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 Joint research project on wastewater for reuse examines pond system in Namibia
19.12.2016 | Technische Universität Darmstadt

nachricht Scientists produce a new roadmap for guiding development & conservation in the Amazon
09.12.2016 | Wildlife Conservation Society

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: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

Im Focus: How to inflate a hardened concrete shell with a weight of 80 t

At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).

Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...

Im Focus: Bacterial Pac Man molecule snaps at sugar

Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.

The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

Nothing will happen without batteries making it happen!

05.01.2017 | Event News

 
Latest News

Water - as the underlying driver of the Earth’s carbon cycle

17.01.2017 | Earth Sciences

Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

17.01.2017 | Materials Sciences

Smart homes will “LISTEN” to your voice

17.01.2017 | Architecture and Construction

VideoLinks
B2B-VideoLinks
More VideoLinks >>>