ON THE TREATMENT OF
POLYCHLORINATED BIPHENYL
IN WATER BY
IONIZING RADIATION
S. KINOSHITA and T. SUNADA
Division of Sanitary Engineering, Radiation Center of Osaka Prefecture,
Sakai, Osaka, Japan
We have attempted to use atomic energy as a means of destroying such hazardous
pollutants in water as phenol, alkyl benzene sulfonate (1), phenylmercurie acetate,
methylmercuric chloride (2), parathion, pentachlorophenol (3), benzidine and
ί-naphthylamine (4), and found the reduction of concentrations of them by irradiation;
the products had no toxic effects on the test animals. Thus, the application of atomic
energy to pollution problems was considered to be hopeful because of its wide spectrum
of treating toxic, or harmful pollutants. Recently, pollution with polychlorinated
biphenyl (PCB) has become serious because of its resistance to heating, chemicals or
biolysis (5), (6). The solution to this problem is to inhibit its use and replacement by less
hazardous substitutes, but this would not affect the material already in use which will
ultimately be concentrated in some living organisms in which so-called chlorobiphenylosis
would be induced. In Japan it has been reported that the concentrations of PCB in some
river waters which are the sources of water supplies ranged from 0.1 to a maximum value
of 1 ppb. This occurrence of PCB in the source of water supplies prompted our
investigation of the effects of irradiation on PCB in water. The study has had two
objectives: (1) to investigate the irradiation effects on PCB in water, (2) to investigate its
effects on other conventionally used or proposed methods.
EXPERIMENTAL MATERIALS AND METHOD
Materials
Polychlorinated biphenyl is so insoluble in water that it can be considered to exist in a
form of colloidal microparticulates in contaminated river or lake waters. Therefore,
experimental materials were prepared in such a form. PCB (Kanechlor 300) was added to
distilled water and shaken vigorously for half an hour by a shaking machine. This mixture
was then filtered through four sheets of fluted filter paper. The filtrate was collected and
stored for use. Before use, the stock filtrate was analyzed for its concentration of PCB by
extraction with n-hexane which was gas chromatographed and peak heights were
compared with those from a standard 1 ppm n-hexane solution of PCB, and adjusted to
100 ppb with distilled water.
Irradiations
Colloidal aqueous solution of PCB in "Pyrex bottles" was exposed to 0.01, 0.1, 1.0
and 10 Mrad of γ-rays from Co-60 at the rate of 2 X 10
5 r/h respectively. The bottles
were set on the tables which were rotated during irradiation in order to get as uniform a
dose distribution as possible.
Analytical determination
PCB in colloidal aqueous solution was extracted with n-hexane. The extracts were
concentrated in a 50°C water bath to the final volume, which was then analyzed on a
GLC column 150 cm long and 3 mm outer diameter containing a 1.5% coating of methyl
silicone (SE-30) on 60-80 mesh Chromosorb W (AW/DMCS). The Chromatograph used
607
POLYCHLORINATED BIPHENYL
IN WATER BY
IONIZING RADIATION
S. KINOSHITA and T. SUNADA
Division of Sanitary Engineering, Radiation Center of Osaka Prefecture,
Sakai, Osaka, Japan
We have attempted to use atomic energy as a means of destroying such hazardous
pollutants in water as phenol, alkyl benzene sulfonate (1), phenylmercurie acetate,
methylmercuric chloride (2), parathion, pentachlorophenol (3), benzidine and
ί-naphthylamine (4), and found the reduction of concentrations of them by irradiation;
the products had no toxic effects on the test animals. Thus, the application of atomic
energy to pollution problems was considered to be hopeful because of its wide spectrum
of treating toxic, or harmful pollutants. Recently, pollution with polychlorinated
biphenyl (PCB) has become serious because of its resistance to heating, chemicals or
biolysis (5), (6). The solution to this problem is to inhibit its use and replacement by less
hazardous substitutes, but this would not affect the material already in use which will
ultimately be concentrated in some living organisms in which so-called chlorobiphenylosis
would be induced. In Japan it has been reported that the concentrations of PCB in some
river waters which are the sources of water supplies ranged from 0.1 to a maximum value
of 1 ppb. This occurrence of PCB in the source of water supplies prompted our
investigation of the effects of irradiation on PCB in water. The study has had two
objectives: (1) to investigate the irradiation effects on PCB in water, (2) to investigate its
effects on other conventionally used or proposed methods.
EXPERIMENTAL MATERIALS AND METHOD
Materials
Polychlorinated biphenyl is so insoluble in water that it can be considered to exist in a
form of colloidal microparticulates in contaminated river or lake waters. Therefore,
experimental materials were prepared in such a form. PCB (Kanechlor 300) was added to
distilled water and shaken vigorously for half an hour by a shaking machine. This mixture
was then filtered through four sheets of fluted filter paper. The filtrate was collected and
stored for use. Before use, the stock filtrate was analyzed for its concentration of PCB by
extraction with n-hexane which was gas chromatographed and peak heights were
compared with those from a standard 1 ppm n-hexane solution of PCB, and adjusted to
100 ppb with distilled water.
Irradiations
Colloidal aqueous solution of PCB in "Pyrex bottles" was exposed to 0.01, 0.1, 1.0
and 10 Mrad of γ-rays from Co-60 at the rate of 2 X 10
5 r/h respectively. The bottles
were set on the tables which were rotated during irradiation in order to get as uniform a
dose distribution as possible.
Analytical determination
PCB in colloidal aqueous solution was extracted with n-hexane. The extracts were
concentrated in a 50°C water bath to the final volume, which was then analyzed on a
GLC column 150 cm long and 3 mm outer diameter containing a 1.5% coating of methyl
silicone (SE-30) on 60-80 mesh Chromosorb W (AW/DMCS). The Chromatograph used
607