Analysis of greenhouse gas emissions from 10 biogas plants within the agricultural sector.

With the increasing number of biogas plants in Germany the necessity for an exact determination of the actual effect on the greenhouse gas emissions related to the energy production gains importance. Hitherto the life cycle assessments have been based on estimations of emissions of biogas plants. The lack of actual emission evaluations has been addressed within a project from which the selected results are presented here. The data presented here have been obtained during a survey in which 10 biogas plants were analysed within two measurement periods each. As the major methane emission sources the open storage of digestates ranging from 0.22 to 11.2% of the methane utilized and the exhaust of the co-generation units ranging from 0.40 to 3.28% have been identified. Relevant ammonia emissions have been detected from the open digestate storage. The main source of nitrous oxide emissions was the co-generation unit. Regarding the potential of measures to reduce emissions it is highly recommended to focus on the digestate storage and the exhaust of the co-generation.

The impact of ammonia nitrogen concentration and zeolite addition on the specific methanogenic activity of granular and flocculent anaerobic sludges.

This work presents the effect of ammonia nitrogen concentration and zeolite addition on the specific methanogenic activity (SMA) of different anaerobic sludges with various physical structures (granular and flocculent), operating in batch conditions. Piggery, malting production and urban sludges derived from full-scale anaerobic reactors were tested in the experiment as the source of inoculum in batch digesters. It was found that piggery sludge was the most affected by the increase of ammonia nitrogen concentration while malting producing and municipal sludges were less affected. In general, the addition of zeolite at doses in the range of 0.01-0.1 g/g VSS reduced the inhibitory effect of N-NH(4)(+) for piggery sludge (P.S.). For this sludge, the propionic:acetic ratio increased when the concentration of N-NH(4)(+) increased, indicating that methanogenesis was affected. Finally, a study of the microbial population involved in this study for P.S. by using 16S rRNA based molecular techniques revealed a presence of microorganisms following the order: Methanococcaceae > Methanosarcina > Methanosaeta.

Population dynamic of algae and bacteria in an oxidation channel.

A study on algae and bacteria population changes, as a function of time, was carried out in a pilot scale oxidation channel bioreactor using a carrousel system. Total Coliforms, Pseudomonas aeruginosa, and Streptococcus faecalis, the most common bacteria found in sewage, Scenedesmus obliquus and Chlorella vulgaris were the microalgae considered in this work. Physicochemical parameters such as COD, BOD, Chlorophyll a, nitrogen, and phosphorous compounds were studied and determined during the experiments. It was demonstrated that the level of wastewater contamination could be predicted based on the bacterial and algae composition. The relationships between the algae and bacteria population, and the variation of these microorganism populations as a measurement of the level of purification were established. The oxidation channel was able to remove a considerable amount of organic matter and pathogenic microorganisms in a relatively short time. The nitrification process could not be measured. The increase in the relative concentration of microalgae contributed toward improving the global efficiency of the system as well as reducing the pathogenic bacteria population.

Influence of different natural zeolite concentrations on the anaerobic digestion of piggery waste.

The effect of different natural zeolite concentrations on the anaerobic digestion of piggery waste was studied. Natural zeolite doses in the range 0.2-10 g/l of wastewater were used in batch experiments, which were carried out at temperatures between 27 degrees C and 30 degrees C. Total chemical oxygen demand (COD), total and volatile solids, ammonia and organic nitrogen, pH, total volatile fatty acids (TVFA), alkalinity (Alk) and accumulative methane production were determined during 30 days of digestion. The anaerobic digestion process was favored by the addition of natural zeolite at doses between 2 and 4 g/l and increasingly inhibited at doses beyond 6 g/l. A first-order kinetic model of COD removal was used to determine the apparent kinetic constants of the process. The kinetic constant values increased with the zeolite amount up to a concentration of 4 g/l. The values of the maximum accumulative methane production (Gm) increased until zeolite concentrations of 2-4 g/l. The addition of zeolite reduced the values of the TVFA/ Alk ratio while increasing the pH values, and these facts could contribute to the process failure at zeolite doses of 10 g/l.

Anaerobic waste digestion in Germany--status and recent developments.

Anaerobic treatment processes are especially suited for the utilization of wet organic wastes from agriculture and industry as well as for the organic part of source-separated household wastes. Anaerobic degradation is a very cost-effective method for treating biogenic wastes because the formed biogas can be used for heat and electricity production and the digester residues can be recycled to agriculture as a secondary fertilizer. Anaerobic technology will also be used for the common treatment of wastes together with renewable energy crops in order to reduce the CO2-emissions according the Kyoto protocol. Various process types are applied in Germany which differ in material, reaction conditions and in the form of the used reactor systems. The widespread introduction of anaerobic digestion in Germany has shown that biogenic organic wastes are a valuable source for energy and nutrients. Anaerobic waste treatment is done today in approx. 850 biogas plants on small farm scale as well as on large industrial scale with the best beneficial and economic outcome. Due to some new environmental protection acts which promote the recycling of wastes and their utilization for renewable energy formation it can be expected that several hundreds new biogas plants will be built per year in Germany. In order to use the synergetic effects of a combined fermentation of wastes and energy crops new process types must be developed in order to optimize the substrate combinations and the process conditions for maximum biodegradation.

[Successful treatment of progressive dialysis encephalopathy. Case report]. / Erfolgreiche Behandlung der progressiven Dialyseencephalopathie. Ein kasuistischer Beitrag.

A case of severe aluminium-induced dialysis dementia and osteopathy is described. Under DFO-therapy a complete remission could be achieved within 8 months.

[Current status of tuberculosis in children and adolescents of East Germany]. / Die heutige Tuberkulosesituation bei Kindern und Jugendlichen in der DDR.

The morbidity from juvenile tuberculosis in the GDR amounts presently to 0.6 per 100.000 in the age group 0 to 15 years. The GDR's centre for treating children affected by tuberculosis is the above hospital for lung diseases in the town of Harzgerode. Between 1980 and 1983 a total of 89 children (48 boys and 41 girls) with various forms of tuberculosis have been treated there. The anamnesis of the children with lung tuberculosis was largely unspecific, only 6 from 29 had pneumonia or pneumonia was suspected respectively. All patients with abdominal tuberculosis had pains in the peritoneal cavity, whereas 26 from 31 children with cervico-glandular tuberculosis developed local lymphatic nodes. The family anamnesis showed primary tuberculous infections, lung tuberculosis and other forms of tuberculosis in the respiratory system among the patient's parents, grandparents and other relatives. The cases were initially registered mainly with the special outpatients' departments for lung diseases and tuberculosis or with other surgically orientated departments. Whilst tuberculin tests with 2 TE on children with lung tuberculosis gave a clear diagnosis, the same tests proved to be negative in nearly all cases with histologically confirmed lymphatic tuberculosis. Tuberculous bacteria could be detected in only 15 from 29 cases of lung tuberculosis. A strict initial therapy with three antituberculous drugs, usually Streptomycin, INH and Ethambutol, is decisive for the successful treatment. In the following intermittent period Streptomycin and INH are preferred. The total duration of chemotherapy of all forms of juvenile tuberculosis is at present 9 months.

[Problem of adaptive hyperparathyroidism in chronic renal failure]. / Beitrag zum Problem des adaptiven Hyperparathyreoidismus bei chronischer Niereninsuffizienz.

It is reported on a case of adaptive hyperparathyroidism (HPT) with diffuse hyperplasia of the adrenal glands including formation of an adenoma, in which during the first 5 weeks of the dialytic therapy massive pulmonary, vascular and periarticular calcifications developed. The previously existing untreated HPT and factors specific for dialysis (composition of the dialysate, heparin therapy) are made responsible for this course of the disease. Within one year the parathyroidectomy led to the regression of the calcifications. Prophylactic and therapeutic possibilities in the adaptive HPT are shown.

[Chronic hemodialysis from the perspective of the dialysis team]. / Die chronische Hämodialyse aus der Sicht des Dialyseteams.

By means of a questionnaire the authors checked the views of dialysis teams on ethical and psycho-emotional questions, on on the adaptation of dialysis patients and on dialysis work itself. The results show that psycho-emotional considerations are of considerable importance in the contact with patients over long periods. The staff think about them but are often not able to arrive at a clear opinion. This indicates that psychological training of the staff is necessary in oder to facilitate and encourage the formation of clear points of view.