CAPILLARY ELECTROPHORETIC ANALYSIS OF ORGANIC-ANIONS IN TANNERY WASTE-WATER INCLUDING HIGH CONTENTS OF CHLORIDE AND SULFATE

A new sample preparation method for capillary electrophoresis is prese nted to analyze organic anions in industrial wastewater which is highl y contaminated with inorganic salts. Chloride and sulfate can be compl etely removed by use of strong cation exchangers in their Ag- and Ba-f orm. Good recoveries were found for 10 small organic acids out of spik ed pure water after removal of up to 2 g/L for both, chloride and sulf ate. Recoveries of oxalic acid were decreasing from 92 to 47% with inc reasing salt contents. Using tannery wastewater samples, irreversible adsorption of the organic load onto the cation exchangers could be min imized by an additional washing step. Included in these samples, 17 pe aks could be identified by spiking 46 organic and inorganic compounds. The alteration of the organic anions present in the wastewater sample s could be characterized along a biological treatment pilot plant. Som e of these anions proved to be persistent to biological degradation.