; Oxygen transfer coefficient model; Slurry bioreactor; Soil slurry
• ISSN: 1385-8947; 1873-3212
• DOI: 10.1016/j.cej.2018.05.193

•Clay presence has a negative impact on the oxygen transfer coefficient (kLa).•Bubble contamination seems to cause the decrease in kLa at low clay content (XS).•Changes in density and viscosity mainly determine the decrease in kLa at high XS.•Clay content has little influence on the effects of air flow and agitation on kLa.•A model to predict kLa in slurry using Archimedes number is proposed. Oxygen transfer can be a limiting step in aerobic biodegradation processes. Therefore, this process has been widely investigated for wastewater treatment, but only few research works have been done on soil slurry systems. This study focuses on the gas-liquid oxygen mass transfer in clay slurry conditions in an aerated and agitated reactor using a marine propeller. Conversely to most studies on oxygen transfer, pneumatic power input is not negligible compared to mechanical power input. Clay presence has a negative impact on the oxygen transfer. However, the effect of agitation and aeration on this process remains unaffected at the clay concentrations tested. Three different phases explaining the depletion in the oxygen transfer rate are hypothesized. A model to predict the oxygen transfer coefficient in slurry reactors, including the three operational parameters tested within their respective ranges, is proposed.