Volume 8 (2012): Issue -1 (November 2012)

The water effluents of olive presses contain a number of phenols that are hardly biodegradable and therefore constitute an environmental hazard, mainly in the Mediterranean countries. The present work presents the results obtained from the study of artificial solutions containing one kind of phenol, namely gallic acid that consists of the main type of phenols present.

According to the experimental procedure, the phenol is removed from the water solution by absorption on different naturally occurring raw rock materials. The first material is caustic magnesia produced after the calcination of a magnesite sample from Macedonia, Greece, the second is a sample of sedimentary psammitic marl from the area of Chania, Crete, Greece, and the third solid absorbent is a bentonite sample from the island of Milos, Greece.

According to the results obtained, magnesia seems to be by far the best absorbent, with an absorbing capacity of 3500 mg of phenol per gram, followed by the psammitic marl. The absorbing capacity of bentonite is almost negligible

Poultry Wastes (PW) are rich biomass types which can be utilized as renewable energy sources in energy conversion systems. The PW is a mixture of poultry litter and organic materials spread on the poultry houses ground. In this paper, combustion of the poultry waste alone and mixed with coal in a combustor set up are implemented, and emissions are monitored. Experimental results reveal that, co-combustion of PW in an existing combustor firing coal can be considered as the best environment-friendly remedy to dispose the facility wastes while reducing the combustion emissions of the system.

The article presents the results of experimental work in the first waste mechanical Pre-treatment Centre in Latvia Daibe. The goal - to detect the main parameters for sorted waste parts and to compare them with parameters stated for refuse derived fuel (RDF) in a cement plant in Latvia (Cemex). Samples were taken in four fractions - coarse, medium, fine, metal. The parameters - upper, lower heating values, moisture, ash content, S, Cl, metals were determined. Results - coarse fraction has greater potential of the production of the RDF, but reduction of its content of Cl would be necessary.

Energy engineering is facing new challenges in educating experts in sustainable energy. The aim of this paper is to characterise expertise related to sustainability in higher education. Future challenges and required skills are explored through recent studies, which have listed key competencies that engineers need in their working life. Sustainability and expertise are discussed on the basis of literature and energy curricula are explored on universities’ internet pages.

The goal of this paper is to analyse the volumes of greenhouse gas (GHG) emissions from the European Union Emissions Trading System’s (EU ETS) participants in Latvia in relation to their participation therein. After describing and discussing the EU ETS mechanism and its operation in Latvia in the period 2005-2010, the interconnectedness between the GHG emissions and the EU ETS participants’ operation is analysed. The analysis concludes that, although the EU ETS has contributed towards GHG emission reduction, due to the growth of the economy, overall GHG emissions from the EU ETS participants in Latvia are increasing.

The objectives of the paper are to determine the quality of pellets available on the market in Latvia and to compare results with the European standard EN 14961-2:2011. The following parameters have been determined for samples of pellets: length, diameter, moisture and ash content, mechanical durability, lower calorific value and bulk density. The results showed that all samples confirm to the B class requirements of the standard. If one considers the A1 class - only 4 out of 9 samples fit the requirements. The paper emphasizes the need for the introduction of a quality control system for the wood pellets market in Latvia.

The long-term annual regime of shallow groundwater levels is analysed in two different time periods

according to the dominance of continental and oceanic air masses in Latvia. Observed and modelled long-term mean monthly groundwater levels for the reference period (1961-1990) and a future period (2070-2100) are transformed into relative values and the contours are derived for each month of the year. In both periods, the main difference between the mildly oceanic western coastal part of Latvia and the continental eastern part is the pattern of the winter regime which responds differently to snowmelt. In the coastal areas, where the degree of climatic continentality is low, groundwater levels during the winter are higher than those areas in the inland eastern part of the country. From May to September, there is only temporal difference between the groundwater levels in those two parts of Latvia. There are significant differences of relative groundwater levels between reference and future periods during the winter months.

The focus of the recent experimental research is to analyze the regulation possibilities of biomass combustion. Three possibilities were chosen as part of this research: a) biomass cofiring with propane, b) swirling flow with re-circulation zone, and c) use of a permanent magnet. The aim of the research is to provide stable, controllable and effective biomass combustion with minimum emissions. The special pilot device was created where biomass can be combusted separately and co-fired with propane. Wood pellets were used during the experiments.