Microbiological characteristics of bioaerosol at the composting plant

The diversion of biodegradable waste from landfill is of key importance in developing a sustainable waste strategy for the next decade and beyond. The proliferation of waste treatment technologies such as mechanical biological treatment, anaerobic digestion and composting will be paramount in achieving this strategic goal. Composting plant is one of the end technology, which is widely used in waste processing of the biodegradable waste. These wastes originate from the maintenance of green areas in the cities and the municipalities and from the separatelly collected biodegradable waste from the citizens. There is also possible to process other biodegradable materials whose origin may be in other technologies of waste management at the composting plant. The most commonly used technology of composting is windrow system. Technological operations, which are necessary for the proper conduct of the composting process, may have negative influence on the environment in the immediate vicinity of composting plant. As pollutants we can mark particular odor and microorganisms. The largest group of microorganisms in the monitored air were psychrophilic and mesophilic bacteria and microscopic thermotolerant fungi. The amount of thermophillic actinomycetes ranged from 10 to 84.000 CFU∙m−3 (colony forming units per m3). Furthermore, it was confirmed that the maximum air contamination has been found during aeration of windrow by compost turner and during the sieving of the mature compost. For each indicator, the increase in concentrations due to the turning of compost windrow as compared to the background concentration obtained in natural environments and upwind of composting plants was determined. At a distance of 150 m from the composting plant, only low numbers of indicator organisms at a regular occurrence in the air has been found.