The objective of the performed investigations was to determine the impact of the addition of various glycerol doses and different types of straws (wheat, lupine and maize straws) on some parameters of the composting process of sewage sludge. The experiment was carried out in a four-chamber isothermal bioreactor equipped in sensors for continual recording of some parameters of the composting process, e.g. temperature or degree of concentration of liberated ammonia. The performed investigations involved determination in the composted biowastes of total numbers of heterotrophic bacteria, actinomycetes, molds, Enterobacteriaceae numbers of helminth eggs (ATT). In addition, levels of dehydrogenases activity, temperature, pH and concentration of liberated ammonia in the composted material were analysed. The obtained results prove that despite changes occurring in the course of the composting process, numbers of actinomycetes and molds remained unchanged. It was found that the composting process resulted in the reduction of total bacterial counts and a complete elimination of Enterobacteriaceae. On the other hand, high level of dehydrogenases activities during the process can indicate high efficiency of organic matter mineralisation in the composted biowastes. It was concluded, on the basis of the obtained research results, that the addition of glycerol to composted sewage sludge, supplemented with such structure-forming materials as straw or sawdust, is an effective method of utilisation of these materials and provides possibilities for its further management for agricultural purposes.
No indications were found to confirm that levels of glycerol doses exerted a significant impact on microbiological and biochemical parameters of composting. Furthermore, the final products obtained as a result of the composting process were characterised by similar C/N and NH3 values, as well as metabolic activity of microorganisms. Therefore, it can be concluded that glycerol composting provides: an effective and environmentally-friendly way of its disposal which is of considerable importance in connection with the increasing biodiesel production and, in addition, a method for obtaining a valuable fertiliser of considerable ecological potentials.
|MLA||Wolna-Maruwka, Agnieszka, et al. "Impact of crude glycerol on numbers of selected microorganisms during composting of sewage sludge with sawdust and different types of straws." Nauka Przyr. Technol. 6.2 (2012): #28.|
|APA||Agnieszka Wolna-Maruwka1, Krzysztof Pilarski2, Jacek Dach2 (2012). Impact of crude glycerol on numbers of selected microorganisms during composting of sewage sludge with sawdust and different types of straws. Nauka Przyr. Technol. 6 (2), #28|
|ISO 690||WOLNA-MARUWKA, Agnieszka, PILARSKI, Krzysztof, DACH, Jacek. Impact of crude glycerol on numbers of selected microorganisms during composting of sewage sludge with sawdust and different types of straws. Nauka Przyr. Technol., 2012, 6.2: #28.|
Department of General and Environmental Microbiology
Poznań University of Life Sciences
ul. Szydłowska 50