Stand und Perspektiven der Phosphorrückgewinnung aus Abwasser und Klärschlamm - Teil 1: Zweiter Arbeitsbericht der DWA-Arbeitsgruppe KEK-1.1 "Wertstoffrückgewinnung aus Abwasser und Klärschlamm"

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

The cosmic dust analyser onboard cassini: ten years of discoveries

The interplanetary space probe Cassini/Huygens reached Saturn in July 2004 after 7 years of cruise phase. The German cosmic dust analyser (CDA) was developed under the leadership of the Max Planck Institute for Nuclear Physics in Heidelberg under the support of the DLR e.V. This instrument measures the interplanetary, interstellar and planetary dust in our solar system since 1999 and provided unique discoveries. In 1999, CDA detected interstellar dust in the inner solar system followed by the detection of electrical charges of interplanetary dust grains during the cruise phase between Earth and Jupiter. The instrument determined the composition of interplanetary dust and the nanometre-sized dust streams originating from Jupiter’s moon Io. During the approach to Saturn in 2004, similar streams of submicron grains with speeds in the order of 100 km/s were detected from Saturn’s inner and outer ring system and are released to the interplanetary magnetic field. Since 2004 CDA measured more than one million dust impacts characterising the dust environment of Saturn. The instrument is one of the three experiments which discovered the active ice geysers located at the south pole of Saturn’s moon Enceladus in 2005. Later, a detailed compositional analysis of the water ice grains in Saturn’s E ring system led to the discovery of large reservoirs of liquid water (oceans) below the icy crust of Enceladus. Finally, the determination of the dust-magnetosphere interaction and the discovery of the extended E ring (at least twice as large as predicted) allowed the definition of a dynamical dust model of Saturn’s E ring describing the observed properties. This paper summarizes the discoveries of a 10-year story of success based on reliable measurements with the most advanced dust detector flown in space until today. This paper focuses on cruise results and findings achieved at Saturn with a focus on flux and density measurements. CDA discoveries related to the detailed dust stream dynamics, E ring dynamics, its vertical profile and E ring compositional analysis are published elsewhere (see Hus et al. in AIP Conference Proccedings 1216:510–513, 2010; Hsu et al. in Icarus 206:653–661, 2010; Kempf et al. in Icarus 193:420, 2008; 206(2):446, 2010; Postberg et al. in Icarus 193(2):438, 2008; Nature 459:1098, 2009; Nature, 2011, doi:10.1038/nature10175)

In situ dust measurements in the inner Saturnian system

Srama R, Kempf S, Moragas-Klostermeyer G, et al. In situ dust measurements in the inner Saturnian system. Planetary and Space Science. 2006;54(9-10):967-987.In July 2004 the Cassini-Huygens mission reached the Saturnian system and started its orbital tour. A total of 75 orbits will be carried out during the primary mission until August 2008. In these four years Cassini crosses the ring plane 150 times and spends approx. 400 h within Titan's orbit. The Cosmic Dust Analyser (CDA) onboard Cassini characterises the dust environment with its extended E ring and embedded moons. Here, we focus on the CDA results of the first year and we present the Dust Analyser (DA) data within Titan's orbit. This paper does investigate High Rate Detector data and dust composition measurements. The authors focus on the analysis of impact rates, which were strongly variable primarily due to changes of the spacecraft pointing. An overview is given about the ring plane crossings and the DA counter measurements. The DA dust impact rates are compared with the DA boresight configuration around all ring plane crossings between June 2004 and July 2005. Dust impacts were registered at altitudes as high as 100 000 km above the ring plane at distances from Saturn between 4 and 10 Saturn radii. In those regions the dust density of particles bigger than 0.5 mu m can reach values of 0.001 m(-3). (c) 2006 Published by Elsevier Ltd