Ecological Engineering and Environment Protection

¹Department of Extremophilic Microorganism Biology, Zabolotny Institute of Microbiology and Virology of the NAS of Ukraine, 154, Zabolotny str., Kiev, 03143, Ukraine.

² Department of the Research Nuclear Reactor, Institute for Nuclear Research of the NAS of Ukraine, b.47, Prospekt Nauky, Kiev, 03680, Ukraine.

Abstract. Despite the achievements in development of environmental biotechnologies, the total amount of waste is continuously increasing. Development of novel methodological approach is the only possible effective solution of problems. The aim was to develop the base of universal biotechnologies for effective treatment of all four classes of waste and obtain valuable products. To obtain biotechnologically promising results the method of thermodynamic prognosis of microbial interaction with toxic compounds (multi component food waste and filtrate, metal containing wastewater, radioactive waste) was developed. The following results of food waste degradation were obtained: time detention T=6 days, coefficient of waste destruction Kd=90; biohydrogen yield – 120 L from 1 kg of waste. Wastewater treatment provided purification from 10020 to 20 ppm of total Carbon and toxic metals. Purification of liquid radioactive waste allowed several orders decreasing its activity within 4-5 days. These biotechnologies are promising for their industrial implementation in order to stop pollution of environment and preserve ecosystems.

Keywords: thermodynamic prognosis, environmental biotechnologies, biohydrogen, toxic metals, radioactive waste

doi.org/10.32006/eeep.2020.1.1829
MATHEMATICAL MODELLING OF A TWO-STAGE ANAEROBIC DIGESTION PROCESS WITH HYDROGEN AND METHANE PRODUCTION USING ADM1

Milen Borisov¹, Dencho Denchev², Ivan Simeonov²

¹Institute of Mathematics and Informatics, Bulgarian Academy of Sciences, Sofia, 1113, Bulgaria.

²The Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences, Sofia, 1113, Bulgaria.

Abstract: The aim of this study is to implement a mathematical model to simulate the dynamic behaviour of a two-stage anaerobic digestion process for simultaneous production of hydrogen and methane. The process is carried out in two connected continuously stirred bioreactors. The proposed model is developed by reducing the well known IWA Anaerobic Digester Model No 1 (ADM1). In the present study the original model concept was adapted and applied to replicate a two-stage process. The proposed model involves 13 ODEs for the 1^st stage and 7 ODEs for the 2^nd stage. The numerical coefficient values in the model are taken from specified literature and adapted to the case of wheat straw AD. Important input-output static characteristics and existence of maxima of the input-output static characteristics concerning the biohydrogen and biomethane production in function of the control variable (dilution rate) are presented. Supposing that both bioreactors are operating nearby these maxima the optimal ratio of the working volumes was obtained. Numerical simulations using a specially elaborated web-based software environment are presented to demonstrate the dynamic behavior of the model solutions.

Keywords: anaerobic two-stage digestion; hydrogen and methane production; mathematical model; ADM1, static characteristics, simulation

doi.org/10.32006/eeep.2020.1.3035
CONVERSION OF COAL FLY ASH TO ZEOLITE-BASED IRON OXIDE MAGNETIC NANOCOPOSITES BY MODIFIED FUSION-HYDROTHERMAL SYNTHESIS

Silviya Boycheva, Denitza Zgureva

Department of Thermal and Nuclear Power Engineering, Technical University of Sofia, Sofia 1000, Bulgaria

Abstract. Coal fly ash generated in Thermal Power Plants is utilized for synthesis of zeolites due to its aluminosilicate composition. The highest degree of zeolitization of coal ash in a particular zeolite phase is achieved by double-stage synthesis involving successive alkaline melting and hydrothermal activation of the reaction mixtures, while the uniform distribution of the iron oxides transferred from the raw coal ash is ensured by ultrasonic treatment. However, the applied melting step results in the oxidation of the magnetic iron oxide phases to non-magnetic ones, which results in the loss of magnetic properties of the resulting materials. The present investigation focuses on an improved double- stage synthesis procedure by the addition of raw coal ash containing magnetite between high temperature and low temperature processing. In this way, the magnetic phase is retained in the final product and the magnetic properties of the zeolites are preserved, which is important for their application in the adsorption of pollutants from wastewater.

Keywords: coal ash utilization, coal ash zeolites, magnetic adsorbents, water treatment, nanoactivated zeolites

doi.org/10.32006/eeep.2020.1.3639
WATER CONTENT OF MIXED HONEY BEES-COLLECTED POLLEN

Zheko Radev

Cosmocert S.A., 49А, Sofia ,1404, Bulgaria

Absract: The knowledge of the water content of pollen is important to determine the amount of protein content, lipids, sugars, minerals and other components in the dry matter. The water content of mixed honey bee-collected pollen was determined by a method of drying. A table of the water content in the mixed pollen from different harvesting periods was made. The percentage of water content in the mixed bee-collected pollen samples ranged between 12.3% and 26.6% and the average was 18.8%. Pollen from different harvesting periods has different water content. There are also differences among the same months during three years. The average value of water content for each year is also different. According to the results, can’t be said during which season (spring, summer, autumn) the pollen has higher or lower water content. Ecological factors, especially rainfalls, can also affect water content.

Key words: water content, pollen, honey bee, method of drying

doi.org/10.32006/eeep.2020.1.4049
ARE THE HYBRID NUCLEAR REACTORS THE ANSWER FOR THE FUTURE ENERGY NEEDS?

Alexander B. Blagoev

Scientific Research Center of the University of Sofia, 5, Sofia 1164, Bulgaria

Abstract: Now the chances to get the energy released by the transformation of nuclei (fusion and fission) are significantly larger than they were 10 or 20 years ago due to the development of the hybrid nuclear reactors. They can provide energy with abundant resource, safe, and clean at reasonable cost. The research in nuclear fusion shows that several of the present day plasma devises (both stationary and pulse) have the potential to become the background of a hybrid (fusion-fission) industrial facility for energy production. They will burn the high-level radioactive waste, thus closing the nuclear cycle and will hinder the spread of hazardous materials. A breakthrough in nuclear power is expected in the near future, whichever of the three technologies - fast neutron reactors, accelerators driven systems or fusion-fission hybrid reactors will prove to be the most technologically or economically viable base for hybrid reactors.

Keywords: fusion reactors, fission reactors, synergy, concepts of hybrid nuclear reactors, biology treatment of fission reactor’s water

doi.org/10.32006/eeep.2020.1.5057
THE PRODUCTION AND SPECIFICATION ANALYSIS OF AVIATION BIOFUEL AS THE ALTERNATIVE FUEL OF AIRPLANE

Cheppy Asnadi¹, Septhian Marno², Poppy Sri Lestari³, Difany Tsabita Islami^₁, Nelliza Putri², Wawan Rustyawan²

¹Department of Chemical Analysis, Politeknik AKA Bogor, Bogor 16154, INDONESIA.

²PT. Pertamina Research and Technology Centre, Jl. Raya Bekasi KM 20, Pulogadung, Jakarta Timur, INDONESIA.

³Department of Industrial Waste Treatment, Politeknik AKA Bogor, Bogor 16154, INDONESIA.

Abstract: CO₂ emissions and scarcity of petroleum supplies can be reduced by the use of renewable energy sources. This has led to the development of low emission aviation turbine fuel derived from vegetable materials. The process used Hydroprocessed Esters and Fatty Acids (HEFA) that consisted of hydrotreating and isomerization. This experiment consisted of production and analysis. The production of aviation biofuel developed based on coconut oil through the process of hydrotreating deoxygenation (HDO) and hydrotreating isomerization (HDI) on the hydrotreater reactor. Further analysis of aviation biofuel products and aviation biofuel blending includes Total Acid Number (TAN), existent gum, density at 15 °C, flash point, smoke point, freezing point, distillation, total sulfur content, distribution of C₁₀-C₁₄ carbon, and levels of Iso-Paraffin Olefin Naphthene (PION). Based on the experimental results, it can be concluded that the Aviation Biofuel complied for TAN, density at 15 °C, and freezing point parameters. Aviation Biofuel blending of 2%, 5%, and 10% were in accordance with the Aviation Biofuel Defence Standard 91-91 for all parameters.

Keyword: coconut oil, aviation biofuel, hydrotreating deoxygenation, hydrotreating isomerization

doi.org/10.32006/eeep.2020.1.5862
VARIABILITY OF LEAVES PARAMETERS IN ORIENTAL PLANE TREE (PLATANUS ORIENTALIS L.)

Mira L. Georgieva
Forest Research Institute, Bulgarian Academy of Sciences, Sofia, 132 "KLiment Ohridski" Blvd., 1756 Sofia,,Bulgaria.

Abstract: This paper presents the results of leaves parameters measuring of Oriental plane tree (Platanus orientalis L.), a rare tree species of Bulgarian flora naturally occurring only along the river streams in the southern part of the country. Based on morphometric parameters, the variability of the leaves of the oriental plane tree in 8 natural habitats (Asenovgrad, Topolovo, Sandanski, Melnik, Petrich, Slavyanka, Gotse Delchev and Ivaylovgrad) of the species in Bulgaria has been investigated. A higher degree of variability was observed between half-sib offspring than between populations. Eight parameters of the leaves were measured, in most cases the population from Asenovgrad is superior to the other origins. The results show that the most differentiated features are the length of the leafstalk (LD) and the length of the middle lobe (L). The size and shape of the leaves are relatively homogeneous and this makes difficult to determine individual origins only by leaves.

Keywords: Platanus orientalis, leaf shapes, variability, oriental plane tree

doi.org/10.32006/eeep.2020.1.6372
LAND CAPABILITY EVALUATION FOR THE EFFECTIVE LAND USE AND SOIL PROTECTION MEASURES IN DOBRICH REGION

Vihra Stoinova, Diyana Nekova

Institute of Soil Science, Agrotechnologies, and Plant Protection (ISSAPP) "Nikola Pushkarov”, Sofia, 1000, Bulgaria

Abstract: An assessment of the suitability of the arable land in the Dobrich region for its effective agricultural use has been prepared using an eight rate classification where the land valuation strategy guarantees the conservation of natural resources, with particular attention to erosion as a limiting factor. Maps of the area with Land Capability evaluation classes for effective agricultural and erosion control land use and the actual risk of water erosion have been developed.This allows the use of an integrated approach to the definition of soil protection measures - taking into account both soil constraints (labeled with subclass land) and the need for prevention against erosion processes.

A set of different soil protection practices is recommended, each determined according to the specific soil, topographical and climatic features of the studied area, determined by the class and subclass of the land and depending on the degree of erosion risk and the way of land use (defined by Physical Blocks, 2016).

The agronomic assessments according to the soil and climate conditions of the main agricultural crops are linked to the detailed large-scale database created in the GIS format and the most suitable places for their cultivation on the territory of the Dobrich region have been identified. The agronomic fitness of arable land for the cultivation of wheat, maize, peaches and vines is assessed. Maps for the degree of their agronomic fitness were prepared. It is clear that almost all of the entire territory has a very good and good land for cultivation of these crops.

Keywords: Land capability evaluation – classes, subclasses and blocks (units), soil erosion, soil protection measures, agronomic assessment, mapping

Antibiotics, antibiotic resistant bacteria and antibiotic resistance genes – emerging pollutants in surface waters and anthropogenically influenced waters

Zvezdimira Tsvetanova, Dimitar Dimitrov, Hristo Najdenski

Abstract. The growing antimicrobial resistance of pathogenic bacteria is considered to be one of the main threats to human and animal health. Despite the relationships of the problem mainly with clinically important pathogens, there is growing evidence of an association with anthropogenic impacts on water. The review examines the prevalence of antimicrobial resistance among the microbiome in drinking, surface and wastewaters, water-associated biofilms, and summarizes available data on the content of antibiotics, antibiotic-resistant bacteria and resistance genes as pollutants of increasing importance to aquatic ecosystems.
Keywords: antibiotics, antimicrobial resistance, antibiotic resistant bacteria, antibiotic resistance genes, natural waters, wastewaters

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