Alachlor — ecotoxicity of ozonation by-products

Abstract This work focuses on the assessment of alachlor toxicity, its impact on aquatic and terrestrial ecosystems, non-target organisms, and humans, as well as with pesticide legislation in the European Union and Slovakia. In the experimental part, the pesticide alachlor was degraded by various ozone-based processes. Toxicity of the original substance and its degradation products was evaluated by ecotoxicity tests on white mustard and bulb onion. Respirometric measurements were performed to assess their effect on the microorganisms of activated sludge process. From the results it is possible to evaluate that the degradation of alachlor by ozonation at alkaline pH resulted in less toxic substances compared to the original pesticide.