Author(s)

E Otal, C F Pereira, L F Vilches & X Querol

Abstract

Application of synthetic zeolites to the depuration of a waste landfill leachate E. Otal1, C. F. Pereira1, L. F. Vilches1 and X. Querol2 1Dpto. Ingenieria Quimica y Ambiental, E.S. Ingenieros Industriales, Universidad de Sevilla, Spain. 21nstituto de Ciencias de la Tierra Jaume Almera (CSIC), Barcelona, Spain. Abstract In this paper the application of synthetic zeolites to the decontamination of a highly contaminated municipal waste landfill leachate has been studied. Thus, the reduction of organic matter (COD), total Kjeldhal nitrogen (TKN), suspended solids and metals contents in the diluted leachate were measured after two different treatments. One of them consisted in a two-stage process: a physico- chemical coagulation-flocculation treatment combined with the zeolite treatment. Two synthetic zeolites have been tested: a commercial zeolite and one obtained after a coal fly ash alkaline hydrothermal process (CV-Z). The results showed that the physico-chemical treatment using aluminium sulphate and an organic flocculant yielded an important reduction in the leachate COD, not improved by the zeolite treatment. Nevertheless, zeolites, especially CV-Z, clearly produced a strong reduction in the leachate nitrogen content. In addition, although the leachate metal concentrations are not very high, the zeolite addition also improved the metal removal. In the light of the low metal content in the leachate, a new treatment in one stage was used in a second phase. This treatment achieved an important improvement in the COD reduction, though the TKN nitrogen removal was somewhat worse than in the two stage process. 1 Introduction It is well known the cationic exchange capacity of natural and synthetic zeolites, and thus this material has been used for solving different environmental

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