Shimada et al. [306] used waste newspaper as raw material
for the production of activated carbon. The developed adsorbent
showed good sorption capacity as evident by iodine (1310 mg/g)
and methylene blue numbers (326 mg/g). The removal of Cu2+
from water was investigated using adsorbents prepared from paper
industry waste (de-inking paper sludge and sludge from virgin
pulp mill) [307]. Experimental results showed that de-inking paper
sludge lead to mesoporous materials whereas the sludge from virgin
pulp mill produced high microporous adsorbents. Adsorbent
materials were then used for Cu2+ removal from water at acid pH.
During water treatment, heavy metals lixiviation from adsorbent
materials was not produced. However, Ca and Mg leaching was
observed. Final pH significantly increased after treatment of water
with adsorbent materials probably due to their elevated CaCO3 content.
In general, highest Cu2+ removal was obtained using adsorbent
materials from de-inking paper sludge. This result could be due
to their higher content in oxygenated surface groups, high average
pore diameter, elevated superficial charge density, high CaCO3
amount and high Ca and Mg exchange content.