Evaluation of correlations between absorbance at 254 nm and COD of river waters

Correlations between the absorbance module at 254 nm (A_{254 nm}^{1 cm}) and COD by the permanganate and dichromate methods in rivers in the lower part of the Odra river basin are given. For the purpose of the conducted study a clean reach of the river, two short reaches with medium and high pollution, especially with lignin and humic substances and phenolic wastes below industrial waste outfalls have been selected. Investigation results from 1973 to 1978 have been evaluated mathematico-statistically: regression equations and empirical relations with average conversion factors and variation coefficient are presented. Relationships between absorbance and COD are also given graphically. Close relations have been found and the absorbance module at 254 nm has been recommended to be used as indicator of organic pollution in selected reaches of the river. The method is suitable for laboratory work as well as automatic monitoring of concentration changes in dissolved organic matter. This work is in relation with the results of many authors who carried out investigations in various localities.