the transfer factor of.pdf

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Continental J. Water, Air and Soil Pollution 3 (1): 26 32, 2012 ISSN: 2251 - 0508

Wilolud Journals, 2012 http://www.wiloludjournal.com

Printed in Nigeria doi:10.5707/cjwasp.2012.3.1.26.32

THE TRANSFER FACTOR OF 134Cs FROM CONTAMINATED WATERIN PHYTOREMEDIATION USING Salvinia molesta

Eko Susanto, Poppy Intan Tjahaja, Putu Sukmabuana, Neneng Nur Aisyah

Div. of Environmental Radiation, Center for Nuclear Technology, Material and Radiomentry - BATAN

ABSTRACTThe trasfer of134Cs from various concentration of contaminated water has been conducted to study the

availability of Salvinia molesta to accumulate 134Cs for phytoremediation. Salvinia molesta was grown

on water containing various concentration of134

Cs, i.e. 2481,8 Bq134

Cs (treatment 1); 3056,8 Bq134

Cs

(treatment II); 14314 Bq 134Cs (treatment III) and without 134Cs (control). The 134Cs concentration in the

plant as well as in the water were determined after the plants were grown to the 134Cs contaminated

water for 2 hours, 4 hours, 6 hours, 1 days, 5 days, 7 days, 14 days, 21 days and 26 days. Theaccumulation of134Cs in the plants is expressed as transfer factor. The transfer factor values obtained

from this research were 600.38 ml/g; 655.33 ml/g and 570.75 ml/g for treatment I, II, and III. These

value are still in the range of transfer factor values published by IAEA. The highest transfer factor value

of134Cs from water to Salvinia molesta proves that these plants are able to accumulate 134Cs so it can be

considered to be used as phytoremediator.

KEYWORDS : Transfer factor, phytoremediation,134Cs, Salvinia molesta

INTRODUCTION

Transfer factors have been used for many years to predict concentrations of radionuclides that could be expected

in plants after accidental releases of radionuclides into the environment. The transfer factors have been

developed based on the small field experiment where various radionuclides are added to the water ( Korobova et

al., 2007). Transfer factor is defined as the ratio of radionuclide activity concentration in plants or parts of plantscompared with that contained in media (Robinson et al., 2007).Transfer factor can also be expressed as the ratio

of activity Bq/g in dry weight of plants to activity Bq/L in water (Golmakani et al., 2008).

The transfer factors are very useful in radiological dose-prediction models to estimate radionuclide

concentrations in the aquatic plant after a release of radionuclides to the environment. However, in cases where

prediction of radionuclide concentrations in the aquatic plant in large contaminated areas with an aged source

term is important, the water sampling required to develop transfer factors values for a specific radionuclide for

the aquatic plant.

Accumulation of radionuclides by aquatic plants is a dynamic process, more models assume bioaccumulation

aquatic plants are in equilibrium with either water or sediment media which exist in the environment around it.

Most transfer factors from the literature do not distinguish the pathways that represent the value of concentration

ratio which is also called a bioaccumulation factor (Anonimous, 2010).Utilization of nuclear energy activities allowed the contamination of radioactive materials both natural andartificial to the environment (Handl et al., 2008). Environment contaminated by radionuclides requires remedial

action to reduce the concentration of radionuclide contaminants to levels that are permitted. Environmental

restoration actions are popular nowadays and has been developed today is phytoremediation.

Phytoremediation is recovery technology that uses various types of plants to degrade, extract, accumulate, or

immobilization of contaminants in soil, water and sediments. Salvinia molesta is one plant that can beconsidered to be used as phytoremediator because it is able to adapt to the environment with lower salinity


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Eko Susanto et al.,: Continental J. Water, Air and Soil Pollution 3 (1): 26 32, 2012

and lower nutrient conditions (Biber P.D, 2008). Salvinia molesta has small leaves with diameter of 2-4 cm and

has long and dense roots that can effectively absorb pollutants. Radioactive materials can not be degraded, so it

has the potential to accumulate in plants. The accumulation in the plant could eventually endanger human case

of transfer of radionuclides from plants or animals to humans through the food chain. Nuclear installation is aninstallation that most need attention because in the event of an accident or a nuclear facility decommissioning

process, required to restore the environment in accordance with the first conditions (Grytsyuket. al., 2006).

In the event of nuclear facility accident it is possible that fission product radionuclides such as134

Cs to be

released into the environment through the air. Radionuclides released can enter environmental compartments

such as water, soil, plants, animals and humans that eventually lead to radiological effects on humans or the

environment (Kaduka et al., 2006). In this research the transfer of134

Cs from contaminated water has been

studied to be applied in the remediation of aquatic environments contaminated by 134Cs using Salvinia molesta.

MATERIALS AND METHOD

This research was conducted using green house and laboratory experiments method with measurements of

radionuclide134

Cs in plant samples using gamma-ray spectrometer. Salvinia molesta were grown on water

containing various concentration of134

Cs, i.e. 2481,8 Bq134

Cs (treatment 1); 3056,8 Bq134

Cs (treatment II);14314 Bq 134Cs (treatment III) and without 134Cs (control).

Salvinia molesta obtained from rice plants in the Bandung area were according to be selected to be in the

uniform size, then acclimatized in a tank in green house for about two weeks. The plants were inserted into the

pots made by PVC filled with 2.3 liter of contaminated water. Plants that have been able to adapt then

transferred into134

Cs contaminated water in the pots and in not contaminated water as control.

Radioactivity accumulation was determined after 2 hours, 4 hours, 6 hours, 1 days, 5 days, 7 days, 14 days, 21

days and 26 days. At each time of observations, tree plants and water sample were taken from each treatment.

Each plant sample then separated into the leaves and roots and then weighed using a digital balance. To obtain

the dry weight, samples were dried by oven at a temperature of about 800

C until a constant weight of about 1

hour. The activity of134

Cs in the samples were measured by using a gamma-spectrometer with NaITL

scintillator detectors (diameter of 110 mm). The transfer of 134Cs in plants is determined by comparing theconcentration of

134Cs in plants with the concentration in water.

RESULTS AND DISCUSSION

The134

Cs Concentration in Water

Figure 1 shows the concentration of134

Cs in water from three different treatments i.e. 2481,8 Bq134

Cs(treatment 1); 3056,8 Bq 134Cs (treatment II); 14314 Bq 134Cs (treatment III) and without 134Cs (control). The

concentration of134

Cs in the water has a tendency to decline. Water concentration obtained from activity

measurements using a gamma spectrometer SCA (Single Channel Analyzer) in 100 ml water samples. The

activity obtain from mesurements using a gamma spectrometer are lower than the activity of 134Cs from the

decay products. The decline occurred due to the absorption by plants and decay of134

Cs with half live of 2.05years (Soudeket al., 2006;Intan et al., 2006).


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Figure 1. Concentration of134Cs in water

Concentration Distribution of134

Cs

Figure 2 shows the concentration 134Cs in the leaves of Salvinia molesta. The plants were separated into the

leaves and roots and counted using a gamma spectrometer SCA (Single Channel Analyzer). The concentration

of134

Cs in plants is obtained strongly influenced by the activity and dry weight of plant samples and obtained by

dividing the 134Cs activity by dry weight of plant samples (Golmakani et al., 2008; Anonimous, 2010).

Figure 2. Concentration of134

Cs in the leaves

The value of 134Cs concentration in leaves is increasing over time until it reaches a maximum value before

finally declines since it has a saturation point. In treatment I the highest concentration of134

Cs in leaves

occurred at the 120 hours (day 5) i.e. 197 Bq/g. For treatment II and III the highest 134Cs concentration occurs at

the day 14 which is 191 Bq/g and 1137 Bq/g. At the point of saturation the leaves have been experiencing are nolonger able to increase the accumulation of

134Cs. The radionuclides were not distributed uniformly, but tend to

concentrate in certain organs of the plant. The plants take up the nutrient ions, in accordance to their

requirement. The elements are transported to specific tissues based on the function of the element in plant

metabolism, and it is reflected in its higher concentration in a particular part when compared with others.

Radionuclides can also be picked up along with nutrients and may have similar chemical behaviour as the

essential nutrient.


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Figure 3. Concentration of134Cs in the roots

Figure 3 shows the values of134

Cs concentration in the roots. The concentration of134

Cs in the roots tended to

increase over time until it reaches a maximum value before finally decline as saturation point. In treatment I the

highest concentration of134Cs occurred at the 120 hours (day 5) i.e. 579 Bq/g, while in treatment II occurred at

the 168 hours (day 7) i.e. 666 Bq/g. In treatment III the accumulation of134

Cs concentration was highest at the

336 hours (day 14) i.e. 2482 Bq/g.

Similarly, the concentration of134

Cs in the root was also increased until it reaches the highest value. At the point

of saturation roots have been experiencing are no longer able to increase the accumulation of 134Cs. The highest

concentration of134Cs distribution at roots can be understood as the roots is in direct contact with contaminated

water and the water is absorbed through the roots of plants and then distributed to other parts (Soudeket al.,

2006;Intan et al., 2006).

The concentration of134

Cs in the roots was relatively higher than the concentration in leaves. Accumulation of134Cs in Giant Salvinia molesta also occurs in the roots, this is different with the water hyacinth plant

accumulation of 134Cs occurs in the stems and leaves (Intan et al., 2006). The leaves of Salvinia molesta has

hairy structure so that evaporation from the leaf surface is relatively small. The absorption of water is also much

less when compared with water hyacinth plants are broad-leaved and smooth surface (Intan et al., 2006).

The highest134

Cs accumulation point is used in the calculation of transfer factors. As seen in Figs. 2 and 3

accumulated concentration in leaves and roots at 336 hours on treatment III showed the highest value of 1137

Bq/g and 2482 Bq/g. In studies of phytoremediation using aquatic plants Salvinia molesta, the largest

radionuclide activity results obtained in the roots, they are consistent with the references which explained that in

order to process rhizofiltration using radionuclide 134Cs accumulation value contained the greatest activity on the

roots (Soudeket al., 2006;Intan et al., 2006).

Value of Transfer FactorTransfer factor or bioconcentration factor is essentially the ratio of radionuclide activity concentration in the

plants tissues and its concentration in the medium after reaching a saturation. Transfer factor values calculated

when the plant absorbs the highest concentration, because if the concentration of 134Cs in plants has declined

mean plant has undergone a saturation point. After the absorption by the roots, 134Cs then will be translocated to

the leaves (Golmakani et al., 2008). Figure 4 shows the largest transfer factor for the leave in treatment I

occurred on the sampling at the day 7 i.e. 145.71 ml/g, while transfer factor in treatment II and III for the leaveswere highest at the day 14 i.e. 140.36 ml/g and 179.04 ml/g.


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Figure 4. Transfer factors134

Cs to the leaves

Figure 5 shows the transfer factor of 134Cs in roots. The largest 134Cs transfer factor for treatment I and II in

roots occurred on day 5 i.e. 471.92 ml/g and 549.52 ml/g respectively. Transfer factor in treatment III washighest at day 14 i.e. 391.70 ml/g. Transfer factor value after 624 hours was decline because the plant has been

saturated in accumulating 134Cs. There is a relationship between the chemical forms of radionuclides and the

ability of the plant to accumulate these radionuclides. Plants will absorb minerals and organic ingredients from a

medium that will automatically impact on bioavailiability of the plant. The difference in physical and chemical

characteristics of different plant species have a large effect on the accumulation of radionuclides in the plant

(Golmakani et al., 2008).

Figure 5. Transfer factors 134Cs to the roots

The transfer factor of134

Cs from water to the whole plant is shown in Fig. 6, and it shows that the highest

transfer factor is at 336 hours for all treatment. The decline of transfer factor will occurred because the plant has

a maximum capacity of accumulating

134

Cs beside the increase of plant mass. There is a great variability in themobility of different elements in the phloem: K, Rb, P, S, Mg, Na and Cl are mobile; Fe, Mn, Mo, Zn and Cuhave an intermediate mobility, Ca, Li, Sr, B and Ba are considered immobile and are transported only to a very

small extent in the phloem (Golmakani et al., 2008). Mobility of134Cs element is identical with potassium

which is needed by plants so that the accumulation of134

Cs in plants tend to be high.


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Figure 6. Transfer factors to the whole plant

The 134Cs transfer factor to the whole plant in treatment I and II occurred at day 5 (hours 120) i.e. 600.38 ml/g

and 655.33 ml/g respectively, while the transfer factor in treatment III was highest at day 14 (hours 336) i.e.

570.75 ml/g. The occurrence of differences in transfer factors in all three treatment is expected because of

differences in activity. The transfer factor value obtained are relatively high if compared with previous study in

Giant Salvinia molesta. Giant Salvinia molesta transfer factor i.e. 5.9 ml/g which were grown in134

Cscontaminated water with a concentration of 11.565 Bq/ml (Intan et al., 2006). Cs transfer factor from water to

water plants according to data from the International Atomic Energy Agency (IAEA) of at least 1.9 x 10 0 ml/g

and a maximum of 3.3 x 103

ml/g (Anonimous, 2010). The transfer factor values obtained from this research i.e.

600.38 ml/g; 655.33 ml/g and 570.75 ml/g are still in the range of the IAEA issued.

CONCLUSION

The result of this study indicated that the 134Cs is accumulated in the roots. The highest 134Cs transfer factor to

whole plant in treatment I and II occurred on day 5 i.e. 600.38 ml/g and 655.33 ml/g respectively. Transfer

factor in treatment III was highest at day 14 i.e. 570.75 ml/g. The value of the transfer factor of134

Cs in Salvinia

molesta indicated high ability of the plant to accumulate 134Cs, according to data from the International Atomic

Energy Agency (IAEA) so it can be considered as phytoremediator plant. The time when the highest transfer

factor was reached indicates the best time to harvest the plants and treated as combustable radioactive waste.

ACKNOWLEDGEMENTS

The author would like to thank to Prof. Dr. Masno Ginting, M. Sc and Amalia Khoir for contribution in helping

in this research actifity.

REFERENCES

Korobova, E.M., J.B. Brown., N.G. Ukraintseva and Vitaly V (2007), 137Cs and 40K in terrestrial vegetation of

the Yenisey Estuary : lanscape, soil and plant relationships.Journal of Environmental Radioactivity. 96 : 144-

156.

Robinson, W.L., T.F. Hamilton., K.T. Bogen, Cyntia L. Conrado and S.R. Kehl, (2007), 137Cs inter-plant

concentration ratios provide a predictive tool for coral atolls with distinct benefits over transfer factors.Journal

of Environmental Radioactivity. 99 : 181- 189.

Golmakani, S., M.V Moghaddam and T. Hosseini, (2008), Factors Affecting The Transfer of Radionuclides

from The Environment To Plants.Radiation Protection Dosimetry. Vol. 130, No. 3, 368375.

Anonimous (2010), Handbook of parameter Values for the prediction of radionuclide transfer in terestrial and

freshwater environments. Technical Report Series. 472. IAEA, Viena.


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Handl, J., R. Sachse, D. Jakob, R., Michel., H. Evangelista., A.C. Gonc, alves, and de Freitas (2008),

Accumulation of137

Cs in Brazilian soils and its transfer to plants under different climatic conditions.Journal of

Environmental Radioactivity. 271 287.

Biber, P.D (2008), Determining Salinity Tolerance of Giant Salvinia Using Chlorophyll Fluorescence. Gulf and

Caribbean Research. Vol 21.

Grytsyuk, N., G. Arapis and V. Davydchuk (2006), Root uptake of137

Cs by natural and semi-natural grasses as

a function of texture and moisture of soil.Journal of Environmental Radioactivity. 85 : 48 - 58.

Kaduka M.V., V.N. Shutov., G.Ya. Bruk, M.I. Balonov., J.E. Brown and P.Strand (2006), Soil-dependent

uptake of137Cs by mushrooms:experimental study in the chernobyl accidents areas. Journal of EnvironmentalRadioactivity. 89 : 199-211.

Soudek P., S.A. Valenova., Z. Vavrikova and T. Vanek (2006), 137Cs and 90Sr uptake by sunflower cultivated

under hydroponic conditions.Journal of Environmental Radioactivity. 88 : 236 250.

Intan, P.T., Suhulman, P. Sukmabuana, Ruchiyat (2006), Phytoremediation of freshwater environment:

Radiocaessium uptaake by kiambang (Salvinia molesta). Indonesian Journal of Nuclear Science and

Technology. 07 : 83 96.

Received for Publication: 24/03/2012

Accepted for Publication: 15/05/2012

Corresponding author

Eko Susanto

Div. of Environmental Radiation, Center for Nuclear Technology, Material and Radiomentry - BATAN

e-mail : [email protected]

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