Reusing Landfill Leachate Within the Framework of a Proper Management of Municipal Landfills

The possibility of reusing leachate substances for agronomical purposes might be of interest, especially in arid areas when used in addition to the leachate water content. This study presents a simple procedure for the revegetation of the walls of closed landfills, reusing the leachate as a fertigant. The results demonstrated the real possibility of employing blended leachate as a fertigant for the revegetation of the walls of closed landfills. The native plants Lepidium sativum, Lactuca sativa and Atriplex halimus, which suit the local climate, were chosen for this study in Southern Italy. The methodology was structured into three phases: (i) early-stage toxicity assessment phase (apical root length and germination tests), (ii) adult plant resistance assessment phase and (iii) soil properties verification phase. The rationale of the proposed approach was first to look at the distinctive qualities and the potential toxicity in landfill leachates for fertigation purposes. Afterwards, through specific tests, the plants used were ranked in terms of resistance to the aqueous solution that contained leachate. Finally, after long-term irrigation, any possible worsening of soil properties was evaluated. In particular, the plants maintained good health when leachate was blended at concentrations of lower than 25% and 5%, respectively, for Atriplex halimus and Lepidium sativum. Irrigation tests showed good resistance of the plants, even at dosages of 112 and 133.5 mm/m², at maximum concentrations of 25% and 5%, respectively, for Atriplex halimus and Lepidium sativum. The analysis of the total chlorophyll content and of aerial parts dried weight confirmed the results reported above.