Leaching, geochemical modelling and field verification of a municipal solid waste and a predominantly non-degradable waste landfill. (May 2017)

• Record Type: Journal Article
• Authors: van der Sloot, H.A.; Kosson, D.S.; van Zomeren, A.
• Is Part Of: Waste management. Volume 63(2017)
• Page Start: 74
• Page End: 95
• Publication Date: 2017-05
• Subjects: MSW municipal solid waste -- PNW predominantly non-degradable waste -- CSF chemical speciation fingerprint -- TCLP toxicity characteristic leaching procedure -- LEAF leaching environmental assessment framework -- HA humic acid -- FA fulvic acid -- DHA dissolved humic acid -- SHA solid humic acid -- DOC dissolved organic carbon -- TOC total organic carbon -- POM particulate organic matter -- HFO hydrated iron oxide -- SI saturation index -- L/S liquid to solid ratio (L/kg) -- pH+pe measure of redox state; Leaching -- Municipal solid waste -- Geochemical modelling -- Field verification -- Release prediction; Hazardous wastes -- Periodicals; Refuse and refuse disposal -- Periodicals; 363.728
• DOI: 10.1016/j.wasman.2016.07.032
• Languages: English
• ISSNs: 0956-053X

Abstract

Graphical abstract: Highlights: Multi-element geochemical description covering mineral and sorptive phases over a wide pH and L/S range. Identification of solubility controlling mineral and sorptive phases for substances of potential concern. Chemical speciation fingerprint (CSF) for MSW will form a sound basis for other worldwide MSW sources. The CSF for MSW allows an assessment beyond the testing conditions in the laboratory. The CSF forms a good basis for geochemical reaction/transport modelling of MSW scenarios including multi-layered systems. Abstract: In spite of the known heterogeneity, wastes destined for landfilling can be characterised for their leaching behaviour by the same protocols as soil, contaminated soil, sediments, sludge, compost, wood, waste and construction products. Characterisation leaching tests used in conjunction with chemical speciation modelling results in much more detailed insights into release controlling processes and factors than single step batch leaching tests like TCLP (USEPA) and EN12457 (EU Landfill Directive). Characterisation testing also can provide the potential for mechanistic impact assessments by making use of a chemical speciation fingerprint (CSF) derived from pH dependence leaching test results. This CSF then forms the basis for subsequent chemical equilibrium and reactive transport modelling to assess environmental impact in a landfill scenario under relevant exposure conditions, including conditions not readily evaluated through direct laboratory testing. This approach has been applied to municipal solid waste (MSW) and predominantly non-degradable waste (PNW) that is representative of a significant part of waste currently being landfilled. This work has shown that a multi-element modelling approach provides a useful description of the release from each of these matrices because relevant release controlling properties and parameters (mineral dissolution/precipitation, sorption on Fe and Al oxides, clay interaction, interaction with dissolved and particulate organic carbon and incorporation in solid solutions) are taken into consideration. Inclusion of dissolved and particulate organic matter in the model is important to properly describe release of the low concentration trace constituents observed in the leachate. The CSF allows the prediction of release under different redox and degradation conditions in the landfill by modifying the redox status and level of dissolved and particulate organic matter in the model runs. The CSF for MSW provides a useful starting point for comparing leachate data from other MSW landfills.