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
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