Anna Smurzyńska

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.

A STUDY OF THE SOLUBILITY OF BIODEGRADABLE FOAMS OF THERMOPLASTIC STARCH

The paper presents the results of a study on the water absorption capacity and solubility of biodegradable starch foams produced with single-screw extruder TS-45 with L/D=12. Two different moulding dies were used: one with a circular hole with the diameter of 3 mm and one with a ring hole with the inner diameter of 5 mm. During the extrusion process, the temperature of the cylinder ranged from 80 to 130°C and the screw speeds applied were: 100 and 130 rpm. For the application of the ring die, it was observed that regardless of the speed of the screw, the use of the raw material of higher moisture content led to the production of materials with higher solubility. As a result, the obtained materials revealed solubility at a level of 40%. The results demonstrate good solubility of the starchy fillers of the packaging, which may indicate their susceptibility to decomposition in the conditions of high ambient humidity. A statistical analysis showed a significant impact of moisture of the raw material on the WSI of starch foams used irrespective of the other parameters of the extrusion-cooking process. The raw material moisture had a significant effect on the water absorption capacity of only TPS foams produced in the ring die at the screw speed of 100 rpm.

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.

The possibility of functioning micro-scale biogas plant in selected farm

Abstract Renewable energy sources (RES) become more and more popular. In Poland, biomass has the highest energy potential among all RES. Methane fermentation is one of possible ways to use it. The aim of the study was to perform energy and economic calculations for the biogas plant installation project in an existing farm situated in the Wielkopolska voivodeship. Because of the small area of the farm and the type of production, the calculations were carried out for micro-installation biogas plants. During the preparation of the project the production potential of the substrates was determined, allowing for further analyses. It was calculated that the electrical power of the designed biogas plant was 8.10 kW, with a total annual production of biogas at 29 471 m3. The obtained amount allows to generate in the cogeneration system 66 450 kWh of electricity and 71 190 kWh of heat energy. Some of the energy produced can be used on the farm and its surplus sold to the grid, which will allow for financial and environmental benefits.

APPLICATION OF ZEOLITE AND BENTONITE FOR STABILIZING LEAD IN A CONTAMINATED SOIL

Lead is a toxic element, which is often incorporated into the trophic chain. It is resistant to migration into the soil profile and its presence in the upper layers of the soil is caused by anthropogenic factors. Zeolites are crystalline hydrated aluminosilicates containing a system of connected chambers and channels in their structure. The same properties apply to the bentonite which contains at least 75% montmorillonite. Both clay mineral / sorbents are characterised by high sorptive properties, which are greater in the case of the bentonite. Incorporation of these sorbents into the soil can effectively immobilize contaminants, especially heavy metals. The study evaluated the properties of zeolite and bentonite for stabilizing lead (Pb) in a contaminated soil. Sorbents were applied at different rates – 0, 0.25, 0.5, 1.0, 2.0, and 3.0% – to the contaminated soil and incubated for four months. Soil reaction (pH) and the electrical conductivity (EC) were measured. The total content of Pb and the reactive forms (extracted by 0.11 mol CH3HCOOH dm -3) were determined in the examined soil samples. Evaluation of the stabilization efficiency of Pb was performed on the basis of the fractions of the reactive lead. It was found that the addition of both zeolite and bentonite decreased the concentrations of the active forms of lead in soils. Thus, the two sorbents are characterized by a good stability and can be used for efficiently immobilizing lead in the soil contaminated through anthropogenic activity.

The effect of temperature on the methane yield of the slurry contaminated with heavy metals

The intensive livestock production is responsible for a number of environmental threats. The main source of animal waste is generated in the form of slurry. The inadequate fertilizing (against the BAT rules) can often lead to contamination of soil and water. In turn, the presence of heavy metals found in factory farms by the use of animal feed supplements, prevents its use as a fertilizer. Therefore, other possibilities to recycle the waste are being studied. The aim of the research was to analyze the effect of heavy metal ions on the methane fermentation process yield in contaminated slurry. The manure studied came from dairy cattle farm in Greater Poland region. The tested substrate has been contaminated by heavy metal salts. In the experiment, the following salts have been used ZnO4·7H20, CdCl2·2,5H2O, CuSO4·5H2O, Pb(NO3)2. Anaerobic biodegradation of the fertilizer has been carried out in thermophilic conditions, which enables to indicate the effect of temperature on the efficiency of the occurring process. Furthermore, by comparing mesophilic and thermophilic fermentation, one can notice a higher methane yield from the contaminated slurry during the fermentation at lower temperatures.

TECHNOLOGIES TO REDUCE EMISSIONS OF NOXIOUS GASES RESULTING FROM LIVESTOCK FARMING

During the animal production, which is increasingly expanding, it comes to harmful gas emissions. These emissions relate to both greenhouse and odorous gases emissions. The resulting volatile compounds also contribute to the formation of acid rain, eutrophication of water aquens and soils, corrosion in livestock buildings and damage of the ozone layer. Considering the existing problem, solutions neutralizing the impact of animal production on the environment, are being looked for. Moreover, numerous activities in the way of nutritional and technological solutions are undertaken. Nutritional techniques are based on diet modification and require continuous monitoring of livestock animals. On the other hand, technological solutions are taking action to reduce emissions of gases from livestock buildings and slurry management. The proposed ways of disposing slurry result in different effects in terms of reduction of dangerous gases. They require the implementation of additional actions leading, among other things, to the proper animal waste disposal.