Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Adding high doses of sludge to neutralise soil acidity not advisable

08.01.2009
A University of the Basque Country PhD thesis has analysed the application of waste sludge from EDAR (Estación Depuradora de Aguas Residuales - Waste Water Purification Plant) to acid soils which have limited capacity for neutralising the acidity.

Sludge obtained from water purification plants can be reused, as fertiliser for soils, for example or to reduce their acidity. The main aim of this University of the Basque Country (UPV/EHU) PhD research thesis was to study the effects of the application of EDAR (Estación Depuradora de Aguas Residuales - Waste Water Purification Plant) waste sludge on the chemical properties of the soil and on the water filtering through it — with special attention being paid to the behaviour of heavy metals. Moreover, the effects on forest plantations — concretely those of Pinus radiata —, have been studied.

The author of the thesis is Dr. Goio Egiarte Castañeira, who presented it with the title, Application of sewage sludge as amendment on acid forest soils. Effect on the soil-water system plan, with special attention to the behaviour of heavy metals. Dr Egiarte is an agricultural engineer currently working as a secondary school teacher. He undertook his PhD under the direction of Ms Estilita Ruiz Romera from the Department of Chemical and Environmental Engineering at the Higher School of Engineering of the UPV/EHU and Ms Marta Camps Arbestain from the Department of Agricultural Systems and Natural Resources at Neiker-Tecnalia.

When carrying out the research for the thesis, Dr. Egiarte had the help of the Dipartimento de Science Ambientali e delle Produzioni Vegetali at the Università Politecnica delle Marche in Ancona (Italy), of the Department of Pedology and Agricultural Chemistry at Biology Faculty of the University of Santiago de Compostela (Galicia) and the Bilbao Bizkaia Water Consortium.

Suitable dose

The study approach for the thesis was particularly innovative, not only for the possible use of fertilising sludge on forest soils, but also because it studied the effect of heavy metals and nitrogenated forms. To this end, experiments were carried out over a four-year period.

With the results obtained from these experiments, Dr. Egiarte has come to the conclusion that adding high doses of EDAR sludge is totally inadvisable, even when the sludge complies with current norms as regards levels of heavy metals. When the compounds of the sludge begin to oxidise, they produce acidity and, in order to reduce this acidity, an alkaline system is necessary. But the alkanility of the system created on uniting the sludge with the soil is not capable of neutralising the acidity generated.

On the other hand, the application of much lower doses of waste sludge — three times less —considerably reduces acidification of the soil and heavy metal content. Moreover, the production of forest biomass is very similar to that obtained by applying higher doses.

Nevertheless, Dr. Egiarte emphasises that the use of other types of sludge from waste water purification plants — with a greater capacity of neutralisation of acids and a greater stability of organic elements — on acid soils, such as the one studied, is much more recommendable.

Lucía Álvarez | alfa
Further information:
http://www.elhuyar.com
http://www.basqueresearch.com/berria_irakurri.asp?Berri_Kod=2016&hizk=I

More articles from Agricultural and Forestry Science:

nachricht Kakao in Monokultur verträgt Trockenheit besser als Kakao in Mischsystemen
18.09.2017 | Georg-August-Universität Göttingen

nachricht Ultrasound sensors make forage harvesters more reliable
28.08.2017 | Fraunhofer-Institut für Zerstörungsfreie Prüfverfahren IZFP

All articles from Agricultural and Forestry Science >>>

The most recent press releases about innovation >>>

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

Im Focus: The pyrenoid is a carbon-fixing liquid droplet

Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.

A warming planet

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...

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

Rainbow colors reveal cell history: Uncovering β-cell heterogeneity

22.09.2017 | Life Sciences

Penn first in world to treat patient with new radiation technology

22.09.2017 | Medical Engineering

Calculating quietness

22.09.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>