BIOSORPTION OF Pb2+, Cd2+, & Ni2+ FROM WATERS BY ...

For the recovery of metal ions from the biosorbent, at first sorption experiment
was performed using 10.0 mL of 100.0 mg/L metal ion solution at pH 6.0 contacted
with 10.0 mg of biosorbent at 25ºC. Then, the desorption of Pb 2+ , Cd 2+ , and Ni 2+ was
carried out with 10.0 mL of 0.100 M HNO3, 0.100 M HCI, and 0.100 M Na-citrate for
15 min and the obtained results are given in Figure 3.18-3.19.
From the result, the desorption of Pb 2+ and Ni 2+ from Oocystis sp. is higher
when compared with Cd 2+ . In the case of Scenedesmus protuberans, Pb 2+ and Cd 2+
recovered in greater amount than Ni 2+ . Lower recovery of Ni 2+ from Scenedesmus
protuberans can be due to the higher affinity of Ni 2+ for this algae.
However, the treatment of Oocystis sp. and Scenedesmus protuberans with
HNO3 and HCI damaged the algae, while Na-citrate treatment for the recovery of Pb 2+ ,
Cd 2+ , and Ni 2+ from Oocystis sp. and Scenedesmus protuberans did not damage the
biosorbents.
Desorption Desorption (%)
(%)
100.0
80.0
60.0
40.0
20.0
0.0
0.1 M HNO 3
0.1 M HCl 0.1 M Na-citrate
Figure 3.18. Desorption of Pb 2+ , Cd 2+ , and Ni 2+ from Oocystis sp. using 0.100 M HNO3,
0.100 M HCI, and 0.100 M Na-citrate
Pb
Cd
Ni
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