Reinigung und Verwertung von Abwässern der Kartoffelstärkeindustrie mit Hilfe von biologischen Kläranlagen

Purification and Utilization of Waste Water of Potato Industry by Means of Biological Clarification Plants. The importance of waste water pre-clearing in potato starch industry by means of a hig-grade separation of fruit water has been examined in both model and semi-technological scale. Observing the recirculation principle better economical as well as technical possibilities for biological purification of starch waste waters have been demonstrated by these investigations.

• 1 Starch waste waters which are extensively freed of fruit water can be profitable purified in fresh state as well as after storing in collection tanks in biological clarification plants.
• 2 Potato starch waste waters can be purified without difficulty in public clarification plants together with domestic waste waters.
• 3 By their contents of nitrogenic matter and P₂O₅ potato starch waste waters support the biological process in such waste waters, which are poor of these activating substances, i.e. waste waters of wood processing industry.

     

Untersuchung der energetischen Verwertung von L-Fructose bei Ratten

Investigation of energetic utilization of L-fructose in rats The energetic utilization of L-fructose (LF) and D-fructose (DF) was investigated by means of indirect calorimetry in a difference trial on 9 male Wistar rats in the live weight range of 250 to 300 g. The daily rations in the two comparable periods with added fructose consisted of 10 g basal diet plus 2.7 g LF or 2.5 g DF. The digestibility and metabolizability of energy of the LF-ration were decreased by about 4 and 6%, resp., in comparison to the DF-ration. The efficiency of total utilization of energy (energy deposition/gross energy) amounted to (7 ± 3)% (mean ± SD) for the LF-ration and (10 ± 3)% for the DF-ration. The lower digestibility of energy of the LF-ration was mainly due to a depression of apparent digestibility of crude protein, crude fat and crude fibre — obviously caused by increased microbial fermentation. With correction of the depression of digestibility the following values of energetic utilization resulted from the difference evaluation for LF and DF, resp.: digestibility (90 ± 8)% and (100 ± 6)%, metabolizability (85 ± 8)% and (102 ± 5)%, utilization of gross energy for energy deposition (69 ± 11)% and (86 ± 11)% and utilization of metabolizable energy (81 ± 7)% and (84 ±xs 11)%, resp.     

Internationales symposium über „Verwertung von kartoffeln und beseitigung von kartoffelabfällen bei der industriellen verarbeitung„ in frederiction,New Brunswick,Kanada

European Food Research and Technology -     

Untersuchungen über Emissionen bei der thermischen Verwertung von holzschutzmittelhaltigen Holzresten

Since the introduction of strict legal conditions, the disposal of used wood and wood residues treated with wood preservatives became subject of many and diverse discussions. An alternative to disposal and recycling in principle is the thermal utilization, the application of which, however, is ruled by the emission behaviour of the individual fuel components during the combustion process. Due to the fact that up to now only few experimental findings on emissions of organic and inorganic substances during the combustion of wood treated with wood preservatives were known, the combustion behaviour of wood residues and used wood containing wood preservatives, after mixing with untreated wood in a ratio of 1∶4, was investigated in several test series. The presented results for organic solvents, creosote, Cu-HDO and CCB show that the concentrations of the harmful chemicals occuring in the exhaust gas correspond approximately to those registered for untreated wood. Even properties decreasing the emissions were found for Cu-HDO and CCB. The fixed limit values for polychlorinated dibenzodioxins and dibenzofurans also can be observed provided there exist good combustion conditions.     

Untersuchungen über Emissionen bei der thermischen Verwertung von holzschutzmittelhaltigen Holzresten

The combustion properties of waste wood and residues containing wood preservatives were investigated in several test series after having been blended with untreated wood at a ratio of 1:4. The presented results for CFB, SF and boric salt show that, provided an optimized combustion, the concentrations of the stack pollutants correspond approximately with those found for untreated wood. Only during the combustion of particleboards bonded with aminoplast and the preservative KHF, higher emissions in nitrogen oxide were observed which, however, were due to the nitrogen-containing binder. The results of tests made with other preservative components described in a recent work (Salthammer et al. 1994a) are confirmed.     

Probleme bei der thermischen Verwertung von Wald-, Rest- und Altholz

One of the most difficult problems is the distinction between treated and untreated wood. The thermal utilization of treated wood in Germany is more restrictively regulated than that for untreated wood. Accordingly, due to insufficient possibilities for use in particle board production, biological treatment, dumping, and the strong restrictively regulated export, it is necessary to burn wood and wood residues. Even in untreated woods chemical elements are present, which are also contained in wood preservatives, e.g. you can find mercury, arsenic, fluorine, chromium, copper, or tin in different quantities in natural wood. In Germany, it is prohibited to burn treated wood in plants without air cleaning equipment. Under economic aspects it would be too expensive to use plants with air cleaning equipment for burning wood. It is therefore necessary in Germany to determine some parameters to characterize the natural condition. This would be additional a basis for the distinction between treated und untreated wood.     

Verwertung von Zwangsnutzungen— Technik und Ökonomie der Langzeitlagerung von Stamm- und Schnittholz

By case studies about longtime storage, irrigation of log wood and dry storage of sawn wood, some alternatives for the economic use of emergency exploitations are analysed. The problem of the contribution to cost covering is elucidated from the standpoints of sawyers forest owners and other people, who must use such special wood storage. Furtheron, the development of costs and profits of the alternative activities is analysed. The relatively best strategy is questioned, to convert log wood, or without longtime storage, into saleable timber. Under certain preconditions with respect to price and profit development, preference must be given to the “irrigation and sawing on request” as against “sawing and dry storage”. The longtime storage of log wood offers, at least for some years, a contribution to cost covering, whereas the longtime storage of sawn timber, in advance leads into red figures. The data given here are only valid for the conditions of the case studies.     

Bewertung der Eigenschaften von Kartoffelstärken

Evaluation of Potato Starch Properties . Different potato starches were studied by determination of their consistency curves with a Brabender viscosigraph, their absolute viscosity values and the ranges of swelling temperatures of the starch grains. Gradual elution analyses for comparison were carried out, and a simple potentiometric method was introduced in order to determine the average number of molecular weights M_n. Between different potato starches essential differences of the physical and colloidalchemical properties could be revealed in spite of the fact that their quality corresponded to didacted standards. The physical and colloidal-chemical changes of the starches may be ascribed to prolonged or inadequate storage. At the evaluation of the starch qualities the existing standards are no longer satisfactory. The starches should be classified especially by viscographic measurements and determinations of the average number of molecular weigths.     

Zur Bestimmung der Scherbeständigkeit von Stärkekleistern

On Determination of Shearing Stability of Starch Pastes. Test conditions for the shearing stability test of starch pastes are not sufficiently outlined in existing publications. In the present paper, first of all a determination of optimum parameters (type of paste production, type of stirrer, stirring time, stirrer revolutions, viscosity measurement etc.) for a shearing stability test was attempted. It became apparent that shearing treatment of 5 min by means of a blade stirrer at a number of stirrer revolutions of 1800 r.p.m. with a 5% paste concentration is sufficient to determine shearing stability of a starch paste. For viscosity measurement which as well as pasting and shearing stress is carried out a 95 °C, a Brookfield viscosimeter is used. Provided measuring conditions (type of spindle, spindle revolutions) are kept constant before and after shearing stress, shearing stability can be expressed as remaining viscosity as a percentage of the initial viscosity. Furthermore, reproducibility of paste production as well as that of the whole shearing stability test were determined. Finally, a test was carried out as to wether there is a connection between shearing and heat stability of paste. Values obtained from 11 commercial products made such a connection between the two criteria apparent.