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International Journal of Applied Radiation and Isotopes, 1976, pp. 185-186. Pergamon Press. Printed in Northern Ireland
The Disposal of Radioactive Solvent Waste
(Received 27 August 1975) USE Of radioisotope tracer techniques has increased in recent years and m a n y laboratories are now faced with the need to dispose of considerable quantities of organic solvent and aqueous liquid wastes, particularly those arising from the technique of liquid scintillation counting. Whilst the radioactive content of such wastes is usually low and would not normally preclude disposal by the drainage system, the inflammable and explosive potential and the possible effect of these materials on the efficient working of the sewerage plant often does. The two c o m m o n l y adopted alternatives are incineration on site or collection by a waste disposal contractor. Incineration on site requires a suitable incinerator and adequate m a n p o w e r and is often too costly. Disposal through a contractor involves the accumulation and storage of wastes in corrodable metal containers and handling on working premises by ancillary staff THE
with no scientific training. The dangers of le-' fire or explosion associated with this are aggr~ by the presence of radioactivity. Particular cc arises when individual users are scattered over departments on premises in close proximi residential areas. Since most of the radiochemicals in these was~ preferentially water soluble we have investigat, possibility of decontamination at source by w~ the radiochemicals out into water and disch~ into the normal drainage system in a highly d form. A small, cheap apparatus to do this wo~ required so that one could be provided in area where isotopes are used. To this end we have constructed the app~ shown schematically in the diagram which c, of a stainless steel funnel fixed by means of a si rubber bung into the neck of a 20 1. glass I The bottle stands by a sluice or drain outle which the overflow is discharged. The top funnel carries a spray connected to a mains supply so that the funnel is continually washed Waste solvent added to the apparatus accumul~ the top of the bottle; water flows through the s, down the funnel wall forming an interface a t water soluble substances are extracted. W solvent can be withdrawn fi'om the apparau
~ Water sprayed down
"'~ ~ I
wall of funnel
TABLE I bl,e~ t
~t r!~ e,,
d~.:~ d - -
_ I inn ¢,nlven!
~0 e.9 :"
O, 20 -
]~[ L~s~avtate (G) 3H or n - ~ e c ~ o i c acid-l-]~C w,~re added to of NE213 ~oiuene based scintillation fluld~ p!i:ed in a /L 4i~'~oso
~uH washed ~i/~i wa%er a% 140~i rain-!° was withdrah~ ~ d
At t}e z m e s
added %o 9 m! W~21~ for c~unib\~
stated, I ml 5 "rl effluent
freeze dried ~uad t6.en up in ]0 in! m~213 for ~o .~dur~7,, ~&tp!e~ we
FIo. 1 4
in a Packard Tri-Carb. liquid g - b r ]]at o~I " tinter, '~d~] 3'°9.