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(39-01) Tracking toxicity causing compounds in wastewater effluents. Schultz, Eija1, Pessala, Piia*,1, Luukkainen, Sami2,3, Herve, Sirpa2, Joutti, Anneli1, Knuutinen, Juha3, Lahtiperä, Mirja3, Nakari, Tarja1, Paasivirta, Jaakko3, 1 Finnish Environment Institute, Helsinki, Finland2 Central Finland Regional Environment Centre, Jyväskylä, Finland3 University of Jyväskylä, Jyväskylä, Finland ABSTRACT- Different types of treated industrial and municipal wastewater effluents were screened for their possible biological effects with a battery of ecotoxicological tests. The composite effluent samples (24 h) were fractionated with methods based on the U.S. EPA toxicity identification evaluation (TIE) Phase I protocol. The Phase I protocol was modified to better suit the small-scale ecotoxicity tests used in this study, and it was also improved to detect toxicity caused by polar organic compounds. The TIE procedure was carried on to Phases II and III with an effluent sample from the pulp and paper industry, which showed an initial EC50 value of 14% in the reverse electron transport assay. The solid phase extraction with OasisTM columns seemed to remove the toxicity causing substances. The wastewater was further fractionated by eluting the OasisTM columns with a methanol series (50-100% methanol/water mixture). The fractions which were eluted with 50% methanol/water mixture turned out to be the most toxic fractions. Chemical characterization of the effluent has so far revealed organic substances such as wood extracts and oxalic acid and rather high concentrations of chloride and sulphate. Evaluation and confirmation of the chemically identified compounds as the cause for toxicity is accomplished with reference substances. Key words: wastewater effluent, toxicity identification evaluation, pulp and paper industry, solid phase extraction |
