2. ENVIRONMENTAL ChEMISTRy & TEChNOLOGy 2.1. Lectures

Chem. Listy, 102, s265–s1311 (2008) Environmental Chemistry & Technology
tion of zeolite was quartz 85 %, kaolinite 8 %, mica 6 % and
iron minerals 3–5 %.
Table III
Chemical composition of quartz sands
Components SiO 2 Al 2 O 3 Fe 2 O 3 MgO na 2 O
% wt. 96.1 1.7 0.4 0.05 0.03
C a l c i t e
The natural materials, calcite was obtained from Horné
Srnie location in Slovakia. The mineralogical composition of
rock was calcite 80 %, quartz 5 %, kaolinite 2 %, plagioclase
0.5 %, and iron minerals 0.7 %.
Table IV
Chemical composition of calcite
Components SiO 2 Al 2 O 3 Fe 2 O 3 MgO na 2 O
% wt. 11.8 3.9 1.2 0.8 0.05
M a g n e z i t e
The fired material of magnezite was obtained from Jelšava
location in Slovakia. The mineralogical composition of
sample was periclase 98 %.
Table V
Chemical composition of fired magnezite
Components SiO 2 CaO Fe 2 O 3 MgO K 2 O
% wt. 0.02 0.11 0.01 97.3 0.06
Results
The individual mineral phases of silicates (zeolite, bentonite,
quartz sands) and carbonates (magnezite, calcite) can
control the efficiency of biofiltration when sorption and precipitation
of metals occurs. Moreover, in both cases, Zn, Cu,
Pb were accumulated at the mineral and cell surface as precipitates.
An important parameter for packing material is the
removal capacity of the minerals.
Removal of Zn from solution by silicate was of lower
efficiency, 20 % Zn by zeolite, 46 % by bentonite, 21 % by
quartz sands was removed, while up to 55 % by calcite and
88 % by magnezite (Fig. 1.).
Removal of Cu was similar approximately 24 % by
these minerals (Fig. 2.).
Pb was very effective removed 93 % by bentonite and
magnezite and 74 % by zeolite and calcite (Fig. 3.).
The experimental results of the selected natural mineral
materials showed that bentonite has higher adsorption capacities
than zeolite for Pb and Zn. However, magnezite appear
to be more effective than calcite in precipitation of Pb and
Zn.
The affinity series for bacterial removal of these metals
decrease in the order Pb > Zn > Cu with the low sorption
capacity only approximately 0.06 mM dm –3 . At 0.1 g bacte-
s477
ria dm –3 is a small amount of cells for adsorption metals onto
the bacterial surface.
Fig. 1. Time dependence of Zn biosorption and precipitation
by minerals and bacterial cells
Fig. 2. Time dependence of Cu biosorption and precipitation
by minerals and bacterial cells
Fig. 3. Time dependence of Pb biosorption and precipitation
by minerals and bacterial cells