As a consequence, some compounds, like ammonia, potassium, sulfate, nitrate or phosphate, which are in sewage used for irrigation, are released again when it rains, so as they slowly arrive to the saturated area of the aquifer.
The thesis, entitled Impacto del riego con aguas residuales sobre el suelo de la zona no saturada de la Vega de Granada (Impact of sewage irrigation on soil of the non-saturated area of the Vega of Granada), has been carried out by Kaltoum El Mabrouki under the direction of Professors José Javier Cruz San Julián and José Miguel Rodríguez Maroto. In addition to laboratory experiences, the work has been prepared by means of trials carried out in an experimental area.
Due to the shortage of water resources, especially in arid or semi-arid areas like those of Andalusia and Granada, sewage irrigation, treated or not, has become a usual practice. The researchers from Granada intended to confirm or refute a stated opinion, according to which soil retains sewage compounds, so that polutants do not reach the saturated area of the aquifer.
To the contrary, the thesis has proved that, in El Mabrouki´s words, “there is a certain retention adsorption and a certain release desorption mechanism, since soil is a non-renewable resource and it adsorps and desorps the compounds, although this process is slower”. Professor Cruz stresses that “it has been proved that soil adsorps and retains a lot of sewage compounds, but they are released again when it rains, although this process is slower and, therefore, it will reach groundwaters some day”.
The thesis concludes that the natural attributes of soils to filter compounds are more effective when it is about organic and microbiological pollution, which is the most representative part of sewage; however, such decontamination “does not take place to the extent thought until today”. Soil receives other compounds like fertilizers, pesticides and nitrates, provided by farmers. Researchers specify that chlorination and drinking water treatment guarantee the helthiness of water when it reaches homes.
The authors of the research work recommend to use “with caution” sewage irrigation since “you can not irrigate with any sort of water, at any pace and in any season” and they insist that “the higher purification level, the better”. In this sense, they remind that in other Spanish towns, like Vitoria, water is so pure that it could be consumed by people thanks to its high quality, although nowadays it is used for irrigation.
New 3-D model predicts best planting practices for farmers
26.06.2017 | Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign
Fighting a destructive crop disease with mathematics
21.06.2017 | University of Cambridge
Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.
For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...
What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.
To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...
The research team of Prof. Dr. Oliver Einsle at the University of Freiburg's Institute of Biochemistry has long been exploring the functioning of nitrogenase....
A one trillion tonne iceberg - one of the biggest ever recorded -- has calved away from the Larsen C Ice Shelf in Antarctica, after a rift in the ice,...
Physics supports biology: Researchers from PTB have developed a model system to investigate friction phenomena with atomic precision
Friction: what you want from car brakes, otherwise rather a nuisance. In any case, it is useful to know as precisely as possible how friction phenomena arise –...
21.07.2017 | Event News
19.07.2017 | Event News
12.07.2017 | Event News
21.07.2017 | Earth Sciences
21.07.2017 | Power and Electrical Engineering
21.07.2017 | Physics and Astronomy