Ecological Engineering and Environment Protection

Abstract: Water is essential for human life, the socio-economic improvement of the state and the protection of its natural environment. Senegal has a rich and diversified hydrological potential, most of whose surface water reserves are located in the basins of the Senegal and Gambia rivers and in groundwater. Unfortunately, water resources can be threatened by anthropogenic actions of various origins and by the adverse effects of climate change. This article aims to analyze the current state of water resources, water problems and prospects for the sustainable development of water resources in Senegal. Information is collected from secondary sources and available statistics (books and the Internet). The results show the importance of Senegal's water resources potential (in terms of surface and groundwater), water resources that are often severely deteriorated due to pollution, agricultural activities and the rised water demand from the population. This degradation is likely to worsen with population growth, development and climate change. For example, the Senegalese government has been conducting a water control policy for several decades aimed at providing the various sectors with water in sufficient quantity and of appropriate quality according to custom to accelerate development balanced. There are several policies and actions for the formulation of rules and regulations on the general use of water. To be in line with the sustainable development goals (SDG), including SDG 6, Senegal is committed to the sustainable management of water resources to ensure universal and equitable access to safe and affordable drinking water for all population by 2030.

Keywords: integrated management, water resources, sustainable development, socio-economic development, Senegal

doi.org/10.32006/eeep.2019.1.1725
INFLUENCE OF THE MAGNETIC FIELD ON THE LIVING ORGANISMS AND HUMANS

Stefan Naydenov, Sonia Petkova, Petar Getsov, Garo Mardirossian

Summary: The question of the influence of magnetism on biological objects for years has been a debate with many contradictory opinions. The article provides a brief overview of publications and various and contradictory views on the influence of magnetic fields on living organisms and humans. An explanation is sought for findings made in various scientific studies, as well as an answer to the question: Can a permanent magnetic field be useful for our health and under what conditions?

Key words: magnetic field, health, diagnostic, physiotherapy, physiological response

doi.org/10.32006/eeep.2019.1.2636

BIODEGRADATION OF CRUDE OIL AND LIGNIN-MODIFYING ENZYME ACTIVITY OF WHITE ROT BASIDIOMYCETES

Tina Jokharidze, Eva Kachlishvili, Vladimir Elisashvili

Abstract. In the present study, the ability of eighteen white-rot basidiomycetes was evaluated for crude oil biodegradation. Cerrena unicolor strains, Panus tigrinus 433, P. lecometei 903, Pleurotus ostreatus 70, Trametes maxima 403, and T. versicolor 159 showed especially abundant mycelial growth on the surface of agar covered with droplets of crude oil. In the submerged cultivation in the glucose (3 g/L) containing medium, complete decolorization of indicator Resazurin was observed during two weeks in the presence of Bjerkandera adusta 139, C. unicolor 303, Coriolopsis gallica 142, P. ostreatus 70, P. pulmonarius 148, and T. versicolor 159. When artificially oil-polluted soil was inoculated with fungal mycelium pre-grown on a mixture of wheat straw and mandarin peels the maximum degradation rate (65%) was obtained when C. unicolor 305 was incubated in the 1% oil-containing soil for 28 days. At the same cultivation conditions, P. ostreatus 2175 eliminated 43.9% of initial oil when its concentration in the soil was increased to 2%. In the lignocellulose-containing soil, neither glucose nor yeast extract enhanced oil degradation, but wetting of soil with the distilled water to maintain its humidity favored oil elimination. The tested WRB secreted lignin-modifying enzymes in the presence of petroleum hydrocarbons; the higher was the concentration of lignocellulosic substrate in the soil the higher was the fungi enzyme activity. However, the data received did not show any direct relationship between the fungi enzyme activity and the degree of oil elimination.

Key words: mycoremediation, crude oil, basidiomycetes, cultivation conditions, lignin-modifying enzymes

doi.org/10.32006/eeep.2019.1.3753
CLASSICAL AND NEW ASPECTS IN DEGRADATION OF AROMATIC XENOBIOTICS

Evgenia K. Vasileva, Tsvetomila I. Parvanova-Mancheva, Venko N. Beschkov

Abstract: Organic chemical mixtures are prevalent in waste waters from industrial and municipal sources as well as in contaminated groundwater. Phenols are pollutants found in wastewaters from oil refineries, chemical plants, explosives, resins and coke manufacture, coal conversion, pesticide and textile industries. The main contaminants of refinery wastewater include phenols, polycyclic aromatic hydrocarbons (PAHs) as well as heavy metals. Among these toxic pollutants, phenols are considered to be the most hazardous ones, and they are certainly the most difficult to remove. Phenolic compounds are toxic at relatively low concentration. Because of these low concentrations the most suitable methods for their removal are the microbial ones.
The present work is a review of biodegradation of phenol. Degradation of phenol occurs as a result of the activity of a large number of microorganisms including bacteria, fungi and actinomycetes. There are reports on ma33ny microorganisms capable of degrading phenol through the action of variety of enzymes. These enzymes may include oxygenases, hydroxylases, peroxidases, tyrosinases, oxidases etc. Batch experiments were carried out in a different bioreactors. Biodegradation of organic chemicals by microbes using pure cultures can produce toxic intermediates. This problem may be overcome by the use of mixed cultures that have a wider spectrum of metabolite degradation properties.
In this revew we described also some new technology for biodegradation of phenol like: different immobilization, FISH (Fluorescence in-situ hybridization) analysis, nanobiotechnologies and etc.

Key words: phenol, biodegradation, microorganisms, enzymes, immobilization, FISH analysis, nanobiotechnologies

doi.org/10.32006/eeep.2019.1.5461

AN EXPERIMENTAL STUDY FOR THE CHARACTERIZATION OF BIOGAS PRODUCTION FROM COW DUNG AND DROPPINGS
Younoussa Moussa Baldé, Cellou Kanté, Sette Diop, Sihem Tebbani

Abstract: The present work is an account of an ongoing work on biogas production from animal wastes at LEREA (Laboratoire d’enseignement et de recherche en énergétique appliquée) in Mamou, Guinea. The work consists of biogas production from anaerobic digestion and co-digestion of cow dung and droppings. We focus in this report on the determination of the physico-chemical characteristics of the experimental setup. We have carried out three experiments of anaerobic digestion each one lasting 45 days at mesophilic temperature (temperature was maintained in the range 27°C - 28°C). Biogas - 28.4 liters have been obtained from droppings, 22.6 liters from cow dung and 38.7 liters from co-digestion of the previous two wastes. The following physico-chemical characteristcs were observed for cow dung: humidity 43%, dry matter 20.83%, organic matter 57%, density 625kg/m³, carbon content 31%, nitrogen content 1.46%, nitrogen-carbon ratio 21/30. For droppings we measured: humidity 35%, dry matter 65%, organic matter 62%, density 250 kg/m³, carbon content 36%, nitrogen level 1.83%. This characterization was carried out on a sample of 3 g of each type of substrate. These results agree with those of the literature that we were able to compare with.

Keywords: Anaerobic digestion; anaerobic co-digestion; physico-chimical characterization; cow dung weste; droppings weste; methanation; animal waste

doi.org/10.32006/eeep.2019.1.6270

PARAMETERS OPTIMIZATION FOR INCREASED INTRACELLULAR INULINASE ACTIVITY OF A YEAST STRAIN

Lyudmila Kabaivanova, Adriana Goushterova, Mariya Brazkova, Petar Grozdanov, Elena Chorukova, Albert Krastanov

Abstract: This study reveals the selection of a yeast strain, possessing inulinase activity and finding the optimal conditions of cultivation. Intra- and extracellular activity assay was performed after cultivation on media, containing inulin as a sole source of carbon. Optimization of the cultivation conditions was carried out for establishing the favorable conditions for biosynthesis of inulinase. Modifying the physicochemical and nutritional parameters of a cultivation process lead to major improvement of the enzyme activity. Highest intra- and extracellular inulinase activity was registered when 1.5% inulin was used, 5 % inoculum, temperature 28°C, pH=6.5 and agitation of 200rpm. The selected strain Kluyveromyces sp. C showed higher values for the intracellular inulinase activity, making it suitable for immobilization and further use.

Key words: Kluyveromyces sp., inulinase activity, parameters optimization

doi.org/10.32006/eeep.2019.1.7178

LABORATORY BIODEGRADATION OF POTENTIAL CELLULOSE WASTES GENERATED DURING LONG-TERM MANNED SPACE MISSIONS

Najdenski H., V. Ilyin, P. Angelov, V. Hubenov, D. Korshunov, V. Kussovski, L. Dimitrova, I. Simeonov

Abstract: Anaerobic microbial biodegradation of cellulose containing wastes generated during the long-term manned space missions is a key technological approach for resolving the problem of wastes accumulated onboard of the spacecraft. Herewith are presented data on the possibilities of structurally stable multispecies microbial consortia originating from methanogenic bioreactors to decompose different cellulose substrates – filter paper, medical gauze and vegetable mix as potential cellulose wastes during space missions. The rates of biodegradation processes carried out at mesophilic and thermophilic conditions are not only measured and compared but are providing new opportunities for development of technology for microbial biodegradation of cellulose-rich organic wastes. Moreover, the studies have shown that paper and gauze hydrolysis with the help of cellulolytic bacterial communities can be an effective component of utilization of cosmonaut hygiene items. Biodegradation of plant wastes by community of anaerobic bacteria is promising and applicable tool also under terrestrial conditions. Light microscopy of bacterial communities reveals the presence of Gram-positive spore forming bacilli (short and long forms, bipolar and dividing cells) and typical clostridia forms.

Keywords: cellulose containing wastes, biodegradation, anaerobic digestion, bacterial consortia, long-term manned space missions

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