Sirvi Autor "Ivanovs, K." järgi
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Kirje Evaluation of reed biomass use for manufacturing products, taking into account environmental protection requirements(2018) Muizniece, I.; Kazulis, V.; Zihare, L.; Lupkina, L.; Ivanovs, K.; Blumberga, D.In many countries reed is considered as invasive or unnecessary plant, because it is spreading rapidly, causing decrease in biodiversity and creating unacceptable living conditio ns for many bird species in their natural habitats. Due to environmental considerations it is necessary to cut reed, to decrease their over exceeding growth. Reed burning or leaving for decomposition on fields, that has been practiced until now, creates ad ditional carbon dioxide air pollution. Therefore, the question on what to do with cut reed has become vital from environmental protection perspective. In addition, this question applies to bioeconomy principles in compliance with their use in national econ omy, which makes it clear, that solutions for the use of reed biomass for production have to be found. But any production process can leave a negative effect on surrounding environment. Further to product production, economic motivation, possible market an d availability of resources are primarily essential to see whether it is worth to produce the product at all. Therefore, reed biomass use possibilities in production have to be analysed as a complex question, taking into account environmental and climate, economic and technological aspects. In this study, solutions to perspective reed biomass use are evaluated, considering environmental protection requirements. For this task, multi - criteria analysis method TOPSIS is used, which includes 11 environmental and climate, economic and technological criteria. Evaluation includes both – already existing and new products that are divided in 3 sectors: power industry, construction and other products. Results of the research clearly state, which of reed biomass made pr oducts are perspective, taking into account not only traditional economic and technological aspects, but also envi ronmental and climate aspects.Kirje Low temperature BMP tests using fish waste from invasive Round goby of the Baltic Sea(2018) Gruduls, A.; Balina, K.; Ivanovs, K.; Romagnoli, F.Round goby (Neogobius melanostomus ) is an invasive fish species in the Baltic Sea. While meat can be used for human consumption, fish processing residues are considered as a waste. Within circular economy and bio - economy perspectives fish waste could be used as a valuable feedstock for biogas prod uction. However, the research is mostly focused on evaluating biogas yield at mesophilic conditions (i.e. 37 °C ). In this study the impact of low temperature on Biochemical Methane Potential (BMP) tests has been investigated. Round goby’s processing leftov ers - heads, intestines and skin/bone mixture were tested in codigestion with sewage sludge. Anaerobic digestion (AD) was carried out in 100 mL batch tests at low temperature 23 °C and 37 °C conditions, over an incubation period of 31 days. The results sho w that AD at low temperature occurs twice as slowly as under 37 °C conditions. However, after 31 days the BMP values for 23 °C samples were only 2% lower than for high temperature samples. Heads and skins showed similar BMP values reaching on average 502 L CH 4 kg VS - 1 and 556 L CH 4 kg VS - 1 respectively. BMP for fish intestines was higher, reaching on average 870 L CH 4 kg VS - 1 . Average BMP for mixes of fish heads, skins, intestines and bones was 660 L CH 4 kg VS - 1 . Acquired BMPs were further compared with the theoretical BMPs from Buswell's formula. Research results suggests that anaerobic digestion of fish waste under low temperature conditions could be feasible as the process still efficiently occurs, in fact ope ning a new opportunity to explore the overall sustainability of technologies based on these conversion processes.Kirje Psychrophilic plug-flow digester with assisted solar heat – small-scale system feasibility(Estonian University of Life Sciences, 2023) Ivanovs, K.; Blumberga, D.Paper discusses using a low-temperature biogas reactor with a solar support system technology as a management tool of biodegradable waste in small scale. A feasibility study looks at primary factors affecting anaerobic digestion process and solar heat production, design examination of a solar heating for anaerobic digester and possible technology application, also defines the multilocality of biogas, illustrates diffusion of innovation for diversification of biogas production. Analysis confirms solar heat increases efficiency and production of biogas, decreases costs and toxicity of digestate. Results show that for implementation of technology in rural areas further research in socio-economic, sourcing of feedstock and customization is needed.Kirje Single cell protein production from waste biomass: review of various agricultural by-products(2018) Spalvins, K.; Ivanovs, K.; Blumberga, D.Agricultural waste constitutes for most of the manmade waste streams. Processing of biodegradable waste materials ensures the treatment of harmful substances and allows to reduce environmental pollution. In addition, conversion of these waste materials in value - added products makes these recycling methods more economically viable. Single - cell protein is one of the value - added products that can be produced by microbial fermentation of waste materials. In this review various biodegradable agricultural by - prod ucts as substrates for production of SCP are categorized and compared.