between the plates, packing per stage. Aeration is provided from the bottom of the
column and mixing achieved by the reciprocating plates fixed on the central
shaft [25].
3.3.5 Bubble Column Reactors
In bubble column reactor, the aeration and mixing are brought about by air flow from
the bottom of the column. These are cylindrical columns that are aerated at the
bottom where the air produces a random flow pattern and thus similar to pneumatically agitated reactors as shown in Fig. 5 [68]. The desired temperature is controlled
by passing water from the bath into the jacket around the column. Air flow rate is the
most important factor to be considered in this reactor [24]. Bubble columns in series
are reported for continuous generation of biogenic Fe
3+ to be used as lixiviant in the
first column and for the spent medium bioleaching process in the second [69]. The
e-waste loading to be used in this reactor should be optimized such that the air can
homogeneously pass through the liquid and solid phases. The particle size range
should be selected to reduce pressure drop. A comparative study on the stirred tank
reactor with the bubble column suggests that the column reactor is closely efficient
as the mechanically stirred reactor [31].
Fig. 5 Bubble column
reactor
38
M. Minimol et al.
column and mixing achieved by the reciprocating plates fixed on the central
shaft [25].
3.3.5 Bubble Column Reactors
In bubble column reactor, the aeration and mixing are brought about by air flow from
the bottom of the column. These are cylindrical columns that are aerated at the
bottom where the air produces a random flow pattern and thus similar to pneumatically agitated reactors as shown in Fig. 5 [68]. The desired temperature is controlled
by passing water from the bath into the jacket around the column. Air flow rate is the
most important factor to be considered in this reactor [24]. Bubble columns in series
are reported for continuous generation of biogenic Fe
3+ to be used as lixiviant in the
first column and for the spent medium bioleaching process in the second [69]. The
e-waste loading to be used in this reactor should be optimized such that the air can
homogeneously pass through the liquid and solid phases. The particle size range
should be selected to reduce pressure drop. A comparative study on the stirred tank
reactor with the bubble column suggests that the column reactor is closely efficient
as the mechanically stirred reactor [31].
Fig. 5 Bubble column
reactor
38
M. Minimol et al.