Chemistry June 2002 Vol 51/2 []

CONTENTS & ABSTRACTS

InEnglish. Summaries in Estonian

Proceedings of the Estonian Academy of Sciences.

Chemistry



Volume 51 No. 2June 2002



Advances in biodiesel fuel research; 75–117

Jüri Kann, Heino Rang, andJüri Kriis

Abstract. The paper gives a thorough review of research on biodiesel fuelsources, properties, preparation methods, production, exhaust gases emitted byusing biodiesel fuel, analytical methods, and economic aspects. The mainadvantage of biodiesel fuel is lower concentration of greenhouse gases(especially CO2) and other pollutants in motor exhaust gasescompared to petroleum diesel fuel. The main concerns with biodiesel fuel areits relatively high price, instability, and low-temperature properties. Thefuture aims in biodiesel fuel research are improvement of production technologyand reduction of the costs of production of plant oil by plant breeding,selection, and gene technology. The low-temperature properties and stability ofbiodiesel fuel can be improved by additives and genetic engineering of oilplants. The paper includes 250 references.

Key words: biodiesel fuel, diesel fuel, plant oils, pollutants, fueladditives.

Treatment of landfill leachates: aerobicbio-oxidation and post-ozonation; 118–125

Inna Kamenev, Lui Pikkov, andJuha Kallas

Abstract. The purpose of the study was to improve the purificationprocess of landfill leachate. Aerobic bio-oxidation of landfill leachate andpost-ozonation of biologically treated leachate were studied. The results ofexperiments indicate that aerobic bio-oxidation is efficient for purifyingyoung landfill leachate only under stable operating conditions with a longretention time. Subsequent ozonation results in significantly improvedbiodegradability of the wastewater.

Key words: landfill leachate, aerobic bio-oxidation, post-ozonation.

Determination of manganese in thermoluminescentmaterials by inductively coupled plasma atomic emission spectrometry andspectrophotometry; 126–133

Aime Lust, Lilli Paama,Mihkel Kerikmäe, Mare Must, and Paavo Perämäki

Abstract. The content of manganesein the mixed fluorides CaF2: MnF2 and CaF2: Mnthermoluminophors was determined by inductively coupled plasma atomic emissionspectrometry (ICP-AES) and spectrophotometry. The various Mn emission lineswere compared and the manganese emission line at 257.610 nm was used forICP-AES analysis. For the spectrophoto­metric determination the manganese(II)ions were oxidized to intensively coloured permanganate ions using potassiumperiodate. No statistically significant differences were found between theresults of ICP-AES and spectrophotometric methods of analysis. Thethermoluminophors were synthesized by coprecipitation of manganese with CaF2,varying the concentration of manganese in the initial solutions in the range of0.01–2.0% (m/m). The coprecipitated mixed fluorides CaF2: MnF2were heated at 1423 K. The glow curves of synthesized CaF2: Mnthermoluminophors were measured.

Key words: manganese determination, ICP-AESspectrophotometry, thermoluminophors CaF2 : Mn, glowcurves.



Instructions to authors; 134–136