Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Space technology disposes of sludge

16.05.2002


Research funded by the European Space Agency into ways of feeding future astronauts on missions to Mars is about to find a very down-to-earth application - how to dispose of the sewage sludge left over after wastewater treatment.



The MELISSA (Micro-Ecological Life Support Alternative) project, which ESA is funding in companies and research institutes throughout Europe, is developing a system of recycling as much of the waste as possible produced by astronauts on long-duration space missions into food and other consumables. EPAS, a Belgian company participating in the project, is using some of the research results to devise methods of substantially reducing the amount of solid material left over after sewage treatment on Earth.
Presently-available technologies reduce the amount of solid waste left in effluent such as pig waste, vegetable waste or sewage by 40-60% at most, according to Dries Demey from EPAS. In space, it`s essential to find ways of using the remainder. On Earth, it`s not essential, but would be highly desirable. At present, this undigested fraction is disposed of in landfill sites or, when suitable, by spreading on agricultural land. "In Flanders, there`s not a lot of land and the tax on sludge disposal at landfill sites is getting higher," says Demey.

Whether in space or on Earth, waste initially enters a fermentation chamber where carefully chosen bacteria break down the solids. As this process is unable to biodegrade recalcitrant fractions, EPAS began investigating additional treatments to reduce the waste further.



The method that worked best involves using hydrogen peroxide, a reactive but harmless oxidant, to break down the resistant fraction which can then be reintroduced to the original fermentation chamber after removal of the peroxide. "The results have been quite positive," says Demey. "We`ve been able to remove 85% of the solid waste and convert it into water and methane gas, which can be used to generate electricity. We`ve tested the method on sludge waste from a Flemish food company. The only obstacle is that the cost is higher than that of current disposal methods, but this will change in future".

Flammable methane may be a desirable end product on Earth, but in space it could be a disaster. "By adapting the process conditions, we can slow down the fermentation process and stop it before methane is produced, " says Christophe Lasseur, MELISSA project manager at ESTEC, ESA`s technical centre in the Netherlands. This could involve maintaining a high ammonium (urea) concentration, high acidity, or by washing methane-producing bacteria out of the fermentation chamber.

During fermentation, long organic (carbon-based) molecules are gradually broken down until ultimately carbon dioxide and methane, molecules containing just one carbon atom, are produced. "In the MELISSA system, we stop when the long molecules have broken down into fatty acids," says Lasseur. The fatty acids are then used to feed bacteria which also consume some of the ammonium. The remaining ammonium is fed into the third MELISSA compartment where it is converted into nitrates which are used to feed the plants that astronauts eat for dinner.



Christophe Lasseur | alphagalileo
Further information:
http://www.esa.int

More articles from Ecology, The Environment and Conservation:

nachricht Conservationists are sounding the alarm: parrots much more threatened than assumed
15.09.2017 | Justus-Liebig-Universität Gießen

nachricht A new indicator for marine ecosystem changes: the diatom/dinoflagellate index
21.08.2017 | Leibniz-Institut für Ostseeforschung Warnemünde

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Highly precise wiring in the Cerebral Cortex

Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.

The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...

Im Focus: Tiny lasers from a gallery of whispers

New technique promises tunable laser devices

Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...

Im Focus: Ultrafast snapshots of relaxing electrons in solids

Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!

When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...

Im Focus: Quantum Sensors Decipher Magnetic Ordering in a New Semiconducting Material

For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.

Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...

Im Focus: Fast, convenient & standardized: New lab innovation for automated tissue engineering & drug

MBM ScienceBridge GmbH successfully negotiated a license agreement between University Medical Center Göttingen (UMG) and the biotech company Tissue Systems Holding GmbH about commercial use of a multi-well tissue plate for automated and reliable tissue engineering & drug testing.

MBM ScienceBridge GmbH successfully negotiated a license agreement between University Medical Center Göttingen (UMG) and the biotech company Tissue Systems...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

Comet or asteroid? Hubble discovers that a unique object is a binary

21.09.2017 | Physics and Astronomy

Cnidarians remotely control bacteria

21.09.2017 | Life Sciences

Monitoring the heart's mitochondria to predict cardiac arrest?

21.09.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>