AN ASSAY FOR NATRIUM CONTENT IN WASTE WATER DISCHARGED FROM PAPERMAKING PROCESS BY ATOMIC ABSORPTION SPECTROMETRY

This paper represents the assay results for natrium content in the waste water discharged from papermaking process by means of atomic absorption of spectrum in flame of air and acetylene with secondary sensitive line330.2/330.3nm. A series of assays were made on chlorine, sulfur and calcium with non-disturbance test, and phosphate and basic ammonia with the test of disturbance but without electrolytic dissociation disturbance with in the range of straight line 0-110μg/ml. The waste water discharged from papermaking process was tested after filtration and adjusting the acidity to 1 HNO₃. The waste water mixture and dark waste water were tested after nitrating the strong H₂SO₄ and HNO₃, filtrating the insoluble residues, adding 1% HNO₃ and diluting it. The recovery ratio is 95.5% to 104%, while the coefficient of variation is 0.2 to 3.7%. This method is simple, rapid, accurate and stable.