Influence of ozonation on the in vitro mutagenic and toxic potential of secondary effluents

• Published in: Water research (Oxford) Vol. 42; no. 20; pp. 4929 - 4940
• Main Authors: Petala, M., Samaras, P., Zouboulis, A., Kungolos, A., Sakellaropoulos, G.P.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01-12-2008; Elsevier
• Subjects: Advanced (tertiary) treatment; Aliivibrio fischeri - drug effects; Aliivibrio fischeri - isolation & purification; Ames test; Applied sciences; Bioassays; byproducts; dose response; ecotoxicology; effluents; Exact sciences and technology; Greece; in vitro studies; Kinetics; Local Government; metabolism; Microbial Sensitivity Tests; Microtox; Mutagenicity; Mutagens - toxicity; Other industrial wastes. Sewage sludge; Oxidants, Photochemical - toxicity; Ozonation; ozone; Ozone - toxicity; physicochemical properties; Pollution; Salmonella typhimurium; Salmonella typhimurium - drug effects; Salmonella typhimurium - isolation & purification; strains; Toxicity; toxicity testing; Vibrio fischeri; Waste Disposal, Fluid - methods; Wastes; wastewater treatment; Water Microbiology; Water Purification - methods; Water treatment and pollution; Greece; Ames test; Toxicity; Bioassays; Ozonation; Mutagenicity; Microtox; Advanced (tertiary) treatment; Bioassay; Reaction product; Ozone; In vitro; Waste water; Ozonization; Decontamination; Tertiary purification; Urban waste water; Oxidation; Waste water purification
• ISSN: 0043-1354; 1879-2448
• DOI: 10.1016/j.watres.2008.09.018

Reclamation of municipal effluents by advanced treatment processes is an attractive perspective for facing certain water shortage problems. However, the application of tertiary techniques should be thoroughly examined for their potential hazardous effects. Ozonation is an efficient chemical oxidation method, often used in wastewater reclamation, which may result in by-products that may alter the toxic and mutagenic properties of effluents. In this study, Ames test and Microtox test were used for the evaluation of ozonation efficiency to upgrade secondary effluents quality. In general, the toxic response and mutagenic effect without metabolic activation of test species were influenced mainly by the ozone dose and ozonation duration, whereas the mutagenic effect with metabolic activation was influenced mainly by ozone dose, indicating that ozone conditions strongly affect the formation of by-products. In most cases, the toxicity was increased and reached up to 100% (in relation to that of secondary effluent) after ozonation with 8.0 mg O
3/L for 5 min. On the contrary, in most cases the mutagenic activity towards strain TA98 without metabolic activation was reduced, when ozone dose and contact time increased. However, the mutagenicity was also increased after ozonation at low ozone doses and for contact times less than 5 min. The mutagenic activity of treated effluents towards strain TA98 with metabolic activation remained about the same or was reduced, compared to that of secondary effluent, and was even eliminated after ozonation with 8.0 mg O
3/L for contact times higher than 5 min.