Application of Advanced Electrochemical Techniques for the Purification of Leachate in Landfills

Landfill leachate is one of the problems related to waste landfills with the most important environmental impact, as the extreme variability of the substances inside the landfill gives rise to high heterogeneity of the leachate itself. In the present work, an electrochemical approach has been considered as a relatively simple and low-cost solution to the problem of ammonia removal, given the impossibility of resorting to biological treatments. An extensive experimental campaign was conducted to identify the best solution, evaluating any preventive filtration or precipitation sections, and considering the efficiency of the process in terms of energy costs. Based on the data obtained, the electrochemical approach appears feasible, and it is possible to operate either with high current densities (and higher energy costs) or with lower current densities (which, in addition to lower energy costs, allow longer service life for the electrodes), after pre-treatment of the solution by coagulation/flocculation with aluminum polychloride.