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DESORPCIJA 137CS IZ MAHOVINE BRACHYTHECIUM MILDEANUM
KISELIM RASTVORIMA PH 4.60-6.50

DESORPTION OF 137CS FROM BRACHYTHECIUM MILDEANUM MOSS USING
SOLUTIONS THAT IMITATE ACID RAIN PH 4.60-6.50

Autor: Danica Anđelićm učenica drugog razreda “Šeste beogradske gimnazije” Regionalni centar za
talente Beograd II Mentor: Prof. dr Ana Čučulović Iinstitut za primenu nuklearne energije

REZIME

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U radu je pradena desorpcija Cs iz mahovine Brachythecium mildeanum (Schimp.) rastvorima čiji
sastav imitira sastav kiselih kiša: H 2 SO 4 (I), HNO 3 (II), H 2 SO 4 +HNO 3 (III) pH vrdenosti 4,60; 5,15 i 5.75,
respektivno, kao i destilovanom vodom (D). pH vrednost destilovane vode je bila 6,50. Posle pet uzastopnih
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desorpcija, svake u trajanju 24 časa, iz mahovine je kiselim rastvorima desorbovano 20,5-37,6% Cs, a
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destilovanom vodom 30,7% od početne vrednosti. Prvom desorpcijom desorbuje se najviše Cs (11,3%-
18,4%) u odnosu na početnu vrednost.

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Dobijeni rezultati ukazuju na potrebu ispitivanja uticaja kiselih kiša, odnosno uticaja H jona, na
desorpciju i drugih jona iz bioloških sistema, tj. delovanja na pojavu drugih zagađujudih supstanci, odnosno
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sekundarnog zagađivanja životne sredine. Iz rezultata u ovom radu sledi da de kisele kiše, delovanjem H jona
dovesti do povedanja zagađivanja vode padavina drugim jonskim supstancama, koje ne moraju biti prisutne u
vodi pre njenog kontakta sa biljkama i time dovesti do širenja zagađenja. U ispitivanom sistemu došlo je do
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zamene H jona iz kiselih kiša znatno opasnijim radioaktivnim jonom, odnosno do povedanja zagađenosti vode
radioaktivnim jonom, što se dešava i u vodama padavina. Ključne reči: Desorpcija, 137 Cs, mahovina,
Brachythecium mildeanum

Summary

The desorption of 137 Cs from the moss Brachythecium mildeanum (Schimp.) was performed using the

following solutions: H 2 SO 4 (I), HNO 3 (II), H 2 SO 4 +HNO 3 (III) with pH values of 4.60, 5.15 and 5.75, respectively, as
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well as distilled water (D) with pH 6.50. After five successive desorptions, each lasting 24h, 20.5-37.6% Cs
was desorbed from the moss using the solutions, while 30.7% of the starting content was desorbed using
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distilled water. The first desorption removed the highest percent of the original content of Cs in the moss
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(11.3%-18.4%). This was determined by measuring Cs activity. If the current results are compared with those
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obtained earlier it may be concluded that Cs desorption from mosses is not species-dependent.
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The obtained results indicate the necessity of investigating the influence of acid rain, or rather, of H
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ions, on desorption of other ions from biological systems, i.e. the role of H ions in spreading other polluting
compounds and thus producing secondary environmental pollution. From the results of this study it follows
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that acid rain will lead, through H ion action, to a similar increasing pollution of fallout waters with other ionic
compounds which may not be present in the water before the contact with the plants and thus enable the
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pollution spreading. In the investigated system, there occurred the replacement of H ions from acid rains by
more dangerous radioactive ions, increasing the concentration of the radioactive ions in the water, which

demonstrates that the same process takes place in fallout water.

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Key words: Desorption, Cs, moss, Brachythecium mildeanum

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