Biosorption of Microelements by Spirulina: Towards Technology of Mineral Feed Supplements

Table 5

Surface functional groups and their concentration evaluated with potentiometric titrations.

Functional group	Microalga(e)
	Spirulina maxima		Spirulina sp.
		Concentration meq g^−1		Concentration meq g^−1
Carboxyl	2.66	2.99	2.77	0.998
Phosphoryl	6.68	1.73	6.96	0.573
Amine or hydroxyl	10.9	3.27	10.8	0.889
Total		7.99		2.46