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This report shows that pig manure can be used for algal production in small farms. Huge pig sludge amounts produced using actual methods in large-scale pig breeding farms is a major issue due to the lack of disposal options and potential water pollution. This issue may be solved by using pig sludge for algal biofuel production. Therefore, we studied an economical method of algae production on pig sludge that can be operated on animal farms in Hungary with modest levels of investment. We analyzed four algae species, Chlorella vulgaris, Scenedesmus quadricauda, Scenedesmus dimorphus, and Arthrospira platensis, in the laboratory and C. vulgaris in outdoor conditions. The following parameters were studied: pot size, illumination, temperature, filtered versus unfiltered pig manure, water depth, aeration, CO 2 enrichment, inoculums solution, fertilization level, and length of rotation period. Produced alga biomass was measured every 4 days, and the protein-and lipid content was analyzed using the method of Bradford (1976) and Erickson (1993). Our results show first that the unfiltered pig manure is not suitable for algae production due to illumination shortage. By contrast, using filtered pig manure, we found that C. vulgaris yield in 70-l indoor pots was 64% higher than in smaller pots. In a larger outdoor system, the annual dry yield of C. vulgaris reached 141-259 t/ha during 12-day-long rotation periods. Here, we demonstrate that only filtered liquid pig manure can be recommended for algae production. C. vulgaris is the most suitable alga species for use in large-scale experiments on pig sludge. Based on our outdoor experiments, the adaptation of a 12-to 14day rotation period could be considered the most reasonable. An algae farm can therefore be operated with relative modest amount of capital, can hence address the issue of sludge management, and provide a substrate for energy production.

Biodiesel use in local public transport could be especially significant in improving air quality in cities. The purpose of the experiments described in this paper was to evaluate the various (10, 20 and 50%) blends of biodiesel with diesel in the context of the engine and pollution aspects. As regards the experimental use of these findings on municipal buses, these experiments were the first reference in Hungary. The ages (15-20 years) and types of buses (Ikarus-280, Ikarus-260) used in the experiments are still common vehicles in Hungarian public transport. During our measurements, there was a significant difference between the change in fuel consumption of articulated and solo buses in traffic when compared to test bench measurements. The proportion of the engine performance reduction is nearly the same as that for biodiesel share in the blends. Most pollutants were decreasing (both at idle and full rpm), but this reduction is not directly proportional to the increase of the blending percentage. However, as for CO2, emission increase was observed in the case of idle rpm in comparison to normal diesel operation, even though this phenomenon was not due to biodiesel use, but the catalytic converter and the fact that biodiesel was used for the first time in the engine concerned. Highlights (for review) Highlights1. Our experiments in this topic were the first references in Hungary.2. Biodiesel use results 13.3% increase in the fuel consumption of articulated buses.3. Increasing the proportion of biodiesel results to similar decrease in performance. 4. All pollutants except for CO 2 showed a reduction.5. The extent of this reduction is not proportional to share of blended biodiesel.

The 2008/2009 world economic crisis had significant impact on oil and fuel markets. This crisis has been developed from the meltdown of the American mortgage and financial market and spread throughout the global economy. As each country reacted differently to the crisis, the changes in the fuel market have also shown significant geographic variation. In our present research, the changes of the US, German and Hungarian fuel markets were analysed, looking for answers to the reasons behind different crisis reactions. We examined the tendency of fuel consumption, the changes of gasoline and diesel price elasticity and the possible effects of the crisis on the regulatory system.