The cost of treating wastewater contaminated with nitrogen could be lowered in future. Soil scientists at the Helmholtz Centre for Environmental Research (UFZ) have developed a new mathematical model which can help determine the optimum conditions for microbiological water treatment.
One of the key concerns of the European Water Framework Directive (WFD), which came into force in 2000, is the reduction of nitrogen-containing nutrients in waterbodies. One approach is to avoid or optimise the use of nitrogen fertilizers in agriculture. Another approach is to improve wastewater treatment technologies.
Current biological treatment methods are based on the microbial processes of nitrification and denitrification. Although these methods make it possible to treat wastewater containing high levels of nitrogen safely, they also have a considerable disadvantage: the nitrogen that is removed is primarily released into the atmosphere in the form of the greenhouse gas N2O. This is a dilemma in that water protection and climate protection have until now been mutually exclusive.
During experiments with the treatment of nitrogen-contaminated wastewater at the beginning of the 1990s, a previously unknown microbial process was discovered that can break down the main components of the nitrogen contamination in the wastewater (ammonium and nitrate) in the presence of atmospheric oxygen (anaerobically). The only end product is environmentally neutral molecular nitrogen (N2). Exploiting this process, called ‘anammox’, to clean nitrogenous wastewater could in future lead to an entirely climate-neutral treatment of municipal wastewater. In addition, unlike the microbial processes used until now, the anammox process does not require organic nutrients, so in future it will be possible to manage without the addition of nutrients during the treatment process. This will reduce the cost of wastewater treatment still further.
However, particularly with regard to the development of efficient wastewater treatment systems, research into the anammox process is still posing significant problems more than 15 years after it was discovered. The main reason for this is that the end product of the anammox process under investigation (N2) can also be produced simultaneously in the course of the denitrification process, so it has been almost impossible to quantify the conversion rate accurately. In addition, the molecular nitrogen (N2) resulting from the microbiological processes is in principle ‘invisible’ because of the high background concentration of N2 in the atmosphere (≈79 vol. %), since the quantities of N2 released are extremely small compared with the existing atmospheric nitrogen levels. Now for the first time, the two soil scientists Oliver Spott and Florian Stange of the Helmholtz Centre for Environmental Research (UFZ) have succeeded in developing a new mathematical model that can calculate precisely the quantities of N2 from anammox, from denitrification and from the atmosphere. The model is based on analyses using stable isotopes, and means that in future it will be possible to investigate in greater detail the optimum conditions for microbiological treatment of nitrogenous wastewater using the anammox process. This will in turn make it possible to reduce the costs of wastewater treatment in the long term, increase its effectiveness and avoid N2O emissions. The two scientists have published their discovery in the internationally renowned specialist journal Rapid Communications in Mass Spectrometry.
The idea for developing the new mathematical approach using the stable nitrogen isotope 15N came from their collaboration with UFZ colleagues Peter Kuschk and Diego Paredes, who have been looking at the possibility of microbial treatment of nitrogenous wastewater using anammox for a long time. But the new equations are also of great significance for their own work. In 1992 Japanese scientists described for the first time a metabolic process involving soil fungi (Fusarium oxysporum) which is very similar to the process of anaerobic oxidation of ammonium and which was called codenitrification, after the familiar process of denitrification. Despite this, even 15 years after the discovery of codenitrification, scientists still work on the assumption that when nitrogen from the soil is broken down, it is only denitrification that is responsible for the release of molecular nitrogen (N2). Using the 15N isotope technique and the new mathematical approach, it is now possible to calculate precisely the N2 released from the soil during both processes – denitrification and codenitrification. An initial, very recent study by two British scientists has already come to the surprising conclusion that up to 92 per cent of microbially released N2 is attributable to the process of codenitrification. If these initial results can be confirmed and extended to other soils around the world, this would completely change our current understanding of N2 emissions from the soil. The two scientists Oliver Spott and Florian Stange will be using the new equations to tackle this question in collaboration with international scientists.top
http://dx.doi.org/10.1002/rcm.3098Spott O, Russow R, Apelt B, Stange CF:
Preservation of floodplains is flood protection
27.09.2017 | Technische Universität München
Conservationists are sounding the alarm: parrots much more threatened than assumed
15.09.2017 | Justus-Liebig-Universität Gießen
University of Maryland researchers contribute to historic detection of gravitational waves and light created by event
On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...
Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.
Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....
Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).
When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...
Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.
How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...
Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.
It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...
17.10.2017 | Event News
10.10.2017 | Event News
10.10.2017 | Event News
20.10.2017 | Interdisciplinary Research
20.10.2017 | Materials Sciences
20.10.2017 | Earth Sciences