I. ×ÎÂÅÊ È ÁÈÎÑÔÅÐÀ
Atanaska D. Deleva 5-14
Anton Sotirov, Nikola Pistalov, Dana Mawlood, Mihaela Yerusalimova, Siana Savova, Rositsa Vezenkova, Melani Eftimova, Daniel Velinov, Denislav Kirilov 15-21
Maria Dimitrova, Roumen Nedkov 22-28
Simeon Bogdanov, Slavcho Savev, Evgeni Tzavkov 29-35
Nadezhda Stoyanova, Biljana Hristova 36-41
III. ÂÅÈ È ÁÈÎÃÎÐÈÂÀ
Tsvetomila I. Parvanova-Mancheva, Venko Beschkov, Evgenia Vasileva 42-46
Zahari Zarkov, Ludmil Stoyanov, Hristiyan Kanchev, Valentin Milenov, Vladimir Lazarov 47-56
IV. ÒÅÕÍÎËÎÃÈÈ ÇÀ ÏÐÅ×ÈÑÒÂÀÍÅ
Svetla Marinova, Nikola Katidjotes,Viktor Kolchakov, Elena Zlatareva,Vera Petrova 57-63
Venelin Hubenov, Dencho Denchev, Ivan Simeonov 64-72
Atanaska D. Deleva
Abstract. Experimental results from remote investigations
of atmospheric aerosol loading over
Key words: lidar, aerosols, fire smoke, troposphere
Anton Sotirov, Nikola Pistalov, Dana Mawlood, Mihaela Yerusalimova, Siana Savova, Rositsa Vezenkova, Melani Eftimova, Daniel Velinov, Denislav Kirilov
Aim of the present study is to focus attention on solid
anthropologic waste as a factor for cotemporary forming of
sediments and soils. As a result of the study various solid
micro-detritus was found in river sediment and alluvial soils
at place of a former illegal landfill in town of
Key words: anthropogenic micro-detritus and fragments, soils, sediments, contamination
Maria Dimitrova, Roumen Nedkov
this paper we present spatial and temporal distribution of
significant floods, land and forest fires on the
Key words: eco monitoring, floods, land and forest fires.
Simeon Bogdanov, Slavcho Savev, Evgeni Tzavkov
Abstract. The paper presents results from
investigation on soils located in the southern area of the
Key words: humus-carbonate soils, factors of soil formation, physical properties, chemical properties
Nadezhda Stoyanova, Biljana Hristova
Abstract: The article presents the main research activity of the Forest Research Institute at BAS on ecolgy and conservation of forest ecosystems in Vitosha Mountain since 1980. This study is motivated by the importance of Vitosha forests for environmental improvement of Sofia region. The short review shows that investigations at the Forest Research Institute covers various aspects in the field of ecology and biology of the forests. Climatic conditions are characterized. Data of health state of forest ecosystems are established. The study obtained information about soil conditions and regeneration processes in the forests. The results may be useful for the sustainable management of forest ecosystems of Vitosha Mountain.
Key words: ecology, climate, forest ecosystems, state
Tsvetomila I. Parvanova-Mancheva, Venko Beschkov, Evgenia Vasileva
Abstract. Microbial fuel cells (MFC) offer a novel approach in the field of wastewater treatment, which can generate electricity through degradation of the substrates containing nitrates.
Nitrate and nitrite have been a worldwide groundwater contaminant mainly due to the use of fertilizers, industrial wastes, animal wastes and septic systems. High concentrations of nitrate and nitrite in drinking water can cause several health problems such as ‘‘blue baby syndrome’’ for infants, and also can lead to liver damage and cancer in adults.
Microbial production of electricity may become an important form of bioenergy in future because MFCs offer the possibility of extracting electric current from a wide range of soluble or dissolved complex organic wastes and renewable biomass.
Microbial fuel cells (MFCs) have emerged in recent years as a promising yet challenging technology.
Key words: Microbial fuel cells (MFC), biosensor, wastewater treatment
Zahari Zarkov, Ludmil Stoyanov, Hristiyan Kanchev, Valentin Milenov, Vladimir Lazarov
Abstract: The purpose of the work is to compare the characteristics of photovoltaic (PV) generators built with panels manufactured by different technologies and operating in real conditions. The paper shows results from an experimental study of PV systems with different module types (mono-Si, poly-Si, μc-Si, CIGS and CdTe). The experiment was carried out at a research platform for PV systems developed by the authors, built and located at an experimental site near the Technical University of Sofia. Comparisons are made between the performances of the studied PV generators for the same operating conditions. Some differences of the operation of the PV systems in sun tracking mode and in fixed angle mode are also shown.
Keywords: PV systems, photovoltaic modules, comparison
Svetla Marinova, Nikola Katidjotes,Viktor Kolchakov, Elena Zlatareva,Vera Petrova
Abstract: In recent years, are built and entered into operation a large number Wastewater plant treatment station (WWTP). In biological purification, purified water and sludge. Sludge accumulate around stations hamper their functioning and pollute the environment. In connection with EU requirements is necessary to seek ways to implement them in practice. An analysis and assessment of sludge in pulification station in Kazanlak, after storage , as required by the law - are studied chemical, agrochemical and microbiological parameters.The results establish that the sludges are biomass, rich in macro and micro- elements and can be used in practice.The problem is the microbiological indicators that do not meet the requirements of the legislation. It is necessary seek ways and methods for decontamination and sludge stabilization before to utilization.
Keywords: sludge, recovery, characterization.
INFLUENCE OF C/N RATIO ON ANAEROBIC DIGESTION OF CATTLE MANURE
V. Hubenov, D. Denchev, I. Simeonov
Abstract. One of the most important factors in the process of anaerobic digestion (AD) is the C/N ratio in the substrate. If it is too high, the nitrogen reduction will be a process-limiting factor. At too low levels a large quantity of NH3 will be formed, which is toxic for the microbial populations. Despite lots of examinations, the exact value of this ratio is still undetermined.
The aim of this study is to elucidate the influence of the C/N ratio on the metabolites, enzyme activity and biogas production during the anaerobic degradation of cattle manure.
The variations in the volatile fatty acids (VFAs) concentration, the activity of the enzymes - cellulases, proteases, lipases and amylases, as well as the biogas production were studied in a batch process at 35ºC during 14 days. The initial C/N ratio was 15:1, 20:1, 25:1 and 30:1.
The VFAs formation during the AD of cattle manure increased with changing the C/N ratio up to 25:1. The maximum concentration of these metabolites was 46 mg/L on day 7 from the beginning of cultivation. This value was 38 mg/L at the C/N ratio of 30:1. The produced biogas quantity was proportional to the C/N ratio and maximum also at 25:1. The rate of inclusion of VFAs in biogas production increased continuously during the process and after 7 days it superseded the rate of VFAs formation from the substrate. As a result, their quantity in the bioreactor decreased. The activity of all studied enzymes was highest at the ratio of 25:1. The cellulases and amylases participate most actively in the substrate degradation.
The process of AD of cattle manure with biogas production runs with the highest rate at the initial C/N ratio of 25:1 ensuring an optimal quantity of metabolites and specific enzyme activity values reflecting the assimilation of cellulose, monosaccharides, proteins and lipids from the substrate.
Key words: anaerobic digestion, biogas, carbon/nitrogen ratio, cattle manure