2. ENVIRONMENTAL ChEMISTRy & TEChNOLOGy 2.1. Lectures

Chem. Listy, 102, s265–s1311 (2008) Environmental Chemistry & Technology
as accompanying minerals. The impact of the mentioned sorbent
on the reduction of the Hn content in the sediment load
was observed in laboratory conditions in compliance with the
producer’s recommendation in form of a 120 and 333 days
experiment
The procedure of the 120-day experiment was as follows.
First, 9.5 g of the sediment were weighted and 0.5 g
of the sorbent added corresponding to 5 per cent by weight.
The samples were put in 250 ml PVC bottles for 120 days and
poured with 10 ml of the destilled water. After expiration of
120 days to each of the samples a 100 ml of 2M HnO 3 were
added as a leaching agent. Then, the samples were shaken for
6 hours and sedimented for 1 hour.
A similar procedure was carried out in connection with
the 333 days experiment. First 9.5 g of the sediment were
weighted and 0.5 g of the mentioned sorbent added corresponding
to 5 per cent by weight in accordance with producer´s
recommendation. The samples were put in 250 ml PVC bottles
for 333 days and poured with 10 ml of the destilled water.
After expiration of 333 days to each of the samples a 100 ml
of 2M HnO 3 were added as a leaching agent. Then, the samples
were shaken for 6 hours and sedimented for 1 hour.
In both cases the contents of selected elements Cu, Cr,
ni, Pb and Zn were ascertained using AAS methods. For
determination of the content of Cu and Zn flame atomic
absorption spectrometry and for Cr, ni and Pb graphite tube
atomizer were used.
Results and Discussion
The results of the experiment when the composite sorbent
affected the samples of sediment load from water reservoir
for 120 and 333 days are contained in Table I.
The results of the experiment when the composite sorbent
affected the samples of mining waste from sludge bed
for 120 and 333 days are contained in Table II.
The content of elements of ni, Cr and Pb in the samples
marked like 1C–4C as well as in the samples containing the
composite sorbent (CS) is under the lowest limit TV, norm for
environment 15 and that is why the results are not in Table I
and are not commented. The remaining samples marked like
120 d CS have shown the decrease of Cu from 4.53 to 8.20 %
and from 11.55 to 38 % for Zn after 120 days. After 333 days
the decrease of the content of Cu was ascertained from 5.55
to 15.83 % and Zn showed the content decrease from 11.26
to 37.1 %.
The cont ent of ni and Cr in procured control samples
(C) as well as in samples containing the composite sorbent
(CS) was under the lowest limit TV, of the norm for environment15
and that is why the results are not commented.
The remaining samples marked as CS have shown the
decrease of Cu from 7.25 to 11.65 %, Pb from 7.10 to 13.81 %
and Zn from 15.36 to 19.68 % after 120 days. After 333 days
the decrease of the content of Cu was ascertained from 11.23
to 14.76 %, Pb from 5.87 to 11.57 % and the content of Zn
decreased from 7.67 to 9.81 %.
s346
Table I
Influence of composite sorbent on content of heavy metals of
sediment load from the water reservoir
Sample
Cu
[mg kg
Zn
–1 ]
1 C 151 76.4
120 d CS 140.5 (7 %) 47.35 (38 %)
333 d CS 127.1 (15.83 %) 48.05 (37.1 %)
max. % of decrease 15.83 38
2 C 168 386.8
120 d CS 157 (6.55 %) 306.6 (20.57 %)
333 d CS 142.9 (14.94 %) 311.7 (19.25 %)
max. % of decrease 14.94 20.57
3 C 48.8 54.9
120 d CS 44.8 (8.20 %) 36.3 (33.88 %)
333 d CS 44.0 (9.84 %) 38.8 (29.33 %)
max. % of decrease 9.84 33.88
4 C 342 310.8
120 d CS 326.5 (4.53 %) 274.9 (11.55 %)
333 d CS 323 (5.55 %) 275.8 (11.26 %)
max. % of decrease 5.55 11.55
1C–4C control sample of sediment load without composite
sorbent;
120 d CS a 333 d CS – samples of sediment load with composite
sorbent after 120 and 333 days
Table II
Influence of the composite sorbent on the content of heavy
metals in the waste from the mining sludge bed
Sample
Cu Pb
[mg kg
Zn
–1 ]
Dam C 103 1,296 1,382
120 d CS
91
(11.65 %)
1,117
(13.81 %)
1,110
(19.68 %)
333 d CS
87.8
(14.76 %)
1,146
(11.57 %)
1,276
(7.67 %)
max. % of dec. 14.76 13.81 19.68
Lagoon C 552 2,351 2,364
120 d CS
512 2,184 2,001
(7.25 %) (7.10 %) (15.36 %)
333 d CS
490
(11.23 %)
2,213
(5.87 %)
2,132
(9.81 %)
max. % of dec. 11.23 7.10 15.36
C – control sample from the mining sludge bed without composite
sorbent
120 d CS a 333 d CS – samples with composite sorbent
Application of the composite sorbent also decreased the
contents of Cu, Pb and Zn in both samples but the percentage
of the content of HM is insignificant. Due to very significant
exces of the content of Cu, Pb and Zn compared to the highest
limit – IV, of the norm for environment 15 . Recycling of
the waste deposited in the sludge bed should be considered