Toxicity-directed fractionation of organic compounds in tannery wastewater with regard to their molecular weight and polarity

A toxicity-directed fractionation scheme for organic compounds in industrial wastewaters is presented. The sequential application of the three separation methods (ultrafiltration, preparative gel permeation chromatography, and solid-phase extraction) allows the separation of wastewater constituents with regard to their molecular weight and their polarity. After each separation step the dissolved organic carbon (DOC) and the luminescence inhibition of the fractions are measured. With this information the nature of the inhibiting substances in a wastewater sample can be characterized. Additionally, the fractions which show increased toxic effects can undergo further testing for identification of the responsible compounds. An untreated and biologically treated (anaerobic and anaerobic/aerobic) tannery wastewater were used for the development of the fractionation scheme.