EEEP 1/ 2021
H. Najdenski 3-4
I. MAN AND BIOSPHERE
K. Sharma, D. Karamanev 5-16
K. Popova, M. Mincheva, M. Yavahchova, N. Goutev, D. Tonev 17-24
II. CLOSED ECOLOGICAL SYSTEMS IN EXTREME ENVIRONMENTS
Chr. Lasseur, M.
III. ENVIRONMENTAL BIOTECHNOLOGIES
V. Hovorukha, O. Havryliuk, G. Gladka, B. Iryna, Y. Danko, O. Shabliy, O. Tashyrev 36-48
H. Najdenski, L. Dimitrova, V. Akivanov, V. Hubenov, S. Mihailova, P. Grozdanov, M. Iliev, V. Kussovski, L. Kabaivanova, I. Simeonov 49-60
IV. BIOAUTOMATICS AND BIOINFORMATICS
J. Harmand 61-67
V. ECOLOGICAL AND SUSTAINABLE AGRICULTURE
A. Sadovski 68-77
VI. FOREST ECOLOGY AND BIOLOGY
P. Glogov, D. Dimitrov
ARTICLES ABSTRACTS (In Bulgarian) 83-85
VII. SCIENTIFIC FORUMS 86-87
international conference Ecological Engineering
and Environment Protection (EEEP'2021)
with Youth Scientific Session and MELiSSA Summer University, 30 September -3 October 2021, Varna, Bulgaria
environment; temperature rise; global warming; carbon
Keywords: Antisense oligonucleotides, radionuclides, nuclear medicine, radiolabeling, advantages, disadvantages
Keywords: MELiSSA conference, closed life support system
Abstract. Fossil carbon-containing fuel is currently one of the most common in industry and economy. The rapid depletion of reserves of this fuel makes it necessary to search for the alternative one. Landfills are a place where methane is spontaneously synthesized due to the decay of organic waste. Controlled and regulated fermentation of the landfill organics can provide biomethane as well as environmental bioremediation. The aim of the work was to study the patterns of methane fermentation of multi component organic waste and optimize the process to increase the efficiency of biomethane synthesis and waste decomposition. Colorimetric and potentiometric methods were used for pH and Eh measurement. Volumetric and chromatographic methods were applied to control volume and composition of synthesized gas. Fermentation parameters were calculated with the use of mathematical and statistical ones. The achievement of high efficiency of methane fermentation of organic waste due to the process regulation was shown. The modeling of unregulated fermentation of organic waste in landfills showed low efficiency of the process. It took 69 days. Weight of waste decreased only 5 times. Hydrogen yield was 5 L/kg of waste. Methane was not synthesized. The regular mass transfer, regulation of the process and waste grinding showed the greatest efficiency. Weight of waste decreased 20 times during only 14 days. Hydrogen yield was 27 L/kg, methane yield was 12 L/kg of waste. Thus, the absence of regulation caused long term decay of waste. The high efficiency is achieved due to regulation of the fermentation process. The results will serve as a basis for the development of industrial biotechnology for the utilization of organic waste to reduce the volume of existing landfills and produce methane energy. This will further allow bioremediation of contaminated areas, obtaining an alternative to fossil fuel biomethane.
Keywords: methane, hydrogen, multi component organic
waste, fermentation, landfills, environmental
Abstract: A study on the anaerobic digestion of wheat straw in a pilot scale bioreactor with an organic load of 2, 5, 7, 10 and 20 g/l and a process duration of 18 to 80 days was performed. The pilot bioreactor used has a computerized system for control and monitoring of various operational parameters – temperature, pH, biogas composition, etc. Total solids, total organics and volatile fatty acids were measured by standard methods and gas chromatography. Daily biogas yield and its main components (CH4, CO2, H2S) were analysed too. During the anaerobic digestion, different species of microorganisms have been isolated from the genera Bacillus, Pseudomonas, Enterococcus and Aeromonas, as well as the species Terribacillus halophilus. With a known pathogenic potential are described Pseudomonas sp., Enterococcus sp. and Aeromonas sp. Studies on the antimicrobial resistance of all isolated strains show resistance to ampicillin, amoxicillin, bacitracin, ceftriaxone, gentamicin and vancomycin. The cellulose degrading activity of some of the bacterial isolates, their pathogenic potential and antimicrobial resistance are discussed in detail in the light of the data on the mechanisms of proven resistance.
Keywords: anaerobic digestion, wheat straw, batch processes, organic load, computer controlled pilot-scale biogas plant, mesophilic bacterial consortia, digestate
Abstract. This paper aims at discussing the two main modeling schemes that are used to describe dynamically the growth of microbial ecosystems, that are resource and density-dependent growth functions, respectively. Monod has been the first to hypothesize that this growth is, before all, an increasing saturated function of the main limiting substrate concentration. Contois assumed that the growth is not only a function of the substrate but also of the biomass density-itself, and thus the name « density-dependent ». In re examining their respective experiments (species used, conditions of experiments, mode of reactor functioning, measurement techniques), we try to understand the engines for a density-dependent phenomenon to appear. In particular, we refer to recent experiments where it was shown that density-dependent appeared as soon as the biomass structures into flocs or in the presence of filamentous bacteria even at relatively low concentrations. Based on this historical review of data, it is shown that density-dependent kinetics is not systematically a question of biomass density but rather related to its structure within the medium and to the mobility of microbial cells.
Keywords: modeling growth
rate, Monod, Contois, microbial ecosystems, microbial
interactions, mathematical ecology.
Keywords: crop rotation; sustainable agriculture; asymmetry analysis, Procrustes analysis
Abstract: The paper presents a comparative analysis of the data on the main climatic components for three periods: 1921-1945; 1965-1975; 2000-2015 and their connection with the distribution of Invasive alien plant species (IAS) on the territory of Lozenska Mt. Among the most important features of the mountain’s climate that favourably affect the spread of IAS are the two precipitation maximums and minimums and the period of drought. In response to climate and other environmental changes, IAS on the territory of the mountain are spread in two ways: by forming monodominant communities in extreme habitats or by integrating their populations into the local communities and gradually increasing their presence in them, accompanied by changing ecological conditions of the habitat.
Key words: adaptation, climate change, Invasive Alien Species, flora, vegetation