2. ENVIRONMENTAL ChEMISTRy & TEChNOLOGy 2.1. Lectures
2. ENVIRONMENTAL ChEMISTRy & TEChNOLOGy 2.1. Lectures
2. ENVIRONMENTAL ChEMISTRy & TEChNOLOGy 2.1. Lectures
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Chem. Listy, 102, s265–s1311 (2008) Environmental Chemistry & Technology<br />
tion of zeolite was quartz 85 %, kaolinite 8 %, mica 6 % and<br />
iron minerals 3–5 %.<br />
Table III<br />
Chemical composition of quartz sands<br />
Components SiO 2 Al 2 O 3 Fe 2 O 3 MgO na 2 O<br />
% wt. 96.1 1.7 0.4 0.05 0.03<br />
C a l c i t e<br />
The natural materials, calcite was obtained from Horné<br />
Srnie location in Slovakia. The mineralogical composition of<br />
rock was calcite 80 %, quartz 5 %, kaolinite 2 %, plagioclase<br />
0.5 %, and iron minerals 0.7 %.<br />
Table IV<br />
Chemical composition of calcite<br />
Components SiO 2 Al 2 O 3 Fe 2 O 3 MgO na 2 O<br />
% wt. 11.8 3.9 1.2 0.8 0.05<br />
M a g n e z i t e<br />
The fired material of magnezite was obtained from Jelšava<br />
location in Slovakia. The mineralogical composition of<br />
sample was periclase 98 %.<br />
Table V<br />
Chemical composition of fired magnezite<br />
Components SiO 2 CaO Fe 2 O 3 MgO K 2 O<br />
% wt. 0.02 0.11 0.01 97.3 0.06<br />
Results<br />
The individual mineral phases of silicates (zeolite, bentonite,<br />
quartz sands) and carbonates (magnezite, calcite) can<br />
control the efficiency of biofiltration when sorption and precipitation<br />
of metals occurs. Moreover, in both cases, Zn, Cu,<br />
Pb were accumulated at the mineral and cell surface as precipitates.<br />
An important parameter for packing material is the<br />
removal capacity of the minerals.<br />
Removal of Zn from solution by silicate was of lower<br />
efficiency, 20 % Zn by zeolite, 46 % by bentonite, 21 % by<br />
quartz sands was removed, while up to 55 % by calcite and<br />
88 % by magnezite (Fig. 1.).<br />
Removal of Cu was similar approximately 24 % by<br />
these minerals (Fig. <strong>2.</strong>).<br />
Pb was very effective removed 93 % by bentonite and<br />
magnezite and 74 % by zeolite and calcite (Fig. 3.).<br />
The experimental results of the selected natural mineral<br />
materials showed that bentonite has higher adsorption capacities<br />
than zeolite for Pb and Zn. However, magnezite appear<br />
to be more effective than calcite in precipitation of Pb and<br />
Zn.<br />
The affinity series for bacterial removal of these metals<br />
decrease in the order Pb > Zn > Cu with the low sorption<br />
capacity only approximately 0.06 mM dm –3 . At 0.1 g bacte-<br />
s477<br />
ria dm –3 is a small amount of cells for adsorption metals onto<br />
the bacterial surface.<br />
Fig. 1. Time dependence of Zn biosorption and precipitation<br />
by minerals and bacterial cells<br />
Fig. <strong>2.</strong> Time dependence of Cu biosorption and precipitation<br />
by minerals and bacterial cells<br />
Fig. 3. Time dependence of Pb biosorption and precipitation<br />
by minerals and bacterial cells