F. Wurst

Combustion dioxin supression in municipal solid waste incineration with sulphur additives

Combustion of municipal solid waste (MSW) has - among other most probably more relevant sources - shown to produce PCDD/Fs which in some countries has led to emission limits for an I-TE value as low as 0.1 ng/m3 “End-of-pipe” technology has so far only made available “add-on” filters and purification stages which may introduce additional safety problems (filter burn), increase down-time of the whole plant or induce over-sized design of the final stages due to incomplete knowledge of pre-dust-filter raw gas concentration of PCDD/Fs. Since some theoretical conclusions have suggested a negative influence of elevated SO2-concentration with regard to dioxin/furan formation or re-formation 2 sets of very careful full-scale tests were carried out at a MSW incinerator whereby sulphurcontaining Austrian lignite of similar physical fuel features compared to MSW (lower heating value, ash, humidity) was added in different quantities at constant feed-rate (t/h input) and compared with respect to their PCDD/F release. Results show a dramatic decrease from “usual” MSW incinerator dioxin levels in the order of 2.5 to nearly 10 ng TE/nm3 down to less than 1 ng TE/nm3 with addition of coal. Unlike other experiments which have not shown a significant decline of PFDD/Fs in the raw gas and usually no decrease in PCDD/F concentration in the filter dust at all, our large scale tests have revealed a decrease in PCDD/F concentration in both gas and dust measurements, both before and after the dust filter as well as in the dust itself.

Enzymatic hydroxylation of 6′-deoxychalcones with protein preparations from petals of Dahlia variabilis

Abstract Yellow colouration of Dahlia variabilis flowers is mainly based on isoliquiritigenin and butein 4′-malonylglucosides. Microsomal preparations from petals of the yellow strain ‘Johann Nestroy’ catalyse the enzymatic 3-hydroxylation of isoliquiritigenin to butein in the presence of NADPH. The reaction showed a pH optimum of 7.5, and was inhibited by p -hydroxymercuribenzoate and a number of cytochrome P450 specific inhibitors. These and further properties suggest that the 3-hydroxylation of isoliquiritigenin is mediated by a cytochrome P450-dependent monooxygenase. The apparent K m value for isoliquiritigenin was 50 μM.

Flavonol Synthase Activity and the Regulation of Flavonol and Anthocyanin Biosynthesis during Flower Development in Dianthus caryophyllus L. (Carnation)

Flavonol synthase (FLS) was demonstrated in crude extracts from flower buds of Dianthus caryophyllus (carnation). The enzyme catalyzed the conversion of dihydrokaempferol and ihydroquercetin to kaempferol and quercetin, respectively. The reaction required 2-oxoglutarate, ferrous ion and ascorbate as co-factors and had a pH optimum at about 7.4. The demonstration of FLS activity allowed comparative studies on flavonol and anthocyanin biosynthesis during bud and flower development. Besides FLS the flavonoid enzymes chalcone synthase (CHS), flavanone 3-hydroxylase (FH T) and dihydroflavonol 4-reductase (DFR) were measured. DFR is specifically involved in anthocyanin synthesis, while CHS and FHT provide dihydroflavonol, the common substrate for both FLS and DFR . Maximum expression of CHS, FHT and FLS activity was already observed in small buds, whereas DFR activity started to increase much later and reached its highest level in opened flowers. A substantial correlation was observed between the time courses of FLS and DFR activity and the accumulation of flavonols and anthocyanins, respectively. The competition of FLS and DFR for dihydroflavonols was found to be largely circumvented by different substrate specificities and by the sequential expression of the two enzymes. Both flavonols and anthocyanins are obviously not, or only to some extent, subject to degradation.

Determination of PCDDs and PCDFs in soil samples from Salzburg, Austria

Abstract In 1990/91, a soil-sampling survey was conducted in the federal state of Salzburg, Austria, to determine the levels of concentration of PCDDs and PCDFs in rural, urban, and industrial sites. Background sampling was performed in undisturbed Alpine settings. The analyses were carried out isomer specifically to express the concentrations in TCDD-equivalents (TE) as defined by FHO/Berlin and NATO/CCMS.

Enzymatic glucosylation of 4-deoxyaurones and 6'-deoxychalcones with enzyme extracts of Coreopsis grandiflora, Nutt. I.

Abstract The orange-yellow colouration of Coreopsis grandiflora is mainly provided by the 6′-deoxychalcone butein and its 4′-glucoside respectively, as well as the corresponding 4-deoxyaurones sulfuretin and leptosidin (7-methoxysulfuretin) and their 6-glucosides. Incubation of butein or sulfuretin with enzyme preparations from petals of Coreopsis grandiflora in the presence of uridine 5′-diphosphoglucose led in each case to the formation of one single product, which was identified as butein 4′-glucoside and sulfuretin 6-glucoside, respectively. The 6′-deoxychalcone isoliquiritigenin was a poor substrate. Glucosylation of hydroxyl groups in other positions was not observed. Naringenin chalcone and eriodictyol chalcone were not accepted as substrates. The glucosylation reaction of butein and sulfuretin exhibited an optimum at pH 8.0 and 7.0, respectively. Bivalent ions like Mg2+ and Ca2+ stimulated only slightly, whereas the addition of Cu2+, Zn2+, N-ethylmaleimide and p- hydroxymercuribenzoate led to a total loss of enzyme activity. The apparent Km values for butein and sulfuretin were 146 and 44 μM, respectively. The specific enzyme activity increased slowly during bud and flower development and declined in the later stages. The highest specific activity was observed in open flowers with 30 mm diameter. The rates of the glucosylation reaction with butein and sulfuretin had similar patterns.

Dünnschicht- und Gaschromatographie natürlich vorkommender Gemische von Zuckern und Zuckeralkoholen

SummaryThe quantitative determination of these food components with both methods showed good results. For the evaluation of the sugars on the thin layer plate, the identification with anilinphatalate was selected from several colorimetric methods, whereas after TLC separation the sugar alcohols are quantitative analysed with an iodometric titration in a microchemical scale. Gaschromatographic results of the acetylated sugars and sugar alcohols correspond with TLC values.ZusammenfassungAn einer Reihe von Lebensmitteln wurden dünnschicht- und gaschromatographische Methoden für die Analytik der Zucker bzw. Zuckeralkohole getestet. Dabei ergab sich, daß für eine quantitative Bestimmung dieser Lebensmittelbestandteile beide Methoden gute Ergebnisse liefern. Für die Auswertung der Zucker auf der DC-Platte wurde aus mehreren colorimetrischen Verfahren der Nachweis mit Anilinphtalat ausgewählt, die quantitative Erfassung der Zuckeralkohole nach DC-Auftrennung erfolgt mit jodometrischer Titration im mikrochemischen Maßstab. Die Ergebnisse aus der Gaschromatographie an acetylierten Zuckern und Zuckeralkoholen stimmen mit den Werten der dünnschichtchromatographischen Methodik gut überein.

High temperature gasification (HTG) pilot plant studies with different waste materials: Formation of PCDD/F and other organic pollutants

Abstract This paper presents the results of test runs with the High Temperature Gasification (HTG), a newly developed technology of a thermal treatment of hazardous waste of the VOEST-ALPINE Industrieanlagenbau. When measuring the emissions special attention was paid to organic pollutants, such as polychlorinated dibenzo-p-dioxins (PCDD), polychlorinated dibenzofurans (PCDF), polychlorinated biphenyls (PCB), chlorobenzenes (CB), chlorophenols (CP), polycyclio aromatic hydrocarbons (PAH) and others. The results of the tests with various waste show that the HTG pilot plant produces a relatively low emission level as far as organic pollutants are concerned. The concentrations of PCDDs and PCDFs in flue gas reaches from not detectable up to 0,04 ng/Nm 3 of 2,3,7,8-TCDD-equivalents (I-TEF), thus remaining remarkably lower than the Austrian limit for municipal waste incinerators of 0,1 ngTE/Nm 3 (I-TEF).

Reduction of PCDD/PCDF emissions from a waste incineration facility by a full scale DeNox-unit

Abstract During 1990 a extensive program was launched at the MWI Spittelau/Vienna in order to investigate the levels of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) at different points of the flue gas pathway on a full technical scale and to determine the possibility of reducing PCDD/F emissions below 0.1 ng toxic equivalents (TE)/Nm 3 . The primary aim of these investigations was to obtain information concerning PCDD/F levels before and after the SCR-DeNox-unit in order to determine the degree of catalytic oxidation of these organohalogen compounds. The findings of two test runs are summarized in this paper.

Formation of 6'-Deoxychalcone 4'-Glucosides by Enzyme Extracts from Petals of Dahlia variabilis.

Yellow colouration of Dahlia variabilis is mainly provided by isoliquiritigenin 4′-glucoside and butein 4′-glucoside. Incubation of petal extracts with uridin 5′-diphosphoglucose and isoliquiritigenin or butein led to the formation of one product which was identified as the respective 6′-deoxychalcone 4′-glucoside. Glucosylation of hydroxyl groups in other positions was not observed. Naringenin chalcone and eriodictyol chalcone were not accepted as substrates. The 4′-glucosylation of isoliquiritigenin and butein showed a broad pH optimum ranging from pH 7 to 8 and was stimulated by Mg2+, Ca2+ and Mn2+. N-Ethylmaleimide, p-hydroxymercuribenzoate, Cu2+, Zn2+, and Fe2+ clearly reduced the activity of the enzyme. The apparent Km values for UDP-glucose, isoliquiritigenin and butein were 90, 26 and 276 [μᴍ respectively.

Zur quantitativen Bestimmung von Thebain in Papaver bracteatum

SummaryA method is described for the quantitative determination of thebaine in extracts of Papaver bracteatum by high performance thin-layer chromatography on silica plates. The separation of extracts is achieved in about 30 mm using benzene/methanol (8/2) as developing solvent. Quantitation is effected with a chromatogram spectrophotometer. The relative standard deviation is 1.5%.ZusammenfassungEs wird eine Methode zur quantitativen Bestimmung von Thebain in Extrakten von Papaver bracteatum unter Verwendung der Hochleistungs-Dünnschicht-Chromatographie auf Kieselgelplatten beschrieben. Die Auftrennung der Extrakte wird mit dem Fließmittelsystem Benzol/Methanol (8/2) in etwa 30 min erreicht. Die quantitative Auswertung erfolgt mit Hilfe eines Chromatogramm-Spektralphotometers. Die relative Standardabweichung beträgt 1,5%.