engleski

In vitro assessment of genotoxicity of landfill leachate on human lymphocytes using multi-biomarker aproach

Landfill leachate contains high amount of pollutants that can contaminate ecosystems, and in that manner can pose a risk not only to environment but to human health as well. The aim of this research was toxicological characterization of the landfill leachate prior/after the treatment using two different approaches on human lymphocytes as sensitive biomarkers of exposure. Landfill leachate was taken from the Piškornica (Koprivnica, Croatia) sanitary landfill. The landfill area was placed in the alluvial depression with high groundwater level which represents reductive aquifer characterized by increased turbidity and high concentration of iron, manganese and ammonia. Chemical treatment combined precipitation with CaO followed by coagulation with ferric chloride and final adsorption by clinoptilolite, whereas electrochemical treatment included pre-treatment with ozone followed by electrooxidation/electrocoagulation, and final polishing by microwave irradiation. After the both treatments all measured parameters decreased significantly and were in accordance with the regulated values. Cytotoxic potential on human lymphocytes was determined using vital staining with ethidium bromide and acridine orange, while genotoxicity assessment was conducted using comet and micronucleus assay carried out at two exposure periods, 4 and 24 h. Original leachate was cytotoxic for both exposure periods while chemically/electrochemically treated samples showed no cytotoxicity, even after prolonged exposure. Untreated leachate exhibited significantly higher values for all comet assay parameters compared to control, whereas chemically/electrochemically treated leachate did not affect any of the parameters tested. Additionally, original leachate significantly affected all measured micronucleus assay parameters compared to chemically/electrochemically treated leachate, which did not have any influence on the tested parameters for both exposure periods. It is to be concluded that both methods are suitable for the treatment of such complex waste effluent due to high removal efficiency of all measured parameters and toxicological safety.

Landfill leachate; Wastewater treatment; Cytotoxicity; Genotoxicity

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