Chemistry March 2003 Vol 52/1 []

CONTENTS & ABSTRACTS

InEnglish. Summaries in Estonian

Proceedings of the Estonian Academy of Sciences.

Chemistry



Volume 52 No. 1March 2003



Recentadvances in bioethanol fuel research.
1. Bioethanol, methyl tert-butyl ether,and other oxygenates in petrol blends; 3–19

Heino Rang and Jüri Kann

Abstract. In this review recent advances in the research on bioethanol, methyltert-butyl ether (MTBE), and other oxygenates in petrol blends are presented.MTBE is nowadays the most common additive of petrol in order to enhance itsoctane value and to reduce the concentration of toxic components in motorexhaust gases. The extensive use of MTBE has caused contamination of surfaceand groundwater. The carcinogenicity of MTBE has been demonstrated by animaltests. Replacing MTBE with ethanol is currently on the agenda in the USA; theproblem should be taken into consideration in Europe as well.

Key words: bioethanol, methyl tert-butyl ether (MTBE), petrol blends,carcinogenicity, water contamination, greenhouse effect.

Researchof algal polysaccharides and related natural compounds in Estonia;20–37

Kalle Truus and Merike Vaher

Abstract. The results of the investigations of the structure and compositionof real natural algal polysaccharides, their fractionation, and chemicalmodification are summarized against the general scientific background.Elucidation of a suitable agarose matrix from the red alga Ahnfeltia tobuchiensis and the synthesis of affinity carriers onthis basis are shown. Elaboration of technological schemata of red algaeprocessing, immunochemical investigations, and lectin research are covered aswell.

Key words: algal polysaccharides, gelling galactans, alginates, agarose,affinity carriers, furcellaran.

Degradationof nitroaromatics with the Fenton reagent; 38–47

Marina Trapido, Ave Dello, Anna Goi, and Rein Munter

Abstract. The feasibility of the Fenton reagent treatment for thedegradation and detoxification of nitroaromatic compounds (NAC) such as p-nitrotoluene, nitrobenzene, and m-dinitrobenzene was studied. Thedegradation rate of NAC with the Fenton treatment was strongly dependent on themolar ratio NAC/hydrogen peroxide/catalyst (Fe2+). The 90%conversion times of NAC in the Fenton treatment followed the order p-nitrotoluene ≈ nitrobenzene < m-dinitrobenzene. The degree of nitrogenconversion to nitrate with the Fenton treatment varied from 25% to 100%,depending on the treatment conditions. Total organic carbon removal of 45–47%was obtained when the Fenton reagent treatment with the concentration ofhydrogen peroxide 10 mM and catalyst 1 mM was applied. According tothe Daphnia magna toxicity test theFenton reagent treatment enabled to reduce the toxicity of NAC.

Key words: nitroaromatic compounds, Fenton reagent, degradation, toxicityassay, by-products.

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