Biological reactivity of residual wastes and dependence on the duration of pretreatment

The Austrian Landfill Ordinance ( BGBL 169/96, 1996) sets standards for the types of waste which are allowed to be landfilled. There are limits for total organic compound (TOC), ignition loss (IL), calorific value and many other parameters describing the potential of harmful substances but no parameters checking the biological reactivity of waste. Experimental determination of gas‐generating potential is well suited for the assessment of this reactivity because such methods (an incubation test developed by the Austrian Department of Waste Management [ABF‐BOKU]), allow researchers to reproduce the majority of ‘natural conditions’ in the laboratory. The problem with anaerobic tests is that the period over which the tests run tends to be long, which is why aerobic tests were also carried out. To reduce gas generating potential to less than 10%, a gas generation GS90 ≤20 Nl kg–1 dry substance (DS) Nl kg–1 DS is to be maintained. This research shows that the correlating respiration activity AT7 is between 12 and 15 mg O2 g–1 DS.