Recycling and Assessment of Struvite Phosphorus from Sewage Sludge

AbstractThis study presents an integrated approach for the recovery of P from the wastewater path. Since natural P sources are limited, recycling processes are making an increasingly important contribution to meeting the nutritional requirements of plant production. The groundwork for developing a new fertilizer from upgraded sewage sludge includes an evaluation of nutrients and heavy metal contents. Struvite (NH4MgPO4 • 6 H2O) derived from sewage sludge had a total P content of 6.1% with 3.5% being water-soluble. Plant availability was tested in pot experiments with wheat and maize. P uptake rates were 66.7% and 85.9%, respectively. In terms of heavy metal contents, struvite showed contaminant levels at least three times below the limiting values of the German Sewage Sludge Ordinance. Stricter rules of the German Federal Soil Protection Act are also fulfilled if the loading of heavy metals is considered during periodical fertilization. This implies that P recovery as struvite may be one way of declaring a new type of fertilizer.

Effect of Mid-Diameter and Log-Parameters on the Conversion Factor of Cubic Measure to Solid Measure Concerning Industrial Timber

Concerning industrial timber, the measure of stacked logs with equal wood length is cubic meter with bark (FVA 1997). It is consequently a volumetric measure including the non wood-containing spaces. The following work determines by extensive tests the solid measure of several stacks of wood by the means of an electronically measuring system, and calculates the resulting conversion factor. It was possible to make a statement about how the mid-diameter of logs from a stack and particularly log-parameters influences the conversion factor. The measurements in 3D, the mid-diameter, the crook, the taper and the ovality are considered and their influence on the factor were analysed. The results are illustrated and evaluated by using a correlation and regression analysis. The greater influence had the mid-diameter and the crook, which show strong correlations on the factor

Leitlinie Antibiotika in der Oralchirurgie: Eine Stellungnahme der Schweizerischen Gesellschaft für Oralchirurgie (SSOS)

Antibiotics can be used in oral surgery. The effective benefits are offset by the dangers of resistance and sensitization, which requires a strict indication. There are controversial views regarding indication, dosage and, above all, duration and timing of antibiotic medication in oral surgery

Effects of different oocyte retrieval and in vitro maturation systems on bovine embryo development and quality

Cyclic adenosine monophosphate (cAMP) modulators have been used to avoid spontaneous oocyte maturation and concomitantly improve oocyte developmental competence. The current work evaluated the effects of the addition of cAMP modulators forskolin, 3-isobutyl-1-methylxanthine (IBMX) and cilostamide during in vitro maturation on the quality and yields of blastocysts. The following experimental groups were evaluated: (i) slicing or (ii) aspiration and maturation in tissue culture medium (TCM)199 for 24 h (TCM24slicing and TCM24aspiration, respectively), (iii) aspiration and maturation in the presence of cAMP modulators for 30 h (cAMP30aspiration) and in vivo-produced blastocysts. In vitro-matured oocytes were fertilized and presumptive zygotes were cultured in vitro to assess embryo development. Cleavage, blastocyst formation, blastocyst cell number, mRNA abundance of selected genes and global methylation profiles were evaluated. Blastocyst rate/zygotes for the TCM24aspiration protocol was improved (32.2 ± 2.1%) compared with TCM24slicing and cAMP30aspiration (23.4 ± 1.2% and 23.3 ± 2.0%, respectively, P 0.05), while those from the other groups were significantly elevated. It is concluded that retrieval, collection systems and addition of cAMP modulators can affect oocyte developmental competence, which is reflected not only in blastocyst rates but also in global DNA methylation and gene expression patterns

Risikobewertung und Einwilligung in der Medizin - aus juristischer Sicht

In Deutschland wird seit Jahren im Bereich der Phosphorrückgewinnung intensiv geforscht, und innerhalb zahlreicher Forschungs- und Entwicklungsvorhaben wurden inzwischen einige technische Anlagen zur gezielten Phosphorrückgewinnung errichtet und betrieben. Es fehlen jedoch vielfach noch belastbare und übertragbare Erkenntnisse aus dem kontinuierlichen halboder großtechnischen Betrieb. Die DWA-Arbeitsgruppe KEK-1.1 stellt in ihrem zweiten Arbeitsbericht den aktuellen Stand von Forschung und Entwicklung der Phosphorrückgewinnung aus Stoffströmen der Abwasserreinigung zusammen und schließt den Bericht mit Empfehlungen ab. Mit organisatorischen, finanziellen und ordnungspolitischen Maßnahmen soll die weitere Entwicklung und der großtechnische Einsatz von Verfahren zur Phosphorrückgewinnung gezielt vorangetrieben werden