TY - JOUR
T1 - A different approach for predicting reaeration rates in gravity sewers and completely mixed tanks
AU - Lahav, Ori
AU - Binder, Assaf
AU - Friedler, Eran
PY - 2006/7
Y1 - 2006/7
N2 - A new semiempirical approach is presented for predicting air-to-water oxygen transfer rates in mixed tanks and gravity sewers, using methods adopted from mixing theory. First, a flocculation unit was used to impart selected mean velocity gradients (G) into a completely mixed tank, from which oxygen was first removed, and dissolved oxygen concentrations were measured with time. Regression analysis was used to fit the rate of oxygen transfer equation against G. The reaeration rate in completely mixed reactors was found to be proportional to G2 (R2 = 0.987). Subsequently, G was linked to headless in sewers, and the equation was calibrated using a slope-adjustable, 27-m-long, gravity-flow, experimental sewer (internal diameter, D = 0.16 m). Here, the reaeration rate was proportional to G 1 (R2 = 0.981). The equation was compared with existing oxygen transfer models and validated against experimental data from the literature, to which the overall mass transfer coefficient for oxygen, K La, derived by the new approach, conformed well.
AB - A new semiempirical approach is presented for predicting air-to-water oxygen transfer rates in mixed tanks and gravity sewers, using methods adopted from mixing theory. First, a flocculation unit was used to impart selected mean velocity gradients (G) into a completely mixed tank, from which oxygen was first removed, and dissolved oxygen concentrations were measured with time. Regression analysis was used to fit the rate of oxygen transfer equation against G. The reaeration rate in completely mixed reactors was found to be proportional to G2 (R2 = 0.987). Subsequently, G was linked to headless in sewers, and the equation was calibrated using a slope-adjustable, 27-m-long, gravity-flow, experimental sewer (internal diameter, D = 0.16 m). Here, the reaeration rate was proportional to G 1 (R2 = 0.981). The equation was compared with existing oxygen transfer models and validated against experimental data from the literature, to which the overall mass transfer coefficient for oxygen, K La, derived by the new approach, conformed well.
KW - Gas transfer
KW - Gravity sewers
KW - Mean velocity gradient
KW - Reaeration equation
UR - http://www.scopus.com/inward/record.url?scp=33746960229&partnerID=8YFLogxK
U2 - 10.2175/106143006X101764
DO - 10.2175/106143006X101764
M3 - 文章
C2 - 16929644
AN - SCOPUS:33746960229
VL - 78
SP - 730
EP - 739
JO - Water Environment Research
JF - Water Environment Research
SN - 1061-4303
IS - 7
ER -