Tests for doc-leaching from waste materials (NT TR 582)

Abstract

  Decision 2003/33/EC establishes procedures and criteria for different parameters needed in the acceptance of waste at landfills in accordance with the EU Landfill Directive. One of these parameters is dissolved organic carbon (DOC). This parameter is a consequence of the need for gradually reducing the landfilling of biodegradable waste in order to reduce green house emissions. It has also been stated that elevated levels of DOC in landfill leachates mobilise metals and organic pollutants and thus increase the leachate oxygen consumption. Generally the compliance with the Annex 2 DOC criteria is proven by testing the waste at its own pH-level using leaching tests such as up-flow percolation test (prCEN/TS14405) or batch leaching test (EN12457). Annex 2 however also gives the possibility to test the DOC leaching at controlled neutral pH-values between 7.5-8.0, under a liquid to solid ratio of 10 l kg-1 dry matter, in case of failure of the DOC criteria at material’s own pH. For these purposes two draft methods, a pH static test and an ANC-method (acid-base neutralisation capacity method) are being considered by CEN TC292/WG6. This document is the final report of the project entitled: “Test för DOC-utlakning ur avfallsmaterial” financed by the NICe. The aim of this work was to both to compare two different standard methods developed for DOC-leaching testing and to assess their applicability for different types of wastes. The project also included the comparison of two different DOC determination methods and the identification of critical waste streams with the respect to DOC-leaching and the identification of parameters affecting the DOC-leaching.