Characterization of dandfill soil contaminated with leachate in comparison with uncontaminated soil

Abstract

This study evaluates the effects of landfill leachate on the physicochemical and microbiological quality of the soil, comparing a contaminated soil (SCL) with a non-contaminated soil (SNC). The SCL has high levels of moisture (22.67%), salinity (19.705 dS/m), organic matter (6.2%) and heavy metals such as arsenic (34.28 mg/kg) and mercury (0.49 mg/kg), which exceed the maximum permitted levels. Microbiologically, the SCL is dominated by Cytobacillus firmus (27 %), while the SNC shows a higher presence of Pseudomonas oleovorans (53 %), indicating microbial adaptation to chemical stress. The results illustrate how leachates accumulate pollutants, alter microbial communities and limit the agricultural use of the soil, but also show the potential of adapted microorganisms as bioremediation agents. This study emphasizes the need for proper management of municipal solid waste and the development of strategies to remediate soils and mitigate ecological risks.