Human health is being
threatened by cationic pollutants in wastewater,
for example, methylene blue (MB) and Cu(II). Our research team successfully
fabricated biofoam adsorbents from recycled bamboo waste that removed
cationic pollutants via introducing bamboo fiber sources,
i.e.
, bamboo fiber, bamboo α-cellulose fiber, and
bamboo nanocellulose fiber, into a polyurethane (PU) foam matrix.
The biofoam adsorbent with 1 g of nanocellulose (PUN
1
)
presented high removal efficiencies for MB (95.52%) and Cu(II) (100%)
in low cationic pollutant concentration aqueous solutions. The biofoam
adsorbent with 1 g of bamboo fiber (PUB
1
) also displayed
excellent removal efficiency for MB (98.61%) at pH 11. Meanwhile,
100% removal of Cu(II) was obtained by PUB
1
at pH 7 (initial
content = 15 mg/L). Furthermore, the PUN
1
sample had excellent
reusability, evidenced by 61.25% removal of MB after five adsorption–desorption
cycles, suggesting that PUN
1
is a promising renewable adsorbent
for cationic pollutants. In addition, PUB
1
is a low-cost
adsorbent with good adsorption efficiencies for MB in weak alkaline
solutions and Cu(II) in neutral aqueous solutions.