Fresenius Envir Bull 9: 328 - 332 (2000)~ Editors, Freising-WeihenstephanlFRG1018-4619/1000/S-6/328-0S DM 20 or 3,SO/p Áfl~l

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FIELD TRIALS OF BRASSICA CARINATA ~ND BRASSICA JUNCEA IN POLLUTEDSOll-S OF THE GUADm.:MAR RIVER AREA.

M. del Río*, R. Font*, 1. Fernández-Mart~nez*, 1. Domínguez** and A. de Haro*.

* Institute of Sustainable Agriculture, ICSlc. Av. Alameda del Obispo s/n.** CIFA Av. Alameda del Obis~o s/n E-1480. Córdoba. Spain.

SUMl\'IARy

Phytoextraction is a subjet of phytoremediation 'n which metal-accumulating plants are used totransport and concentrate metals from soils joto he harvestable parts1. In this study we test thecapacity of some genotypes of Brassica juncea L. Czern. & Coss.) and Brassica carinata (A.Braun) for uptaking heavy metals from polluted oils after the toxic spill of the Aznalcollar mine(southern Spain). We present the levels of P , Zn, Cu and Cd found in the soil and theconcentrations ofPb, Zn and Cu in the harvested p anís. High concentrations ofPb, Zn and Cu werepresent in the soil. B. juncea had greater eapacit for uptaking than B. carinata for all the metalsanalysed except for Cu.

Key words: heavy metals, uptake, Brassica carina~a,Brassicajuncea, phytoremediation

INTRODUCTION

The toxic spill of the Aznal

.

cÓllar mine on APril

i

2S, 1998, in the proximity of a majar wild life

reserve such as the Doñana National Park (south m Spain) eaused a discharge of aeid waters and

pyritie slurry (S 106m3)to the Guadiamar river a d adjacent agricultural areas (SOOOHa.). Due to

this soils have remained polluted by heavy metalslsuch as Pb, Cu, Zn, Cd, TI, Sb and metalloids as

As.

Recently, phy10remediation has emerged as an aIt~rnative to the engineering based methods. In this

new approach plants are used to uptake eontamin~nts freID the soil and to transIoeate them to the

shoots. Pollutants are then removed by harvestin~ the aboveground tissue for subsequent volume

reduction (i.e. ashing) and storage. Phytoreme4iation is a eost-effective technique that could

remediate a site without dramatically disturbing thF landseape.

A small number of plant species have been identi~ed that are not only eapable of growing on soils

eontaining high levels of met,als but also aeeumul~ti~g those polluta~ts ~o high e~ncentrations in theshoots. These pIants were comed hyperaccumuIat~rs-. On sueh spee1es 1SThlaspz caerulescens L, a

Presented at the 10thIntemational Symposium o~MESAEP in Alicante, Spain, 2 - 6 Oet. 1999

M. del Rio et al. 329

member of the Brassicaceae family and a well known Z~ and Cd hyperaccumulator3.

The success of any phytoremediation technique depends upon the identification of suitable plant

species that hyperaccumulate heavy metals and produce

r

arge amounts ofbiomass using established

crop production and management practices.

Recent evidence has suggested that other species from fhe Brassicaceae family, particularly those

ITomthe genus Brassica, may be more effective. specir such as Brassica juncea, Brassica napusL and Brassica rapa L, have been shown to accumulate moderate levels of heavy metals4-5.

B. juncea and B. carinata were chosen in our study bec4use they are well adapted to mediterranean

climate and they produce at least 20 times more b~omass iban T. caerulencens under field

conditions6.

The specific objective of ibis experiment was to dettrmine the suitability of B. juncea and B.carinata as phytoextraction species based on its growth responses and heavymetal uptake when

grown on contaminated soil.

MA TERIAL A1'j) METHODS

B. carinata and B. juncea were the species selected tJ_~onduct this study. The sowing was made

handly on March 15, 1999. The distance between rors was 50 cm with 50 seeds/linear meter.Plants were harvested on June 18, 1999.At ibis time, the plants had low biomass and seed yield due

to the late sowing and lack of rain during the growing Pfriod.The levels of heavy metals in the soil were estimated *y Departament of Edafology and Chemical

Agriculture of the University of Granada (Spain). T

I

' e samples were digested with nitric and

hydrochloric acids and analysed fo, Pb. Zn. Cu and Cd sing an inductively coupled plasma (ICP)

spectrometer (Perkin Elmer Model SCIEX-Elan-5000A .

All plants were divided into leaves, seeds, pods, ste1s and reGís. The samples were thoroughly

washed with tap water and given a final rinsing with delonized water and then dried at 80°C (degree

celsius) for 48 hours in an oyen and ground in a mili, ,nalysing them separately for Pb, Zn, Cu and

Cd. To prepare the samples for heavy metals analysis,ldry material (ca 250 mg) was digested with3mI..ofnitric acid in a conical flask at a temperature o

l13O0Cand then with 1ml. of perchloric acid

at 230°C. After cooling H2O was added to the acid sol tion until a volume of 15m!. Pb, Zn, Cu, Fe

and Mn were determined using flame by atomic abs; rption spectrometry (perkin Elmer. 1100B)I

and expressed as mg Kg-1dry weight ofplant tissue.

330 M. del Río et al.I

RESULTS AND DISCUSSION

jThe results obtained showed that the soil anal sed contained low concentrarían of Cd and high

concentrations of Pb, Zn and Cu (Table 1), al hough plant available metal was low due to the

previous chemical treatments (soi! amendments ~ith calcium carbonato and ferric oxides) used to

fix metals in the soil. \

Table 1. Total, lant available metal and soluble ea metal concentrations in soil.Heavy metal Horizons Total metal Available metal Soluble metal

cm

The polluted soil showed a gradient of concentrrtion for all the metals analysed, decreasing thevalues freIDthe first horizon to the third.

The total content of metal found in the three hon ons ranged 30.64 to 309.57 mgKg-1for Pb; 64.24

to 461.72 rngKg-1for Zn; 20.93 to 127.97 mgKg-1 or Cu and 0.12 to 1.51 rngKg-1for Cd.

Plants of B. juncea accumulated higher amounts t an B. carinata for all the metals analysed except

for Cu (Table 2), as has been previously reported4.

Table 2. Concentrations ofPb, Zn and Cu in BrafiCajunCea and Brassica carinata plants. Results

are means of 5 replicates of B. juncea and 5 replic~tes o/B. carinata.

Species Pb Zn Cn

(mg Kg-1dry weight)5.91 14.767.51 14.91

~1,08 6,704,14 5,82

B. carinata (nc) 1.62B. juncea (nc) 0.07B. carinata 4,43B. juncea 6,23Significative concentrations of Cd were not detectednc: no contaminated soil

It is well known that multiple interactions among t~e metals in the soil can affect the capacity of the

I

mg Kg-I dry soilPb 1 309,57 14,13 1,45

2 258,06

\

14,86 0,303 30,64 5,27 0,27

Zn 1 461,72 114,71 0,702 393,43

\

130,56 0,553 64,24 13,37 0,27

Cu 1 127,97

\

32.53 0.382 107,30 28.52 0.213 20,93

\

15.24 0.09Cd 1 1,51 1,20 0,01

2 1,27 0,88 0,0073 0,12 0,09 0,002

t 1, 2, 3 are horizons 1-10 cm. 10-30 cm and >30 cm re'pe l.ve1Y.

M. del Río et al. 331

plant for uptaking, i.e. studies have shown that the prese e of Cd can increase the accumulation of

Zn in some species7, and in addition Cu decreases Zn ptake in the soil5. This could explain the

differences in Cu content between plants grown in no contaminated soil ITom a locality of the

Guadiamar river afea and those grown in contaminated s il. The first one exhibited values of 14.91

mg Kg-l in the case of B. juncea and 14.76 mg Kg-l fo B. carinata which are higher than those

found in plants grown in contaminated soils (6.70 and 5. 2. mg Kg-\ respectively).

Both B. juncea and B. carinata accumulated the highe content of Pb and Cu in the leaves (pb

55.21%; Cu 34.53% and Pb 46.10%; Cu 39.79% in B. ju cea and B. carinata, respectively. Similar

results were obtained by Tlustos8 for Cd, who investi ated the uptake of this metal by radish

(Raphanus sativus L), found the highest concentrarían o~Cd in the leaves ofthis species.The majar part of Zn was concentrated in the stems (~8.62% and 38.92% in B. juncea and B.

Table 3. Percentages ofPb, Zn and Cu in Brassica carin'pta and Brassicajuncea leaves, stem, pod, seeds and root. Results ate means of 25replicates of B. juncea and 126 replicates o/B. carinata.Species parís (%)

Pb Zn46,10 31,2132,47 38,922,83 3,3918,60 26,4855,21 26,9122,91 48,6217,03 12,713,22 11,643,21 4,78

carinata, respectively) (Table 3).

B. carinata leafstempod and seedrootleafstempodseedroot

B.juncea

Cu

39,7928,133,82

28,2634,5326,4621,9122,553,57

In B. juncea the levels of Pb and Cu were in the arder leaves>stem>pods>seeds>roots. The only

exception was Zn which had concentrations in stem>leaves>pods>seeds>roots due to the higher

biomass of the stem. B carinata showed the same relation but pods and seeds had the lowest levels

for al! the metals due to the sowing conditions described previously.

These results show that in spite of the unfavourable agronomic conditions since the sowing until the

harvest, these species concentrated Pb, Zn and Cu contents much higher than the soluble metal

levels present in the soil. To improve the agronomic conditions in the sowing and growing times,

will bring an increase ofthe phytoextraction capacity by these species

332 M. del Rio et al.

ACKNO\YLEDGEl\'IENTS

The authors thank Consejo Superior de Investigaciones Científicas (CSIC) and Consejería de MedioAmbiente (Junta de Andalucía) for supporting this research, and Gloria Femández Martínez(Instituto de Agricultura Sostenible, CSIC, Córdoba), for her help in performing the analyses of soiland plants.

REFERENCES

1-Kumar, P.B.A. N. 1995. Phytoextraction: The use of plants to remove heavy metals from soils.Environ. Sci. Techn. 29 (5): 1232-1238.2- Brooks, RR., Lee, J., Reeves, R.D., Jaffre, T. 1977. Detection of nickeliferous rocks by analysisofherbarium specimens of indicator plants. J. Geochem. Explor. 7: 49-57.3- Baker, AJ.M., Reeves, R.D., Rajar, A S.M. 1994. Reavy metal accumulation and tolerance inBritish population of the metallophyte Thlaspi caerulescens. J. & Presl. (Brassicaceae). NewPhytol. 127: 61-68.4-Kumar, P.B.A N., Dushenkov, V. and Ensley, B.D., Raskin, 1. 1995a. The use of crop Brassicasin phytoeXtraction: a subset of phytoremediation to remo ve toxic metals from soils. In: NinthIntemational Rapeseed Congress. Cambridge, UK. 4 to 7 July. Vol. 3. pp: 753-756.5-Ebbs, S.D. and Kochian, Lv. 1997. Toxicity ofzinc and correr to Brassica species: implicationsfor phytoremediation. J. Environ. Qual. 26: 776-7816-Salt, D.E., Blaylock, M., Kumar, N.P.B.A., Dushenkov, V., Ensley, B.D., Chet, 1. 1995Phytoremediation: A novel strategy for the removal of toxic metals from the enviroment usingplants. Biotechnology. 13: 468-474.7-Tumer, ~f.A. 1973. Effect of cadmium treatment on cadmium and zinc uptake by selectedvegetable species. J. Environ. Qual. 2: 118-119.8-Tlustos, P., Pavlíková, D., Balík, J., Száková, J., Rane, A., Balíková, M. 1998. The aeeumulationofarsenie and cadmium in plants and their distribution. Rostlinná Vyroba. 44 (lO): 463-469.

Received for publieation:

Accepted lar publication:

November 08, 1999

May 08,2000