TREATMENT OF MUNICIPAL LANDFILL LEACHATE BY THE PROCESS OF REVERSE OSMOSIS AND EVAPORATION

A major drawback of landfilling is the production of polluted leachate. An applied environmental study was performed in order to purify municipal landfill leachate by reverse osmosis technology, using a RO98pHt polyamide membrane and a consecutive evaporation process, was used to minimize the volume of residual waste. Retention factors of individual components during the separation process were studied. Retention factors for monovalent ions exceeded 97% and divalent ions exceeded 99% on average. Acidification of the leachate resulted in lower concentrations of ammonia nitrogen in the permeate. The resulting permeate accounted for 90% of the original input volume. The total amount of 50.7 g dry residual solids was obtained from 1 L of retentate by vacuum evaporation. A series of trace elements were detected in residual solids by XRF spectrometry. The landfill leachate studied can be considered a source of trace metals, thus this study makes possible the recovery of trace elements from waste.