Ecotoxicological study of landfill leachate treated in the ANAMMOX process

The exacerbated production of solid residues represents a major problem in the management and handling of urban wastes. The by-product of stored municipal and industrial solid waste production is landfill leachate. Leachate is characterized by a high concentration of organic compounds, ammonia, and the presence of heavy metals. Because of its composition, this kind of wastewater can cause serious environmental pollution and should be treated to reduce its toxic effects. Increasingly, the interest is directed to the application of the ANAMMOX (anaerobic ammonium oxidation) process for the landfill leachate treatment. In this study, for the first time, the effect of treatment with the ANAMMOX process on the toxicity of leachate was investigated. Based on the research performed in this study, it could be stated that the untreated landfill leachate from the municipal landfill and the influent of the ANAMMOX reactor present phytotoxicity to Lemna minor, due to a correlation of high concentrations of organic compounds, heavy metals, such as Cd2+, Cu2+, Zn2+, and the presence of an unionized form of ammonia (NH3). The results of the Allium cepa test demonstrated that the treatment was not efficient in eliminating the genotoxic substances that are responsible for the mutagenic potential in the effluent. This article has been made Open Access thanks to the kind support of CAWQ/ACQE (https://www.cawq.ca).