Results of FTIR analysis (Figure 7) proved the variety of
functional groups found on the cell wall surface of examined
biosorbents. Each group in its free form,Figure 7 shows the bands representing the specific groups
detected on the cell wall of pristine and Cu(II)-loaded
Spirulina maxima (Figures 7(B) and 7(C), resp.), as well
as lyophilized Spirulina sp. (Figure 7(A)). Spectra of both
natural microalgal biomasses proved their great similarity in
the composition of surface groups. At the same time, small
differences in the wave number, at which particular band was
noted, confirmed the efficacy of FTIR analysis in identifying
samples of biological material. Run sequence plot of ionenriched
microalga differed, at some points, from pristine
microalgae results due to interactions of cell wall groups with
metal cations, which caused visible signal changes. that is, withoutmetal
ion loaded, was detected at strictly defined wave number,
giving a specific signal (band). A set of all bands spectrum,
which depicts the full surface composition of particular
biomass is named as IR “fingerprint” [32].