2. ENVIRONMENTAL ChEMISTRy & TEChNOLOGy 2.1. Lectures

Chem. Listy, 102, s265–s1311 (2008) Environmental Chemistry & Technology
P70 SELECTION OF PACKING MATERIALS FOR
bIOFILTER DEVELOPMENT
IVETA ŠTYRIAKOVá and ALEXAnDRA VAŠKOVá
Institute of Geotechnics of the Slovac Academy of Sciences,
Watsonova 45, 043 53 Košice, Slovakia,
bacil@saske.sk
Introduction
natural materials that are available in large quantities
may have potential as inexpensive sorbents. Cost effective
alternative technologies or sorbents for treatment of metals
contaminated waste streams are needed. A study 1 reported
that zeolites, clinoptilolite in particular, demonstrate strong
affinity for Pb and other heavy metals. Adsorbing Cd and
Zn examined by both modifications with natural bentonite 2 .
Results showed that the acid-treatment decreased the adsorption
capacity, while the heat treatment did improve capacity.
Retention of Pb and Zn on pure calcite was the subject of a
number of investigations 3,4 . On the contrary, the number of
sorption studies of both ions on magnesite is very limited.
Investigations on the biosorption mechanism of heavy
metals show that the metal ions are deposited by adsorption
to the functional groups present on the cell wall. Dead as well
as living cells are used in the removal of metal ions 5,6 . The
batch adsorption experiments demonstrate that the surface
complexation approach can be used successfully to quantify
the adsorption of Cd in a mixed B. subtilis – quartz system as
functions of both pH and solute/sorbent ratios 7 .
We are interested in the surface complexation approach
of zeolite, bentonite, calcite, magnezite and also these materials
with bacteria in the behavior various heavy metals in the
batch experiments. The objectives of this work were to determine
the differences of mineral/water and mineral-bacteria/
water interface in sorption capacities of metals.
Experimental
The biosorption experiments were carried out in Erlenmeyer
flasks which contained 10 g samples and 100 ml
medium. The medium contained (per liter) 0.5 g naH 2 PO 4 ,
1.0 g (nH 4 ) 2 SO 4 , 0. g naCl, and 2 g glucose. The flasks were
inoculated with a mixture of Bacillus cereus and B. megaterium
(0.1 g wet bacteria dm –3 ) that had been previously isolated
from Horná Prievrana. The two strains were purified by
heat treatment at 80 °C for 15 min followed by streak plating
on nutrient agar cultures. The isolates were identified with
the BBL Crystal Identification System (Becton, Dickinson
and Co., Franklin Lakes, nJ). For identification, the isolates
were cultivated on Columbia agar plates per manufacturer’s
instructions.
The flasks were incubated under dynamic conditions
(150 rev min –1 ) for 3 hours at 25 °C. The liquid phase was
contained individual metals in 0.5mM concentration in the
forms ZnSO 4 , CuSO 4 , PbCO 3 . The spent media (leachates)
were sampled for metal analysis. The chemical controls
s476
did not receive an inoculum but were incubated under otherwise
similar conditions.
Solid residues were analyzed by X-ray diffraction using
a Philips X’Pert SW–binary diffractometer with CuKα radia tion (40 kV, 50 mA), equipped with an automatic divergence
slit, sample spinner, and a graphite secondary monochromator.
Data were collected for 2–60 °2Θ with a step width of
0.05 ° and a counting time of 30 s per 0.05 °. The mineralogy
has been evaluated in quantitative terms from X-ray powder
diffraction patterns using a Rietveld-based data processing
technique.
Quantitative changes in the liquid phase were measured
with a Model 30 Varian atomic absorption spectrometer
(Varian, Inc., Melbourne, Vic., Australia).
Batch experiments were conducted to measure:
• Zn, Cu, Pb and zeolite adsorption in a mixed singly
metals – zeolite – Bacillus system
• Zn, Cu, Pb and bentonite adsorption in a mixed singly
metals – bentonite – Bacillus system second
• Zn, Cu, Pb and quartz sands adsorption in a mixed singly
metals – quartz sands – Bacillus system
• Zn, Cu, Pb and calcite adsorption in a mixed singly
metals – calcite – Bacillus system
• Zn, Cu, Pb and magnezite adsorption in a mixed singly
metals – magnezite – Bacillus system
Z e o l i t e
The natural materials, zeolite was obtained from nižný
Hrabovec location in Slovakia. The mineralogical composition
of zeolite was clinoptilolite 51–68 %, quartz + cristobalite
9–20 %, feldspars 8–13 %, mica 13 % and iron minerals
0.3 %.
Table I
Chemical composition of zeolite
Components SiO 2 Al 2 O 3 Fe 2 O 3 MgO na 2 O
% wt. 67.0 12.3 1.3 0.7 0.7
B e n t o n i t e
The natural materials, zeolite was obtained from Lastovce
location in Slovakia. The mineralogical composition
of bentonite was smectite 63%, quartz 21%, kaolinite 11%,
feldspars 4-6% and calcite 2%.
Table II
Chemical composition of bentonite
Components SiO 2 Al 2 O 3 Fe 2 O 3 MgO na 2 O
% wt. 59.2 18.6 2.8 4.2 0.7
Q u a r t z S a n d s
The natural materials, zeolite was obtained from nižný
Hrabovec location in Slovakia. The mineralogical composi