CHROMIUM ACCUMULATION BY PHYTOREMEDIATION WITH MONOCOT WEED PLANT SPECIES AND A HYDROPONIC SAND CULTURE SYSTEM

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1 Journl of Environmentl Reserh And Development Vol. 4 No. 3, Jnury-Mrh 21 CHROMIUM ACCUMULATION BY PHYTOREMEDIATION WITH MONOCOT WEED PLANT SPECIES AND A HYDROPONIC SAND CULTURE SYSTEM Pntwt Smpnpnish *1,2, Krongkew Tippysk nd Pitsmi Chirt-uti 3 1. Ntionl Center of Exellene for Environmentl nd Hzrdous Wste Mngement, Chullongkorn University, Bngkok (THAILAND) 2. Environmentl Reserh Institute, Chullongkorn University, Bngkok (THAILAND) 3. Deprtment of Chemistry, Fulty of Siene, King Mongkut s Institute of Tehnology Ldkrng, Bngkok (THAILAND) Reeived Deemer 22, 29 Aepted Mrh 3, 21 ABSTRACT The umultion of hromium y three monoot speies Cynodon dtylon, Ehinohlo olonum nd Vetiveri nemorlis ultivted in hydroponi snd ulture system ws investigted in this study. The pity for hromium removl nd the umultion of hromium in different prts of the three monoot speies were studied t onentrtions of, 5, 1 nd 15 mg Cr VI /kg of snd for growing periods of 3, 6, 9 nd 12 dys. The results otined from this study show tht the highest umultion of hromium in Cynodon dtylon ourred t onentrtion of 5 mg Cr VI /kg of snd fter 6 dys nd equled mg/kg dry weight of plnt. For the onentrtions of 1 nd 15 mg Cr VI /kg of snd, hromium umultions were nd mg/kg dry weight of plnt t 3 dys, respetively. Cynodon dtylon showed the highest umultion t the period of 3-6 dys ut hd tendeny towrd deresed umultion levels s hrvesting time inresed. Ehinohlo olonum showed the most umultion of hromium t 12 dys nd ws equl to 58.22, 9.8, nd mg/kg dry weight of plnt for onentrtions of 5, 1, nd 15 mg Cr VI /kg of snd, respetively. The highest umultion of hromium in ll prts of Vetiveri nemorlis for the onentrtion of 5 mg Cr VI /kg of snd ourred t 9 dys nd ws equl to mg/kg dry weight of plnt nd lso equl to 63.2 nd mg/kg dry weight of plnt t 12 dys for the onentrtions of 1 nd 15 mg Cr VI /kg of snd, respetively. The results of this study lerly indite tht the highest hromium umultion in ll three monoot speies ourred in the root, nd tht the hromium susequently trnsloted to stem nd lef. This proess is lled phytoextrtion or phytoumultion nd the results show tht Cynodon dtylon performed this funtion etter thn Ehinohlo olonum nd Vetiveri nemorlis. Key Words : Chromium, Phytoremedition, Hydroponi, Monoot speies, Cynodon dtylon, Ehinohio olonun, Vetiveri nemorlis * Author for orrespondene 654

2 Journl of Environmentl Reserh And Development Vol. 4 No. 3, Jnury-Mrh 21 INTRODUCTION Presently, environmentl pollution resulting from the use of hemils in griulture nd the prodution of hzrdous wste in industril proesses is one of the world s most importnt prolem. Chemils, oth orgni nd inorgni, re relesed into the environment nd this results in soil, wter nd ir pollution. The ontmintion y hevy metls suh s rseni, opper, merury, dmium, led, nikel, hromium, mngnese nd zin in wter nd soil sludge is espeilly worrying. Ninety perent of hzrdous wste is produt of industril proessing. In the pst, the hevy metl hromium (Cr), ws often used in the tnning industry nd spred widely into the environment, ontminting the soil, underground wter nd surfe wter resoures, using hrm to humns, nimls nd plnts. Trivlent Chromium - Cr (III) nd Hexvlent Chromium - Cr (VI) re the two speies of hromium whih re found nturlly in the environment. Cr (VI) ppers to e more toxi thn Cr (III) 1. Mny tehnologies, physiohemil nd iologil tehniques, preipittion, oxidtion redution, miroil sorption nd phytoremedition hve een used for hromium removl. Phytoremedition is iologil methodlogy in whih seleted plnts re used for treting hevy metls tht hve ontminted soil nd/or wter. The proesses in Phytoremedition re, 1) Phytoextrtion or Phytoumultion: the uptke of ontminnts y plnt roots nd trnslotion within the plnts, 2) Phytostiliztion: the use of plnts nd plnt roots to immolilize ontminnt migrtion nd trnsporttion through soil nd groundwter, 3) Rhizofiltrtion: the dsorption or preipittion of ontminnts solution surrounding the root zone onto plnt roots, or sorption into the roots y ioti or ntiioti proesses, 4) Phytovoltiliztion: the uptke nd trnspirtion of ontminnt y plnt, 5) Phytodegrdtion: the rekdown of ontminnts tken up y plnts through metoli proesses within the plnt nd, 6) the rekdown of n orgni ontminnt in soil through miroil tivity tht is enhned y the presene of the root zone nd referred to s Rhizodeg-rdtion or Enhned Rhizosphere Biode-grdtion or Phytostimultion or Pln-ted Assisted Bioremedition/Degrdtion 2,3. Phytoremedition tehnology hs een reeiving ttention ltely s n innovtive nd ost-effetive lterntive to the more estlished tretment methods used t hzrdous wste sites 4. Therefore, the removl of hromium ontminte from soil nd wter y using expendle monoot speies suh s Cynodon dtylon, Ehinohlo olonum nd Vetiveri nemorlis is of interest s n lterntive tehnology. Ojetives 1. To study the removl pity of three monoot speies: Cynodon dtylon, Ehinohlo olonum nd Vetiveri nemorlis ultivted in snd medi ontminted with hromium syntheti wstewter. 2. To study the umultion nd trnslotion of hromium in the plnt root, stem nd lef of ll three monoot speies t vrious lengths of time nd onentrtions of Cr (VI). 3. To ompre the umultion nd trnsformtion of hromium in eh prt of three different monoot speies whih were grown in snd medi. 655

3 Journl of Environmentl Reserh And Development Vol. 4 No. 3, Jnury-Mrh 21 MATERIAL AND METHODS Mteril preprtion River snd ws olleted nd ir dried for 1-2 dys, then soked in 1% nitri id for 2-3 dys for lening, nd susequently ir-dried. Plsti pots with 3-m dimeter used in this study were soked with 1% nitri id for 1-2 dys then wshed with tp nd deionized wter. All pots were ir-dried for 2-3 hrs. Next, 5 kilogrms of snd were pled in eh pot. Plnt preprtion Monoot speies: Cynodon dtylon, Ehinohlo olonum nd Vetiveri nemorlis s illustrted in Fig. 1 were used in this study. 1) Cynodon dtylon, Ehinohlo olonum nd Vetiveri nemorlis seedlings were seleted nd pruned to hve similr height of stem nd length of roots. 2) Seleted monoot speies were grown in tp wter for 3-5 dys in order to stimulte the growth of plnt roots. 3) The young plnts were trnsplnted into pots tht ontined 5 kilogrms of snd. They were kept properly wtered in green house for 2-3 weeks in order to oserve their survivl potentil efore Cr (VI) solution ws dded to the snd. 1) 2) 3) Fig. 1 : Monoot speies used in the study (1) Cynodon dtylon, (2) Ehinohlo olonum nd (3) Vetiveri nemorlis Syntheti wstewter preprtion (hromium solution) Syntheti wstewter (hromium solution) ws prepred y dissolving Potssium Dihromte (K 2 Cr 2 O 7 ) in deionized wter until rehing onentrtions of 5, 1 nd 15 mg Cr (VI)/ kg of snd. A ontrol environmemt ws lso prepred ontining mg Cr (VI) /kg of snd. Experimentl design nd proedure kilogrms of snd, nd mintined in nursery for 2-3 weeks. Next, syntheti wstewter (hromium solution) t onentrtions of 5, 1 or 15 mg Cr (VI) /kg of snd ws dded to the pots. In ddition, the ontrol group ( mg Cr (VI)/ kg of snd) ws lso prepred. No studied group reeived ny fertilizer. Snd nd plnt smples were olleted every 3 dys throughout the 12- dy tril period. The 12 young smples of eh plnt Smple olletion speies: Cynodon dtylon, Ehinohlo After 3, 6, 9 nd 12 dys, 5 grms olonum nd Vetiveri nemorlis were of snd were olleted rndomly. The plnted into plsti pots ontining 5 smples were ir-dried t room temperture 656

4 Journl of Environmentl Reserh And Development Vol. 4 No. 3, Jnury-Mrh 21 for 2 3 hr in order to determine fresh weight. After tht, snd smples were llowed to dry t 15 o C to mesure moisture ontent. The TCr, Cr (VI) nd Cr (III) in the snd smples were determined. Plnt smples were hrvested fter 3, 6, 9 nd 12 plnting dys. Smples were wshed nd lened with tp wter twie, rinsed with deionized wter, nd then irdried t room temperture for 2 3 hrs in order to determine fresh weight. After tht, they were seprted into three prts: roots, stems nd leves. Susequently moisture ontent of eh prt ws determined. The smples were dried t 15 C for 24 hrs nd dry-mtter yields were lso determined. Next, the smples were ground with n eletri mill nd thoroughly mixed to homogenize. They were then nlyzed for TCr, Cr (VI) nd Cr (III) levels. Smple nlysis 1) Syntheti wstewter smples were mesured for ph, oxidtion-redution potentil (ORP) nd ondutivity. 2) Totl hromium in snd nd plnt smples were nlyzed y US EPA method 352 (mirowve-ssisted id digestion of silieous nd orgnilly-sed mtries). Then the digested solution ws nlyzed y Atomi Asorption Spetrosopy; AAS 5. 3) The nlysis of Cr (VI) in snd nd plnt smples ws onduted y the olorimetri method: US EPA method 36 6 nd susequently mesured y using UV spetrophotometer. 4) The mount of Cr (III) in smples ws otined y lulting the differene etween TCr nd Cr (VI). RESULTS AND DISCUSSION The umultion of hromium in three monoot speies: Cynodon dtylon, Ehinohlo olonum nd Vetiveri nemorlis ws exmined in the present study. All speies were plnted in snd medi 657 ontminted with Cr (VI) syntheti wstewter for 12 dys. All three monoot speies were grown normlly without the ddition of fertilizer. The results re summrized s follows. The hrteristis of hromium syntheti wstewter Oxidtion Redution Potentil (ORP) The nlysis of hromium syntheti wstewter t onentrtions of 5, 1 nd 15 mg Cr (VI) /kg of snd shows tht the oxidtion redution potentil tended to derese with inresing onentrtion. Moreover, the onentrtions of syntheti wstewter (Cr solution) plnted with the three monoot speies: Cynodon dtylon, Ehinohlo olonum nd Vetiveri nemorlis tended to derese with inresing length of the hrvesting period. Cr (VI) is strong oxidizing gent with redution potentil of volts 7. Therefore, the trnsformtion of Cr (VI) to Cr (III) n our nd lso leds to deresed oxidtion-redution potentil 8. ph For ph vlues of syntheti wstewter (Cr solution) mesured t the different hrvesting times (3, 6, 9 nd 12 dys) the results show tht ph vlues of the syntheti wstewter t onentrtion of 5 mg Cr (VI) /kg of snd tended to inrese with inresing time for ll three monoot speies. This result my e due to the onentrtion 2- of CO 2 nd CO 3 speies in syntheti wstewter. However, hnges of the ronte lne, resulting from iohemil retion nd nutrient sorption, ould e ftor in inresing ph vlues of the Cr solution. Moreover, the deresing mole nd mount of Cr (VI) ould lso ontriute to the inrese in ph vlues. This phenomenon my result from the idity stte tht ourred when Cr (VI) is dissolved.

5 Journl of Environmentl Reserh And Development Vol. 4 No. 3, Jnury-Mrh 21 Condutivity The ondutivity of syntheti wstewter t 3, 6, 9 nd 12 dys ws lso mesured. The results from the study indite tht the ondutivities trended to inrese with inresing Cr onentrtion. This finding my e explined y the dissolved ions in wter, hnging ph vlue, nd other ftors whih ould e using the deioniztion of orgni ompounds 8. Therefore, inresed ph nd hnges in other ontrol ftors n influene ondutivity. Chromium umultion in snd medi For the nlysis of totl Cr umultion in Cynodon dtylon, Ehinohlo olonum nd Vetiveri nemorlis ultivted snd, the results from sttistil nlysis show signifintly different totl Cr umultion in snd medi t the onentrtion of 5 mg Cr (VI) /kg of snd for vlues of 4.59, 6.17, 7.13 nd 7.81 mg/kg t 3, 6, 9 nd 12 dys, respetively. For onentrtion of 1 mg Cr (VI) /kg of snd, the study found no signifint differene (t p<.5) with vlues of 5.15, 6.94, 7.71, nd 8.3 mg/kg, respetively. The study did find signifint differene ( nd ) of Cr umultion in snd medi equl to 7.12, 8.13, 9.62 nd 1.96 mg/kg for onentrtion of 15 mg Cr (VI) /kg of snd t 3, 6, 9 nd 12 dys, respetively. These results indite tht Cr umultion in soil inresed with inresing time for ll rtes of Cr onentrtion (5, 1 nd 15 mg Cr (VI) /kg of snd) s presented in Fig This outome my result from the toxiity of hromium solution to the plnt. Moreover, in Fig. 2.1, the dt lerly illustrte tht the speies of Cr tht is umulting in snd medi is mostly in the form of hromium trivlent. Fig. 2.2 shows the totl Cr umultion in the Ehinohlo olonum-plnted snd medi t onentrtions of 5, 1 nd 15 mg Cr (VI) /kg of snd. For the onentrtion of mg Cr (VI) /kg of snd, the sttistil nlysis shows signifint differene of Cr umultions t p<.5 (letters,, nd d) equivlent to 16.92, 15.47, 1.32, nd 5.71 mg/kg t 3, 6, 9 nd 12 dys, respetively. The study found Cr umultions of 19.7, 15.32, 9.45 nd 5.55 mg/kg for onentrtion of 1 mg Cr (VI) /kg of snd; nd 19.11, 18.34, nd 5.18 mg/kg for onentrtion of 15 mg Cr (VI) /kg of snd t 3, 6, 9 nd 12 dys, respetively (Fig. 2.2). In ddition, Cr umultion in the Ehinohlo olonumplnted snd medi mostly ppered in the form of Cr (III). Moreover, the umultion of TCr in the Ehinohlo olonum-plnted snd medi tended to derese with inresing time. The dt for totl hromium umultion in the Vetiveri nemorlisplnted snd medi re presented in Fig For the onentrtion of 5 mg Cr (VI) /kg of snd, the dt indite signifint differene (p<.5) of hromium umultion in the snd medi rnging from 11.59, 14.42, 1.51 nd mg/kg for the hrvesting times of 3, 6, 9 nd 12 dys, respetively. For the onentrtion of 1 mg Cr (VI) /kg of snd, the results re 13.17, 15.52, 1.52 nd mg/kg, respetively, however, theses differenes re not sttistilly signifint. There ws signifint differene (letters nd ) for hromium umultion in the snd medi equl to 15.34, 18.78, 8.68, nd 7.73 mg/kg for onentrtion of 15 mg Cr (VI) /kg of snd for 3, 6, 9 nd 12 dys, respetively. In ddition, Cr (III) ws the preferle speies for hromium umultion in the snd medi ompred to Cr (VI) s presented in Fig Moreover, the results lso indite tht, t onentrtion of 5 mg Cr (VI) /kg of snd, totl Cr umultion in the snd medi tended to

6 Journl of Environmentl Reserh And Development Vol. 4 No. 3, Jnury-Mrh 21 inrese slightly. However, t the onentrtions of 1 nd 15 mg Cr (VI) /kg of snd, the umultion of Cr in Vetiveri nemorlis ultivted snd medi hd tend - eny to derese with inresing time s presented in Fig This finding my result from the umultion of Cr in vrious prts of Vetiveri nemorlis. 3 T Cr Cr(VI) Cr(III) Chromium umulte (mg/kg) ppm 1ppm 15ppm Hrvesting Time (dys) 1) 3 Chromium umulte (mg/kg) d ppm 1ppm 15ppm Hrvesting Time (dys) 2) 3 Chromium umulte (mg/kg) ppm 1ppm 15ppm Hrvesting Time (dys) 3) Fig. 2 : Chromium umultions in snd medi 1) Cynodon dtylon 2) Ehinohlo olonum nd 3) Vetiveri nemorlis Note: The sme letter shows no signifint differene t p<.5 y Dunn s multiple rnge tests 659

7 Journl of Environmentl Reserh And Development Vol. 4 No. 3, Jnury-Mrh 21 Chromium umultion in plnts As illustrted in Fig. 3.1 Cr umulted in vrious prts of Cynodon dtylon t the onentrtions of 5 mg Cr (VI) /kg of snd t 3, 6, 9 nd 12 dys. Cr ws found mostly in the roots followed y leves nd stems, nd equled 94.59, nd mg/kg dry weight fter 6 dys respetively, ut these differenes were not signifintly different. However, the results did indite signifint differene t p<.5 (letters, nd ) for smples t 3, 9 nd 12 dys. The results of this study show tht the lowest umultion of hromium in Cynodon dtylon ourred t 9 dys. For the onentrtion of 1 mg Cr (VI) /kg of snd, the highest umultions of Cr in vrious prts of Cynodon dtylon ourred t 3 dys nd were equl to 47.72, 38.4 nd mg/kg dry weight of plnt for root, stem nd lef, respetively (Fig. 3.2). In ddition, these differenes were signifint t p<.5 (letters, nd ) for the umultion of Cr in the different plnt prts for the periods of 3, 6 nd 9 dys, ut not signifintly different t 12 dys. For onentrtion of 15 mg Cr (VI) /kg of snd, Cr umultion in the root, stem nd lef of Cynodon dtylon t 3 dys ws equl to , nd mg/kg dry weight of plnt, respetively. Signifint differenes (p<.5) of Cr umultion in different prts of Cynodon dtylon were found t 3 nd 6 dys (letters, nd ). The lowest umultion of Cr ws found t the end of the study (12 dys). (See dt in Fig. 3.3.) The results of this study indite tht the most effiient prt of Cynodon dtylon is the root, whih umulted pproximtely 1-1 times more Cr thn the stem nd lef. This finding my e the result of the trnslotion of Cr into the xylem whih is mostly found in the roots of plnts 9. The umultions of Cr in vrious prts of Cynodon dtylon hd tendeny to derese with inresing time. 15 Chromium umulte (mg/kg) root stem lef root stem lef root stem lef root stem lef 3 dys 6 dys 9 dys 12 dys Hrvesting Time (dys) 1) 66

8 Journl of Environmentl Reserh And Development Vol. 4 No. 3, Jnury-Mrh Chromium umulte (mg/kg) Chromium umulte (mg/kg) root stem lef root stem lef root stem lef root stem lef T Cr Cr(VI) Cr(III) 6 dys 9 dys 12 dys Hrvesting Time (dys) 2) root stem lef root stem lef root stem lef root stem lef 6 dys 9 dys 12 dys Hrvesting Time (dys) 3) Fig. 3 : Chromium umultions in root, stem nd lef of Cynodon dtylon t different hromium onentrtions : 1) 5 mgcr/kg of snd 2) 1 mgcr/kg of snd nd 3) 15 mgcr/kg of snd Fig. 4 demonstrtes the umultion of hromium in vrious prts of Ehinohlo olonum t the different onentrtions of hromium (5, 1 nd 15 mg Cr (VI) /kg of snd). The dt show signifint differenes (p<.5; letters, nd ) for 3, 6, 9 nd 12 dys t ll onentrtions of Cr. The results of this study show tht the gretest umultion ourred t 12 dys t onentrtion of 5 mg Cr (VI) /kg of snd. The highest umultion ws in the root whih umulted n mount of Cr equivlent to mg/kg dry weight of plnt. The 661 umultion of Cr in Ehinohlo olonum lso tended to inrese with inresing time. Moreover, Cr umultions in the other plnt prts (stem nd lef) were found (Fig. 4.1). Fig. 4-2 displys the umultions of Cr t the onentrtion of 1 mg Cr (VI) /kg of snd, nd shows tht Cr umulted mostly in the root nd ws equl to 9.8 mg/kg dry weight of plnt t 12 dys. The lowest umultion in the root of Ehinohlo olonum ourred t 6 dys nd ws equl to mg/kg dry weight. For the onentrtion of 15 mg Cr (VI) /kg of snd, the

9 Journl of Environmentl Reserh And Development Vol. 4 No. 3, Jnury-Mrh 21 results show tht the highest umultion of Cr in the root ws equl to mg/kg dry weight nd ourred t the period of 12 dys. The lowest umultion ws equl to mg/kg dry weight t 3 dys (Fig. 4.3). Cr umultions were lso found in oth stem nd lef of Ehinohlo olonum. The highest umultion of Cr ourring in the root my e due to its more diret ontt to the Cr solution. Also, the root hs high pity for tion exhnge euse of its high level of inorgni nd mino ids. These ids ould join with hevy metls nd trnslote hevy metl ions to the root of the plnt. The umultion of Cr in the stem nd lef of plnts results from the trnslotion proess. The results of this study lso onform to those of 1 who studied the umultion of hromium nd led in Hydrootyle umellte L. The results of tht study showed inresing hromium nd led umultion in Hydrootyle umellte L. with inresing onentrtions of hevy metls nd time, nd lso found tht the most umultion of hromium nd led ourred in the root ompred to other prts (i.e., the stem nd lef). 15 Chromium umulte (mg/kg) root stem lef root stem lef root stem lef root stem lef 3 dys 6 dys 9 dys 12 dys Hrvesting Time (dys) 1) 15 Chromium umulte (mg/kg) root stem lef root stem lef root stem lef root stem lef 3 dys 6 dys 9 dys 12 dys Hrvesting Time (dys) 2) 662

10 Journl of Environmentl Reserh And Development Vol. 4 No. 3, Jnury-Mrh 21 6 Chromium umulte (mg/kg) root stem lef root stem lef root stem lef root stem lef 3 dys 6 dys 9 dys 12 dys Hrvesting Time (dys) 3) Fig. 4 : Chromium umultions in root, stem nd lef of Ehinohlo olonum t different hromium onentrtions : 1) 5 mg Cr/kg of snd 2) 1 mg Cr/kg of snd nd 3) 15 mg Cr/kg of snd The results of Cr umultion in the root, stem nd lef re illustrted in Fig. 5.1 to Fig The highest umultion y Vetiveri nemorris ws in the root. For onentrtion of 5 mg Cr (VI) /kg of snd, the differenes were sttistilly signifint. We lso found tht the gretest umultion of Cr ourred in the root nd ws equl to mg/kg dry weight t 9 dys. The umultion of Cr tended to inrese through 9 dys; fter tht, it tended to derese until 12 dys t whih point it ws equl to mg/kg dry weight of plnt. For onentrtions of 1 nd 15 mgcr (VI) /kg of snd, the results were signifintly different t 3, 9 nd 12 dys. However, sttistil nlysis showed no signifint differene of Cr umultion in vrious prts of Vetiveri nemorris t the period of 6 dys. The figure shows the highest nd lowest umultions of Cr in the root whih re 63.2 nd 8.67 mg/kg dry weight of plnt for onentrtion of 1 mg Cr (VI) /kg of snd t 12 nd 6 dys, respetively. In ddition, this study found tht the umultion of Cr t the onentrtion of 15 mg Cr (VI) /kg of snd hd tendeny to inrese during the period of 3-12 dys. The lowest Cr umultion in Vetiveri nemorris ws t 3 dys nd ws equl to mg/kg dry weight of plnt; the highest umultion ws found t 12 dys nd ws equl to mg/kg dry weight of plnt. The results of this study re in ordne with the study of 11 in the removl of Cr in wstewter from the plting industry y using Nymphe spontne (lotus plnt). Tht study reported the most umultion y Nymphe spontne in the root t onentrtion of 1 mg Cr/kg. Less umultion ws found in the lef nd stem. 663

11 Journl of Environmentl Reserh And Development Vol. 4 No. 3, Jnury-Mrh 21 Moreover, the reserhers lso found tht Cr (III) umulted more redily thn Cr (VI). 15 Chromium umulte (mg/kg) root stem lef root stem lef root stem lef root stem lef 3 dys 6 dys 9 dys 12 dys 15 Hrvesting Time (dys) 1) Chromium umulte (mg/kg) root stem lef root stem lef root stem lef root stem lef 3 dys 6 dys 9 dys 12 dys Chromium umulte (mg/kg) Hrvesting Time (dys) root stem lef root stem lef root stem lef root stem lef 3 dys 6 dys 9 dys 12 dys Hrvesting Time (dys) 2) 3) Fig. 5 : Chromium umultions in root, stem nd lef of Vetiveri nemorris t 1) 5 mg Cr/kg of snd 2) 1 mg Cr/kg of snd nd 3) 15 mg Cr/kg of snd 664

12 Journl of Environmentl Reserh And Development Vol. 4 No. 3, Jnury-Mrh 21 CONCLUSION The umultion of Cr in three monoot speies: Cyodon dtylon, Ehinohlo olonum nd Vetiveri nemorlis ultivted in snd medi ontminted with syntheti wstewter (Cr solution) ws investigted in this study. The pity of Cr removl nd the umultion of Cr in different prts of three monoot speies were studied t different onentrtions:, 5, 1 nd 15 mg Cr (VI) /kg of snd; nd for different hrvesting times: 3, 6, 9 nd 12 dys. The results of this study n e summrized s follows: 1. The Cynodon dtylon, Ehinohlo olonum nd Vetiveri nemorlis in the ontrol environment grew normlly. For the plnts exposed to the experimentl onditions, the highest umultion of Cr ourred in the root followed y the stem nd lef ) root>stem>lef), respetively. The highest umultion of Cr in ll three monoot speies ourred t onentrtion of 5 mg Cr (VI) /kg of snd, followed y 1 nd 15 mg Cr (VI) /kg of snd, respetively. Moreover, it ws shown tht the highest umultion of hromium in Cynodon dtylon root ourred t onentrtion of 5 mg Cr (VI) /kg of snd: 8.85, 94.59, 61.3 nd 69. mg/kg dry weight of plnt for the hrvesting times 3, 6 9 nd 12 dys, respetively. For Ehinohlo olonum, the results showed tht t onentrtion of 5 mg Cr (VI) /kg of snd Cr mostly umulted in the root, with vlues of 49.72, 25.6, 48.5, nd mg Cr/kg dry weight of plnt t 3, 6, 9, nd 12 dys, respetively. At onentrtion of 5 mg Cr (VI) /kg of snd, the highest umulting prt of Vetiveri nemorlis ws the root. This system sored 24.87, 33.6, nd mg/kg dry weight of plnt for 3, 6, 9 nd 12 dys, respetively. The umultion rte of Cr onentrtion in ll three monoot speies t 1 nd 15 mg Cr (VI) /kg of snd ppered to inrese slightly when ompred to the extent of umultion t onentrtion of 5 mg Cr (VI) /kg of snd. 2. The plnt prt with the highest Cr (VI) umultion in ll three monoot speies ws the root, followed y stem nd lef (root>stem>lef), respetively. Also, the results lerly indite tht the Cr umultion in eh prt of ll three studied monoot speies ws the non-toxi Cr (III) form rther thn the toxi Cr (VI). The results of this study suggest tht uptke y the root of Cr (VI) nd the susequent trnslotion through the stem nd lef of ll three monoot speies is one potentil proess in the phytoremedition of ontminted lnd y phytoextrtion or phytoumultion. These three monoot speies were hosen for their wide distriution, fst growth, survivility nd, more importntly, y the ft tht they re non-edile nd hve short life spn nd produe lrge iomss, thus mking them highly suitle for phytoremedition. ACKNOWLEDGEMENT The uthors grtefully knowledge finnil support from the Ntionl Center of Exellene for Environmentl nd Hzrdous Wste Mngement (NCE-EHWM), Chullongkorn University Thilnd. Additionl grtitude goes to the Environmentl Reserh Institute, Chullongkorn University (ERIC) nd the Deprtment of Chemistry, Fulty of Siene, King Mongkut s Institute of 665

13 Journl of Environmentl Reserh And Development Vol. 4 No. 3, Jnury-Mrh 21 Tehnology, Ldkrng for ssistne y providing demi filities nd shring reserh instruments throughout this study. REFERENCES 1. Smpnpnish P., Pongspih W., Khodhir S. nd Khn E., Chromium Removl from Soil y Phytoremedition with Weed Plnt Speies in Thilnd, In Wter, Air, nd Soil Fous. Springer Netherlnds, 6(1-2), , (26). 2. Smpnpnish P., Chromium Uptke y Using Hydroponis with Monoot Weed Plnt Speies in Thilnd. In Pro - eeding, the 34 th Austrlsin Chemil Engineering Conferene (CHEMECA 26), Lnghm Hotel, Auklnd, New Zelnd, Septemer 17-2, (26). 3. Smpnpnish P., Pongspih W., Khodhir S. nd Khn E., Alterntive for Chromium Removl: Phytoremedi - tion nd Biosorption with Weed Plnt Speies in Thilnd, SieneAsi, 33(3), , (27). 4. Smpnpnish P. nd Tippysk K., Chromium Uptke on Speition nd Phytotoxiity Using Hydroponis y Aquti Plnts, In Proeeding, the 34 th Austrlsin Chemil Engineering Conferene (CHEMECA 27), Sofitel Melourne, Vitori, Austrli, Septemer 23-26, (27). 5. US EPA., Mirowve Assisted Aid Digestion of Silieous nd Orgnilly Bsed Mtries. Method 352, Ws - hington D.C., USA., (1996). 6. US EPA., Alkline Digestion for Hexvlent Chromium. Method 36, Wshington D.C., USA., (1996). 7. Swyer C.N., MCrty P.L. nd Prkin, G.F., Chemistry for Environmentl Engineering, Fourth Edition, MGrw Hill, In., (1994). 8. Chirt-uti P. nd Smpnpnish P., Chromium removl y Aquti plnt, Journl of Environmentl Reserh, 29 (1), 69-8, (27). 9. Cervntes C., Compos-Gri J., Devrs S., Gutierrez-Coron F., Loz-Tver H., Torres-Guzmn J.C. nd Moreno- Snhez R., Intertion of hromium with miroorgnisms nd plnts., FEMS Miroiology Reviews, 25, , (21). 1. Jirporn Y., Aumultion nd Toxiity of Led nd Chromium in Hydrootyle umellte L., Mster s Thesis, Dep - rtment of Environmentl Biology Siene, Mhidol University, (23). 11. Choo T.P., Lee C.K., Low K.S. nd Hishmuddin O., Aumultion of Chromium (VI) from queous solutions using wter lilies (Nymphe spontne), Chemosphere, 62, , (25). 666

14 Journl of Environmentl Reserh And Development Vol. 4 No. 3, Jnury-Mrh 21 3 rd INTERNATIONAL CONGRESS OF ENVIRONMENTAL RESEARCH ICER-1 ORGANISED BY Journl of environmentl reserh nd development (An Interntionl Reserh Mgzine of Nturl Ss., Tehnology, Soil Ss., Lw nd Mngement for Environment) THEME : Energy, Environment nd Development Venue : university of Muritius, reduit, Muritius Dte : Septemer 16-18, 21 URL : : jerd.org E-mil : ier1.jerd@gmil.om IMPORTANT DATES Lst Dte for strt sumission : June 16, 21 Notifition of Aeptne : July 16, 21 Lst Dte for Reserh Pper Sumission : July 31, 21 AWARDS 1. Young Sientist Awrd (One) 2. Best Poster presenttion Awrds (Five) CONTACT US Diretor ICER-1 A-6 Comfort Grden, Jnki Ngr, Chun Bhtti, Bhopl INDIA Phone : , Moile : , ,