Removal of Hexavalent Chromium by Using Sustainable Green Materials as Low-Cost Adsorbents

Table 3

The content of cellulose in three types of tea residues (in wt%).

	Green tea	Pu-erh	Tieguanyin
Raw tea residue	8.60	12.27	18.72
NaOH-treated tea residue	15.61	27.34	32.30
Charge	+7.01	+15.07	+13.58