MICROBIAL-DEGRADATION OF EDTA IN AN INDUSTRIAL WASTE-WATER TREATMENT-PLANT

For the first time it is shown that EDTA is ultimately biodegraded und er practical industrial wastewater treatment conditions, involving a F innish plant dedicated to treat the effluent from a paper mill. Monito ring measurements on the influent and the treated effluent showed an E DTA elimination of about 80%. The mean EDTA concentration in the influ ent was 23.8 mg l(-1) and in the corresponding effluent 5.8 mg l(-1). The biodegradability of EDTA was verified in the laboratory with activ ated sludge from the treatment plant. Using a combined CO2/DOC method the total mineralization of EDTA was indicated by > 80% CO2 formation and greater than or equal to 99% DOC removal. (C) 1998 Elsevier Scienc e Ltd. All rights reserved.