Abstract:
The biosorption efficiency of biotraps consisting of chemically immobilized
Rhizobium BJVr 12 exopolysaccharides in adsorbing
Cu+2 ions was studied. Preliminary screening using the solubility test
revealed that the most suitable microbial carrier is the ratio 2A1(OH); :
1 SiO; of 20% aluminum hydroxide and silicon dioxide. The effect of
flow rate, time of collection, and kind of biotrap (w/ or w/o EPS) in the
percent removal of Cu+2 ions in wastewater was determined. Atomic
Absorption Spectroscopy was used to determine the residual Cu+2 ion
concentration of the collected 10 ml samples. Three-factor Factorial in
CRD to analyze simultaneously the effect of the three factors (flow
rate, time of collection and kind of biotrap) and the Duncan’s Multiple
Range Test to determine the optimum condition for each factor were
used to analyze the data. Results showed that flow rate and time of
collection significantly affect the percent removal of Cu™ ions in the
wastewater. Maximum percent removal (%) of Cu+2 ions (98.25%)
occurred at the 6-min (0.10 hr) time interval. A slower flow rate (1
ml/min) showed greater adsorption efficiency. Both biotraps (w/ and
w/o EPS) exhibited high percentage removals of Cu+2 ions. Although
the percent removal of Cu+2 ions by the biotraps without EPS is
significantly greater than the biotraps with EPS for the 2.5 ml/min and
5 ml/min flow rates, no significant difference between the two was
noted for the 1 m/min flow rate.
