Figure 3

FT-IR spectroscopy characterization of activated green waste tea: (X) (a) AGWTR before adsorption, (b) AGWTR after adsorption of Cu²⁺ and (c) AGWTR after ADS/EC of Cu²⁺. (Y) (a) AGWTR before adsorption, (b) AGWTR after adsorption of Ni²⁺ and (c) AGWTR after ADS/EC of Ni²⁺.