Evaluation of ion exchange resins for removal and recuperation of ammonium–nitrogen generated by the evaporation of landfill leachate

In the present study, the recovery of ammonium ions from landfill leachate of municipal solid waste was investigated using four ion exchange resins: Amberlyst 15 Wet (strong acid cation), Lewatit VPOC1800 (strong acid cation), Dowex MAC-3 (weak acid cation) and Purolite MN 250 (without acid or basic functional group). The studies of sorption were conducted under batch conditions. The maximum sorption capacities qe (mg g−1) to ammonium ions of the different cationic resins were: Amberlyst 15 Wet: 74.1; Lewatit VPOC1800: 71.4; Dowex Mac-3: 0.1. The resin Purolite MN 250 without functional group also was available but it was not efficient to remove ammonium ions from landfill leachate. For the best resin—Amberlyst 15 Wet—studies of equilibrium and kinetic of the sorption were also performed. The Freundlich model was more adequate to describe the ion exchange equilibrium and the sorption mechanism fit the pseudo-second-order kinetic model for these resins. This resin was efficient to removal around 80 % of ammonium ion present in real leachate landfill and its regeneration with sulphuric acid produced a solution of ammonium sulphate with a recovery of 70 %.