In situ lysimeter experiment of leaching pollutants from municipal waste with physicochemical status and microbiome condition

Abstract

• Effluents have a specific electrical conductivity similar to landfill leachates. • The microbiological activity in the tested leachate samples shows seasonality. • Temperatures in summer reduced the ability of the microbiome to oxidize polymers. Lysimeter tests are an ideal supplement to monitoring tests performed in the area of landfills. This article presents an interdisciplinary lysimeter experiment that used hydrogeological, biochemical, and microbiological studies to evaluate the process of leaching pollutants from waste. The obtained results of leachate tests indicate that the EC value was as high as 31 mS/cm which corresponds to poor water quality. Additionally, high concentrations of chlorides (up to 5095 mg/L) and sulphates (up to 10107 mg/L) were observed. The results of microbiological tests confirm the seasonality. The statistically significant (p < 0.05) difference in the number of heterotrophic bacteria was denoted between autumn (1.6·107 CFU cm-3) and winter (1.5·105 CFU cm-3.The analysis of the ability to utilize nitrogen and phosphorus sources showed seasonal differences in the use of substrates containing these biogenic elements. It was observed that nitrogen-containing compounds were most intensively used in winter and the least in spring while phosphorus compounds were the most intensively oxidized in summer. Presented results confirm that lysimeter studies can play a valuable role in the construction of landfills for the best method of waste isolation and limiting the growth of microorganisms.