The removal of the most prevalent heavy metal
ions [cadmium(II), lead(II), copper(II), and zinc(II)] by
adsorption on Scots pine (
Pinus sylvestris
L.) biochar and
Silver birch (
Betula pendula
) biochar has been investigated,
following the determination of physical and chemical
adsorption properties of biochar. The efficiency of
adsorption of heavy metal ions [cadmium(II), lead(II),
copper(II), and zinc(II)] on biochar was studied at different
concentrations of heavy metals [onefold maximum contaminant
level, twofold maximum contaminant level,
fivefold maximum contaminant level (in accordance with
the requirements set out in the Water Framework Directive
2000/60/EC), dosages of biochar (1.6–140 g), and biochar
types (Scots pine (
P. sylvestris L.) biochar and Silver birch
(
B. pendula) biochar produced at slow and fast pyrolysis) at
constant pH of leaching solution, temperature, and contact
time. Adsorption capacity of Scots pine (
P. sylvestris L.)
biochar and Silver birch (
B. pendula) biochar was assessed
by the application of extended
Freundlich isotherm. In this
study, biochar was evaluated as a potential adsorbent to
efficiently reduce concentration of heavy metal ions in
metal-contaminated water. The maximum adsorption
capacity were reached of copper(II) on Silver birch (
B.
pendula) biochar (128.7 µg g
-1) and of zinc(II) on Scots
pine (
P. sylvestris L.) biochar (107.0 µg g
-1). Adsorption
capacity of lead(II) on Silver birch (
B. pendula) and Scots
pine (
P. sylvestris L.) biochar varied from 1.29 to 3.77 and
from 2.37 to 4.49 µg g
-1, respectively.