Thomas Pümpel | University of Innsbruck (original) (raw)

Papers by Thomas Pümpel

Advances in Engineering Software, 2018

In this article, a finite volume method based CFD analysis of the mixing of Newtonian and non-New... more In this article, a finite volume method based CFD analysis of the mixing of Newtonian and non-Newtonian flows in anaerobic digesters is conducted. The multiple reference frame method is used to model the mixing which is induced by an impeller rotating within a mechanical draft tube. Moreover, the feeding of biomass is considered in the model formulation. Following the validation of the method against reference data, the mixing of cylindrical and egg-shaped digesters is investigated. The distinguishing feature of this article is that the theoretical findings are adopted for the operation of a real-life anaerobic digester. In the context of a case study slurry flows with high total solids concentrations are investigated.

Mycologist, 1994

Fungal Enzymes I am perturbed at the rather unqualified general statement in 'Mycological answers... more Fungal Enzymes I am perturbed at the rather unqualified general statement in 'Mycological answers' (Mycologist 7(1), p. 91), that the fungi causing athlete's foot 'pour out enzymes (proteases and peptidases)' ... and that 'these enzymes and other compounds given out by the fungi act as irritants to the skin, and it is these that cause itching and great discomfort' ... Today proteases, lipases and cellulases from both fungi and bacteria are widely used in the laundry detergent industry and indeed are the world's major commercially produced enzymes. Fungal cellulases are also used in the preparation of 'biostoned blue jeans'. Unfortunately there was a fiasco in the laundry detergent industry when it was claimed a few years back, that proteases in detergents were widely responsible for itching hands of the 'Monday wash crew'. The initial industrial response was the removal of proteases from laundry detergents. The general claims of associated dermatitis were never substantiated. Some instances of hyper allergic response in the lungs in production facilities were recorded, and as a result industry responded by preventing aerosols through micro-encapsulating the laundry enzymes. Today world sales of detergent enzymes are in the range of £130 million and allergic responses are relatively rare. In view of the prior fiasco to the detergent industry, I believe that such cautionary comment should be added to Dr. Isaac's 'mycological answer'.

Hydrometallurgy, 2003

Large volumes of wastewater containing metals such as Cd, Zn, Cu, Pb, Hg, Ni or Co are mainly tre... more Large volumes of wastewater containing metals such as Cd, Zn, Cu, Pb, Hg, Ni or Co are mainly treated by precipitation processes. However, waters treated in such ways do not always meet regulatory standards. And in many cases, ecotaxes must be paid on the heavy metals load in the discharged water. Therefore, a second polishing treatment is often necessary. In

Hydrometallurgy, 2001

The MERESAFIN MEtal REmoval by SAnd Filter INoculation process presented here was designed to com... more The MERESAFIN MEtal REmoval by SAnd Filter INoculation process presented here was designed to combine the optimum conditions for more than one of the well-known processes of biological metal immobilisation like biosorption and bioprecipitation in a treatment system for industrial waste water. The approach makes use of a continuously operated moving-bed Astrasand w filter which has been inoculated with a mixed population of selected metal biosorbing, bioprecipi-Ž. tating and biodegrading bacteria. One of four pilot plants has been erected at a metal plating company in Vienna A to treat waste water from an electroless nickel plating line. In addition to several mgrL of nickel the rinsing water also contains organic acids and inorganic phosphates, which make conventional treatment difficult. Metal laden biomass is continuously removed from the sand grains in the filter and settled in a lamella separator. The Ž. thickened biosludge contained 2% of Ni at only 2-5 mgrL in the feed water , which could be recycled in a shaft furnace. Regeneration of biofilms on the sand is achieved by dosing a cheap carbon source; all other nutrients are available from that specific waste water. For the removal of 0.8 mgrL of nickel the biofilms consumed 8 mg carbonrL and, in addition to 8 mgrL of dissolved oxygen, 3.4 mg NO-NrL as additional electron acceptor. 3 The process was shown to be economically favourable over comparable conventional techniques of metal removal. A Ž further advantage of the biological system is its ability to cleave organo-metal complexes e.g. nickel lactate in the presented. case , to degrade organic molecules like organic acids, surface active substances, etc., often present in industrial waste waters, or to reduce ammonium, nitrite and nitrate. Proposed areas of application comprise the final polishing of industrial and mining water, but also the full treatment of contaminated ground water or drainage water.

Biometals, 2003

Efficient removal of dissolved nickel was observed in a biologically active moving-bed 'MERES... more Efficient removal of dissolved nickel was observed in a biologically active moving-bed 'MERESAFIN' sand filter treating rinsing water from an electroless nickel plating plant. Although nickel is fully soluble in this waste water, its passage through the sand filter promoted rapid removal of approximately 1 mg Ni/l. The speciation of Ni in the waste water was modelled; the most probable precipitates forming under the conditions in the filter were predicted using PHREEQC. Analyses of the Ni-containing biosludge using chemical, electron microscopical and X-ray spectroscopic techniques confirmed crystallisation of nickel phosphate as arupite (Ni3(PO4)2 x 8H2O), together with hydroxyapatite within the bacterial biofilm on the filter sand grains. Biosorption contributed less than 1% of the overall sequestered nickel. Metabolising bacteria are essential for the process; the definitive role of specific components of the mixed population is undefined but the increase in pH promoted b...

World Environmental and Water Resources Congress 2016, 2016

L'invention concerne un procede et un kit de determination de la quantite de bacteries anammo... more L'invention concerne un procede et un kit de determination de la quantite de bacteries anammox dans un bioreacteur, avec les etapes de i) Prelevement d'un echantillon dans le bioreacteur ; (iii) Melange de l'echantillon avec un alcali ; v) Chauffage de l'echantillon a au moins 60 °C ; vi) Separation des fractions solides ; vii) Ajout d'un agent reducteur a la phase liquide ; viii) Mesure de la transmission de lumiere de la phase liquide dans un spectrophotometre a trois longueurs d'onde dans la plage de 500 a 600 nm; ix) Comparaison de la transmission de lumiere mesuree a un spectre de reference. 86

Biosorption of chromium(III) by whole cells and isolated cell walls of Mucor hiemalis was investi... more Biosorption of chromium(III) by whole cells and isolated cell walls of Mucor hiemalis was investigated. A fast initial sorption of Cr(III) on the cell wall was found, reaching 80% of the calculated maximum load after 30min contact time. However, the final biosorption maximum could not be reached after two hours, indicating a complex binding mechanism comprising more than one sub-process. From the Langmuir-fitted biosorption isotherms theoretical maximum biosorption capacities of 132 and 22mg Cr(III)/g d.w. were calculated for cell wall and whole cells, respectively. The composition of isolated cell walls was studied. The major components were chitosan (32%) and chitin (11%). The type of nitrogen source in the cultivation medium (NaNO3 and peptone from casein) strongly influenced the cell wall composition. The contents of chitosan and phosphorus in the cell wall were significantly higher with NaNO3 in comparison to peptone from casein, whereas a higher protein content was found using...

Verfahren und Kit zur Ermittlung der Menge an Anammox-Bakterien in einem Bioreaktor, umfassend di... more Verfahren und Kit zur Ermittlung der Menge an Anammox-Bakterien in einem Bioreaktor, umfassend die Schritte i) Entnehmen einer Probe aus dem Bioreaktor; iii) Versetzen der Probe mit Alkali; v) Erwarmen der Proben auf zumindest 60°C; vi) Abtrennen fester Bestandteile; vii) Zugabe eines Reduktionsmittels zur flussigen Phase; viii) Messen der Lichtdurchlassigkeit der flussigen Phase in einem Spektrophotometer bei drei Wellenlangen im Bereich 500 bis 600 nm; ix) Vergleich der gemessenen Lichtdurchlassigkeit mit einem Referenzsprektrum.

Journal of Material Cycles and Waste Management

Waste-activated sludge (WAS) may be considered a resource generated by wastewater treatment plant... more Waste-activated sludge (WAS) may be considered a resource generated by wastewater treatment plants and used for biogas-generation but it requires pre-treatment (PT) for enhanced biogas-yields and reduced WAS disposal costs. To date, a number of studies on the optimization of such PT focused on improved biogas yields but neglected inferred energy and resource consumption. Here, we aimed to identify the most promising thermo-chemical PT-strategy in terms of net energy output and cost-efficiency by optimizing PT temperature and the amount and sort of the alkaline reagent used. We compared methanepotentials and disposal costs of untreated and treated WAS and conducted an annual cost-benefit calculation. We defined 70°C and 0.04 M NaOH as ideal PT-conditions being both, low-energy demanding and efficient. Applying these conditions, enhanced biogas-yields and improved dewaterability led to reduced electricity and disposal costs of 22 and 27%, respectively, resulting in savings of approx. 28% of the yearly WAS-related expenditures of a wastewater treatment plant. Despite multiple benefits in running costs, the implementation of WAS-PT was not recommendable in the presented case study due to high investment costs. Keywords Waste-activated sludge Á Thermo-chemical pre-treatment Á Cost-benefit analysis Á Alkaline pre-treatment Á Methane potential

Water research, Oct 18, 2018

Treatment of sewage sludge with a thermal hydrolysis process (THP) followed by anaerobic digestio... more Treatment of sewage sludge with a thermal hydrolysis process (THP) followed by anaerobic digestion (AD) enables to boost biogas production and minimize residual sludge volumes. However, the reject water can cause inhibition to aerobic and anoxic ammonium-oxidizing bacteria (AerAOB & AnAOB), the two key microbial groups involved in the deammonification process. Firstly, a detailed investigation elucidated the impact of different organic fractions present in THP-AD return liquor on AerAOB and AnAOB activity. For AnAOB, soluble compounds linked to THP conditions and AD performance caused the main inhibition. Direct inhibition by dissolved organics was also observed for AerAOB, but could be overcome by treating the filtrate with extended aerobic or anaerobic incubation or with activated carbon. AerAOB additionally suffered from particulate and colloidal organics limiting the diffusion of substrates. This was resolved by improving the dewatering process through an optimized flocculant po...

Process Metallurgy, 1999

... REFERENCES 1. B. Palenik, J.-C. Block, RG Bums, WG Characklis, BE Christensen, WC Ghiorse, AG... more ... REFERENCES 1. B. Palenik, J.-C. Block, RG Bums, WG Characklis, BE Christensen, WC Ghiorse, AG Gristina, FMM Morel, WW Nichols, OH Tuovinen, G.-J. Tuschewitzki and HA Videla, WG Charaklis ... 9. L. Diels, Q. Dong, D. van der Lelie, W. Baeyens and M. Mergeay, J. Industr ...

Mycological Research, 1998

Among the numerous items of equipment with the ' Iceman ', who died more than 5000 years ago on a... more Among the numerous items of equipment with the ' Iceman ', who died more than 5000 years ago on an alpine glacier, were three fungal objects : two different shaped fruitbody pieces of the polypore Piptoporus betulinus, each mounted separately on a leather thong, and, found in his girdle bag, a relatively large quantity of tinder material prepared from the ' true tinder bracket ' Fomes fomentarius. A full description of these items and a chronological report on their identification is given. The question about the possible use of the fungi is discussed on the basis of a comprehensive collection of ethnomycological and pharmacological literature data.

Proceedings of the National Academy of Sciences, 2012

Aspergillus fumigatus is the most common airborne fungal pathogen for humans. In this mold, iron ... more Aspergillus fumigatus is the most common airborne fungal pathogen for humans. In this mold, iron starvation induces production of the siderophore triacetylfusarinine C (TAFC). Here we demonstrate a link between TAFC and ergosterol biosynthetic pathways, which are both critical for virulence and treatment of fungal infections. Consistent with mevalonate being a limiting prerequisite for TAFC biosynthesis, we observed increased expression of 3-hydroxy-3-methyl-glutaryl (HMG)-CoA reductase (Hmg1) under iron starvation, reduced TAFC biosynthesis following lovastatin-mediated Hmg1 inhibition, and increased TAFC biosynthesis following Hmg1 overexpression. We identified enzymes, the acyl-CoA ligase SidI and the enoyl-CoA hydratase SidH, linking biosynthesis of mevalonate and TAFC, deficiency of which under iron starvation impaired TAFC biosynthesis, growth, oxidative stress resistance, and murine virulence. Moreover, inactivation of these enzymes alleviated TAFC-derived biosynthetic demand for mevalonate, as evidenced by increased resistance to lovastatin. Concordant with bilateral demand for mevalonate, iron starvation decreased the ergosterol content and composition, a phenotype that is mitigated in TAFC-lacking mutants. siderophore | isoprenoide | statins