International Topical Meeting on Nuclear

Research Application and Utilization of

Accelerators

4-8 May 2009 Vienna-Austria

Yazd University

Iran

Study of the Effects of Electron Beam on Heavy Metals in Presence of Scavengers for

Decontamination and Purification of the Municipal and Industrial wastewater

A. Behjat, S. Dadfarnia, A. M.

Salmanzadeh, M. Parsaeian, F. Anvari, and

M. Kheirkhah

� Physics Department, Atomic and Molecular group, Yazd University, Yazd, Iran

� Chemistry Department, Yazd University, Yazd, Iran

� Yazd Radiation Processing Center, Atomic Energy Organization, Yazd, Iran

Research works undertaken

� Microbiological treatments (water company, Ministry of energy)

� Decolorization (Textile Industries & wastewater company)

� Removal of heavy metals (water & wastewater company)

Oxidation process usually used

� Use of ozone

� Hydrogen peroxide

� Ultraviolet

Advance oxidation process (AOP)

� Interaction of ionizing radiation with water

� Based on electron beam irradiation of wastewater ( hydroxyl free radicals)

� Capacity to decompose the organic compounds

RHODOTRON TT200 electron beam accelerator parameters

� Beam Energy 5 and 10 MeV

� Beam power at 10 MeV 70 kW

� Beam power at 5 MeV 35 kW

� Energy dispersion at 10 MeV ±300 keV

� Scanning range 30-100 cm

� Total power consumption ≤ 300 kW

� RF 107.5 MHz

� RF power output 200 kW Electron gun average current 0-10 mA

� Resolution ±50 µA

Irradiation of the wastewater samples

Wastewater irradiated by Electron beam

Wastewater samples before and after irradiation

Decolorization of dye molecules

Reactive dyes irradiated by different doses

Irradiation of reactive dyes

Irradiation of disperse dyes

Heavy Metals

� A common hazardous waste

can damage organisms at low concentrations and tends to

accumulate in the food chain.

� Examples are:

Lead, Chromium, Cadmium, and Mercury.

Permitted level

0.1 0.050.05As

--0.001Hg

0.1 0.050.05Cr

0.2 10.05Cu

2 53Zn

50.050.05Pb

0.010.010.005Cd

Water used in agriculture

mg/L

Natural Water and wastewaters

mg/L

Drinking Water

mg/L

element

Mechanism of radiolyticconversions of metal ions

)()( ICdeIICd aq →+

)()( ICdHIICd →+

)()0()()( IICdCdICdICd +→+

nCdnCd )0()0( →

OH radicals

−+→+ OHIICdOHICd )()(

222 )()( OHIICdHHOICd +→+++

−++→+ OHOHIICdOHICd )()( 22

Addition of OH absorber (HCOO-)

format ions converte OH radicals (and H atoms) to COO- radical ions

)()( 22 HOHCOOHOHHCOO +→+−−

2)()( COICdCOOIICd +→+−

2)0()( COCdCOOICd +→+−

Experimental procedure

� Sample preparation

� Irradiation of the samples

� Determination of metal ions

Sample preparation (I)

� Methyl Mercury

CH3HgCl

and

� Dimethyl Mercury

CH3HgCH3

Mercury

� Methyl Mercury, (CH3Hg)

Found in polluted water and wastewater

(Most of the mercury in body)

� Dimethyl Mercury, Hg(CH3)2

Found in polluted air and soil

Sample preparation

Decomposition and recovery of methyl and dimethylmercury

20.3 ± 3.3%15.5 ± 3.3%10 ± 2.9%CH3HgCH3

98.2 ± 2%70.9 ± 3.3%47.1 ± 3

.3%CH3HgCl

5 kGy3 kGy1 kGyOrganic

mercury

Sample preparation (II)

� 1) Wastewater from stabilizing ponds:

� A) influent wastewater (Mixed)

� B) effluent wastewater

� 2) Effluents from textile industry

� 3) Water solution spiking 100 ppb Cd or Pb

Yazd wastewater stabilizing ponds

Textile effluents irradiated (different dose)

40 ml of solution in Petri dishes

Electron beam irradiation

� Absorbed Doses:

1 kGy

3 kGy

6 kGy

9 kGy

Irradiated samples ready for

metal determination

Determination of metal ions by

Furnace Atomic Absorption Spectrometer

Irradiation of raw influent

0

1

2

3

4

5

6

0 1 2 3 4 5 6 7

Irradiation Dose (kGy)

am

ou

nt

(pp

b)

Cd

Laboratory made samples

85

90

95

100

105

0 2 4 6 8 10

Irradiation Dose (kGy)

Am

ou

nt

(pp

b)

Pb

Cd

Addition of scavengers

� Rice bran

size <200 micron

as a natural sorbent.

� 4, 8, and 12 mg

Irradiation of samples by adding

4 mg natural scavenger

0

20

40

60

80

100

120

0 1 2 3 4 5 6 7 8 9 10

Irra dia t io n D o s e (kGy)

P b

C d

Irradiation of the samples with different amounts of scavenger

Absorbrd

Dose

(kGy)

Scavenger

(mg)

Pb

((ppb

Cd

((ppb

0 - 100 100

1 - 0.5%±94.2 1.7%±86.8

3 - 6.3%±79.3 6%±95.8

6 - 7.8%±95.1 1.8%±95.7

9 - 5.4%±93.0 4.3%±94.3

1 4 4.8%±59.1 2.6%±87.8

3 4 5.1%±67.0 2.3%±79.1

6 4 3.5%±69.5 5.8%±81.8

9 4 4.9%±52.5 4%±83.7

9 8 0.3%±51.5 6.1%±79.8

9 12 8.9%±34.3 5.6%±82.2

Adding natural scavenger(+9 kGy)

0

20

40

60

80

100

120

0 2 4 6 8 10 12 14

Natural scavenger(mg)

Am

ou

nt

(pp

b)

Pb

Cd

Water samples containing Cd

and Pb and EDTA (0.001 molar)

Absorb

ed

Dose

( kGy)

Scaveng

er

(mg)

Pb (ppb)

Cd (ppb)

0 ---- 100 100

1 12 %7.10.34 ± %3.53.48 ±

3 12 %6.79.31 ± %8.33.47 ±

6 12 %2.04.25 ± %3.61.38 ±

9 12 %100.27 ± %6.26.47 ±

Irradiation of samples containing Cd and, Pb and Sodium acetate (NaCH3COO, 0.001 Molar)

Absorbed

Dose

(kGy)

Scavenger

(mg)

Pb

(ppb)

Cd

(ppb)

0 0 100 100

1 12 %8.03.7 ± %4.01.10 ±

3 12 %5.56.2 ± %9.29.5 ±

6 12 %2.121.1 ± %1.04.6 ±

9 12 %1.158.0 ± %5.04.5 ±

Addition of NaCH3COO

� As a chemical reagent

-20

0

20

40

60

80

100

120

0 1 2 3 4 5 6 7 8 9 10

Irra dia t io n D o s e (kGy)

P b

C d

Irradiation of samples containing Cdand Pb and EDTA (0.001 Molar) with

and without scavenger

Absorb

ed

Dose

( kGy)

Scaven

ger

(mg)

Pb (ppb)

Cd (ppb)

0 ---- 100 100

1 12 %7.10.34 ± %3.53.48 ±

3 12 %6.79.31 ± %8.33.47 ±

6 12 %2.04.25 ± %3.61.38 ±

9 12 %100.27 ± %6.26.47 ±

Addition of EDTA

� Chemical complexing agent

0

20

40

60

80

100

120

0 1 2 3 4 5 6 7 8 9 10

Irra dia t io n D o s e (kGy)

P b

C d

Irradiation of effluent from wastewater plant

Irrradiation Dose

( (kGy

(Scavenger )

mg))

NaCH3COO

Or

EDTA

Pb

(ppb)

Cd

(ppb)

0 -- - 2.2%±2.8 0.6

1 12 NaCH3COO

N.D.1

18.9%±0.1

3 12 NaCH3COO

N.D. 8.7%±0.1

6 12 NaCH3COO

N.D. ------

1 12 EDTA N.D. 0.3%±0.2

3 12 EDTA N.D. 3.6%±0.2

6 12 EDTA N.D. 44.3%±0.2

Irradiation of effluent from wastewater plant +NaCH3COO+12 mg scavenger

-0.5

0

0.5

1

1.5

2

2.5

3

0 1 2 3 4 5 6 7

Irra dia t io n D o s e (kGy)

Pb

Cd

Irradiation of effluent from wastewater plant +EDTA+12 mg scavenger

-0.5

0

0.5

1

1.5

2

2.5

3

0 1 2 3 4 5 6 7

Ir r a d i a t i o n D o s e ( k Gy )

Am

ou

nt

(pp

b)

P b

Cd

Conclusion

� Electron beam irradiation of water and wastewater samples can increase the concentration of free metal ions in the samples.

� natural scavenger together with EB radiation can increase the heavy metal removal from the wastewater samples.

� capability of the natural scavenger in the presence of chemical agents is increased.

Thank you for your attention