DETERMINATION OF METAL CONTENTS IN SEWAGE SLUDGES AND ASHES OF REFINERY-PETROCHEMICAL ORIGIN USING FLAME ATOMIC-ABSORPTION SPECTROMETRY

The methods of determination of Na, K, Fe, Mg, Ca, Mn, Zn, Cu, Pb, Ni, V, Cd and Cr in refinery-petrochemical sludges and ashes were evaluat ed. The sample preparation procedure depended on the type of sample an d included butyl-sulfuric mineralization, dry mineralization in muffle furnace, digestion in HF + HClO4, H3BO3, HCl, and digestion in HF + H ClO4, H3BO3 followed by fusion with LiBO2. The approved procedure was controlled by the analysis of reference material - fly ash CTA-FFA-1 a nd by comparing results obtained by calibration graph and standard add ition methods. In the case of chromium the results were significantly lower than expected - probably due to the losses of volatile chromium compounds. In most cases the relative standard deviation is at the lev el of a few percent.