Feasibility study for the development of ATR-FTIR spectroscopy models for leachate, pumped water and groundwater to predict the biological stability of landfills and old deposits

In Austria, there are still numerous secured old landfills or domestic waste landfills in the decommissioning phase whose remaining emission potential can pose an environmental risk. These landfills and old deposits must be regularly examined for their risk in order to decide whether further measures are necessary or whether the costly securing or aftercare can be discontinued. Today, the investigations are carried out using standardized chemical-physical methods. In addition to these methods, some of which only identify individual parameters after complex wet-chemical preparation steps, FTIR (Fourier Transform Infrared) spectroscopy was developed a few years ago as a rapid and holistic analysis approach. FTIR spectroscopy produces absorption spectra that allow conclusions to be drawn about organic and inorganic compounds in samples. In the original form of these investigations, transmission measurements of solid samples in KBr compacts were used, which also required considerable time and skill on the part of the analyst to prepare the sample. In recent years, ATR (Attenuated Total Reflection) FTIR spectroscopy, which can directly measure homogenized powdered samples, has been favoured, reducing the time and effort required and enabling higher sample throughput. Thanks to this progress, it is now possible to use the method in many more laboratories and to establish it as a routine method in the future. The disadvantage is that the spectra of ATR-FTIR spectroscopy differ in their band height and the models already established for the transmission FTIR method cannot be used. In order to develop or adapt new models, a sufficient number of samples with known and varying wet chemical parameters must be measured. The aim of this project is to develop and validate models for ATR-FTIR spectra that include the relevant stability parameters AT4 and a gas donation sum GS21 <20 Nl on the basis of already wet-chemically analyzed retention samples of seepage, pumping and groundwater.