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Abstract: Three mathematical and statistical methods - namely correlation, Redundancy and Procrustean analysis were applied to analyze relationships between ecological factors of environment and health indicators. They used data from the International Organization for Environment Protection (UNEP) and the World Bank (World Bank). Environmental factors include emissions of various pollutants - N₂O, NOx, PM₁₀, CO₂, and economic factors such as renewable energy resources. Of the indicators of health are considered life expectancy, mortality, morbidity from diabetes and tuberculosis. The results provide a basis for a series of discussions and conclusions.

Key words: ecological factors, health indicators, correlation, Redundacy analysis, Procrustean analysis

a STUDY OF THE CONNECTION BETWEEN ELECTROMAGNETIC SMOG, AEROSOL POLLUTION AND CLOUD FORMATION

Deyan Gotchev, Maria Dimitrova, Roumen Nedkov

(PDF 1361k)

Abstract: Some important discrepancies in weather forecast for urban area during frontal zones’ transitional periods are constantly observed, when air pollution is combined with electromagnetic smog. Often the days’ lasting phenomenon is due to an unstable phase in humidity transition, which is generated by electromagnetic smog stimulation of anthropogenic aerosol aggregation. This result is a fog-like cover which intensifies pulmonary illness and allergies.

Key words: clouds, air pollution, electromagnetic smog

NEW APPROACHES IN MEDIA ALKALIZATION DURING THE STRUVITE PRECIPITATION

Dian Radev, Gergana Peeva, Husein Yemendzhiev, Bogdan Bonev, Valentin Nenov

(PDF 953k)

Abstract. The crystallization of Magnesium ammonium phosphate hexahydrate (struvite) is a function of several parameters. One of the key factors is the pH which needs to be controlled in order to obtain optimal production conditions. Different alkalization methods applied in struvite precipitation are discussed with emphasis on the comparison between the options related to addition of alkalizing reagents and the alternatives proposed in this study. In order to develop non-reagent alkalization approach, the pH dynamics in model and real reagent mixtures of magnesium, ammonia and phosphates are studied during CO₂ stripping and treatment in Microbial Electrolysis Cell. It was found that CO₂ stripping allows the fluid to reach values of pH 8.5 within 20 minutes at the initial values of 7.2, while in applying Microbial Electrolysis cell the process is much slower but the final values of alkalinity achieved are higher (9.2 within 24 hours).

Keywords: struvite, pH, CO₂ stripping, microbial electrolysis

Effect of mazut on structural and functional indicators of activated sludge in sofia wastewater treatment plant “kubratovo”

Irina Schneider, Mariyana Ducheva, Ivaylo Yotinov, Yovana Todorova, Elmira Daskalova, Yana Topalova, Vesela Stefanova

(PDF 1021k)

Abstract: The effect of inflow of 30 t mazut in Sofia Wastewater Treatment Plant (WWTP) “Kubratovo” on structural and functional parameters of activated sludge was investigated in this paper. Sludge volume index and filamentous index were analyzed in parallel with microscopic examination of activated sludge (AS) with a goal to ascertain eventual deformations in its structure. The metabolic activity of the biological system was investigated by measurement of the total aerobic dehydrogenase activity. The samples were taken from the aeration zone in biobasin.

The obtained data show that the activated sludge structure was deformed. A bulking activated sludge was ascertained because the sludge volume index was higher than 150 ml/g. The filamentous index was over 1.10⁷µm/mg, which was an indicator for a filamentous bulking. The used correlation analysis and the obtained correlation coefficients among these two indexes and the key chemical indicators (BOD₅/COD and hydrocarbon index of petroleum products) showed that the structural deformations are due to the concentration of toxic pollutant and in less degree to the lower percentage of biodegradable organics. The initial effect of mazut on activated sludge structure was also related with disappearance of rotifers and nematodes. The total density of organisms from micro- and metafauna was 2,86.10⁶ ind./l on the 6^th day after mazut inflow and it increased to 8,77.10⁶ ind./l during the next studied period (from the 12^th to the 25^th day after the shock load with mazut). Also, appearance of rotifers and nematodes during this period clearly showed the improvement of the conditions in the aeration tank and decrease of negative effect on the activated sludge. The aerobic dehydrogenase activity was two times lower on the 6^th day after shock load with mazut (0,75.10^-4 μMH⁺/min.mgPr) in comparison to data before risk event (control situation: 1,34.10^-4 μMH⁺/min.mgPr) which was an indicator for inhibition of activated sludge on a functional level. Although the registered deformations, a full recovery of aerobic dehydrogenase activity (2,16.10^-4 μMH⁺/min.mgPr) was established during the period from the 12^th to the 25^th day after shock load with mazut.

Key words: activated sludge, biological wastewater treatment, mazut, structural and functional deformations

Characterization of Biogenic calcite particles from microalgae – Coccoliths as a potential raw material for industrial application

I. Hariskos, M. A. Chairopoulou, C. Posten, U. Teipel, M. Vučak

(PDF 1123k)

Abstract. The coralline algae (Coccolithophores) Emiliania Huxleyi belongs to the phytoplanktion and is one of the most important lime stone producers in the oceans. It produces about 2-5 µm sized calcite particles (Coccolithes), which cover the cell surface completely. Coccolithes are thanks to their structure very interesting for industrial application as lime stone micro-particles e.g. for the production of specialty papers or for medical applications. Biomineralization in algae is a complex process running in the cell interior but is influenced by many environmental factors. Rational design led to a bio-process which allowed to produce and purify larger amounts of intact Coccolithes for the first time. The challenge was to supply the cells with the necessary amounts and concentrations of calcium and inorganic carbon for calcification. This could be accomplishes by pH- and pCO2-control and balanced Ca-feeding. First results from particle characterization will give a first glance on possible application features of these fascinating structures.

Keywords: Coccolith production, biogenic lime products, bio-inspired materials, Emiliania huxleyi

THERMOCHEMICAL PRETREATMENT OF LIGNOCELLULOSIC SUBSTRATES FOR ANAEROBIC DIGESTION AT MESOPHILIC AND THERMOPHILIC CONDITIONS

Lyudmila. Kabaivanova, Ivan Simeonov , Dencho Denchev, Snejanka Mihaylova, Venelin Hubenov, Radoslava Nikolova, Donka Todorova

(PDF 1031k)

Abstract. Finding a method for effective pretreatment of lignocellulosic wastes for further use as a substrate for anaerobic digestion was the main purpose of our study. Lignocellulosic biomass is a renewable inexpensive source, abundant in nature. Involving anaerobic biodegradation of organic wastes by a specific microbial community and defined conditions combines the breakdown of wastes with opportunities to obtain the energy carrier methane. In this study we report on the pretreatment technique with ammonium hydroxide (NH₄OH) and polyethylene glycol (РЕG) which was easy to perform and lead to increased biomethane yield (percent of methane in the biogas).

Key words: biomethane, pretreatment, anaerobic digestion, lignocellulosic substrates

DEVELOPMENT OF A WEB GEOPORTAL FOR THE WATERSHED OF YANTRA RIVER THROUGH OPEN SOURCE SOFTWARE

Tanya Trenkova

(PDF 1327k)

Abstract: The advance in the web mapping technologies enabled the generation and use of vast amount of spatial data. First and foremost, challenge is the extraction of appropriate information from the excessive data overload. In this respect the needs of web-based GIS applications for fast and easy dissemination, display and sharing of spatial information are constantly growing. The work investigates some geovisualization techniques for user friendly data representation. A framework containing different data types is elaborated related to the utilization of spatial datasets for Yantra River Basin area. The prototype is developed to serve as a data-viewer for various users.

The goal is to provide a comprehensive visualization tool for gaining better understanding from the available spatial data for the case study area. The application enables users to view, natural resources information for specific needs. The approach integrates only open source technologies for the development of the web-based GIS applications and tools serving to disseminate the data through the web. Flexibility, extensibility and interoperability of the open source software proves the necessity and benefits of the open source solutions within multi-aspect environments.

Keywords: web-based GIS applications, Open Source Software, geovisualization

A DISCRIMINATVE APPROACH BASED ON AEROSPACE MULTISPECTRAL BANDS DATA IN MONITORING OF SNOW COVER AND WATER

Roumen Nedkov, Temenuzhka Spasova, Deyan Gotchev

(PDF 1535k)

Abstract: The contemporary methods in aerospace-data-based monitoring require the use of combined images with different resolutions and electromagnetic spectral ranges. This is the core of the presented research for the creation of new approaches, data-processing methods and algorithms for analysis. Data from active and passive space-borne sensors are used. Results for quantitative changes of snow and water cover are obtained. Data with different polarization from the micro-wave band are combined with different composite images in the optical band. Results, based on satellite data, about the dynamic of the changes in the researched objects are commented.

Key words: snow cover, satellite data, microwave and optical bands

MODELING AND SOFTWARE SENSORS DESIGN FOR ANAEROBIC DIGESTION PROCESS

E. Chorukova, S. Diop, I. Simeonov, S. Tebbani

(PDF 953k)

Abstract. Anaerobic digestion is an effective biotechnological process for treatment of different agricultural, municipal and industrial wastes. Use of mathematical models is a powerful tool for investigations and optimisation of the anaerobic digestion processes and for softwere sensors design as well. In this paper a new version, conserning the gas phase modelling, of a simple mathematical model of the anaerobic digestion was developed and verified experimentally. The parameter identification was based on a set of 150 days of dynamical experiments in a laboratory bioreactor. Two step identification procedure to estimate 3 model parameters is presented. The results of 15 days of experiment in a pilot-scale bioreactor were then used to validate the model.

On the base of the modified simple mathematical model of the AD software sensors using the differential algebraic approach were designed and studied by simulations.

Keywords: anaerobic digestion, wasted fruits and vegetables, mathematical model, specific growth rate estimation, control systems observability theory.

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