Batch adsorption results
In batch process, 250 mg of water bamboo husk particles were
employed to adsorb heavy metal ions from a 50-mL mixture (23 kinds
of metal ions) with a concentration of 5 mg/L for each single ion
(prepared by diluting the standard solution) at pH 5 and roomtemperature.
In this case apparent equilibrium was established within 3 h of
contact time. The adsorption of water bamboo husk particles was
more favorable to seven metal ions in a competitive circumstance and
their adsorption results are shown in Fig. 4. The other 16 metal ions exhibited
negligible adsorption. In Fig. 4, ions having a strong affinity to
water bamboo husk biosorbent included Cu2+, Cr3+, Pb2+, and Fe3+.
The adsorption percentage ranged from 15.5% (Ni2+) to 99.8% (Fe3+).
Ni2+ and Fe3+ were thus selected for the subsequent investigations
on static and dynamic adsorption.
The adsorption isotherms of Ni2+ and Fe3+ are presented in Fig. 5
(solid symbols, red color), along with the extent of adsorption (open