Stabilisation/solidification of landfill leachate concentrate and its residue obtained by partial evaporation

Abstract

Landfilling of waste is inseparably linked to the production of landfill leachate, which is treated and processed by different procedures. One of the options according to technical and economic development is the application of pressure-driven membrane processes, where landfill leachate concentrate (LLC) is produced. This may be further subjected to a stabilisation/solidification process (S/S) as one of its possible processing methods that leads to limited re-introduction of undesirable substances into the landfill body. This paper presents the research of the S/S of LLC, investigates the effect of the waste/binder ratio, the influence of Portland cement substitution, the influence of the additional concentration of the concentrate by evaporation at different levels from the original LLC, and the use of an innovative special highly absorbing binder based on specifically treated fly ash for selected leachate characteristics and compressive strength of the test specimen. The S/S process in most cases met the legislative requirements for water leachate characteristics for non-hazardous waste. Additionally, the comparison of indicative expense for selected solidificate compositions and scenarios is involved. The results of the study serve as necessary basement for further development of treatment of LLC.