Anaerobic digestion is a waste treatment method which is of increasing interest worldwide. At the end of the process, a digestate remains, which can gain added value by being composted. A study was conducted in order to investigate microbial community dynamics during the composting process of a mixture of anaerobic digestate (derived from the anaerobic digestion of municipal food waste), green wastes and a screened compost (green waste/kitchen waste compost), using the COMPOCHIP microarray. The composting process showed a typical temperature development, and the highest degradation rates occurred during the first 14days of composting, as seen from the elevated CO2 content in the exhaust air. With an exception of elevated nitrite and nitrate levels in the day 34 samples, physical-chemical parameters for all compost samples collected during the 63day process indicated typical composting conditions. The microbial communities changed over the 63days of composting. According to principal component analysis of the COMPOCHIP microarray results, compost samples from the start of the experiment were found to cluster most closely with the digestate and screened compost samples. The green waste samples were found to group separately. All starting materials investigated were found to yield fewer and lower signals when compared to the samples collected during the composting experiment. © 2014 The Authors.

Within this thesis an odour management strategy has been invented, aiming at effective and reliable solutions for specific odour emissions problems with minimum expenses. The concept covers the whole scenario from the odour assessment including a thorough characterization of all emissions source to the technical reduction of odorous emissions. For the characterization of odour emissions a new odour-index method has been developed and applied to various sources. The development and optimization of mobile test systems allow a first evaluation of potentially suitable odour treatment methods for a specific odour emission problem with quite handy equipment. Taking an oil and fat refinery as an example, the odour management strategy has successfully been applied. For the main emissions source, which resulted from the deacidification process, the odorous key substances have been identified, and a suitable treatment system has been designed. Finally, all findings resulting from this work have been fed into a self-designed odour specific data base.