Kamil Kozłowski

Influence of maize straw content with sewage sludge on composting process

Abstract After entrance to EU in 2004, the management of sewage sludge has become more and more important problem for the new members. In Poland, one of the most promising technologies is composting process of sewage sludge with carbonaceous materials. However, the high price of typically used cereal straw forces the specialists to look for new and cheap materials used as donor of carbon and substrates creating good, porous structure of composted heap. This work presents the results of sewage sludge composting mixed with sawdust and maize straw used to create structure favorable for air exchange. The results show dynamic thermophilic phase of composting process in all cases where maize straw was used.

The Effect of Mixing During Laboratory Fermentation of Maize Straw with Thermofilic Technology

The interest in biogas production in Poland is growing rapidly. This is mostly due to the fact that there is a need for handling and managing the increasing quantities of diverse bio-waste generated by industry and agriculture. Therefore, good laboratory practices and correct preparation of batch tests are very important for planning of a full-scale biogas plant. The aim of the paper was to determine the effect of mixing in the laboratory batch reactors on the biogas yield of maize straw under thermophilic conditions. The scope of this work included: (1) the analysis of basic physical and chemical parameters and (2) laboratory determination of biogas and methane yield from anaerobic digestion of maize straw with different frequencies of mixing. The obtained biogas and methane yield from the thermophilic fermentation of maize straw mixed every day was 381.89 m3·Mg-1 FM and 184.97 m3·Mg-1 FM, respectively. The results of this study confirmed the effect of no mixing inside reactors. In the batch test a decrease in biogas and methane yields was observed, by approx. 60 m3·Mg-1 and approx. 28 m3·Mg-1, respectively.

Poznań Air Pollution Analysis for 2015-2017

Air pollution is the result of natural processes and intense urban development. The undesired emission of volatile substances causes environmental threats such as acid rains, aggravated greenhouse effect or the ozone depletion. Moreover, the pollution released into the air is harmful to the human respiratory system, eyes and skin. This paper presents the body of analyses conducted in Poznań between 2015–2017 on the changes in the local emission concentration of PM10 and PM2.5. The data concerning the emission of suspended particulates were provided by the meteorological station on Polanka St. in Poznań. The research included a correlation analysis. The results point to a steady decrease in the amount of produced particulates. It was also noted that the emissions of PM10 and PM2.5 change seasonally, with the highest levels in the autumn and winter. Furthermore, the amount of emitted suspended particulates is correlated with the temperature; hence, it is supposed that the main source of air pollution in Poznań involves low-efficiency heaters and boilers.

The influence of mixing inside the fermentation reactors during the study of biogas efficiency of the substrates in mesophilic technology

Along with the development of environmental friendly technologies, an increasing interest in generating the electricity and heat from renewable sources has been observed in Poland. Perfect example of such installations are agricultural biogas plants, where methane fermentation produces high-energy gas fuel i.e. biogas. Before investing, it is necessary to perform a detailed studies of the biogas efficiency of the substrates used. The proper run of fermentation process, as well as the high biogas production related to the operation, depend on many factors, including the mixing inside the reactor. The DIN 38 414-S8 standard, commonly used in the tests, assumes the mixing of the whole eudiometric sets, used in accredited laboratory units, which due to their uniform construction may cause problems. The aim of the study was to determine the effect of laboratory mixing in the fermentation reactor on the biogas efficiency of the maize straw. The experiment tests were performed in the Laboratory of Ecotechnologies, in the Poznan, in accordance with the current standard DIN 38 414-S8.The obtained research results confirmed the effect of mixing inside the fermentation reactors on the biogas efficiency of the maize straw.

Energetic Usage of Slaughter Waste as the Substrate for Biogas Production

Sector of animal production is growing strongly in Poland within last years. This concerns especially poultry sector (first position in Europe with more than 900 million animals per year) bit also swine and cattle. This sector generates dynamic growth of meat export. However, this sector is responsible also for large scale production of slaughter waste which very often creates problem with its proper management and recycling. This paper describes the possibility of the energetic usage of slaughter waste as the substrate for biogas production. The biogas efficiency analysis of different waste like: waste category II, blood, feathers, soft waste category III and solid waste category III have shown its good usefulness for methane production. The calculations showed the energetic potential for analyzed slaughter house as 700 kWe.