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

2.1. Preparation of Biosorbents
CHAPTER 2
EXPERIMENTAL
All algae used in this study were obtained from Microalga Culture Collection,
Ege University (EGE-MACC). After growth period, the algal cultures were harvested
and filtered through Whatman No:1 filter paper. Then, they were washed with
deionized water to be made free from the ions of their growing media. The growing
media and their contents used in this study are given in Appendix A. The cultures
were kept at -24ºC and lyophilized with Christ alpha 1-4 Ld freeze dryer. Lyophilized
biomass was powdered and kept in the refrigerator (4ºC) before being used in the
related experiments.
2.2. Chemicals and Reagents
All reagents were of analytical grade. Ultra pure water (18MΩ) was used
throughout the study. Glassware and plasticware were cleaned by soaking in 10%
(v/v) nitric acid and rinsed with distilled water prior to use. The chemicals and the
reagents used were tabulated in Table 2.1 and prepared as follows;
1. Standard Pb 2+ stock solution (4000 mg/L): Prepared by dissolving 1.599 g
of Pb(NO3)2 (Riedel-de Haën, 99%) in ultra pure water and diluting to
250.0 mL. This solution also contains 0.14 M HNO3 (Merck).
2. Standard Cd 2+ stock solution (4000 mg/L): Prepared by dissolving 1.630 g
of CdCI2 (Fluka, >99%) in ultra pure water and diluting to 250.0 mL. This
solution also contains 0.14 M HNO3 (Merck).
3. Standard Ni 2+ stock solution (4000 mg/L): Prepared by dissolving 3.539 g
of NiCI2.6H2O (Carlo Erba, 99%) in ultra pure water and diluting to 250.0
mL. This solution also contains 0.14 M HNO3 (Merck).
4. Calibration standards: Lower concentration standards were prepared daily
from standard stock solutions.
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