| Abstrak/Abstract |
This research was conducted to examine aerator microbubble compared to conventional aeration (blower) in formation of dissolved oxygen (DO), to measure standard oxygen transfer rate (SOTR) and standard aeration efficiency (SAE) as well as to consider the oxygen consumption of nile tilapia in order to predict the optimum stocking density. The results showed that aerator microbubble produced DO 6.58 ±0.03 ppm higher than that of aerator blower with DO value of 5.59 ±0.24 ppm (p<0,05) under air discharge of 3 L min-1. The increment of DO on aerator microbubble and blower was 2.13 and 1.14 ppm in average, respectively, from control. The values of SOTR and SAE on aerator microbubble were 0.007±0.001 kg O2 h-1 and 0.09 ± 0.006 kg O2 KW-1.h-1, respectively, higher than those of SOTR and SAE on aerator blower approximately 0.002±0.001 kg O2 h-1 and 0.02±0.01 kg O2 KW-1h-1, respectively. This experiment also tested DO value on recirculation medium with air discharge of 0.03 L sec-1, in which DO value of aerator microbubble was 7.44±0.14 ppm higher than those of aeration blower of 6.51±0.26, and no aeration as control of 5.35±0.06 ppm (p<0.05). The rate of oxygen consumption on feeded nile tilapia was higher than that on starved one. This rate was used to determine the optimum stocking density of fish, using DO value from aeration microbubble of recirculation system. It was concluded that aerator microbubble had higher DO value, transfered much oxygen and more saved the energy compared to aerator blower, and the prediction of stocking density using aerator microbubble was 62% higher than blower. |
