Discussion

Discussion Bioreactor is referring to a device that supports a b iologically active environment. A  bioreactor is a vessel in which a chemical process is carried out which involves organisms organisms or  biochemically active substances. This device with such delicate process has some delicate parts which need to be taken care properly. One of the fragile parts in bioreactor is the sensor probes. During the experiment, the bioreactor used was ! and "#!. $t was found that we do not get an accurate % !a value. $t is important to get an accurate % !a because it describes the efficiency with which oxygen can be delivered to a bioreactor for a given set of operating conditions. The measurement of % !a provides an important information about the bioreactor. $t is suspected that the ! bioreactor that was used during the e xperiment might have malfunction while collecting the data. &hile doing the first part of the experiment, the rp m used for the bioreactors are ##, '##, (## and )## rpm. The reading was taken at every # second interval until a constant saturation value* +! is achieved. Based on the graph that was taken, the % !a value for !  bioreactor are #.###), #.##"", #.##", #.##". The % !a value for "#! bioreactor are #.##', #.##-", #.##', #.##-. There are no similarities between the two value of % !a from different  bioreactors. /upposedly, there should be at least one % !a value that is the same. This mistake of the reading might come from the malfunction of the ! bioreactor. bioreactor. 0owever there is a sample calculation that was done using the % !a value to show the scale up factor and to observe the influence on the operating conditions. &hile doing the second part of the experiment, the agitator speed remains the same which is -## rpm while the air flow rate is changed for every reading which are ", , 1, ' !2min. The reading was taken at every # second interval until a constant saturation value *+! is achieved. Based on the graph, the % !a value for ! bioreactor are #.##"", #.##"1, #.##"' , #.##"-. The % !a value for "#! bioreactor are #.##1, #.##1-, #.##'3, #.##--. There might be some problem on the "#! bioreactor whereby there are no indicator for " !2min. The reading might have differ from the accurate reading and the reading might not be consistent. co nsistent. 0owever, the sample calculation to calculate the scale up factor by using % !a to show the scale up factor and to observe the influence on the operating conditions have been done. The % !a value used for

the calculation is only an assumption and have nothing to do with the data collected from the experiment.

There are plenty of reason that cause the value of % !a to be unobtainable. $t is mainly due to the controlling the air flow rate. The metal ball that is used to measure the flow rate is very hard to be controlled. 4oreover, there is no indication for "!2min. Therefore an assumption was used to assume that the metal ball was at "!2min. $t may be less which cause the result to differ and make the % !a value to be unobtainable.