Identification of organic compounds in a municipal landfill leachate by gas chromatography coupled with mass spectrometry

Abstract

The organic compounds present in leachate can contaminate soil, superficial and underground water, and the majority is considered harmful to the environment and human health. The objective of this study was to identify organic compounds present in landfill leachate located in Maringá-PR by gas chromatography coupled to mass spectrometry (GC-MS). The raw leachate was characterized by measurements of pH, Chemical Oxygen Demand (COD), Biochemical Oxygen Demand (BOQ), Dissolved Organic Carbon (DOC), apparent and true colors, turbidity and absorbance at 254 nm. The extraction of organic compounds in leachate was carried out by liquid-liquid extraction (LLE) with ethyl acetate and dichloromethane solvents, while varying the pH and ionic strength. The analysis of the leachate by GC-MS showed the presence of compounds considered to have toxic effects on the environment and human health, such as pesticides and phenolic compounds. Several compounds containing oxygenated groups such as carboxylic acids and alcohols were also identified, indicating that it was highly probable that the decomposition of waste in the landfill was in the acidogenic phase.