1252 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
adsorption occurs via attachment-controlled process due to
the fewer available sorption sites (Pandey et al., 2014 Saha
et al., 2010). AH, however, showed a noticeable variation
in the contact times in the initial stages of adsorption com-
pared to the other two biochars, attaining equilibrium with
an uptake percentage above 90% within 8h to 24h.
The effect of initial lanthanum concentrations
on adsorption performance was investigated using a
concentration range of 200 ppb to 1200 ppm. This showed
the diverse removal efficiency of the biochars with lantha-
num, even at ppb levels. Figure 7 shows that the adsorption
capacity of the biochars increased with increasing initial
concentration however, at a high initial lanthanum concen-
tration of 640ppm, WCC and AH showed little or constant
adsorption compared to the initial stages. This depicts that
the adsorption capacity of the biochars was saturated due to
0
20
40
60
80
100
2 3 4 5 6 7
pH
SW
WCC
AH
Figure 5. Effect of pH on the adsorption of lanthanum
0
20
40
60
80
100
0 200 400 600 800 1000 1200 1400
t (mins)
SW
WCC
AH
Figure 6. Effect of contact time on the adsorption of lanthanum at pH 5
Uptake
,
%
Uptake,
%