TY - JOUR
T1 - Development of microbubble aerator for waste water treatment using aerobic activated sludge
AU - Terasaka, Koichi
AU - Hirabayashi, Ai
AU - Nishino, Takanori
AU - Fujioka, Satoko
AU - Kobayashi, Daisuke
PY - 2011/7/15
Y1 - 2011/7/15
N2 - In large-scale waste water treatment plants, the aerobic biochemical reactor is the most important process, where the oxygen supply into the microorganisms often limits the overall waste water treatment rate. On the other hand, several kinds of microbubble distributors have been developed to enrich the oxygen dissolution in water. Therefore, the application of microbubbles for a waste water treatment system was investigated in this study. The oxygen absorption performance of typical microbubble generators was compared with typical bubble generators. To evaluate each bubble generator, the liquid-phase volumetric oxygen transfer coefficient, gas hold-up and power consumption per unit liquid volume were measured in a bubble column attached to each bubble generator. All the microbubble generators allowed the oxygen to dissolve faster than the typical aerators. The spiral liquid flow type microbubble generator had the highest oxygen transfer coefficient even at a low air flow rate although it used more energy than the typical distributors. To improve an industrial waste water treatment system, a novel aeration system utilizing a spiral liquid flow type microbubble generator was proposed in this study. The present system has some advantages such as compact size, portability and fast oxygen dissolution rate. To ensure the performance for organic waste water treatment, the effects of the aeration rate, dissolved oxygen concentration and device properties on the specific consumption rate of model organic waste were investigated. For the novel aeration system, the most suitable conditions to treat organic waste were found.
AB - In large-scale waste water treatment plants, the aerobic biochemical reactor is the most important process, where the oxygen supply into the microorganisms often limits the overall waste water treatment rate. On the other hand, several kinds of microbubble distributors have been developed to enrich the oxygen dissolution in water. Therefore, the application of microbubbles for a waste water treatment system was investigated in this study. The oxygen absorption performance of typical microbubble generators was compared with typical bubble generators. To evaluate each bubble generator, the liquid-phase volumetric oxygen transfer coefficient, gas hold-up and power consumption per unit liquid volume were measured in a bubble column attached to each bubble generator. All the microbubble generators allowed the oxygen to dissolve faster than the typical aerators. The spiral liquid flow type microbubble generator had the highest oxygen transfer coefficient even at a low air flow rate although it used more energy than the typical distributors. To improve an industrial waste water treatment system, a novel aeration system utilizing a spiral liquid flow type microbubble generator was proposed in this study. The present system has some advantages such as compact size, portability and fast oxygen dissolution rate. To ensure the performance for organic waste water treatment, the effects of the aeration rate, dissolved oxygen concentration and device properties on the specific consumption rate of model organic waste were investigated. For the novel aeration system, the most suitable conditions to treat organic waste were found.
KW - Aeration
KW - Aerobic activated sludge
KW - Bubble
KW - Filtration
KW - Multiphase flow
KW - Waste water treatment
UR - http://www.scopus.com/inward/record.url?scp=79958731026&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=79958731026&partnerID=8YFLogxK
U2 - 10.1016/j.ces.2011.02.043
DO - 10.1016/j.ces.2011.02.043
M3 - Article
AN - SCOPUS:79958731026
VL - 66
SP - 3172
EP - 3179
JO - Chemical Engineering Science
JF - Chemical Engineering Science
SN - 0009-2509
IS - 14
ER -