and other disturbing isotopes .The second column containing extraction chroma to graphicresin UTEVA was used for elimination of iron.
Eventually,uranium was eluted with 0.02 MH Cland the alpha
source was prepared by means of electro plating .The more detailed
procedure for uranium separation is presented in Warwick(Warwick
et al.,1999). Thanal phasource was measured using high-resolution
alpha spectrometry.
Track-etchdetect or swereused form easuring radionactivity
concentration in air of WTPs .The yare CR-39 type detect or foilsin
diffusion chamber .They were placed for 3 month sindifferent
WTP buildings in ordertoobtain mean radionactivity in rooms,
where water plan to perators spent the most of their working time.
Later on,CR39 foils were etched in 25% NaOH. And finally,the
computer controlled opticalevaluation system which counts the
tracks on the detec tor foil corresponding to concent ration of radon
was used(Fisher etal.,1996).
As it was mentioned previously,in the most cases the sole
applied method for water treatment turned outtobeaeration in
order to precipitate Fe(OH)3 and MnO2, accordingly with the
following chemical reaction:
4Fe2þ þO2þ10H2O-4FeðOHÞ3þ8Hþ
2Mn2þ þO2þ2H2O-2MnO2þ4Hþ
Sludge obtained during aeration and filtration processes
adsorbs radio nuclideson the irsurface and disposed in uncon-
trolled way could posea serious problem for surrounding environment. In our study we collected sludge sample sand after drying
they were deter mined by gamma spectrometry . Finally in order to
assess the potentialne gative impac tof that sludge on natural
environmentthe3-stagese quential extraction according to BCR
procedure(Ureetal.,1993) was performed. Scheme of that
procedure is depicted in the figure below(Fig. 2).